AIR-CONDITIONING DEVICE

TECHNICAL FIELD

[0001]The present disclosure relates to an air-conditioning device.

BACKGROUND ART

[0002]In the related art, a refrigerating cycle device that mixes refrigerants having different enthalpies and that sucks the refrigerants into a compressor is disclosed (for example, see PTL 1). PTL 1 discloses that in order to homogeneously mix a bypass-side refrigerant and a depressurizing unit-side refrigerant, which have different enthalpies, the bypass-side refrigerant and the depressurizing unit-side refrigerant are subjected to heat exchange in a laminated heat exchanger and then are merged with each other. In PTL 1, by homogeneously mixing the bypass-side refrigerant and the depressurizing unit-side refrigerant, which have different enthalpies, the refrigerating cycle device can exhibit a stable heating capacity.

CITATION LIST

Patent Literature

[0003][PTL 1] Japanese Unexamined Patent Application Publication No. 2021-156567

SUMMARY OF INVENTION

Technical Problem

[0004]However, in PTL 1, a heat exchanger for performing heat exchange before two types of refrigerants having different enthalpies are merged is required. Therefore, the device increases in size, and manufacturing costs increase.

[0005]The present disclosure has been devised in view of such circumstances, and an object thereof is to provide an air-conditioning device that can exhibit a stable heating capacity while preventing an increase in size of the device or an increase in manufacturing costs.

Solution to Problem

[0006]In order to solve the above problems, the present disclosure adopts the following means.

[0007]According to an aspect of the present disclosure, there is provided an air-conditioning device including a compressor that compresses a refrigerant, a heating unit that heats a heating target with the refrigerant discharged from the compressor, an accumulator that separates a liquid component in the refrigerant sucked by the compressor, a circulation flow path that guides the refrigerant, which has passed through the heating unit, to the accumulator, a bypass flow path that merges the refrigerant, which does not pass through the heating unit and which is discharged from the compressor, at a first merging portion of the circulation flow path, a first expansion mechanism that is disposed at the circulation flow path and that expands the refrigerant flowing out from the heating unit, and a second expansion mechanism that is disposed at the bypass flow path and that expands the refrigerant discharged from the compressor, in which the first merging portion is disposed on an accumulator side of the first expansion mechanism of the circulation flow path and is disposed in a first spray region of the refrigerant for the first expansion mechanism.

Advantageous Effects of Invention

[0008]According to the present disclosure, it is possible to provide the air-conditioning device that can exhibit a stable heating capacity while preventing an increase in size of the device or an increase in manufacturing costs.

BRIEF DESCRIPTION OF DRAWINGS

[0009]FIG. 1 is a refrigerant circuit diagram of a vehicle air-conditioning device according to a first embodiment of the present disclosure.

[0010]FIG. 2 is a refrigerant circuit diagram showing a refrigerant flow during a heat pump heating operation of the vehicle air-conditioning device.

[0011]FIG. 3 is a refrigerant circuit diagram showing a refrigerant flow during a hot gas heating operation of the vehicle air-conditioning device.

[0012]FIG. 4 is a sectional view of a circulation flow path and a bypass flow path taken along a direction orthogonal to a central axis of the circulation flow path, in the vicinity of a first merging portion.

[0013]FIG. 5 is a sectional view showing a first modification example of the circulation flow path shown in FIG. 4.

[0014]FIG. 6 is a sectional view showing a second modification example of the circulation flow path shown in FIG. 4.

[0015]FIG. 7 is a sectional view of the circulation flow path and the bypass flow path shown in FIG. 4 taken along arrow A-A.

[0016]FIG. 8 is a sectional view showing a modification example of the circulation flow path and the bypass flow path shown in FIG. 7.

[0017]FIG. 9 is a flowchart showing an operation during the hot gas heating operation of the vehicle air-conditioning device.

[0018]FIG. 10 is a flowchart showing an operation during the hot gas heating operation of the vehicle air-conditioning device.

[0019]FIG. 11 is a Mollier diagram showing a state of a refrigerant during the hot gas heating operation.

[0020]FIG. 12 is a refrigerant circuit diagram showing a refrigerant flow during a dehumidification and heating operation of the vehicle air-conditioning device.

[0021]FIG. 13 is a refrigerant circuit diagram showing a refrigerant flow during a cooling operation of the vehicle air-conditioning device.

[0022]FIG. 14 is a refrigerant circuit diagram of a vehicle air-conditioning device according to a second embodiment of the present disclosure.

[0023]FIG. 15 is a sectional view showing the circulation flow path, the bypass flow path, and a branch flow path taken along a direction orthogonal to the central axis of the circulation flow path, in the vicinity of the first merging portion and a second merging portion.

[0024]FIG. 16 is a sectional view of the circulation flow path shown in FIG. 15 taken along arrow B-B.

[0025]FIG. 17 is a view showing a first modification example of an orifice shown in FIG. 16.

[0026]FIG. 18 is a view showing a second modification example of the orifice shown in FIG. 16.

[0027]FIG. 19 is a sectional view of the circulation flow path shown in FIG. 15 taken along arrow C-C.

DESCRIPTION OF EMBODIMENTS

First Embodiment

[0028]Hereinafter, a heat pump type vehicle air-conditioning device (air-conditioning device) 100 according to a first embodiment of the present disclosure will be described with reference to FIG. 1. As shown in FIG. 1, the vehicle air-conditioning device 100 according to the present embodiment includes a compressor 10, a heating unit 20, an accumulator 30, an expansion valve (first expansion mechanism) 40, an expansion valve (second expansion mechanism) 50, an on-off valve (switching unit) 61, an on-off valve (switching unit) 62, an on-off valve 63, an on-off valve (first on-off valve) 64, an on-off valve (second on-off valve) 65, an expansion valve 70, an outside heat exchanger 80, an outside fan 81, a cabin heat exchanger (evaporator) 85, a cabin blower 86, a control unit 90, a refrigerant heating heater 91, a pressure sensor 92, a temperature sensor 93, a temperature sensor 94, a temperature sensor 95, and a pressure sensor 96.

[0029]The vehicle air-conditioning device 100 according to the present embodiment is a device that generates warm air with the heating unit 20 installed in a vehicle or that generates cold air with the cabin heat exchanger 85 installed in the vehicle, and that blows air into the vehicle. The vehicle air-conditioning device 100 operates the outside heat exchanger 80 as an evaporator during a heat pump heating operation and operates the outside heat exchanger 80 as a condenser during a cooling operation. In addition, in a case where an outside air temperature is equal to or lower than a predetermined temperature (for example, −20° C.), the vehicle air-conditioning device 100 can perform a hot gas heating operation of performing heating using only the power of the compressor 10 without passing a refrigerant through the outside heat exchanger 80. The refrigerant used in the vehicle air-conditioning device 100 of the present embodiment is, for example, HFO-1234yf.

[0030]The compressor 10 is a device that compresses a refrigerant flowing in from the accumulator 30. The compressor 10 is, for example, an electric compressor that drives a motor (not shown) to compress the refrigerant. The compressor 10 compresses a refrigerant flowing in from a refrigerant pipe L1 and discharges the refrigerant to a refrigerant pipe L2. The refrigerant discharged to the refrigerant pipe L2 is guided to the heating unit 20 via a refrigerant pipe L3 and a refrigerant pipe L4.

[0031]The heating unit 20 is a device that heats air (heating target) blown by the cabin blower 86 with a high-temperature and high-pressure refrigerant discharged from the compressor 10. The air heated by the heating unit 20 is blown into a vehicle interior. The refrigerant that has been subjected to heat exchange with the air in the heating unit 20 is guided to the expansion valve 40 disposed at an upstream side pipe L5a of a refrigerant pipe L5.

