Air conditioning device

Abstract

An air conditioner for a vehicle is provided with: a compressor that compresses a refrigerant; a heating unit that heats an object to be heated by the refrigerant discharged from the compressor; the energy accumulator is used for separating a liquid component in the refrigerant sucked by the compressor; a circulation flow path that guides the refrigerant that has passed through the heating unit to the accumulator; a bypass flow path that merges the refrigerant discharged from the compressor in a first merging part (JP1) of the circulation flow path and does not pass through the heating part; an expansion valve (40) that is disposed in the circulation flow path and that expands the refrigerant flowing out from the heating unit; and an expansion valve that is disposed in the bypass flow path and that expands the refrigerant discharged from the compressor, and the first confluence part (JP1) is disposed in a first spray region (SA1) of the refrigerant by the expansion valve (40) on the accumulator side of the circulation flow path than the expansion valve (40).

Description

Technical Field

[0001] The invention relates to an air conditioning device. Background Art

[0002] In the past, a refrigeration cycle device has been disclosed that mixes refrigerants with different enthalpies and then sucks them into a compressor (for example, refer to Patent Document 1). Patent Document 1 discloses that in order to evenly mix the bypass-side refrigerant and the pressure-reducing-section-side refrigerant with different enthalpies, the bypass-side refrigerant and the pressure-reducing-section-side refrigerant are heat-exchanged in a stacked heat exchanger and then merged. In Patent Document 1, by evenly mixing the bypass-side refrigerant and the pressure-reducing-section-side refrigerant with different enthalpies, the refrigeration cycle device can exert a stable heating capacity. Previous technical literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-156567 Summary of the invention Technical issues to be solved by the invention

[0004] However, in Patent Document 1, a heat exchanger is required for performing heat exchange before two refrigerants having different enthalpies are merged, which results in an increase in the size of the device and an increase in manufacturing cost.

[0005] The present invention has been made in view of such circumstances, and an object of the present invention is to provide an air-conditioning apparatus that can exhibit a stable heating capacity while preventing an increase in the size of the apparatus or an increase in manufacturing cost. Means for solving technical problems

[0006] In order to solve the above-mentioned problems, the present invention adopts the following means. The air-conditioning device involved in the present invention comprises: a compressor that compresses refrigerant; a heating unit that heats a heating object by using the refrigerant ejected from the compressor; an accumulator that separates the liquid component in the refrigerant sucked into the compressor; a circulation flow path that guides the refrigerant that has passed through the heating unit to the accumulator; a bypass flow path that causes the refrigerant ejected from the compressor to merge at a first confluence portion of the circulation flow path without passing through the heating unit; a first expansion mechanism that is arranged in the circulation flow path and expands the refrigerant flowing out of the heating unit; and a second expansion mechanism that is arranged in the bypass flow path and expands the refrigerant ejected from the compressor, the first confluence portion being arranged in the circulation flow path that is closer to the accumulator side than the first expansion mechanism and is based on a first spray area of ​​the refrigerant of the first expansion mechanism. Effects of the Invention

[0007] According to the present invention, it is possible to provide an air-conditioning apparatus that can exhibit a stable heating capacity while preventing an increase in the size of the apparatus or an increase in the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a refrigerant circuit diagram of a vehicle air conditioning system according to a first embodiment of the present invention. Figure 2 This is a refrigerant circuit diagram showing the flow of refrigerant during the heat pump heating operation of the vehicle air conditioner. Figure 3 This is a refrigerant circuit diagram showing the flow of refrigerant during hot air heating operation of the vehicle air conditioner. Figure 4 This is a cross-sectional view of the circulation flow path and the bypass flow path viewed in a direction perpendicular to the central axis of the circulation flow path in the vicinity of the first confluence portion. Figure 5 Yes means Figure 4 A cross-sectional view of a first modified example of the circulation flow path shown. Figure 6 Yes means Figure 4 A cross-sectional view of a second modified example of the circulation flow path shown. Figure 7 yes Figure 4 A cross-sectional view taken along the line AA of the circulation flow path and the bypass flow path is shown. Figure 8 Yes means Figure 7 A cross-sectional view of a modified example of the circulation flow path and the bypass flow path shown. Fig. 9 This is a flowchart showing the operation of the vehicle air conditioner during hot air heating operation. Fig.10 This is a flowchart showing the operation of the vehicle air conditioner during hot air heating operation. Fig.11 This is a Mollier diagram showing the state of the refrigerant during hot gas heating operation. Fig.12 This is a refrigerant circuit diagram showing the flow of refrigerant during the dehumidification and heating operation of the vehicle air conditioner. Fig.13 This is a refrigerant circuit diagram showing the flow of refrigerant during cooling operation of the vehicle air conditioner. Fig.14 This is a refrigerant circuit diagram of a vehicle air conditioning system according to a second embodiment of the present invention. Fig.15 This is a cross-sectional view of the circulation flow path, the bypass flow path, and the branch flow path viewed in a direction perpendicular to the central axis of the circulation flow path in the vicinity of the first merging portion and the second merging portion. Fig.16 yes Fig.15 A cross-sectional view of the circulation flow path taken along the line BB is shown. Fig.17 Yes means Fig.16 A diagram of a first variant of the throttling device is shown. Fig.18 Yes means Fig.16 A diagram of a second variant of the throttling device shown. Fig.19 yes Fig.15 A cross-sectional view of the circulation flow path taken along the line CC shown. DETAILED DESCRIPTION

[0009] [First embodiment] Below, reference Figure 1 Next, a heat pump type vehicle air conditioner (air conditioner) 100 according to a first embodiment of the present invention will be described. Figure 1 As shown, the vehicle air conditioning device 100 of 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 opening and closing valve (switching unit) 61, an opening and closing valve (switching unit) 62, an opening and closing valve 63, an opening and closing valve (first opening and closing valve) 64, an opening and closing valve (second opening and closing valve) 65, an expansion valve 70, an outdoor heat exchanger 80, an outdoor fan 81, a cabin heat exchanger (evaporator) 85, a cabin blower 86, a control unit 90, a refrigerant heater 91, a pressure sensor 92, a temperature sensor 93, a temperature sensor 94, a temperature sensor 95 and a pressure sensor 96.

[0010] The vehicle air conditioning device 100 of the present embodiment generates warm air by a heating unit 20 provided in the vehicle, or generates cold air by a cabin heat exchanger 85 provided in the vehicle, and blows the air into the vehicle. The vehicle air conditioning device 100 operates the outdoor heat exchanger 80 as an evaporator during heat pump heating operation, and operates the outdoor heat exchanger 80 as a condenser during cooling operation. Furthermore, when the outside air temperature is below a predetermined temperature (e.g., -20°C), the vehicle air conditioning device 100 can perform hot air heating operation for heating only by the power of the compressor 10, without passing the refrigerant through the outdoor heat exchanger 80. The refrigerant used in the vehicle air conditioning device 100 of the present embodiment is, for example, HFO-1234yf.

[0011] The compressor 10 is a device that compresses the refrigerant flowing in from the accumulator 30. The compressor 10 is, for example, an electric compressor that compresses the refrigerant by driving a motor (not shown). The compressor 10 compresses the refrigerant flowing in from the refrigerant pipe L1 and discharges it to the refrigerant pipe L2. The refrigerant discharged to the refrigerant pipe L2 is guided to the heating unit 20 via the refrigerant pipe L3 and the refrigerant pipe L4.

[0012] The heating unit 20 is a device that heats the air (heating object) blown by the cabin blower 86 using the high-temperature and high-pressure refrigerant ejected from the compressor 10. The air heated by the heating unit 20 is blown into the vehicle interior. The refrigerant that has exchanged heat with the air in the heating unit 20 is guided to the expansion valve 40 disposed in the upstream side pipe L5a of the refrigerant pipe L5.

[0013] The accumulator 30 is a device that separates at least a part of the liquid component in the refrigerant sucked into the compressor 10. The accumulator 30 guides the gas phase or gas-liquid two-phase refrigerant to the compressor 10 via the refrigerant pipe L1.

