WO2024048284A1 - Air-conditioning device - Google Patents

Abstract

Provided is a vehicle air-conditioning device including: a compressor that compresses a refrigerant; a heating unit that heats an object to be heated by the refrigerant discharged from the compressor; an accumulator that separates liquid content in the refrigerant taken in 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 joins the refrigerant discharged from the compressor without passing through the heating unit at a first joining part (JP1) of the circulation flow path; a restrictor valve (40) that is disposed on the circulation flow path and that reduces the pressure of the refrigerant flowing out from the heating unit; and a restrictor valve that is disposed on the bypass flow path and that reduces the pressure of the refrigerant discharged from the compressor. The first joining part (JP1) is disposed: more to the accumulator side than the restrictor valve (40) of the circulation flow path; and in a first spray area (SA1) of the refrigerant by the restrictor valve (40).

Description

air conditioner

The present disclosure relates to an air conditioner.

Conventionally, a refrigeration cycle device has been disclosed that mixes refrigerants with different enthalpies and causes the mixture to be sucked into a compressor (for example, see Patent Document 1). Patent Document 1 discloses that in order to homogeneously mix the bypass side refrigerant and the pressure reducing part side refrigerant, which have different enthalpies, the bypass side refrigerant and the pressure reducing part side refrigerant are combined after exchanging heat in a laminated heat exchanger. is disclosed. In Patent Document 1, a bypass side refrigerant and a decompression section side refrigerant having different enthalpies are homogeneously mixed to enable the refrigeration cycle device to exhibit stable heating ability.

JP 2021-156567 Publication

However, in Patent Document 1, a heat exchanger is required to exchange heat before two types of refrigerants with different enthalpies are combined, which increases the size of the device and the manufacturing cost.

The present disclosure has been made in view of these circumstances, and aims to provide an air conditioner that can exhibit stable heating ability while preventing the device from increasing in size and manufacturing cost. shall be.

In order to solve the above problems, the present disclosure employs the following means.
An air conditioner according to the present disclosure includes a compressor that compresses a refrigerant, a heating section that heats an object to be heated with the refrigerant discharged from the compressor, and a liquid component in the refrigerant that is sucked by the compressor. a circulation flow path for guiding the refrigerant that has passed through the heating section to the accumulator; and a circulation flow path for guiding the refrigerant discharged from the compressor without passing through the heating section at a first confluence section of the circulation flow path. a bypass flow path for merging the refrigerant, a first throttling mechanism disposed in the circulation flow path to reduce the pressure of the refrigerant flowing out from the heating section, and a first throttling mechanism disposed in the bypass flow path for reducing the pressure of the refrigerant discharged from the compressor. a second throttle mechanism that reduces the pressure, the first merging section being arranged closer to the accumulator than the first throttle mechanism in the circulation flow path and in a first spray area of the refrigerant by the first throttle mechanism. ing.

According to the present disclosure, it is possible to provide an air conditioner that can exhibit stable heating ability while preventing the device from increasing in size and manufacturing cost.

FIG. 1 is a refrigerant circuit diagram of a vehicle air conditioner according to a first embodiment of the present disclosure. FIG. 3 is a refrigerant circuit diagram showing a refrigerant flow during heat pump heating operation of the vehicle air conditioner. FIG. 2 is a refrigerant circuit diagram showing a refrigerant flow during hot gas heating operation of the vehicle air conditioner. FIG. 3 is a cross-sectional view of the circulation flow path and the bypass flow path as viewed along a direction orthogonal to the central axis of the circulation flow path in the vicinity of the first merging portion. FIG. 5 is a sectional view showing a first modification of the circulation channel shown in FIG. 4; FIG. 5 is a cross-sectional view showing a second modification of the circulation channel shown in FIG. 4. FIG. FIG. 5 is a cross-sectional view taken along the line AA of the circulation flow path and bypass flow path shown in FIG. 4. FIG. 8 is a sectional view showing a modification of the circulation flow path and bypass flow path shown in FIG. 7. FIG. 2 is a flowchart showing the operation of the vehicle air conditioner during hot gas heating operation. It is a flowchart which shows the operation|movement at the time of hot gas heating operation of a vehicle air conditioner. It is a Mollier diagram showing the state of the refrigerant during hot gas heating operation. FIG. 2 is a refrigerant circuit diagram showing a refrigerant flow during dehumidifying and heating operation of the vehicle air conditioner. FIG. 3 is a refrigerant circuit diagram showing a refrigerant flow during cooling operation of the vehicle air conditioner. FIG. 3 is a refrigerant circuit diagram of a vehicle air conditioner according to a second embodiment of the present disclosure. FIG. 3 is a cross-sectional view of the circulation flow path, the bypass flow path, and the branch flow path as seen along a direction orthogonal to the central axis of the circulation flow path in the vicinity of the first merging portion and the second merging portion. 16 is a sectional view taken along the line BB of the circulation flow path shown in FIG. 15. FIG. 17 is a diagram showing a first modification of the orifice shown in FIG. 16. FIG. 17 is a diagram showing a second modification of the orifice shown in FIG. 16. FIG. 16 is a cross-sectional view taken along the line CC of the circulation channel shown in FIG. 15. FIG.