[0032]The accumulator 30 is a device that separates at least a part of a liquid component in a refrigerant sucked by the compressor 10. The accumulator 30 guides the refrigerant in a gas phase or a gas-liquid two phase to the compressor 10 via the refrigerant pipe L1.

[0033]The expansion valve 40 is a mechanism that is disposed at the refrigerant pipe L5 and that expands a refrigerant flowing out from the heating unit 20. An opening degree of the expansion valve 40 is controlled by the control unit 90. The refrigerant depressurized by the expansion valve 40 circulates through the refrigerant pipe L5.

[0034]The expansion valve 50 is a mechanism that is disposed at a refrigerant pipe L6 connected to the refrigerant pipe L3 and that expands a refrigerant discharged from the compressor 10. An opening degree of the expansion valve 50 is controlled by the control unit 90. The refrigerant depressurized by the expansion valve 50 is guided from the refrigerant pipe L6 to the accumulator 30 via a refrigerant pipe L7. The refrigerant pipe L7 is a pipe that connects the cabin heat exchanger 85 and the accumulator 30.

[0035]The on-off valve 61 is a device that is disposed at a refrigerant pipe L8 and that switches between an open state where a refrigerant is circulated through the refrigerant pipe L8 and a closed state where the refrigerant is not circulated through the refrigerant pipe L8. The refrigerant pipe L8 is a pipe that connects the refrigerant pipe L5 and a refrigerant pipe L9. The refrigerant pipe L9 is a pipe that connects a refrigerant pipe L10 and the refrigerant pipe L7. The refrigerant pipe L10 is a pipe that connects the outside heat exchanger 80 and the cabin heat exchanger 85.

[0036]The on-off valve 62 is a device that is disposed at the refrigerant pipe L6 and that switches between an open state where a refrigerant is circulated through the refrigerant pipe L6 and a closed state where the refrigerant is not circulated through the refrigerant pipe L6.

[0037]The on-off valve 63 is a device that is disposed at a refrigerant pipe L11 and that switches between an open state where a refrigerant is circulated through the refrigerant pipe L11 and a closed state where the refrigerant is not circulated through the refrigerant pipe L11.

[0038]The on-off valve 64 is a device that is disposed at a downstream side pipe L5b of the refrigerant pipe L5 and that switches between an open state where a refrigerant is circulated on an outside heat exchanger 80 side of a connection portion of the refrigerant pipe L5 with the refrigerant pipe L8 and a closed state where the refrigerant is not circulated on the outside heat exchanger 80 side of the connection portion of the refrigerant pipe L5 with the refrigerant pipe L8.

[0039]The on-off valve 65 is a device that is disposed at the refrigerant pipe L9 and that switches between an open state where a refrigerant is circulated through the refrigerant pipe L9 and a closed state where the refrigerant is not circulated through the refrigerant pipe L9.

[0040]The expansion valve 70 is a mechanism that is disposed at the refrigerant pipe L10 and that expands a refrigerant guided from the outside heat exchanger 80. An opening degree of the expansion valve 70 is controlled by the control unit 90. The refrigerant depressurized by the expansion valve 70 is guided from the refrigerant pipe L10 to the cabin heat exchanger 85.

[0041]The outside heat exchanger 80 is a device that is installed outside the vehicle and that performs heat exchange between outside air and a refrigerant. The outside heat exchanger 80 operates as an evaporator during the heat pump heating operation and evaporates the refrigerant to cool the outside air. In addition, the outside heat exchanger 80 operates as a condenser during the cooling operation and condenses the refrigerant to heat the outside air. The outside fan 81 is a device that blows outside air to the outside heat exchanger 80 to promote heat exchange between the outside air and the refrigerant.

[0042]The cabin heat exchanger (evaporator) 85 is a device that cools or dehumidifies air by evaporating a refrigerant which has passed through the outside heat exchanger 80 and which is depressurized by the expansion valve 70. The cabin blower 86 blows air toward the cabin heat exchanger 85 to guide the air cooled or dehumidified by the cabin heat exchanger 85 into the vehicle interior via the heating unit 20.

[0043]The control unit 90 is a device that controls each unit of the vehicle air-conditioning device 100. The control unit 90 reads out and executes a control program stored in a storage unit (not shown) to execute various types of processing of controlling each unit of the vehicle air-conditioning device 100.

[0044]The refrigerant heating heater 91 is a device that is disposed on a downstream side of the on-off valve 61 of the refrigerant pipe L8 and that heats a refrigerant which flows into the accumulator 30. For example, the control unit 90 operates the refrigerant heating heater 91 to heat the refrigerant in order to increase the pressure of the refrigerant sucked by the compressor 10 at the start of the hot gas heating operation.

[0045]The pressure sensor 92 is a sensor that detects the pressure of a refrigerant circulating through the refrigerant pipe L1. The temperature sensor 93 is a sensor that detects the temperature of the refrigerant circulating through the refrigerant pipe L1. The temperature sensor 94 is a sensor that detects the temperature of a refrigerant circulating through the refrigerant pipe L2. The temperature sensor 95 is a sensor that detects the temperature of a refrigerant circulating through the refrigerant pipe L5 between the heating unit 20 and the expansion valve 40. The pressure sensor 96 is a sensor that detects the pressure of the refrigerant circulating through the refrigerant pipe L5 between the heating unit 20 and the expansion valve 40.

Heat Pump Heating Operation

[0046]An operation during the heat pump heating operation of the vehicle air-conditioning device 100 according to the present embodiment will be described with reference to FIG. 2. FIG. 2 is a refrigerant circuit diagram showing a refrigerant flow during the heat pump heating operation of the vehicle air-conditioning device 100. The heat pump heating operation is executed, for example, in a case where a temperature outside the vehicle at which the outside heat exchanger 80 is installed is not equal to or less than the predetermined temperature (for example, −20° C.).

[0047]Arrows shown in FIG. 2 indicate a refrigerant circulation direction. As shown in FIG. 2, during the heat pump heating operation, a refrigerant circulates in the order of the compressor 10, the heating unit 20, the expansion valve 40, the outside heat exchanger 80, the accumulator 30, and the compressor 10. The refrigerant pipes L1, L2, L3, L4, L5a (L5), L5b (L5), L9, and L7 form a circulation flow path for circulating the refrigerant.

[0048]The outside heat exchanger 80 operates as an evaporator during the heat pump heating operation and evaporates a refrigerant to cool outside air. During the heat pump heating operation, the control unit 90 sets the on-off valves 64 and 65 to an open state and sets the on-off valves 61, 62, and 63 to a closed state.

Hot Gas Heating Operation

[0049]An operation during the hot gas heating operation of the vehicle air-conditioning device 100 according to the present embodiment will be described with reference to FIG. 3. FIG. 3 is a refrigerant circuit diagram showing a refrigerant flow during the hot gas heating operation of the vehicle air-conditioning device 100. Arrows shown in FIG. 3 indicate the refrigerant circulation direction. The hot gas heating operation is executed, for example, in a case where a temperature outside the vehicle at which the outside heat exchanger 80 is installed is equal to or less than the predetermined temperature (for example, −20° C.).

[0050]As shown in FIG. 3, during the hot gas heating operation, a part of a refrigerant circulates in the order of the compressor 10, the heating unit 20, the expansion valve 40, the accumulator 30, and the compressor 10. The refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, and L7 form a circulation flow path for circulating the refrigerant. The refrigerant pipes L5, L8, L9, and L7 guide the refrigerant, which has passed through the heating unit 20, to the accumulator 30.

[0051]In addition, the other part of the refrigerant is guided from the refrigerant pipe L3 to the upstream side pipe L5a via the refrigerant pipe L6 without being circulated through the refrigerant pipe L4. The refrigerant pipe L6 is a bypass flow path that merges the refrigerant discharged from the compressor 10 at a first merging portion JP1 of the circulation flow path without passing through the heating unit 20.