[0014] The expansion valve 40 is disposed in the refrigerant pipe L5 and is a mechanism for expanding the refrigerant flowing out of the heating unit 20. The opening degree of the expansion valve 40 is controlled by the control unit 90. The refrigerant decompressed by the expansion valve 40 flows through the refrigerant pipe L5.

[0015] The expansion valve 50 is disposed in the refrigerant pipe L6 connected to the refrigerant pipe L3, and is a mechanism for expanding the refrigerant discharged from the compressor 10. The opening of the expansion valve 50 is controlled by the control unit 90. The refrigerant decompressed by the expansion valve 50 is guided from the refrigerant pipe L6 to the accumulator 30 via the refrigerant pipe L7. The refrigerant pipe L7 is a pipe connecting the cabin heat exchanger 85 and the accumulator 30.

[0016] The on-off valve 61 is a device disposed on the refrigerant piping L8, and switches between an open state in which the refrigerant flows through the refrigerant piping L8 and a closed state in which the refrigerant does not flow through the refrigerant piping L8. The refrigerant piping L8 is a pipe connecting the refrigerant piping L5 and the refrigerant piping L9. The refrigerant piping L9 is a pipe connecting the refrigerant piping L10 and the refrigerant piping L7. The refrigerant piping L10 is a pipe connecting the outdoor heat exchanger 80 and the cabin heat exchanger 85.

[0017] The on-off valve 62 is a device disposed in the refrigerant pipe L6 and switches between an open state in which the refrigerant is allowed to flow through the refrigerant pipe L6 and a closed state in which the refrigerant is not allowed to flow through the refrigerant pipe L6 . The on-off valve 63 is a device disposed in the refrigerant pipe L11 and switches between an open state in which the refrigerant is allowed to flow through the refrigerant pipe L11 and a closed state in which the refrigerant is not allowed to flow through the refrigerant pipe L11 .

[0018] The on-off valve 64 is arranged on the downstream side pipe L5b of the refrigerant piping L5, and is a device that switches between an open state in which the refrigerant flows toward the outdoor heat exchanger 80 side that is closer to the connection portion of the refrigerant piping L5 with the refrigerant piping L8, and a closed state in which the refrigerant does not flow toward the outdoor heat exchanger 80 side that is closer to the connection portion of the refrigerant piping L5 with the refrigerant piping L8. The on-off valve 65 is a device disposed in the refrigerant pipe L9 and switches between an open state in which the refrigerant is allowed to flow through the refrigerant pipe L9 and a closed state in which the refrigerant is not allowed to flow through the refrigerant pipe L9 .

[0019] The expansion valve 70 is disposed in the refrigerant pipe L10 and is a mechanism for expanding the refrigerant introduced from the outdoor heat exchanger 80. The opening degree of the expansion valve 70 is controlled by the control unit 90. The refrigerant decompressed by the expansion valve 70 is guided to the cabin heat exchanger 85 from the refrigerant pipe L10.

[0020] The outdoor heat exchanger 80 is a device that is disposed outside the vehicle and performs heat exchange between the outside air and the refrigerant. The outdoor heat exchanger 80 acts as an evaporator when the heat pump is in heating operation, and evaporates the refrigerant to cool the outside air. In addition, the outdoor heat exchanger 80 acts as a condenser when the cooling operation is in operation, and condenses the refrigerant to heat the outside air. The outdoor fan 81 is a device that blows the outside air to the outdoor heat exchanger 80 to promote the heat exchange between the outside air and the refrigerant.

[0021] The cabin heat exchanger (evaporator) 85 is a device that passes through the outdoor heat exchanger 80 and evaporates the refrigerant decompressed by the expansion valve 70 to cool or dehumidify the air. The cabin blower 86 blows air to the cabin heat exchanger 85, thereby guiding the air cooled or dehumidified by the cabin heat exchanger 85 into the vehicle interior via the heating unit 20.

[0022] The control unit 90 is a device that controls each unit of the vehicle air conditioner 100. The control unit 90 reads and executes a control program stored in a storage unit (not shown) to perform various processes for controlling each unit of the vehicle air conditioner 100.

[0023] The refrigerant heater 91 is a device disposed on the downstream side of the on-off valve 61 of the refrigerant pipe L8, and heats the refrigerant flowing into the accumulator 30. For example, when the hot air heating operation is started, the control unit 90 operates the refrigerant heater 91 to heat the refrigerant in order to increase the pressure of the refrigerant sucked by the compressor 10.

[0024] The pressure sensor 92 is a sensor for detecting the pressure of the refrigerant flowing through the refrigerant pipe L1. The temperature sensor 93 is a sensor for detecting the temperature of the refrigerant flowing through the refrigerant pipe L1. The temperature sensor 94 is a sensor for detecting the temperature of the refrigerant flowing through the refrigerant pipe L2. The temperature sensor 95 is a sensor for detecting the temperature of the refrigerant flowing through the refrigerant pipe L5 between the heating unit 20 and the expansion valve 40. The pressure sensor 96 is a sensor for detecting the pressure of the refrigerant flowing through the refrigerant pipe L5 between the heating unit 20 and the expansion valve 40.

[0025] <Heat pump heating operation> refer to Figure 2 Next, the operation of the vehicle air conditioning device 100 according to the present embodiment during the heat pump heating operation will be described. Figure 2 1 is a refrigerant circuit diagram showing the flow of refrigerant during heat pump heating operation of vehicle air conditioner 100. Heat pump heating operation is performed when the temperature outside the vehicle where outdoor heat exchanger 80 is installed is not lower than a predetermined temperature (eg, -20°C).

[0026] Figure 2 The arrows shown indicate the flow direction of the refrigerant. Figure 2 As shown, when the heat pump is in heating operation, the refrigerant circulates in the order of the compressor 10, the heating unit 20, the expansion valve 40, the outdoor 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.

[0027] During the heat pump heating operation, the outdoor heat exchanger 80 operates as an evaporator and evaporates the refrigerant to cool the outside air. During the heat pump heating operation, the control unit 90 opens the on-off valves 64 and 65 and closes the on-off valves 61, 62, and 63.

[0028] <Hot gas heating operation> refer to Figure 3 Next, the operation of the vehicle air conditioning device 100 according to the present embodiment during the hot air heating operation will be described. Figure 3 1 is a refrigerant circuit diagram showing the flow of the refrigerant during the hot gas heating operation of the vehicle air conditioner 100 . Figure 3 The arrows shown indicate the flow direction of the refrigerant. The hot air heating operation is performed, for example, when the temperature outside the vehicle where the outdoor heat exchanger 80 is installed is equal to or lower than a predetermined temperature (eg, -20°C).

[0029] like Figure 3 As shown, during the hot air heating operation, a part of the 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 that has passed through the heating unit 20 to the accumulator 30.

[0030] The other part of the refrigerant does not flow through the refrigerant pipe L4 but is guided from the refrigerant pipe L3 to the upstream pipe L5a via the refrigerant pipe L6. The refrigerant pipe L6 is a bypass flow path that allows the refrigerant discharged from the compressor 10 to merge at the first confluence portion JP1 of the circulation flow path without passing through the heating unit 20.

[0031] In the case of hot air heating operation, the control unit 90 closes the on-off valves 63, 64, and 65 to circulate the refrigerant in the circulation flow path formed by the refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, and L7. In the vehicle air conditioning device 100 of the present embodiment, the amount of refrigerant sealed in the refrigerant pipes formed by the refrigerant pipes L1 to L11 is set so that the air can be heated by the heating unit 20 when the on-off valves 64 and 65 are closed.