[First embodiment]
Below, a heat pump type vehicle air conditioner (air conditioner) 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 conditioner 100 of this embodiment includes a compressor 10, a heating section 20, an accumulator 30, a throttle valve (first throttle mechanism) 40, and a throttle valve (second throttle mechanism). ) 50, the on-off valve (switching part) 61, the on-off valve (switching part) 62, the on-off valve 63, the on-off valve (first on-off valve) 64, the on-off valve (second on-off valve) 65, and the throttle Valve 70, outdoor heat exchanger 80, outdoor fan 81, in-vehicle heat exchanger (evaporator) 85, indoor blower 86, control unit 90, refrigerant heater 91, pressure sensor 92, temperature sensor 93, a temperature sensor 94, a temperature sensor 95, and a pressure sensor 96.

The vehicle air conditioner 100 of this embodiment is a device that generates warm air using a heating unit 20 installed inside the vehicle, or generates cold air using an in-vehicle heat exchanger 85 installed inside the vehicle, and blows the air into the interior of the vehicle. . The vehicle air conditioner 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. In addition, the vehicle air conditioner 100 is equipped with a hot-air system that performs heating using only the power of the compressor 10 without passing refrigerant through the outdoor heat exchanger 80 when the outside temperature is below a predetermined temperature (for example, −20° C.). Gas heating operation is possible. The refrigerant used in the vehicle air conditioner 100 of this embodiment is, for example, HFO-1234yf.

The compressor 10 is a device that compresses the refrigerant flowing from the accumulator 30. The compressor 10 is, for example, an electric compressor that drives a motor (not shown) to compress refrigerant. The compressor 10 compresses the refrigerant flowing 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 section 20 via the refrigerant pipe L3 and the refrigerant pipe L4.

The heating unit 20 is a device that heats the air (heated object) blown by the indoor blower 86 using a high-temperature, high-pressure refrigerant discharged from the compressor 10. The air heated by the heating unit 20 is blown into the vehicle interior. The refrigerant that has undergone heat exchange with the air in the heating section 20 is guided to the throttle valve 40 disposed in the upstream pipe L5a of the refrigerant pipe L5.

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

The throttle valve 40 is a mechanism that is disposed in the refrigerant pipe L5 and reduces the pressure of the refrigerant flowing out from the heating section 20. The opening degree of the throttle valve 40 is controlled by a control section 90. The refrigerant whose pressure has been reduced by the throttle valve 40 flows through the refrigerant pipe L5.

The throttle valve 50 is arranged in the refrigerant pipe L6 connected to the refrigerant pipe L3, and is a mechanism that reduces the pressure of the refrigerant discharged from the compressor 10. The opening degree of the throttle valve 50 is controlled by a control section 90. The refrigerant whose pressure has been reduced by the throttle 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 that connects the in-vehicle heat exchanger 85 and the accumulator 30.

The on-off valve 61 is a device that is disposed in the refrigerant pipe L8 and switches between an open state in which the refrigerant flows through the refrigerant pipe L8 and a closed state in which the refrigerant does not flow in the refrigerant pipe L8. Refrigerant pipe L8 is a pipe that connects refrigerant pipe L5 and refrigerant pipe L9. Refrigerant pipe L9 is a pipe that connects refrigerant pipe L10 and refrigerant pipe L7. The refrigerant pipe L10 is a pipe that connects the outdoor heat exchanger 80 and the in-vehicle heat exchanger 85.

The on-off valve 62 is a device that is disposed in the refrigerant pipe L6 and switches between an open state in which the refrigerant flows through the refrigerant pipe L6 and a closed state in which the refrigerant does not flow in the refrigerant pipe L6.
The on-off valve 63 is a device that is disposed in the refrigerant pipe L11 and switches between an open state in which the refrigerant flows through the refrigerant pipe L11 and a closed state in which the refrigerant does not flow in the refrigerant pipe L11.