[0052]In a case of performing the hot gas heating operation, the control unit 90 sets the on-off valve 63, the on-off valve 64, and the on-off valve 65 to a closed state and circulates a refrigerant in the circulation flow path formed of the refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, and L7. Then, in the vehicle air-conditioning device 100 of the present embodiment, the amount of the refrigerant to be enclosed in the refrigerant pipe formed of the refrigerant pipes L1 to L11 is set such that air can be heated by the heating unit 20 in a case where the on-off valve 64 and the on-off valve 65 are set to a closed state.

[0053]Herein, a configuration where a refrigerant in a liquid phase or a gas-liquid two phase that circulates through the circulation flow path (upstream side pipe L5a) by passing through the heating unit 20 and a refrigerant in a gas phase that is guided from the bypass flow path (refrigerant pipe L6) to the circulation flow path are satisfactorily mixed will be described. FIG. 4 is a sectional view of the circulation flow path (upstream side pipe L5a) and the bypass flow path (refrigerant pipe L6) taken along a direction orthogonal to a central axis Z1 of the circulation flow path, in the vicinity of the first merging portion JP1. The expansion valve 40 shown in FIG. 4 is schematically shown by omitting details of a mechanism for depressurizing the refrigerant.

[0054]As shown in FIG. 4, the first merging portion JP1 is disposed on an accumulator 30 side, which is the downstream side of the expansion valve 40 of the circulation flow path (upstream side pipe L5a) in the refrigerant circulation direction, and so as to include a first spray region SA1 of a refrigerant for the expansion valve 40. The first spray region SA1 is a region where the refrigerant in a liquid phase or a gas-liquid two phase, which is depressurized by the expansion valve 40, is sprayed. In a case where an inner diameter of the upstream side pipe L5a forming the circulation flow path is denoted by D, the first spray region SA1 is, for example, a region within 10 D from the expansion valve 40. A distance Dis1 from the expansion valve 40 to an end portion of the first spray region SA1 along the central axis Z1 shown in FIG. 4 is within 10 D.

[0055]As shown in FIG. 4, at the first merging portion JP1, in a case where the circulation flow path (upstream side pipe L5a) is viewed from a predetermined direction orthogonal to the central axis Z1, an angle θ formed by the central axis Z1 of the circulation flow path (upstream side pipe L5a) and a central axis X1 of the bypass flow path (refrigerant pipe L6) is 90 degrees. The angle θ may be an angle other than 90 degrees.

[0056]It is preferable that the central axis Z1 of the circulation flow path (upstream side pipe L5a) shown in FIG. 4 is disposed along a vertical direction at the first merging portion JP1. By disposing the central axis Z1 along the vertical direction, a bias of a refrigerant caused by gravity does not occur in the circulation flow path, and appropriate mixing of a refrigerant guided to the circulation flow path and a refrigerant guided from the bypass flow path is promoted.

[0057]FIG. 5 is a sectional view showing a first modification example of the circulation flow path (upstream side pipe L5a) shown in FIG. 4. As shown in FIG. 5, at the first merging portion JP1, in a case where the circulation flow path (upstream side pipe L5a) is viewed from the predetermined direction orthogonal to the central axis Z1, the angle θ formed by the central axis Z1 of the circulation flow path (upstream side pipe L5a) and the central axis X1 of the bypass flow path (refrigerant pipe L6) is 135 degrees.

[0058]FIG. 6 is a sectional view showing a second modification example of the circulation flow path (upstream side pipe L5a) shown in FIG. 4. As shown in FIG. 6, at the first merging portion JP1, in a case where the circulation flow path (upstream side pipe L5a) is viewed from the predetermined direction orthogonal to the central axis Z1, the angle θ formed by the central axis Z1 of the circulation flow path (upstream side pipe L5a) and the central axis X1 of the bypass flow path (refrigerant pipe L6) is 180 degrees.

[0059]As shown in FIGS. 4 to 6, the angle θ formed by the central axis Z1 of the circulation flow path (upstream side pipe L5a) and the central axis X1 of the bypass flow path (refrigerant pipe L6) can be, for example, 90 degrees, 135 degrees, or 180 degrees. In addition, the angle θ may be set to any angle of 90 degrees or more and 180 degrees or less. Compared to a case where the angle θ is less than 90 degrees, a relative speed between a refrigerant circulating through the circulation flow path and a refrigerant guided from the bypass flow path increases, and thus the mixing of the refrigerant circulating through the circulation flow path and the refrigerant guided from the bypass flow path can be promoted.

[0060]FIG. 7 is a sectional view of the circulation flow path (upstream side pipe L5a) and the bypass flow path (refrigerant pipe L6) shown in FIG. 4 taken along arrow A-A. The upstream side pipe L5a of the present embodiment is a circular pipe in sectional view. As shown in FIG. 7, at the first merging portion JP1, in a case where the circulation flow path (upstream side pipe L5a) is viewed along the central axis Z1, the bypass flow path (refrigerant pipe L6) is connected to the circulation flow path such that the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path do not intersect each other.

[0061]An offset length L2 between the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path is preferably set to, for example, D/8 or more and D/3 or less. In the present embodiment, the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path do not intersect each other, but the bypass flow path may be connected to the circulation flow path such that the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path intersect each other.

[0062]As shown in FIG. 7, an inner peripheral surface L5a1 of the upstream side pipe L5a of the present embodiment has a circular shape without an undulation at the first merging portion JP1, but may adopt other aspects. For example, at the first merging portion JP1, the inner peripheral surface L5a1 of the upstream side pipe L5a may have an undulating shape. FIG. 8 is a sectional view showing a modification example of the circulation flow path and the bypass flow path which are shown in FIG. 7.

[0063]As shown in FIG. 8, at the first merging portion JP1, convex portions L5a2 are formed at a plurality of locations along a circumferential direction around the central axis Z1 on the inner peripheral surface L5a1 of the circulation flow path (upstream side pipe L5a). For this reason, a flow of a refrigerant is disturbed by the convex portions L5a2 when a refrigerant guided from the bypass flow path to the circulation flow path collides with the inner peripheral surface L5a1 of the circulation flow path, and the mixing of a refrigerant guided to the circulation flow path and the refrigerant guided from the bypass flow path is promoted by this disturbance. The convex portions L5a2 may be formed to extend parallel to the central axis Z1 or may be formed to helically revolve around the central axis Z1.

[0064]Herein, an operation during the hot gas heating operation of the vehicle air-conditioning device 100 will be described with reference to FIGS. 9 to 11. FIGS. 9 and 10 are flowcharts showing the operation during the hot gas heating operation of the vehicle air-conditioning device 100. Each step shown in FIGS. 9 and 10 is executed by the control unit 90. FIG. 11 is a Mollier diagram showing a state of a refrigerant during the hot gas heating operation.

[0065]In step S101, the control unit 90 controls the on-off valves 61, 63, 64, and 65 such that the on-off valves 61, 63, 64, and 65 are set to a closed state.

[0066]In step S102, the control unit 90 determines whether or not a pressure LP of a refrigerant detected by the pressure sensor 92 exceeds a threshold pressure, takes processing to step S108 in a case of YES, and takes processing to step S103 in a case of NO.

[0067]In step S103, the control unit 90 controls the on-off valve 62 such that the on-off valve 62 is set to an open state. The control unit 90 circulates the entire amount of the refrigerant discharged from the compressor 10 such that the refrigerant is guided to the accumulator 30 via the refrigerant pipe L6 by operating the compressor 10 with the on-off valve 62 set in an open state. In this manner, the control unit 90 sets the vehicle air-conditioning device 100 to a first operation mode in which the refrigerant discharged from the compressor 10 is guided to the refrigerant pipe L6 without being guided to the heating unit 20.