[0032] Here, the structure of the liquid phase or gas-liquid two-phase refrigerant that is well mixed through the heating section 20 and circulates in the circulation flow path (upstream side piping L5a) and the gas phase refrigerant that is guided to the circulation flow path from the bypass flow path (refrigerant piping L6) is described. Figure 4 This is a cross-sectional view of the circulation flow path (upstream pipe L5a) and the bypass flow path (refrigerant pipe L6) viewed in the direction orthogonal to the central axis Z1 of the circulation flow path in the vicinity of the first junction JP1. Figure 4 The expansion valve 40 shown is a schematic diagram in which the detailed structure of the mechanism for decompressing the refrigerant is omitted.

[0033] like Figure 4 As shown, the first confluence portion JP1 is configured to include the first spray area SA1 of the refrigerant based on the expansion valve 40, which is located on the downstream side of the circulation flow path (upstream side piping L5a) in the flow direction of the refrigerant, that is, the accumulator 30 side, of the expansion valve 40. The first spray area SA1 is an area where the liquid phase or gas-liquid two-phase refrigerant decompressed by the expansion valve 40 is sprayed. For example, when the inner diameter of the upstream side piping L5a forming the circulation flow path is set to D, the first spray area SA1 is an area within 10D from the expansion valve 40. Figure 4 The distance Dis1 from the expansion valve 40 to the end of the first spray area SA1 along the central axis Z1 shown is within 10D.

[0034] like Figure 4 As shown, in the first confluence portion JP1, when the circulation flow path (upstream pipe L5a) is observed from a predetermined direction orthogonal to the central axis Z1, the angle θ formed by the central axis Z1 of the circulation flow path (upstream pipe L5a) and the central axis X1 of the bypass flow path (refrigerant pipe L6) is 90 degrees. In addition, the angle θ may be set to an angle other than 90 degrees.

[0035] In the first confluence section JP1, if Figure 4 The central axis Z1 of the circulation flow path (upstream pipe L5a) shown is preferably arranged along the vertical direction. By arranging the central axis Z1 along the vertical direction, the refrigerant will not be deflected by gravity in the circulation flow path, thereby appropriately promoting the mixing of the refrigerant introduced into the circulation flow path and the refrigerant introduced from the bypass flow path.

[0036] Figure 5 Yes means Figure 4 sectional view of the first modified example of the circulation flow path (upstream side piping L5a) shown in FIG. Figure 5 As shown, in the first confluence section JP1, when the circulation flow path (upstream pipe L5a) is observed from a specified direction orthogonal to the center axis Z1, the angle θ formed by the center axis Z1 of the circulation flow path (upstream pipe L5a) and the center axis X1 of the bypass flow path (refrigerant pipe L6) becomes 135 degrees.

[0037] Figure 6 Yes means Figure 4 2 is a cross-sectional view of a second modified example of the circulation flow path (upstream side piping L5a) shown in FIG. Figure 6 As shown, in the first confluence section JP1, when the circulation flow path (upstream pipe L5a) is observed from a specified direction orthogonal to the center axis Z1, the angle θ formed by the center axis Z1 of the circulation flow path (upstream pipe L5a) and the center axis X1 of the bypass flow path (refrigerant pipe L6) becomes 180 degrees.

[0038] like Figures 4 to 6 As shown, 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 set to, for example, 90 degrees, 135 degrees, or 180 degrees. In addition, the angle θ can be set to any angle between 90 degrees and 180 degrees. Compared with the case where the angle θ is less than 90 degrees, the relative speed of the refrigerant circulating in the circulation flow path and the refrigerant introduced from the bypass flow path becomes larger, thereby promoting the mixing of the refrigerant circulating in the circulation flow path and the refrigerant introduced from the bypass flow path.

[0039] Figure 7 yes Figure 4 The AA cross-sectional view of the circulation flow path (upstream side pipe L5a) and the bypass flow path (refrigerant pipe L6) shown in FIG. The upstream side pipe L5a of this embodiment is a pipe that is circular when viewed in cross section. Figure 7 As shown, in the first junction JP1, when the circulation flow path (upstream pipe L5a) is observed along the center axis Z1, the bypass flow path (refrigerant pipe L6) is connected to the circulation flow path in such a way that the center axis X1 of the bypass flow path does not intersect the center axis Z1 of the circulation flow path.

[0040] The length L2 of the offset between the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path is preferably set to be, for example, greater than D / 8 and less than D / 3. In addition, in the present embodiment, the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path are not intersected, but the bypass flow path may be connected to the circulation flow path in such a manner that the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path intersect.

[0041] like Figure 7 As shown, the inner peripheral surface L5a1 of the upstream pipe L5a in the first confluence portion JP1 of the present embodiment is a circular shape without projections and depressions, but other forms are also possible. For example, the inner peripheral surface L5a1 of the upstream pipe L5a in the first confluence portion JP1 may be a projection and depression shape. Figure 8 Yes means Figure 7 A cross-sectional view of a modified example of the circulation flow path and the bypass flow path shown.

[0042] like Figure 8 As shown, in the first confluence portion JP1, convex portions L5a2 are formed at multiple locations along the circumferential direction of the central axis Z1 on the inner circumferential surface L5a1 of the circulation flow path (upstream side pipe L5a). Therefore, when the refrigerant guided from the bypass flow path to the circulation flow path collides with the inner circumferential surface L5a1 of the circulation flow path, the flow of the refrigerant becomes turbulent due to the convex portions L5a2, and the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path is promoted by the turbulence. The convex portion L5a2 can be formed to extend in parallel with the central axis Z1, or can be formed to rotate in a spiral shape around the central axis Z1.

[0043] Here, reference Figures 9 to 11 , the operation of the vehicle air conditioning device 100 during the hot air heating operation will be described. Fig. 9 and Fig.10 1 is a flowchart showing the operation of the vehicle air conditioner 100 during the hot air heating operation. Fig. 9 and Fig.10 Each of the steps shown is executed by the control unit 90 . Fig.11 This is a Mollier diagram showing the state of the refrigerant during hot gas heating operation.

[0044] In step S101 , the control unit 90 performs control so that the on-off valves 61 , 63 , 64 , and 65 are in a closed state. In step S102 , the control unit 90 determines whether the refrigerant pressure LP detected by the pressure sensor 92 exceeds a threshold pressure, and if so, proceeds to step S108 , and if not, proceeds to step S103 .

[0045] In step S103, the control unit 90 controls the on-off valve 62 to be in an open state. The control unit 90 controls the on-off valve 62 to be in an open state and operates the compressor 10, so that the total amount of the refrigerant discharged from the compressor 10 circulates in a manner guided to the accumulator 30 via the refrigerant piping L6. In this way, the control unit 90 sets the vehicle air conditioning device 100 to the first operation mode in which the refrigerant discharged from the compressor 10 is guided to the refrigerant piping L6 instead of the heating unit 20.

[0046] In step S104, the control unit 90 controls the expansion valve 50 so as to adjust the opening degree. Step S104 is executed when the determination result in step S102 is "No", and the refrigerant pressure LP detected by the pressure sensor 92 is below the threshold pressure and the hot gas heating operation using the heating unit 20 cannot be performed.

[0047] Therefore, in step S104, in order to set the state in which the hot gas heating operation using the heating unit 20 can be performed, the opening of the expansion valve 50 is adjusted to adjust the flow rate of the refrigerant guided to the accumulator 30 through the refrigerant pipe L6. The control unit 90 controls the opening of the expansion valve 50 in such a manner that the larger the difference between the pressure LP of the refrigerant detected by the pressure sensor 92 and the threshold pressure, the larger the opening of the expansion valve 50. Thus, the startup time required to set the state in which the hot gas heating operation using the heating unit 20 can be performed can be shortened.

[0048] In step S105, the control unit 90 determines whether the refrigerant pressure LP detected by the pressure sensor 92 exceeds the threshold pressure. If yes, the process proceeds to step S106. If no, the opening degree of the expansion valve 50 is adjusted again in step S104.

[0049] In step S106, the control unit 90 adjusts the opening of the expansion valve 40 before opening the on-off valve 61 in step S107. The opening of the expansion valve 40 is adjusted to suppress a decrease in the pressure of the refrigerant circulating in the refrigeration cycle when the on-off valve 61 is opened.