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

The throttle valve 70 is a mechanism that is disposed in the refrigerant pipe L10 and reduces the pressure of the refrigerant guided from the outdoor heat exchanger 80. The opening degree of the throttle valve 70 is controlled by the control section 90. The refrigerant whose pressure has been reduced by the throttle valve 70 is guided to the in-vehicle heat exchanger 85 from the refrigerant pipe L10.

The outdoor heat exchanger 80 is a device that is installed outside the vehicle and exchanges heat between outside air and refrigerant. The outdoor heat exchanger 80 operates as an evaporator during heat pump heating operation, and evaporates the refrigerant to cool the outside air. Furthermore, the outdoor heat exchanger 80 operates as a condenser during cooling operation, condensing the refrigerant and heating the outside air. The outdoor fan 81 is a device that blows outside air to the outdoor heat exchanger 80 to promote heat exchange between the outside air and the refrigerant.

The in-vehicle heat exchanger (evaporator) 85 is a device that cools or dehumidifies air by evaporating the refrigerant that has passed through the outdoor heat exchanger 80 and has been reduced in pressure by the throttle valve 70. The indoor blower 86 blows air toward the in-vehicle heat exchanger 85, thereby guiding the air cooled or dehumidified by the in-vehicle heat exchanger 85 into the vehicle interior through the heating section 20.

The control unit 90 is a device that controls each part of the vehicle air conditioner 100. The control unit 90 executes various processes for controlling each unit of the vehicle air conditioner 100 by reading and executing a control program stored in a storage unit (not shown).

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

The pressure sensor 92 is a sensor that detects the pressure of the refrigerant flowing through the refrigerant pipe L1. The temperature sensor 93 is a sensor that detects the temperature of the refrigerant flowing through the refrigerant pipe L1. The temperature sensor 94 is a sensor that detects the temperature of the refrigerant flowing through the refrigerant pipe L2. The temperature sensor 95 is a sensor that detects the temperature of the refrigerant flowing through the refrigerant pipe L5 between the heating section 20 and the throttle valve 40. The pressure sensor 96 is a sensor that detects the pressure of the refrigerant flowing through the refrigerant pipe L5 between the heating section 20 and the throttle valve 40.

<Heat pump heating operation>
The operation of the vehicle air conditioner 100 according to the present embodiment during heat pump heating operation will be described with reference to FIG. 2. FIG. 2 is a refrigerant circuit diagram showing a refrigerant flow during heat pump heating operation of the vehicle air conditioner 100. The heat pump heating operation is performed, for example, when the temperature outside the vehicle where the outdoor heat exchanger 80 is installed is not lower than a predetermined temperature (for example, −20° C.).

The arrows shown in FIG. 2 indicate the flow direction of the refrigerant. As shown in FIG. 2, during the heat pump heating operation, the refrigerant circulates in the order of the compressor 10, the heating section 20, the throttle 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 that circulates the refrigerant.

During heat pump heating operation, the outdoor heat exchanger 80 operates as an evaporator to evaporate the refrigerant and cool the outside air. During 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.

<Hot gas heating operation>
The operation of the vehicle air conditioner 100 according to the present embodiment during hot gas heating operation will be described with reference to FIG. 3. FIG. 3 is a refrigerant circuit diagram showing a refrigerant flow during hot gas heating operation of the vehicle air conditioner 100. The arrows shown in FIG. 3 indicate the direction of flow of the refrigerant. The hot gas heating operation is performed, for example, when the temperature outside the vehicle where the outdoor heat exchanger 80 is installed is below a predetermined temperature (for example, −20° C.).

As shown in FIG. 3, during hot gas heating operation, a part of the refrigerant circulates in the order of the compressor 10, the heating section 20, the throttle 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 that circulates the refrigerant. The refrigerant pipes L5, L8, L9, and L7 guide the refrigerant that has passed through the heating section 20 to the accumulator 30.

In addition, another part of the refrigerant is guided from the refrigerant pipe L3 to the upstream pipe L5a via the refrigerant pipe L6 without flowing through the refrigerant pipe L4. The refrigerant pipe L6 is a bypass flow path in which the refrigerant discharged from the compressor 10 without passing through the heating section 20 is merged at the first merging portion JP1 of the circulation flow path.