[0068]In step S104, the control unit 90 performs control such that the opening degree of the expansion valve 50 is adjusted. Step S104 is executed in a case where NO is determined in step S102 and in a state where the pressure LP of the refrigerant detected by the pressure sensor 92 is equal to or lower than the threshold pressure and the hot gas heating operation using the heating unit 20 cannot be performed.

[0069]Therefore, in step S104, the opening degree of the expansion valve 50 is adjusted to adjust a flow rate of the refrigerant guided to the accumulator 30 via the refrigerant pipe L6, in order to cause a state where the hot gas heating operation using the heating unit 20 can be executed. The control unit 90 controls the opening degree of the expansion valve 50 such that the opening degree of the expansion valve 50 increases as a difference between the pressure LP of the refrigerant detected by the pressure sensor 92 and the threshold pressure increases. By doing so, a start time required to cause a state where the hot gas heating operation using the heating unit 20 can be executed can be shortened.

[0070]In step S105, the control unit 90 determines whether or not the pressure LP of the refrigerant detected by the pressure sensor 92 exceeds the threshold pressure, takes proceeding to step S106 in a case of YES, and adjusts the opening degree of the expansion valve 50 in step S104 again in a case of NO.

[0071]In step S106, the control unit 90 adjusts the opening degree of the expansion valve 40 before the on-off valve 61 is set to an open state in step S107. The opening degree of the expansion valve 40 is adjusted to suppress a decrease in the pressure of the refrigerant that circulates in a refrigerating cycle when the on-off valve 61 is set to an open state.

[0072]In step S107, the control unit 90 controls the on-off valve 61 such that the on-off valve 61 is set to an open state. By setting the on-off valve 61 to an open state, a part of the refrigerant discharged from the compressor 10 circulates in the order of the compressor 10, the heating unit 20, the expansion valve 40, the accumulator 30, and the compressor 10.

[0073]As described above, the control unit 90 switches the vehicle air-conditioning device 100 from the first operation mode in which the refrigerant discharged from the compressor 10 is guided to the refrigerant pipe L6 without being guided to the heating unit 20 to a second operation mode in which the refrigerant discharged from the compressor 10 is guided to both the heating unit 20 and the refrigerant pipe L6. The on-off valve 61 functions as a switching unit that switches between the first operation mode and the second operation mode. The control unit 90 controls the on-off valve 61 to switch from the first operation mode to the second operation mode in accordance with the pressure of the refrigerant sucked by the compressor 10 exceeding the threshold pressure.

[0074]In step S108, the control unit 90 controls the on-off valve 62 such that the on-off valve 62 is set to an open state. In step S109, the control unit 90 controls the on-off valve 62 such that the on-off valve 62 is set to an open state. The control unit 90 sets the on-off valve 62 and the on-off valve 61 to an open state and operates the compressor 10, resulting in a state where a part of the refrigerant discharged from the compressor 10 is guided to the heating unit 20 and the other part of the refrigerant discharged from the compressor 10 is guided to the accumulator 30 from the refrigerant pipe L6 without passing through the heating unit 20.

[0075]In step S110, the control unit 90 adjusts the opening degree of the expansion valve 40 such that the refrigerant which has passed through the heating unit 20 becomes a liquid refrigerant in performing the hot gas heating operation of guiding the refrigerant to the heating unit 20. The control unit 90 adjusts the opening degree of the expansion valve 40 such that a subcooling degree SC, which is a difference between the temperature of the refrigerant at point b and the temperature of the refrigerant at point b′ shown in FIG. 11, is a predetermined value. The control unit 90 calculates the subcooling degree SC from a temperature detected by the temperature sensor 95 and a pressure detected by the pressure sensor 96.

[0076]In step S111, the control unit 90 calculates specific enthalpies ha, hb, and hc of points a, b, and c shown in FIG. 11, respectively. The specific enthalpy ha of point a is calculated from a temperature detected by the temperature sensor 94 and the pressure detected by the pressure sensor 96. The specific enthalpy hb of point b is calculated from the temperature detected by the temperature sensor 95 and the pressure detected by the pressure sensor 96. The specific enthalpy hc of point c is calculated from any one of a temperature detected by the temperature sensor 93 or a pressure detected by the pressure sensor 92 and a rotation speed of the motor that drives the compressor 10.

[0077]In step S112, the control unit 90 calculates a refrigerant flow rate Gr1 of the refrigerant pipe L6. The refrigerant flow rate Gr1 is calculated from the opening degree of the expansion valve 50, a pressure HP of point a, the pressure LP of point c, and the temperature detected by the temperature sensor 93.

[0078]In step S113, the control unit 90 calculates a refrigerant flow rate Gr2 of the refrigerant pipe L5. The refrigerant flow rate Gr2 is calculated from the opening degree of the expansion valve 40, the pressure HP of point b, the pressure LP of point c, and the temperature detected by the temperature sensor 93.

[0079]In step S114, the control unit 90 determines whether or not the pressure LP of the refrigerant detected by the pressure sensor 92 exceeds a predetermined pressure, takes processing to step S115 in a case of YES, and takes processing to step S116 in a case of NO. The predetermined pressure is determined in advance as a pressure that is higher than the threshold pressure described above and that is suitable for the hot gas heating operation.

[0080]In step S115, the control unit 90 increases the opening degree of the expansion valve 50 such that (ha−hc)×Gr1>(hc−hb)×Gr2 is satisfied. By doing so, the proportion of a gas refrigerant in an inflow refrigerant that flows into the accumulator 30, including the refrigerant depressurized by the expansion valve 40 and the refrigerant depressurized by the expansion valve 50, can be made larger than the proportion of a gas refrigerant in an outflow refrigerant that flows out from the accumulator 30.

[0081]In FIG. 11, by increasing the opening degree of the expansion valve 50, point c corresponding to an outlet side (a suction side of the compressor 10) of the accumulator 30 can be closer to point e than point d. Point d corresponds to the downstream side of the expansion valve 40, and point e corresponds to the downstream side of the expansion valve 50.

[0082]By setting the proportion of the gas refrigerant in the inflow refrigerant that flows into the accumulator 30 to be larger than the proportion of the gas refrigerant in the outflow refrigerant that flows out from the accumulator 30, the amount of the liquid refrigerant stored in the accumulator 30 is reduced. Accordingly, the pressure of the refrigerant that flows into the compressor 10 increases with an increase in the refrigerant circulating through the refrigerating cycle, and a decrease in the power of the compressor 10 can be suppressed.

[0083]In step S116, the control unit 90 reduces the opening degree of the expansion valve 50 such that (ha−hc)×Gr1<(hc−hb)×Gr2 is satisfied. By doing so, the proportion of the liquid refrigerant in the inflow refrigerant that flows into the accumulator 30, including the refrigerant depressurized by the expansion valve 40 and the refrigerant depressurized by the expansion valve 50, can be made larger than the proportion of the liquid refrigerant in the outflow refrigerant that flows out from the accumulator 30. In FIG. 11, by reducing the opening degree of the expansion valve 50, point c corresponding to the outlet side (the suction side of the compressor 10) of the accumulator 30 can be closer to point d than point e.

[0084]By setting the proportion of the liquid refrigerant in the inflow refrigerant that flows into the accumulator 30 to be larger than the proportion of the liquid refrigerant in the outflow refrigerant that flows out from the accumulator 30, the amount of the liquid refrigerant stored in the accumulator 30 is increased, and the proportion of the liquid refrigerant included in the refrigerant that flows out from the accumulator 30 is reduced. Accordingly, the pressure of the refrigerant that flows into the compressor 10 is reduced with a reduction in the amount of the refrigerant circulating through the refrigerating cycle, and an increase in the torque of the compressor 10 can be suppressed.

[0085]In step S117, the control unit 90 determines whether or not an instruction to finish the hot gas heating operation is input and finishes processing of the present flowchart in a case of YES. In a case of NO, processing after step S110 is executed again.