[0050] In step S107, the control unit 90 controls the on-off valve 61 to be in an open state. By opening the on-off valve 61, 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.

[0051] In this way, the control unit 90 switches the vehicle air conditioning device 100 from the first operation mode, in which the refrigerant ejected from the compressor 10 is guided to the refrigerant pipe L6 instead of the heating unit 20, to the second operation mode, in which the refrigerant ejected 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 for switching between the first operation mode and the second operation mode. The control unit 90 controls the on-off valve 61 in such a manner as to switch the first operation mode to the second operation mode in response to the pressure of the refrigerant sucked by the compressor 10 exceeding the threshold pressure.

[0052] In step S108, the control unit 90 controls the on-off valve 62 to be in an open state. In step S109, the control unit 90 controls the on-off valve 62 to be in an open state. The control unit 90 opens the on-off valve 62 and the on-off valve 61 and operates the compressor 10, thereby setting a state in which a part of the refrigerant ejected from the compressor 10 is guided to the heating unit 20, and another part of the refrigerant ejected from the compressor 10 is guided from the refrigerant pipe L6 to the accumulator 30 without passing through the heating unit 20.

[0053] In step S110, the control unit 90 adjusts the opening of the expansion valve 40 so that the refrigerant passing through the heating unit 20 becomes a liquid refrigerant when performing the hot gas heating operation by guiding the refrigerant to the heating unit 20. Fig.11 The opening of the expansion valve 40 is adjusted so that the degree of subcooling SC, which is the difference between the refrigerant temperature at point b and the refrigerant temperature at point b′ shown, becomes a predetermined value. The control unit 90 calculates the degree of subcooling SC based on the temperature detected by the temperature sensor 95 and the pressure detected by the pressure sensor 96 .

[0054] In step S111, the control unit 90 calculates Fig.11 Specific enthalpy ha, hb, hc of points a, b, and c are shown. The specific enthalpy ha of point a is calculated based on the 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 based on 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 based on either the temperature detected by the temperature sensor 93 or the pressure detected by the pressure sensor 92 and the rotation speed of the motor driving the compressor 10.

[0055] In step S112 , the control unit 90 calculates the refrigerant flow rate Gr1 of the refrigerant pipe L6 . The refrigerant flow rate Gr1 is calculated based on the opening degree of the expansion valve 50 , the pressure HP at the point a, the pressure LP at the point c, and the temperature detected by the temperature sensor 93 .

[0056] In step S113 , the control unit 90 calculates the refrigerant flow rate Gr2 of the refrigerant pipe L5 . The refrigerant flow rate Gr2 is calculated based on the opening degree of the expansion valve 40 , the pressure HP at the point b, the pressure LP at the point c, and the temperature detected by the temperature sensor 93 .

[0057] In step S114, the control unit 90 determines whether the refrigerant pressure LP detected by the pressure sensor 92 exceeds a predetermined pressure, and if so, the process proceeds to step S115, and if not, the process proceeds to step S116. The predetermined pressure is a pressure that is higher than the aforementioned threshold pressure and is preset as a pressure suitable for hot gas heating operation.

[0058] In step S115, the control unit 90 increases the opening of the expansion valve 50 so that (ha-hc)×Gr1>(hc-hb)×Gr2. As a result, the ratio of the gaseous refrigerant in the inflowing refrigerant including the refrigerant decompressed by the expansion valve 40 and the refrigerant decompressed by the expansion valve 50 flowing into the accumulator 30 can be made greater than the ratio of the gaseous refrigerant in the outflowing refrigerant flowing out of the accumulator 30.

[0059] exist Fig.11 By increasing the opening of the expansion valve 50, point c corresponding to the outlet side of the accumulator 30 (the suction side of the compressor 10) can be brought 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.

[0060] Furthermore, the liquid refrigerant stored in the accumulator 30 is reduced by making the ratio of the gaseous refrigerant in the refrigerant flowing into the accumulator 30 greater than the ratio of the gaseous refrigerant in the refrigerant flowing out of the accumulator 30. As a result, the pressure of the refrigerant flowing into the compressor 10 increases as the refrigerant flowing through the refrigeration cycle increases, thereby suppressing a reduction in the power of the compressor 10.

[0061] In step S116, the control unit 90 reduces the opening of the expansion valve 50 so that (ha-hc)×Gr1<(hc-hb)×Gr2. As a result, the proportion of liquid refrigerant in the refrigerant flowing into the accumulator 30, including the refrigerant decompressed by the expansion valve 40 and the refrigerant decompressed by the expansion valve 50, can be made greater than the proportion of liquid refrigerant in the refrigerant flowing out of the accumulator 30. Fig.11 In FIG. 5 , by reducing the opening degree of the expansion valve 50 , the point c corresponding to the outlet side of the accumulator 30 (the suction side of the compressor 10 ) can be brought closer to the point d than the point e.

[0062] Furthermore, by making the ratio of liquid refrigerant in the refrigerant flowing into the accumulator 30 greater than the ratio of liquid refrigerant in the refrigerant flowing out of the accumulator 30, the liquid refrigerant stored in the accumulator 30 increases and the ratio of liquid refrigerant contained in the refrigerant flowing out of the accumulator 30 decreases. As a result, the pressure of the refrigerant flowing into the compressor 10 decreases as the refrigerant circulating in the refrigeration cycle decreases, thereby suppressing an increase in the torque of the compressor 10.

[0063] In step S117, the control unit 90 determines whether an instruction to terminate the hot gas heating operation has been input, and if so, the process of this flowchart is terminated. If not, the process after step S110 is executed again.

[0064] In the hot gas heating operation described above, when the power of the compressor 10 is reduced, the control unit 90 controls the opening (first opening) of the expansion valve 40 and the opening (second opening) of the expansion valve 50 so that the ratio of the liquid refrigerant in the inflow refrigerant flowing into the accumulator 30 does not change. And, when the power of the compressor 10 is increased, the control unit 90 controls the opening (first opening) of the expansion valve 40 and the opening (second opening) of the expansion valve 50 so that the ratio of the liquid refrigerant in the inflow refrigerant flowing into the accumulator 30 does not change.

[0065] <Dehumidification and heating operation> refer to Fig.12 Next, the operation of the vehicle air conditioning device 100 according to the present embodiment during the dehumidification and heating operation will be described. Fig.12 1 is a refrigerant circuit diagram showing the flow of the refrigerant during the dehumidification and heating operation of the vehicle air conditioner 100 .

[0066] Fig.12 The arrows shown indicate the flow direction of the refrigerant. Fig.12 As shown, during the dehumidification and heating operation, the refrigerant circulates in the order of the compressor 10, the heating unit 20, the expansion valve 40, the outdoor 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.

[0067] During the dehumidification and heating operation, the outdoor heat exchanger 80 operates as an evaporator and evaporates the refrigerant to cool the outside air. During the dehumidification and heating operation, the control unit 90 opens the on-off valve 64 and closes the on-off valves 61, 62, 63, and 65. The control unit 90 drives the cabin blower 86 to guide the air dehumidified by the cabin heat exchanger 85 to the heating unit 20, thereby dehumidifying the moisture contained in the air and heating and blowing the air in the heating unit 20.

[0068] <Cooling operation> refer to Fig.13 , the operation of the vehicle air conditioning device 100 according to the present embodiment during cooling operation will be described. Fig.13 2 is a refrigerant circuit diagram showing the flow of the refrigerant during the cooling operation of the vehicle air conditioning apparatus 100 .

[0069] Fig.13 The arrows shown indicate the flow direction of the refrigerant. Fig.13 As shown, during cooling operation, the refrigerant circulates in the order of the compressor 10, the outdoor 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.