When performing hot gas heating operation, the control unit 90 closes the on-off valve 63, the on-off valve 64, and the on-off valve 65, and starts the circulation formed by the refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, and L7. Circulate refrigerant through the flow path. In the vehicle air conditioner 100 of this embodiment, the amount of refrigerant sealed in the refrigerant pipes consisting of the refrigerant pipes L1 to L11 is determined by the heating unit 20 when the on-off valve 64 and the on-off valve 65 are closed. It is set to allow heating of the air.

Here, a liquid phase or gas-liquid two-phase refrigerant that passes through the heating section 20 and flows through the circulation channel (upstream pipe L5a), and a gas phase that is guided from the bypass channel (refrigerant pipe L6) to the circulation channel. A configuration that allows good mixing of the refrigerant and the refrigerant will be explained. FIG. 4 is a cross-sectional view of the circulation flow path (upstream pipe L5a) and the bypass flow path (refrigerant pipe L6) viewed along the direction perpendicular to the central axis Z1 of the circulation flow path in the vicinity of the first confluence part JP1. be. The throttle valve 40 shown in FIG. 4 is schematically shown with the details of the mechanism for reducing the pressure of the refrigerant omitted.

As shown in FIG. 4, the first confluence part JP1 is located on the accumulator 30 side, which is downstream of the throttle valve 40 in the circulation flow path (upstream piping L5a) in the flow direction of the refrigerant, and on the first side of the refrigerant by the throttle valve 40. It is arranged so as to include the spray area SA1. The first spray area SA1 is an area where the liquid phase or gas-liquid two-phase refrigerant whose pressure has been reduced by the throttle valve 40 is sprayed. The first spray area SA1 is, for example, an area within 10D from the throttle valve 40, where D is the inner diameter of the upstream pipe L5a forming the circulation flow path. The distance Dis1 from the throttle valve 40 to the end of the first spray area SA1 along the central axis Z1 shown in FIG. 4 is within 10D.

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

It is preferable that the central axis Z1 of the circulation flow path (upstream pipe L5a) shown in FIG. 4 is arranged along the vertical direction at the first merging portion JP1. By arranging the central axis Z1 along the vertical direction, the refrigerant is not biased due to gravity in the circulation flow path, and proper mixing of the refrigerant guided into the circulation flow path and the refrigerant guided from the bypass flow path is promoted. be done.

FIG. 5 is a sectional view showing a first modification of the circulation flow path (upstream pipe L5a) shown in FIG. 4. As shown in FIG. 5, in the first confluence part JP1, when the circulation channel (upstream pipe L5a) is viewed from a predetermined direction orthogonal to the central axis Z1, the center axis Z1 of the circulation channel (upstream pipe L5a) and The angle θ formed by the central axis X1 of the bypass flow path (refrigerant pipe L6) is 135 degrees.

FIG. 6 is a sectional view showing a second modification of the circulation flow path (upstream piping L5a) shown in FIG. 4. As shown in FIG. 6, in the first confluence part JP1, when the circulation flow path (upstream piping L5a) is viewed from a predetermined direction orthogonal to the central axis Z1, the central axis Z1 of the circulation flow path (upstream piping L5a) and The angle θ formed by the central axis X1 of the bypass flow path (refrigerant pipe L6) is 180 degrees.

As shown in FIGS. 4 to 6, the angle θ between 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, for example, 90 degrees or 135 degrees. , or 180 degrees. Further, the angle θ may be set to any angle greater than or equal to 90 degrees and less than or equal to 180 degrees. Compared to the case where the angle θ is less than 90 degrees, the relative speed between the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path becomes larger, and the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path increase. can promote the mixing of

FIG. 7 is a cross-sectional view taken along the line AA of the circulation flow path (upstream pipe L5a) and bypass flow path (refrigerant pipe L6) shown in FIG. The upstream pipe L5a of this embodiment is a pipe with a circular cross-sectional view. As shown in FIG. 7, in the first confluence part JP1, when the circulation flow path (upstream pipe L5a) is viewed along the central axis Z1, the bypass flow path (refrigerant pipe L6) is located along the central axis X1 of the bypass flow path. and the central axis Z1 of the circulation passage do not intersect with each other.

The offset length L2 between the central axis X1 of the bypass channel and the central axis Z1 of the circulation channel is preferably set to, for example, D/8 or more and D/3 or less. Note that in this embodiment, the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path do not intersect, but the central axis X1 of the bypass flow path and the central axis Z1 of the circulation flow path intersect. The bypass flow path may be connected to the circulation flow path in this way.