[0086]In the hot gas heating operation described hereinbefore, in a case of reducing the power of the compressor 10, the control unit 90 controls the opening degree (first opening degree) of the expansion valve 40 and the opening degree (second opening degree) of the expansion valve 50 such that the proportion of the liquid refrigerant in the inflow refrigerant that flows into the accumulator 30 is not changed. In addition, in a case of increasing the power of the compressor 10, the control unit 90 controls the opening degree (first opening degree) of the expansion valve 40 and the opening degree (second opening degree) of the expansion valve 50 such that the proportion of the liquid refrigerant in the inflow refrigerant that flows into the accumulator 30 is not changed.

Dehumidification and Heating Operation

[0087]An operation during a dehumidification and heating operation of the vehicle air-conditioning device 100 according to the present embodiment will be described with reference to FIG. 12. FIG. 12 is a refrigerant circuit diagram showing a refrigerant flow during the dehumidification and heating operation of the vehicle air-conditioning device 100.

[0088]Arrows shown in FIG. 12 indicate the refrigerant circulation direction. As shown in FIG. 12, during the dehumidification and heating operation, a refrigerant circulates in the order of the compressor 10, the heating unit 20, the expansion valve 40, the outside heat exchanger 80, the cabin heat exchanger 85, the accumulator 30, and the compressor 10. The refrigerant pipes L1, L2, L3, L4, L5a, L5b, L10, and L7 form a circulation flow path for circulating the refrigerant.

[0089]During the dehumidification and heating operation, the outside heat exchanger 80 operates as an evaporator and evaporates a refrigerant to cool outside air. During the dehumidification and heating operation, the control unit 90 sets the on-off valve 64 to an open state and sets the on-off valves 61, 62, 63, and 65 to a closed state. The control unit 90 can heat air in the heating unit 20 to blow air while dehumidifying moisture contained in the air by driving the cabin blower 86 to guide the air dehumidified by the cabin heat exchanger 85 to the heating unit 20.

Cooling Operation

[0090]An operation during the cooling operation of the vehicle air-conditioning device 100 according to the present embodiment will be described with reference to FIG. 13. FIG. 13 is a refrigerant circuit diagram showing a refrigerant flow during the cooling operation of the vehicle air-conditioning device 100.

[0091]Arrows shown in FIG. 13 indicate the refrigerant circulation direction. As shown in FIG. 13, during the cooling operation, a refrigerant circulates in the order of the compressor 10, the outside heat exchanger 80, the cabin heat exchanger 85, the accumulator 30, and the compressor 10. The refrigerant pipes L1, L2, L11, L5b, L10, and L7 form a circulation flow path for circulating the refrigerant.

[0092]During the cooling operation, the outside heat exchanger 80 operates as a condenser and condenses a refrigerant to heat outside air. During the cooling operation, the control unit 90 sets the on-off valve 63 to an open state and sets the on-off valves 61, 62, 64, and 65 to a closed state. The control unit 90 can drive the cabin blower 86 to blow air cooled by the outside heat exchanger 80 into the vehicle interior.

[0093]The workings and effects of the vehicle air-conditioning device 100 of the present embodiment described hereinbefore will be described.

[0094]With the vehicle air-conditioning device 100 of the present embodiment, a part of a high-temperature and high-pressure refrigerant discharged from the compressor 10 is supplied to the heating unit 20, and the heating unit 20 heats air (heating target). The refrigerant that has passed through the heating unit 20 is depressurized by the expansion valve 40 and is guided to the accumulator 30 through the refrigerant pipes L5, L8, L9, and L7. In addition, the other part of the high-temperature and high-pressure refrigerant discharged from the compressor 10 is guided to the refrigerant pipe L6 (bypass flow path) and is depressurized by the expansion valve 50. The refrigerant depressurized by the expansion valve 50 merges in a refrigerant circulating through the refrigerant pipe L7 and is guided to the accumulator 30.

[0095]With the vehicle air-conditioning device 100 of the present embodiment, the first merging portion JP1 is disposed on the accumulator 30 side of the expansion valve 40 in the circulation flow path (upstream side pipe L5a) and in the first spray region SA1 of a refrigerant for the expansion valve 40. In a state where the refrigerant that circulates through the circulation flow path (upstream side pipe L5a) is depressurized by the expansion valve 40 to be in a sprayed state and a state where a specific surface area is increased, the high-temperature and high-pressure refrigerant guided from the bypass flow path (refrigerant pipe L6) merges in the circulation flow path. Therefore, the mixing of the refrigerant that circulates through the circulation flow path and the refrigerant that is guided from the bypass flow path is promoted. The vehicle air-conditioning device 100 can exhibit a stable heating capacity while preventing an increase in size of the device or an increase in manufacturing costs.

[0096]With the vehicle air-conditioning device 100 of the present embodiment, since the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path do not intersect each other at the first merging portion JP1, a revolving flow in which a refrigerant guided from the bypass flow path to the circulation flow path revolves around the central axis Z1 of the circulation flow path is formed. Since the refrigerant guided from the bypass flow path to the circulation flow path becomes a revolving flow, the mixing of the refrigerant circulating through the circulation flow path and the refrigerant guided from the bypass flow path is further promoted.

[0097]With the vehicle air-conditioning device 100 of the present embodiment, since the angle θ formed by the central axis Z1 of the circulation flow path and the central axis X1 of the bypass flow path is 90 degrees or more and 180 degrees or less, a relative speed between the refrigerant that circulates through the circulation flow path and the refrigerant that is guided from the bypass flow path increases, and the mixing of the refrigerant that circulates through the circulation flow path and the refrigerant that is guided from the bypass flow path is further promoted, compared to a case where the angle θ is less than 90 degrees.

[0098]With the vehicle air-conditioning device 100 of the present embodiment, since the convex portions L5a2 are formed on the inner peripheral surface L5a1 of the circulation flow path at the first merging portion JP1, a flow of a refrigerant is disturbed when a refrigerant guided from the bypass flow path to the circulation flow path collides with the inner peripheral surface L5a1 of the circulation flow path, and the mixing of a refrigerant guided to the circulation flow path and the refrigerant guided from the bypass flow path is promoted by the disturbance.

[0099]With the vehicle air-conditioning device 100 of the present embodiment, in a case where the inner diameter of the upstream side pipe L5a from an orifice 41 is denoted by D, as a refrigerant is merged from the bypass flow path at the first merging portion JP1 disposed in the first spray region SA1 within 10 D, the appropriate mixing of a refrigerant guided to the circulation flow path and a refrigerant guided from the bypass flow path is promoted.

Second Embodiment

[0100]Next, a vehicle air-conditioning device 100A according to a second embodiment of the present disclosure will be described. The present embodiment is a modification example of the first embodiment and is the same as the first embodiment except for cases particularly described below, and description thereof will be omitted below.

[0101]In the vehicle air-conditioning device 100A of the first embodiment, other depressurizing mechanisms are not disposed on the accumulator 30 side of the expansion valve 40 in the circulation flow path (refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, and L7) during the hot gas heating operation. On the other hand, in the vehicle air-conditioning device 100A of the present embodiment, the orifice (third expansion mechanism) 41, which is the depressurizing mechanism, is disposed on the accumulator 30 side of the expansion valve 40 in the circulation flow path during the hot gas heating operation.

[0102]FIG. 14 is a refrigerant circuit diagram of the vehicle air-conditioning device 100A according to the second embodiment of the present disclosure. As shown in FIG. 14, the vehicle air-conditioning device 100A includes a branch flow path (refrigerant pipe L12) and the orifice 41 in addition to the components of the vehicle air-conditioning device 100 of the first embodiment.