[0070] During cooling operation, the outdoor heat exchanger 80 operates as a condenser and condenses the refrigerant to heat the outside air. During cooling operation, the control unit 90 opens the on-off valve 63 and closes the on-off valves 61, 62, 64, and 65. The control unit 90 can drive the cabin blower 86 to blow the air cooled by the outdoor heat exchanger 80 into the vehicle interior.

[0071] The functions and effects achieved by the vehicle air conditioning device 100 according to the present embodiment described above will be described. According to the vehicle air conditioning device 100 of the present embodiment, a part of the high-temperature and high-pressure refrigerant ejected from the compressor 10 is supplied to the heating unit 20, and the air (heating object) is heated by the heating unit 20. The refrigerant that has passed through the heating unit 20 is decompressed by the expansion valve 40, and is guided to the accumulator 30 through the refrigerant pipes L5, L8, L9, and L7. In addition, another part of the high-temperature and high-pressure refrigerant ejected from the compressor 10 is guided to the refrigerant pipe L6 (bypass flow path), and is decompressed by the expansion valve 50. The refrigerant decompressed by the expansion valve 50 merges with the refrigerant flowing in the refrigerant pipe L7, and is guided to the accumulator 30.

[0072] According to the vehicle air conditioning device 100 of the present embodiment, the first confluence portion JP1 is disposed on the circulation flow path (upstream side piping L5a) closer to the accumulator 30 side than the expansion valve 40 and is the first spray area SA1 of the refrigerant based on the expansion valve 40. In a state where the refrigerant flowing in the circulation flow path (upstream side piping L5a) through the expansion valve 40 is decompressed and becomes a spray state so that the specific surface area increases, the high-temperature and high-pressure refrigerant introduced from the bypass flow path (refrigerant piping L6) merges with the circulation flow path, thereby promoting mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the bypass flow path. In addition, the vehicle air conditioning device 100 can prevent the device from being enlarged or the manufacturing cost from increasing and can exert a stable heating capacity.

[0073] According to the vehicle air conditioning device 100 of the present embodiment, the central axis X1 of the bypass flow path does not intersect the central axis Z1 of the circulation flow path at the first junction JP1, so the refrigerant introduced from the bypass flow path to the circulation flow path forms a swirling flow that swirls around the central axis Z1 of the circulation flow path. The refrigerant introduced from the bypass flow path to the circulation flow path forms a swirling flow, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the bypass flow path.

[0074] According to the vehicle air-conditioning device 100 of the present embodiment, the angle θ formed by the center axis Z1 of the circulation flow path and the center axis X1 of the bypass flow path is greater than 90 degrees and less than 180 degrees. Therefore, compared with the case where the angle θ is less than 90 degrees, the relative speed of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the bypass flow path becomes larger, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the bypass flow path.

[0075] According to the vehicle air conditioning device 100 of the present embodiment, a convex portion L5a2 is formed on the inner circumferential surface L5a1 of the circulation flow path in the first confluence portion JP1, so that when the refrigerant guided from the bypass flow path to the circulation flow path collides with the inner circumferential surface L5a1 of the circulation flow path, the flow of the refrigerant becomes turbulent, and this turbulence promotes the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path.

[0076] According to the vehicle air conditioning device 100 of this embodiment, when the inner diameter of the upstream side piping L5a is set to D, the refrigerant is merged from the bypass flow path in the first confluence portion JP1 arranged in the first spray area SA1 within 10D from the throttling device 41, thereby appropriately promoting the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path.

[0077] [Second embodiment] Next, a vehicle air conditioning device 100A according to a second embodiment of the present invention will be described. This embodiment is a modified example of the first embodiment and is the same as the first embodiment except for the cases particularly described below, so the description thereof will be omitted below.

[0078] In the first embodiment, the vehicle air conditioner 100A does not have any other pressure reducing mechanism arranged at a position closer to the accumulator 30 than the expansion valve 40 in the circulation flow path (refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, L7) during the hot air heating operation. In contrast, in the present embodiment, the vehicle air conditioner 100A has a pressure reducing mechanism, i.e., a throttle device (third expansion mechanism) 41 arranged at a position closer to the accumulator 30 than the expansion valve 40 in the circulation flow path during the hot air heating operation.

[0079] Fig.14 : is a refrigerant circuit diagram of a vehicle air conditioning device 100A according to a second embodiment of the present invention. Fig.14 As shown, the vehicle air conditioner 100A includes a branch flow path (refrigerant pipe L12 ) and a throttle device 41 in addition to the vehicle air conditioner 100 of the first embodiment.

[0080] like Fig.14 As shown, the throttle device 41 is arranged at a position of the circulation flow path (upstream side piping L5a, refrigerant piping L8) closer to the accumulator 30 side than the expansion valve 40. The branch flow path branches a part of the refrigerant from the bypass flow path (refrigerant piping L6) in the branch portion BP and merges with the circulation flow path at the second confluence portion JP2 of the circulation flow path (upstream side piping L5a, refrigerant piping L8) closer to the accumulator 30 side than the first confluence portion JP1.

[0081] Here, the structure of the gas-liquid two-phase refrigerant that is well mixed and circulates in the circulation flow path (upstream pipe L5a, refrigerant pipe L8) through the heating unit 20 and the expansion valve 40 and the gas phase refrigerant that is guided from the branch flow path (refrigerant pipe L12) to the circulation flow path is described. Fig.15 This is a cross-sectional view of the circulation flow path, the bypass flow path, and the branch flow path observed in the direction perpendicular to the central axis Z1 of the circulation flow path near the first confluence portion JP1 and the second confluence portion JP2. Fig.15 In the embodiment, the vicinity of the first merging portion JP1 is the same as that of the first embodiment, and thus the description thereof will be omitted below.

[0082] like Fig.15 As shown, the second confluence portion JP2 is configured to include the second spray area SA2 of the refrigerant based on the throttling device 41, which is on the downstream side of the circulation flow path (upstream side piping L5a, refrigerant piping L8) in the flow direction of the refrigerant, that is, on the accumulator 30 side, of the throttling device 41. The second spray area SA2 is an area for spraying the gas-liquid two-phase refrigerant decompressed by the throttling device 41. For example, when the inner diameter of the refrigerant piping L8 forming the circulation flow path is set to D, the second spray area SA2 is an area within 10D from the throttling device 41. Fig.15 The distance Dis2 from the expansion device 41 to the end of the second spray area SA2 along the central axis Z1 shown is within 10D.

[0083] like Fig.15As shown, in the second confluence portion JP2, when the circulation flow path (refrigerant piping L8) is observed from a predetermined direction orthogonal to the central axis Z1, the angle α formed by the central axis Z1 of the circulation flow path (refrigerant piping L8) and the central axis X2 of the branch flow path (refrigerant piping L12) becomes 90 degrees. In addition, the angle α can be set to an angle other than 90 degrees, preferably any angle greater than 90 degrees and less than 180 degrees.

[0084] Although not shown in the figure, in the second confluence portion JP2, when the circulation flow path (refrigerant piping L8) is observed along the center axis Z1, the bypass flow path (refrigerant piping L6) is connected to the circulation flow path in such a way that the center axis X1 of the bypass flow path does not intersect the center axis Z1 of the circulation flow path.

[0085] Fig.15 The central axis Z1 of the circulation flow path (refrigerant pipe L8) shown is preferably arranged along the vertical direction in the second confluence portion JP2. By arranging the central axis Z1 along the vertical direction, the refrigerant will not be deflected by gravity in the circulation flow path, thereby appropriately promoting the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path.

[0086] like Fig.15 As shown, when the circulation flow path (upstream pipe L5a) is observed from a predetermined direction orthogonal to the center axis Z1 of the circulation flow path, the first inflow direction ID1 in which the refrigerant flows from the bypass flow path (refrigerant pipe L6) to the circulation flow path (upstream pipe L5a) in the first junction JP1 is opposed to the 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) in the second junction JP2. Here, opposing means that when the circulation flow path (upstream pipe L5a, refrigerant pipe L8) is observed from a predetermined direction orthogonal to the center 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.