[0103]As shown in FIG. 14, the orifice 41 is disposed on the accumulator 30 side of the expansion valve 40 of the circulation flow path (the upstream side pipe L5a and the refrigerant pipe L8). The branch flow path branches a part of a refrigerant from the bypass flow path (refrigerant pipe L6) at a branching portion BP to merge in the circulation flow path at a second merging portion JP2 on the accumulator 30 side of the first merging portion JP1 of the circulation flow path (the upstream side pipe L5a and the refrigerant pipe L8).

[0104]Herein, a configuration where a refrigerant in a gas-liquid two phase that passes through the heating unit 20 and the expansion valve 40 and that circulates through the circulation flow path (the upstream side pipe L5a and the refrigerant pipe L8) and a refrigerant in a gas phase that is guided from the branch flow path (refrigerant pipe L12) to the circulation flow path are satisfactorily mixed will be described. FIG. 15 is a sectional view of the circulation flow path, the bypass flow path, and the branch flow path taken along the direction orthogonal to the central axis Z1 of the circulation flow path, in the vicinity of the first merging portion JP1 and the second merging portion JP2. In FIG. 15, since the vicinity of the first merging portion JP1 is the same as that in the first embodiment, description thereof will be omitted below.

[0105]As shown in FIG. 15, the second merging portion JP2 is disposed on the accumulator 30 side, which is the downstream side of the orifice 41 of the circulation flow path (the upstream side pipe L5a and the refrigerant pipe L8) in the refrigerant circulation direction, and so as to include a second spray region SA2 of a refrigerant for the orifice 41. The second spray region SA2 is a region where a refrigerant in a gas-liquid two phase, which is depressurized by the orifice 41, is sprayed. The second spray region SA2 is, for example, a region within 10 D from the orifice 41 in a case where the inner diameter of the refrigerant pipe L8 forming the circulation flow path is denoted by D. A distance Dis2 from the orifice 41 to an end portion of the second spray region SA2 along the central axis Z1 shown in FIG. 15 is within 10D.

[0106]As shown in FIG. 15, at the second merging portion JP2, in a case where the circulation flow path (refrigerant pipe L8) is viewed from the predetermined direction orthogonal to the central axis Z1, an angle α formed by the central axis Z1 of the circulation flow path (refrigerant pipe L8) and a central axis X2 of the branch flow path (refrigerant pipe L12) is 90 degrees. The angle α may be an angle other than 90 degrees and is preferably set to any angle that is 90 degrees or more and 180 degrees or less.

[0107]Although not shown, at the second merging portion JP2, in a case where the circulation flow path (refrigerant pipe L8) is viewed along the central axis Z1, the bypass flow path (refrigerant pipe L6) is connected to the circulation flow path such that the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path do not intersect each other.

[0108]It is preferable that the central axis Z1 of the circulation flow path (refrigerant pipe L8) shown in FIG. 15 is disposed along the vertical direction at the second merging portion JP2. By disposing the central axis Z1 along the vertical direction, a bias of a refrigerant caused by gravity does not occur in the circulation flow path, and appropriate mixing of a refrigerant guided to the circulation flow path and a refrigerant guided from the bypass flow path is promoted.

[0109]As shown in FIG. 15, in a case where the circulation flow path (upstream side pipe L5a) is viewed from the predetermined direction orthogonal to the central axis Z1 of the circulation flow path, a first inflow direction ID1 in which a refrigerant flows from the bypass flow path (refrigerant pipe L6) to the circulation flow path (upstream side pipe L5a) at the first merging portion JP1 and a second inflow direction ID2 in which the refrigerant flows from the branch flow path (refrigerant pipe L12) to the circulation flow path (refrigerant pipe L8) at the second merging portion JP2 face each other. Herein, the phrase “face each other” means that, in a case where the circulation flow path (the upstream side pipe L5a and the refrigerant pipe L8) is viewed from the predetermined direction orthogonal to the central axis Z1 of the circulation flow path, the first inflow direction ID1 and the second inflow direction ID2 are within a range of 180 degrees or a predetermined angle (for example, 10 degrees) from 180 degrees.

[0110]FIG. 16 is a sectional view of the circulation flow path shown in FIG. 15 taken along arrow B-B. As shown in FIG. 16, the orifice 41 of the present embodiment is an expansion mechanism in which a flow path sectional area of a part of a pipe that forms the circulation flow path (refrigerant pipe L8) is smaller than that of the other part. The orifice 41 shown in FIG. 16 is a plate-shaped member formed in a ring shape around the central axis Z1, has an outer diameter of D, which is the same as the inner diameter of the refrigerant pipe L8, and has an opening hole 41a formed at the center thereof.

[0111]The orifice 41 shown in FIG. 16 may be used as the orifice 41 of a first modification example shown in FIG. 17. FIG. 17 is a view showing the first modification example of the orifice 41 shown in FIG. 16. In the orifice 41 shown in FIG. 17, the opening hole 41a is formed at the center thereof, and a plurality of opening holes 41b having a smaller diameter than that of the opening hole 41a are formed.

[0112]The orifice 41 shown in FIG. 16 may be used as the orifice 41 of a second modification example shown in FIG. 18. FIG. 18 is a view showing the second modification example of the orifice 41 shown in FIG. 16. In the orifice 41 shown in FIG. 18, an opening hole is not formed at the center, and the opening holes 41b having a diameter smaller than that of the opening hole 41a are formed at a plurality of locations other than the center.

[0113]As shown in FIGS. 16 to 18, the upstream side pipe L5a of the present embodiment has a circular shape without an undulation in an inner peripheral surface L8a at the second merging portion JP2, but may adopt other aspects. For example, at the second merging portion JP2, the inner peripheral surface L8a of the refrigerant pipe L8 may have an undulating shape. FIG. 19 is a sectional view of the circulation flow path shown in FIG. 15 taken along arrow C-C.

[0114]As shown in FIG. 19, at the second merging portion JP2, convex portions L8b are formed at a plurality of locations along the circumferential direction around the central axis Z1 on the inner peripheral surface L8a of the circulation flow path (refrigerant pipe L8). For this reason, a flow of a refrigerant is disturbed by the convex portions L8b when the refrigerant guided from the branch flow path (refrigerant pipe L12) to the circulation flow path (refrigerant pipe L8) collides with the inner peripheral surface L8a of the circulation flow path, and mixing of the refrigerant guided to the circulation flow path and the refrigerant guided from the bypass flow path is promoted by this disturbance. The convex portions L8b may be formed to extend parallel to the central axis Z1 or may be formed to helically revolve around the central axis Z1.

[0115]In the present embodiment, one branch flow path (refrigerant pipe L12) and one orifice 41 are provided in the vehicle air-conditioning device 100A, but without being limited to the numbers described above, the mixing may be further promoted by increasing the numbers. For example, one or a plurality of other branching portions BP different from the branching portion BP shown in FIG. 14 may be provided, and the branch flow path may be connected to the other branching portions BP and be merged in the circulation flow path (refrigerant pipe L8) at the plurality of merging portions. In this case, it is preferable that the orifice 41 is disposed on each upstream side of the plurality of merging portions of the circulation flow path (refrigerant pipe L8).

[0116]In addition, in the present embodiment, the orifice 41 is disposed on the upstream side of the second merging portion JP2 of the circulation flow path (refrigerant pipe L8), but an aspect in which the orifice 41 is not disposed at the circulation flow path (refrigerant pipe L8) may be adopted. Even in the aspect in which the orifice 41 is not disposed at the circulation flow path (refrigerant pipe L8), a refrigerant can be made to flow from the branch flow path (refrigerant pipe L12) to the circulation flow path (refrigerant pipe L8), and thus the mixing of the refrigerant that circulates through the circulation flow path can be promoted.

[0117]The workings and effects of the vehicle air-conditioning device 100A of the present embodiment described hereinbefore will be described.