[0087] Fig.16 yes Fig.15 The BB-direction cross-sectional view of the circulation flow path shown in FIG. Fig.16 As shown, the expansion device 41 of the present embodiment is an expansion mechanism that reduces the flow path cross-sectional area of ​​a portion of the pipe forming the circulation flow path (refrigerant pipe L8) compared with other portions. Fig.16 The expansion device 41 shown is a plate-like member formed in an annular shape around the central axis Z1, and has an outer diameter D which is the same as the inner diameter of the refrigerant pipe L8, and has an opening hole 41a formed at the center.

[0088] Fig.16 The throttling device 41 shown can also be used as Fig.17A throttle device 41 of the first modified example is shown. Fig.17 Yes means Fig.16 A diagram of a first modified example of the throttle device 41 is shown. Fig.17 The throttle device 41 shown has an opening hole 41 a formed at the center, and has a plurality of opening holes 41 b having a smaller diameter than the opening hole 41 a .

[0089] Fig.16 The throttling device 41 shown can also be used as Fig.18 A throttle device 41 of a second modified example is shown. Fig.18 Yes means Fig.16 A diagram of a second modified example of the throttle device 41 is shown. Fig.18 The expansion device 41 shown does not have an opening hole formed at the center, but has opening holes 41 b having a smaller diameter than the opening hole 41 a formed at a plurality of locations other than the center.

[0090] like Figures 16 to 18 As shown, the inner peripheral surface L8a of the upstream pipe L5a in the second junction JP2 of the present embodiment is a circular shape without projections and depressions, but other forms are also possible. For example, the inner peripheral surface L8a of the refrigerant pipe L8 may be a projection and depression shape in the second junction JP2. Fig.19 yes Fig.15 A cross-sectional view of the circulation flow path taken along the line CC shown.

[0091] like Fig.19 As shown, in the second confluence portion JP2, convex portions L8b are formed at multiple locations on the inner circumferential surface L8a of the circulation flow path (refrigerant piping L8) along the circumferential direction around the central axis Z1. Therefore, when the refrigerant guided from the branch flow path (refrigerant piping L12) to the circulation flow path (refrigerant piping L8) collides with the inner circumferential surface L8a of the circulation flow path, the flow of the refrigerant becomes turbulent due to the convex portion L8b, and the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path is promoted by the turbulence. The convex portion L8b can be formed to extend in parallel with the central axis Z1, or it can be formed to rotate in a spiral shape around the central axis Z1.

[0092] In addition, in the present embodiment, the branch flow path (refrigerant pipe L12) and the throttling device 41 are provided one each in the vehicle air conditioning device 100A, but the number is not limited to the above number, and the mixing can be further promoted by increasing the number. Fig.14 One or more other branch portions BP different from the branch portion BP shown in the figure are connected to the branch flow path in the other branch portion BP, and are made to merge with the circulation flow path (refrigerant piping L8) in multiple confluences. In this case, it is preferred to configure the throttling device 41 on the upstream side of the multiple confluences of the circulation flow path (refrigerant piping L8).

[0093] Furthermore, in the present embodiment, the throttle device 41 is disposed on the upstream side of the second confluence portion JP2 of the circulation flow path (refrigerant piping L8), but it may be disposed in a manner that the throttle device 41 is not disposed on the circulation flow path (refrigerant piping L8). Even in a manner that the throttle device 41 is not disposed on the circulation flow path (refrigerant piping L8), the mixing of the refrigerant flowing in the circulation flow path can be promoted by causing the refrigerant to flow from the branch flow path (refrigerant piping L12) into the circulation flow path (refrigerant piping L8).

[0094] The functions and effects achieved by the vehicle air conditioning device 100A according to the present embodiment described above will be described. According to the vehicle air conditioning device 100A of this embodiment, the central axis X1 of the branch flow path (refrigerant piping L12) does not intersect the central axis Z1 of the circulation flow path (upstream side piping L5a) at the second confluence portion JP2, so the refrigerant introduced from the branch flow path to the circulation flow path forms a swirling flow that swirls around the central axis Z1 of the circulation flow path. The refrigerant introduced from the branch flow path to the circulation flow path becomes a swirling flow, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the branch flow path.

[0095] According to the vehicle air-conditioning device 100A of the present embodiment, the angle formed by the central axis Z1 of the circulation flow path and the central axis X1 of the branch flow path is greater than 90 degrees and less than 180 degrees. Therefore, compared with the case where the angle is less than 90 degrees, the relative speed of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the branch flow path becomes larger, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the branch flow path.

[0096] According to the vehicle air-conditioning device 100A of the present embodiment, the first inflow direction ID1 is opposite to the second inflow direction ID2. Therefore, even if the refrigerant flowing in from the bypass flow path in the first inflow direction ID1 deviates to one side in the radial direction of the piping forming the circulation flow path, the deflection can be reduced by the refrigerant flowing in from the branch flow path in the second inflow direction ID2.

[0097] According to the vehicle air-conditioning device 100A of the present embodiment, a convex portion L5a2 is formed on the inner circumferential surface L5a1 of the circulation flow path in the second confluence portion JP2, so that when the refrigerant guided from the branch flow path to the circulation flow path collides with the inner circumferential surface L5a1 of the circulation flow path, the flow of the refrigerant becomes turbulent, and this turbulence promotes the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the branch flow path.

[0098] According to the vehicle air conditioning device 100A of this embodiment, the central axis Z1 of the circulation flow path is arranged along the vertical direction, so no refrigerant deviation caused by gravity occurs in the circulation flow path, thereby appropriately promoting the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the branch flow path.

[0099] According to the vehicle air-conditioning device 100A of this embodiment, when the inner diameter of the upstream side piping L5a is set to D, the refrigerant is merged from the branch flow paths in the second confluence portion JP2 arranged in the second spray area SA2 within 10D from the throttling device 41, thereby appropriately promoting the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the branch flow path.

[0100] The air conditioning apparatus described in each of the above-described embodiments can be understood, for example, as follows. The air conditioning device (100) according to the first aspect of the present invention comprises: a compressor (10) for compressing a refrigerant; a heating unit (20) for heating a heating object by using the refrigerant ejected from the compressor; an accumulator (30) for separating a liquid component from the refrigerant sucked into the compressor; a circulation flow path (L5, L8, L7) for guiding the refrigerant that has passed through the heating unit to the accumulator; and a bypass flow path (L6) for allowing the refrigerant ejected from the compressor to pass through the circulation flow path (L5, L8, L7) to pass through the bypass flow path (L6) to pass through the bypass flow path (L5, L8, L7) to pass through the bypass flow path (L6) to allow the refrigerant ejected from the compressor to pass through the bypass flow path (L5, L8, L7) to pass through the bypass flow path (L6) ... L8, L7) merge at the first confluence portion (JP1) of the refrigerant without passing through the heating portion; a first expansion mechanism (40) is arranged in the circulation flow path and expands the refrigerant flowing out of the heating portion; and a second expansion mechanism (50) is arranged in the bypass flow path and expands the refrigerant ejected from the compressor, the first confluence portion is arranged in the circulation flow path closer to the accumulator side than the first expansion mechanism and is based on the first spray area (SA1) of the refrigerant of the first expansion mechanism.

[0101] According to the air conditioning device involved in the first aspect of the present invention, a part of the high-temperature and high-pressure refrigerant ejected from the compressor is supplied to the heating unit, and the heating unit heats the heating object. The refrigerant that has passed through the heating unit is decompressed by the first expansion mechanism and guided to the accumulator through the circulation flow path. In addition, another part of the high-temperature and high-pressure refrigerant ejected from the compressor is guided to the bypass flow path and decompressed by the second expansion mechanism. The refrigerant decompressed by the second expansion mechanism merges with the refrigerant circulating in the circulation flow path at the first confluence portion and is guided to the accumulator.