[0118]With the vehicle air-conditioning device 100A of the present embodiment, since the central axis X1 of the branch flow path (refrigerant pipe L12) and the central axis Z1 of the circulation flow path (upstream side pipe L5a) do not intersect each other at the second merging portion JP2, a revolving flow in which a refrigerant guided from the branch flow path to the circulation flow path revolves around the central axis Z1 of the circulation flow path is formed. Since the refrigerant guided from the branch flow path to the circulation flow path becomes a revolving flow, the mixing of the refrigerant circulating through the circulation flow path and the refrigerant guided from the branch flow path is further promoted.

[0119]With the vehicle air-conditioning device 100A of the present embodiment, since an angle formed by the central axis Z1 of the circulation flow path and the central axis X1 of the branch flow path is 90 degrees or more and 180 degrees or less, a relative speed between a refrigerant circulating through the circulation flow path and a refrigerant guided from the branch flow path increases, and the mixing of the refrigerant circulating through the circulation flow path and a refrigerant guided from the branch flow path is further promoted, compared to a case where the angle is less than 90 degrees.

[0120]With the vehicle air-conditioning device 100A of the present embodiment, since the first inflow direction ID1 and the second inflow direction ID2 face each other, even in a case where a refrigerant that flows in from the bypass flow path in the first inflow direction ID1 is biased to one side in a radial direction of the pipe that forms the circulation flow path, a bias can be reduced by a refrigerant that flows in from the branch flow path in the second inflow direction ID2.

[0121]With the vehicle air-conditioning device 100A of the present embodiment, since the convex portion L5a2 is formed on the inner peripheral surface L5a1 of the circulation flow path at the second merging portion JP2, a flow of a refrigerant is disturbed when a refrigerant guided from the branch flow path to the circulation flow path collides with the inner peripheral surface L5a1 of the circulation flow path, and the mixing of the refrigerant guided to the circulation flow path and the refrigerant guided from the branch flow path is promoted by the disturbance.

[0122]With the vehicle air-conditioning device 100A of the present embodiment, since the central axis Z1 of the circulation flow path is disposed along the vertical direction, a bias of a refrigerant is not generated by gravity in the circulation flow path, and the appropriate mixing of a refrigerant guided to the circulation flow path and a refrigerant guided from the branch flow path is promoted.

[0123]With the vehicle air-conditioning device 100A of the present embodiment, in a case where the inner diameter of the upstream side pipe L5a from the orifice 41 is denoted by D, as a refrigerant is merged from the bypass flow path at the second merging portion JP2 disposed in the second spray region SA2 within 10 D, the appropriate mixing of a refrigerant guided to the circulation flow path and a refrigerant guided from the bypass flow path is promoted.

[0124]The air-conditioning device described in each embodiment described above is understood, for example, as follows.

[0125]According to a first aspect of the present disclosure, there is provided an air-conditioning device (100) including a compressor (10) that compresses a refrigerant, a heating unit (20) that heats a heating target with the refrigerant discharged from the compressor, an accumulator (30) that separates a liquid component in the refrigerant sucked by the compressor, a circulation flow path (L5, L8, L7) that guides the refrigerant, which has passed through the heating unit, to the accumulator, a bypass flow path (L6) that merges the refrigerant, which does not pass through the heating unit and which is discharged from the compressor, at a first merging portion (JP1) of the circulation flow path (L5, L8, L7), a first expansion mechanism (40) that is disposed at the circulation flow path and that expands the refrigerant flowing out from the heating unit, and a second expansion mechanism (50) that is disposed at the bypass flow path and that expands the refrigerant discharged from the compressor, in which the first merging portion is disposed on an accumulator side of the first expansion mechanism of the circulation flow path and is disposed in a first spray region (SA1) of the refrigerant for the first expansion mechanism.

[0126]With the air-conditioning device according to a first aspect of the present disclosure, a part of the high-temperature and high-pressure refrigerant discharged from the compressor is supplied to the heating unit, and the heating unit heats the heating target. The refrigerant that has passed through the heating unit is depressurized by the first expansion mechanism and is guided to the accumulator through the circulation flow path. In addition, the other part of the high-temperature and high-pressure refrigerant discharged from the compressor is guided to the bypass flow path and is depressurized by the second expansion mechanism. The refrigerant depressurized by the second expansion mechanism merges in a refrigerant that circulates through the circulation flow path at the first merging portion and is guided to the accumulator.

[0127]With the air-conditioning device according to the first aspect of the present disclosure, the first merging portion is disposed on the accumulator side of the first expansion mechanism of the circulation flow path and in the first spray region of the refrigerant for the first expansion mechanism. In a state where the refrigerant circulating through the circulation flow path is depressurized by the first expansion mechanism to be in a sprayed state and a state where a specific surface area is increased, the high-temperature and high-pressure refrigerant guided from the bypass flow path merges in the circulation flow path. Therefore, the mixing of the refrigerant circulating through the circulation flow path and the refrigerant guided from the bypass flow path is promoted. Then, the air-conditioning device can exhibit a stable heating capacity while preventing an increase in size of the device or an increase in manufacturing costs.

[0128]In the first aspect, the air-conditioning device according to a second aspect of the present disclosure further includes a third expansion mechanism (41) that is disposed on the accumulator side of the first expansion mechanism of the circulation flow path.

[0129]With the air-conditioning device according to the second aspect of the present disclosure, a refrigerant that circulates through the circulation flow path is depressurized by the third expansion mechanism to be in a sprayed state. For this reason, the mixing of a refrigerant that flows into the third expansion mechanism can be further promoted, and the refrigerant can be guided to the accumulator.

[0130]In the first aspect or the second aspect, the air-conditioning device according to a third aspect of the present disclosure further includes the following configuration. That is, a branch flow path that branches a part of the refrigerant from the bypass flow path and that merges in the circulation flow path at a second merging portion on the accumulator side of the first merging portion of the circulation flow path is included.

[0131]With the air-conditioning device according to the third aspect of the present disclosure, by causing a part of the refrigerant branched from the bypass flow path to merge in the circulation flow path at the second merging portion, the mixing of the refrigerant that circulates through the circulation flow path can be promoted.

[0132]In the first aspect, the air-conditioning device according to a fourth aspect of the present disclosure further includes the following configuration. That is, a third expansion mechanism that is disposed on the accumulator side of the first expansion mechanism of the circulation flow path and a branch flow path that branches a part of the refrigerant from the bypass flow path and that merges in the circulation flow path at a second merging portion on the accumulator side of the first merging portion of the circulation flow path are included, in which the second merging portion is disposed on the accumulator side of the third expansion mechanism of the circulation flow path and in a second spray region of the refrigerant for the third expansion mechanism.

[0133]With the air-conditioning device according to the fourth aspect of the present disclosure, the second merging portion is disposed on the accumulator side of the third expansion mechanism of the circulation flow path and in the second spray region of a refrigerant for the third expansion mechanism. In a state where a refrigerant circulating through the circulation flow path is depressurized by the third expansion mechanism to be in a sprayed state and a state where a specific surface area is increased, a high-temperature and high-pressure refrigerant guided from the branch flow path merges in the circulation flow path. Therefore, the mixing of the refrigerant circulating through the circulation flow path and the refrigerant guided from the branch flow path is further promoted.

[0134]In the second aspect or the fourth aspect, the air-conditioning device according to a fifth aspect of the present disclosure further includes the following configuration. That is, the third expansion mechanism is an orifice in which a flow path sectional area of a part of a pipe forming the circulation flow path is smaller than a flow path sectional area of the other part.

[0135]With the air-conditioning device according to the fifth aspect of the present disclosure, by disposing a relatively simple orifice at the circulation flow path, the specific surface area of the refrigerant that circulates through the circulation flow path can be increased, and the mixing of the refrigerant can be promoted.

[0136]In the first aspect or the second aspect, the air-conditioning device according to a sixth aspect of the present disclosure further includes the following configuration. That is, at the first merging portion, in a case where the circulation flow path is viewed along a central axis of the circulation flow path, the bypass flow path is connected to the circulation flow path such that a central axis (X1) of the bypass flow path and the central axis (Z1) of the circulation flow path do not intersect each other.

[0137]With the air-conditioning device according to the sixth aspect of the present disclosure, since the central axis of the bypass flow path and the central axis of the circulation flow path do not intersect each other at the first merging portion, a revolving flow in which a refrigerant guided from the bypass flow path to the circulation flow path revolves around the central axis of the circulation flow path is formed. Since the refrigerant guided from the bypass flow path to the circulation flow path becomes a revolving flow, the mixing of the refrigerant circulating through the circulation flow path and the refrigerant guided from the bypass flow path is further promoted.

[0138]In the third aspect, the air-conditioning device according to a seventh aspect of the present disclosure further includes the following configuration. That is, at the second merging portion, in a case where the circulation flow path is viewed along a central axis of the circulation flow path, the branch flow path is connected to the circulation flow path such that a central axis of the bypass flow path and the central axis of the circulation flow path do not intersect each other.

[0139]With the air-conditioning device according to the seventh aspect of the present disclosure, since the central axis of the branch flow path and the central axis of the circulation flow path do not intersect each other at the second merging portion, a revolving flow in which a refrigerant guided from the branch flow path to the circulation flow path revolves around the central axis of the circulation flow path is formed. Since the refrigerant guided from the branch flow path to the circulation flow path becomes a revolving flow, the mixing of a refrigerant circulating through the circulation flow path and the refrigerant guided from the branch flow path is further promoted.

[0140]In the first aspect or the second aspect, the air-conditioning device according to an eighth aspect of the present disclosure further includes the following configuration. That is, at the first merging portion, in a case where the circulation flow path is viewed from a predetermined direction orthogonal to a central axis of the circulation flow path, the bypass flow path is connected to the circulation flow path such that an angle formed by the central axis of the circulation flow path and a central axis of the bypass flow path is 90 degrees or more and 180 degrees or less.

[0141]With the air-conditioning device according to the eighth aspect of the present disclosure, since the angle formed by the central axis of the circulation flow path and the central axis of the bypass flow path is 90 degrees or more and 180 degrees or less, a relative speed between a refrigerant that circulates through the circulation flow path and a refrigerant that is guided from the bypass flow path increases, and the mixing of the refrigerant that circulates through the circulation flow path and the refrigerant that is guided from the bypass flow path is further promoted, compared to a case where the angle is less than 90 degrees.

[0142]In the third aspect, the air-conditioning device according to a ninth aspect of the present disclosure further includes the following configuration. That is, at the second merging portion, in a case where the circulation flow path is viewed from a predetermined direction orthogonal to a central axis of the circulation flow path, the branch flow path is connected to the circulation flow path such that an angle formed by the central axis of the circulation flow path and a central axis of the branch flow path is 90 degrees or more and 180 degrees or less.

[0143]With the air-conditioning device according to the ninth aspect of the present disclosure, since the angle formed by the central axis of the circulation flow path and the central axis of the branch flow path is 90 degrees or more and 180 degrees or less, a relative speed between the refrigerant that circulates through the circulation flow path and the refrigerant that is guided from the branch flow path increases, and the mixing of the refrigerant that circulates through the circulation flow path and the refrigerant that is guided from the branch flow path is further promoted, compared to a case where the angle is less than 90 degrees.

[0144]In the third aspect, the air-conditioning device according to a tenth aspect of the present disclosure further includes the following configuration. That is, in a case where the circulation flow path is viewed from a predetermined direction orthogonal to a central axis of the circulation flow path, a first inflow direction in which the refrigerant flows from the bypass flow path into the circulation flow path at the first merging portion and a second inflow direction in which the refrigerant flows from the branch flow path into the circulation flow path at the second merging portion face each other.

[0145]With the air-conditioning device according to the tenth aspect of the present disclosure, since the first inflow direction and the second inflow direction face each other, even in a case where a refrigerant that flows in from the bypass flow path in the first inflow direction is biased to one side in the radial direction of the pipe that forms the circulation flow path, a bias can be reduced by the refrigerant that flows in from the branch flow path in the second inflow direction.

[0146]In the first aspect or the second aspect, the air-conditioning device according to an eleventh aspect of the present disclosure further includes the following configuration. That is, at the first merging portion, convex portions (L5a2) are formed on an inner peripheral surface of the circulation flow path at a plurality of locations along a circumferential direction around a central axis of the circulation flow path.

[0147]With the air-conditioning device according to the eleventh aspect of the present disclosure, since the convex portions are formed on the inner peripheral surface of the circulation flow path at the first merging portion, a flow of a refrigerant is disturbed when a refrigerant guided from the bypass flow path to the circulation flow path collides with the inner peripheral surface of the circulation flow path, and the mixing of a refrigerant guided to the circulation flow path and the refrigerant guided from the bypass flow path is promoted by the disturbance.

[0148]In the third aspect, the air-conditioning device according to a twelfth aspect of the present disclosure further includes the following configuration. That is, at the second merging portion, convex portions are formed on an inner peripheral surface of the circulation flow path at a plurality of locations along a circumferential direction around a central axis of the circulation flow path.

[0149]With the air-conditioning device according to the twelfth aspect of the present disclosure, since the convex portions are formed on the inner peripheral surface of the circulation flow path at the second merging portion, a flow of a refrigerant is disturbed when a refrigerant guided from the branch flow path to the circulation flow path collides with the inner peripheral surface of the circulation flow path, and the mixing of the refrigerant guided to the circulation flow path and the refrigerant guided from the branch flow path is promoted by the disturbance.

[0150]In the first aspect or the second aspect, the air-conditioning device according to a thirteenth aspect of the present disclosure further includes the following configuration. That is, at the first merging portion, a central axis of the circulation flow path is disposed along a vertical direction.

[0151]With the air-conditioning device according to the thirteenth aspect of the present disclosure, since the central axis of the circulation flow path is disposed along the vertical direction, a bias of a refrigerant is not generated by gravity in the circulation flow path, and the appropriate mixing of a refrigerant guided to the circulation flow path and a refrigerant guided from the bypass flow path is promoted.

[0152]In the third aspect, the air-conditioning device according to a fourteenth aspect of the present disclosure further includes the following configuration. That is, at the second merging portion, a central axis of the circulation flow path is disposed along a vertical direction.

[0153]With the air-conditioning device according to the fourteenth aspect of the present disclosure, since the central axis of the circulation flow path is disposed along the vertical direction, a bias of a refrigerant is not generated by gravity in the circulation flow path, and the appropriate mixing of a refrigerant guided to the circulation flow path and a refrigerant guided from the branch flow path is promoted.

[0154]In the first aspect or the second aspect, the air-conditioning device according to a fifteenth aspect of the present disclosure further includes the following configuration. That is, in a case where an inner diameter of a pipe forming the circulation flow path is denoted by D, the first spray region is a region within 10 D from the first expansion mechanism.

[0155]With the air-conditioning device according to the fifteenth aspect of the present disclosure, by merging a refrigerant from the bypass flow path at the first merging portion disposed in the first spray region within 10 D from the first expansion mechanism, the appropriate mixing of a refrigerant guided to the circulation flow path and the refrigerant guided from the bypass flow path is promoted.

[0156]In the fourth aspect, the air-conditioning device according to a sixteenth aspect of the present disclosure further includes the following configuration. That is, in a case where an inner diameter of a pipe forming the circulation flow path is denoted by D, the second spray region is a region within 10 D from the third expansion mechanism.

[0157]With the air-conditioning device according to the sixteenth aspect of the present disclosure, by merging a refrigerant from the branch flow path at the second merging portion disposed in the second spray region within 10 D from the third expansion mechanism, the appropriate mixing of a refrigerant guided to the circulation flow path and the refrigerant guided from the branch flow path is promoted.

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