[0102] According to the air conditioning device involved in the first aspect of the present invention, the first confluence portion is arranged in the circulation flow path, which is closer to the accumulator side than the first expansion mechanism and is based on the first spray area of ​​the refrigerant of the first expansion mechanism. In a state where the refrigerant circulating in the circulation flow path through the first expansion mechanism is decompressed and becomes a spray state so that the specific surface area increases, the high-temperature and high-pressure refrigerant introduced from the bypass flow path merges with the circulation flow path, thereby promoting the mixing of the refrigerant circulating in the circulation flow path and the refrigerant introduced from the bypass flow path. In addition, the air conditioning device can prevent the enlargement of the device or the increase of the manufacturing cost and exert a stable heating capacity.

[0103] The air conditioning apparatus according to a second aspect of the present invention, in the first aspect, further comprises a third expansion mechanism (41) disposed in the circulation flow path on the accumulator side relative to the first expansion mechanism. According to the air conditioning apparatus of the second aspect of the present invention, the refrigerant flowing through the circulation flow path is decompressed by the third expansion mechanism and becomes a spray state. Therefore, the refrigerant flowing into the third expansion mechanism can be further mixed and guided to the accumulator.

[0104] The air conditioner according to the third aspect of the present invention further comprises, in the first aspect or the second aspect, a branch flow path that branches a part of the refrigerant from the bypass flow path and merges with the circulation flow path at a second confluence portion of the circulation flow path that is closer to the accumulator than the first confluence portion. According to the air conditioning apparatus of the third aspect of the present invention, by causing part of the refrigerant branched from the bypass flow path to merge with the circulation flow path at the second merging portion, mixing of the refrigerant flowing through the circulation flow path can be promoted.

[0105] The air conditioner according to the fourth aspect of the present invention further comprises the following structure in the first aspect: that is, it comprises: a third expansion mechanism arranged at a position of the circulation flow path closer to the accumulator than the first expansion mechanism; and a branch flow path, which branches a part of the refrigerant from the bypass flow path and merges with the circulation flow path at a second confluence portion of the circulation flow path closer to the accumulator than the first confluence portion, the second confluence portion being arranged at a second spray region of the refrigerant based on the third expansion mechanism and closer to the accumulator than the third expansion mechanism of the circulation flow path.

[0106] According to the air conditioning device involved in the fourth aspect of the present invention, the second confluence portion is arranged in the circulation flow path, which is closer to the accumulator side than the third expansion mechanism and is based on the second spray region of the refrigerant of the third expansion mechanism. In a state where the refrigerant flowing in the circulation flow path through the third expansion mechanism is decompressed and becomes a spray state so that the specific surface area increases, the high-temperature and high-pressure refrigerant introduced from the branch flow path merges with the circulation flow path, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the branch flow path.

[0107] The air conditioner according to the fifth aspect of the present invention is further configured as follows in the second aspect or the fourth aspect: the third expansion mechanism is a throttling device that reduces a flow path cross-sectional area of ​​a portion of the pipe forming the circulation flow path compared to other portions. According to the air conditioning apparatus according to the fifth aspect of the present invention, by arranging a relatively simple throttle device in the circulation flow path, it is possible to increase the specific surface area of ​​the refrigerant flowing through the circulation flow path and promote mixing of the refrigerant.

[0108] The air conditioner according to the sixth aspect of the present invention further comprises the following structure in the first aspect or the second aspect: that is, in the first confluence portion, when the circulation flow path is viewed along the central axis of the circulation flow path, the bypass flow path is connected to the circulation flow path in such a manner that the central axis (X1) of the bypass flow path does not intersect the central axis (Z1) of the circulation flow path.

[0109] According to the air conditioning device involved in the sixth aspect of the present invention, in the first confluence portion, the central axis of the bypass flow path does not intersect the central axis of the circulation flow path, so the refrigerant guided from the bypass flow path to the circulation flow path forms a swirling flow that swirls around the central axis of the circulation flow path. The refrigerant guided from the bypass flow path to the circulation flow path becomes a swirling flow, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the bypass flow path.

[0110] The air conditioner according to the seventh aspect of the present invention further comprises the following structure in the third aspect: that is, in the second confluence portion, when the circulation flow path is observed along the central axis of the circulation flow path, the branch flow path is connected to the circulation flow path in such a manner that the central axis of the bypass flow path does not intersect the central axis of the circulation flow path.

[0111] According to the air conditioning device involved in the seventh aspect of the present invention, in the second converging portion, the central axis of the branch flow path does not intersect the central axis of the circulation flow path, so the refrigerant guided from the branch flow path to the circulation flow path forms a swirling flow that swirls around the central axis of the circulation flow path. The refrigerant guided from the branch flow path to the circulation flow path becomes a swirling flow, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the branch flow path.

[0112] The air conditioner according to the eighth aspect of the present invention further comprises the following structure in the first aspect or the second aspect: that is, in the first confluence portion, when the circulation flow path is viewed from a predetermined direction orthogonal to the central axis of the circulation flow path, the bypass flow path is connected to the circulation flow path in such a manner that the angle formed by the central axis of the circulation flow path and the central axis of the bypass flow path is greater than or equal to 90 degrees and less than or equal to 180 degrees.

[0113] According to the air-conditioning device involved in the 8th embodiment of the present invention, the angle formed by the central axis of the circulation flow path and the central axis of the bypass flow path is greater than 90 degrees and less than 180 degrees. Therefore, compared with the case where the angle is less than 90 degrees, the relative speed of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the bypass flow path becomes larger, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the bypass flow path.

[0114] The air conditioner according to the ninth aspect of the present invention further comprises the following structure in the third aspect: that is, in the second confluence portion, when the circulation flow path is viewed from a predetermined direction orthogonal to the central axis of the circulation flow path, the branch flow path is connected to the circulation flow path in such a manner that the angle formed by the central axis of the circulation flow path and the central axis of the branch flow path is greater than or equal to 90 degrees and less than or equal to 180 degrees.

[0115] According to the air-conditioning device involved in the 9th embodiment of the present invention, the angle formed by the central axis of the circulation flow path and the central axis of the branch flow path is greater than 90 degrees and less than 180 degrees. Therefore, compared with the case where the angle is less than 90 degrees, the relative speed of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the branch flow path becomes larger, thereby further promoting the mixing of the refrigerant flowing in the circulation flow path and the refrigerant introduced from the branch flow path.

[0116] The air conditioner according to the tenth aspect of the present invention further comprises the following structure in the third aspect: when the circulation flow path is viewed from a predetermined direction orthogonal to the central axis of the circulation flow path, a first inflow direction of the refrigerant from the bypass flow path to the circulation flow path in the first confluence portion is opposed to a second inflow direction of the refrigerant from the branch flow path to the circulation flow path in the second confluence portion.

[0117] According to the air-conditioning device involved in the tenth embodiment of the present invention, the first inflow direction is opposite to the second inflow direction. Therefore, even if the refrigerant flowing in from the bypass flow path in the first inflow direction deviates to one side in the radial direction of the piping forming the circulation flow path, the deviation can be reduced by the refrigerant flowing in from the branch flow path in the second inflow direction.

[0118] The air conditioner according to the 11th aspect of the present invention further comprises the following structure in the 1st aspect or the 2nd aspect: That is, in the first confluence portion, convex portions (L5a2) are formed at a plurality of locations on the inner peripheral surface of the circulation flow path along the circumferential direction around the central axis of the circulation flow path.

[0119] According to the air-conditioning device involved in the 11th embodiment of the present invention, a convex portion is formed on the inner circumferential surface of the circulation flow path in the first confluence portion, so that when the refrigerant guided from the bypass flow path collides with the inner circumferential surface of the circulation flow path, the flow of the refrigerant becomes chaotic, and the turbulence promotes the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path.

[0120] The air conditioner according to the twelfth aspect of the present invention further comprises, in the third aspect, a configuration in which, in the second junction, convex portions are formed at a plurality of locations on the inner peripheral surface of the circulation flow path along the circumferential direction of the central axis of the circulation flow path.

[0121] According to the air-conditioning device involved in the 12th embodiment of the present invention, a convex portion is formed on the inner circumferential surface of the circulation flow path in the second confluence portion, so that when the refrigerant guided to the circulation flow path from the branch flow path collides with the inner circumferential surface of the circulation flow path, the flow of the refrigerant becomes chaotic, and this turbulence promotes the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the branch flow path.

[0122] The air conditioner according to the 13th aspect of the present invention, in the first aspect or the second aspect, further comprises a configuration in which, in the first junction, the central axis of the circulation flow path is arranged along the vertical direction. According to the air-conditioning device involved in the 13th mode of the present invention, the central axis of the circulation flow path is arranged along the vertical direction, so no deflection of the refrigerant caused by gravity will occur in the circulation flow path, thereby appropriately promoting the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path.

[0123] The air conditioner according to the fourteenth aspect of the present invention is further provided with the following configuration in the third aspect: That is, in the second junction, the central axis of the circulation flow path is arranged along the vertical direction. According to the air-conditioning device involved in the 14th embodiment of the present invention, the central axis of the circulation flow path is arranged along the vertical direction, so no deflection of the refrigerant caused by gravity will occur in the circulation flow path, thereby appropriately promoting the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the branch flow path.

[0124] The air conditioner according to the fifteenth aspect of the present invention is further provided with the following structure in the first aspect or the second aspect: That is, when the inner diameter of the pipe forming the circulation flow path is D, the first spraying region is a region within 10D from the first expansion mechanism. According to the air-conditioning device involved in the 15th mode of the present invention, the refrigerant is merged from the bypass flow path in the first confluence portion arranged in the first spray area within 10D from the first expansion mechanism, thereby appropriately promoting the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the bypass flow path.

[0125] The air conditioner according to the sixteenth aspect of the present invention is further provided with the following structure in the fourth aspect: That is, when the inner diameter of the pipe forming the circulation flow path is D, the second spraying region is a region within 10D from the third expansion mechanism. According to the air-conditioning device involved in the 16th mode of the present invention, by making the refrigerant merge from the branch flow path in the second confluence part of the second spray area arranged within 10D from the third expansion mechanism, the mixing of the refrigerant guided to the circulation flow path and the refrigerant introduced from the branch flow path is appropriately promoted. Explanation of symbols

[0126] 10- compressor, 20- heating unit, 30- accumulator, 40- expansion valve (first expansion mechanism), 41- throttling device (third expansion mechanism), 41a, 41b- opening hole, 50- expansion valve, 61, 62, 63- opening and closing valve, 64- opening and closing valve (first opening and closing valve), 65- opening and closing valve (second opening and closing valve), 70- expansion valve, 80- outdoor heat exchanger, 81- outdoor fan, 85- cabin heat exchanger (evaporator), 86- cabin blower, 90- control unit, 91- refrigerant heater, 92, 96- pressure sensor, 93, 94, 95- temperature sensor, 100, 100A- vehicle Air conditioning device, Dis1, Dis2-distance, Gr1, Gr2-refrigerant flow rate, ID1-first inflow direction, ID2-second inflow direction, JP1-first confluence, JP2-second confluence, L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, L12-refrigerant piping, L5a-upstream side piping, L5a1-inner circumference, L5a2-convex portion, L5b-downstream side piping, SA1-first spray area, SA2-second spray area, SC-subcooling degree, X1, X2, Z1-center axis, ha, hb, hc-specific enthalpy, θ, α-angle.

Claims

1. An air conditioning device, comprising: compressor, which compresses the refrigerant; a heating unit that heats a heating object using the refrigerant ejected from the compressor; an accumulator for separating a liquid component from the refrigerant sucked by the compressor; a circulation flow path for guiding the refrigerant having passed through the heating unit to the accumulator; a bypass flow path for causing the refrigerant discharged from the compressor to merge at a first merging portion of the circulation flow path without passing through the heating portion; a first expansion mechanism disposed in the circulation flow path and expanding the refrigerant flowing out of the heating unit; and The second expansion mechanism is disposed in the bypass flow path and expands the refrigerant discharged from the compressor. The first joining portion is disposed between the accumulator and the first expansion mechanism of the circulation flow path and is a first spray region of the refrigerant based on the first expansion mechanism.

2. The air conditioning device according to claim 1, comprising: The third expansion mechanism is disposed between the accumulator and the first expansion mechanism in the circulation flow path.

3. The air conditioning device according to claim 1 or 2, comprising: The branch flow passage branches a part of the refrigerant from the bypass flow passage and merges the part with the circulation flow passage at a second merging portion between the accumulator and the first merging portion of the circulation flow passage.

4. The air conditioning device according to claim 1, comprising: a third expansion mechanism disposed between the accumulator and the first expansion mechanism of the circulation flow path; and a branch flow path for causing a part of the refrigerant to branch from the bypass flow path and then merge with the circulation flow path at a second confluence portion between the accumulator and the first confluence portion of the circulation flow path; The second joining portion is disposed between the accumulator and the third expansion mechanism of the circulation flow path and is a second spray region of the refrigerant based on the third expansion mechanism.

5. The air conditioning device according to claim 2 or 4, wherein: The third expansion mechanism is a throttling device that reduces the flow path cross-sectional area of ​​a portion of the pipe forming the circulation flow path compared to other portions.

6. The air conditioning device according to claim 1 or 2, wherein: In the first junction, when the circulation flow path is viewed along the central axis of the circulation flow path, the bypass flow path is connected to the circulation flow path such that the central axis of the bypass flow path does not intersect with the central axis of the circulation flow path.

7. The air conditioning device according to claim 3, wherein: In the second confluence portion, when the circulation flow path is viewed along the central axis of the circulation flow path, the branch flow path is connected to the circulation flow path such that the central axis of the bypass flow path does not intersect the central axis of the circulation flow path.

8. The air conditioning device according to claim 1 or 2, wherein: In the first confluence section, when the circulation flow path is observed from a specified direction orthogonal to the central axis of the circulation flow path, the bypass flow path is connected to the circulation flow path in such a manner that the angle formed by the central axis of the circulation flow path and the central axis of the bypass flow path is greater than 90 degrees and less than 180 degrees.

9. The air conditioning device according to claim 3, wherein: In the second confluence section, when the circulation flow path is observed from a specified direction orthogonal to the central axis of the circulation flow path, the branch flow path is connected to the circulation flow path in such a manner that the angle formed by the central axis of the circulation flow path and the central axis of the branch flow path is greater than 90 degrees and less than 180 degrees.

10. The air conditioning device according to claim 3, wherein: When the circulation flow path is observed from a specified direction orthogonal to the central axis of the circulation flow path, a first inflow direction of the refrigerant from the bypass flow path to the circulation flow path in the first confluence portion is opposite to a second inflow direction of the refrigerant from the branch flow path to the circulation flow path in the second confluence portion.

11. The air conditioning device according to claim 1 or 2, wherein: In the first confluence portion, convex portions are formed at a plurality of locations on the inner peripheral surface of the circulation flow path along a circumferential direction around a central axis of the circulation flow path.

12. The air conditioning device according to claim 3, wherein: In the second confluence portion, convex portions are formed at a plurality of locations on the inner peripheral surface of the circulation flow path along a circumferential direction around a central axis of the circulation flow path.

13. The air conditioning device according to claim 1 or 2, wherein: In the first junction, the central axis of the circulation flow path is arranged along the vertical direction.

14. The air conditioning device according to claim 3, wherein: In the second junction, the central axis of the circulation flow path is arranged along the vertical direction.

15. The air conditioning device according to claim 1 or 2, wherein: When the inner diameter of the pipe forming the circulation flow path is represented by D, the first spray region is a region within 10D from the first expansion mechanism.

16. The air conditioning device according to claim 4, wherein: When the inner diameter of the pipe forming the circulation flow path is represented by D, the second spray region is a region within 10D from the third expansion mechanism.

Images