As shown in FIG. 7, the upstream piping L5a of the present embodiment has an inner circumferential surface L5a1 having a circular shape without unevenness at the first merging portion JP1, but other shapes may be used. For example, in the first merging portion JP1, the inner circumferential surface L5a1 of the upstream pipe L5a may have an uneven shape. FIG. 8 is a sectional view showing a modification of the circulation flow path and bypass flow path shown in FIG. 7.

As shown in FIG. 8, in the first merging portion JP1, convex portions L5a2 are formed at multiple locations on the inner circumferential surface L5a1 of the circulation flow path (upstream pipe L5a) along the circumferential direction around the central axis Z1. There is. Therefore, when the refrigerant guided from the bypass flow path to the circulation flow path collides with the inner peripheral surface L5a1 of the circulation flow path, the flow of the refrigerant is disturbed by the convex portion L5a2, and due to this turbulence, the refrigerant guided to the circulation flow path and the bypass flow Mixing with the refrigerant led from the pipe is promoted. The convex portion L5a2 may be formed to extend parallel to the central axis Z1, or may be formed to spiral around the central axis Z1.

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

In step S101, the control unit 90 controls the on-off valves 61, 63, 64, and 65 to close them.
In step S102, the control unit 90 determines whether the refrigerant pressure LP detected by the pressure sensor 92 exceeds the threshold pressure, and if YES, the process proceeds to step S108, and if NO, the process proceeds to step S103. proceed.

In step S103, the control unit 90 controls the on-off valve 62 to open. The control unit 90 opens the on-off valve 62 and operates the compressor 10 to circulate the entire amount of refrigerant discharged from the compressor 10 so as to lead it to the accumulator 30 via the refrigerant pipe L6. In this way, the control unit 90 sets the vehicle air conditioner 100 to the first operation mode in which the refrigerant discharged from the compressor 10 is not guided to the heating unit 20 but to the refrigerant pipe L6.

In step S104, the control unit 90 controls the opening degree of the throttle valve 50 to be adjusted. Step S104 is executed when the determination 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 is not possible. be.

Therefore, in step S104, in order to make the hot gas heating operation using the heating unit 20 possible, the opening degree of the throttle valve 50 is adjusted so that the amount of refrigerant circulated to the accumulator 30 via the refrigerant pipe L6 is adjusted. Adjust. The control unit 90 controls the opening degree of the throttle valve 50 such that the larger the difference between the refrigerant pressure LP detected by the pressure sensor 92 and the threshold pressure, the larger the opening degree of the throttle valve 50 becomes. By doing so, it is possible to shorten the startup time required to bring the heating unit 20 into a state where the hot gas heating operation can be performed.

In step S105, the control unit 90 determines whether the refrigerant pressure LP detected by the pressure sensor 92 exceeds the threshold pressure, and if YES, the process proceeds to step S106, and if NO, the process proceeds to step S104. The opening degree of the valve 50 is adjusted again.

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

In step S107, the control unit 90 controls the on-off valve 61 to open. 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 section 20, the throttle valve 40, the accumulator 30, and the compressor 10.

In this way, the control unit 90 controls the vehicle air conditioner 100 to set the first operation mode in which the refrigerant discharged from the compressor 10 is not guided to the heating unit 20 but to the refrigerant pipe L6. The refrigerant is switched to the second operation mode in which the refrigerant is guided to both the heating section 20 and the refrigerant pipe L6. The on-off valve 61 functions as a switching section that switches between the first operation mode and the second operation mode. The control unit 90 controls the on-off valve 61 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.

In step S108, the control unit 90 controls the on-off valve 62 to open. In step S109, the control unit 90 controls the on-off valve 62 to open. The control unit 90 opens the on-off valve 62 and the on-off valve 61 and operates the compressor 10, so that a part of the refrigerant discharged from the compressor 10 is guided to the heating unit 20 and discharged from the compressor 10. Another part of the refrigerant is led to the accumulator 30 from the refrigerant pipe L6 without passing through the heating section 20.

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

In step S111, the control unit 90 calculates specific enthalpies ha, hb, and hc at points a, b, and c shown in FIG. 11, respectively. The specific enthalpy ha at point a is calculated from the temperature detected by temperature sensor 94 and the pressure detected by pressure sensor 96. The specific enthalpy hb at point b is calculated from the temperature detected by temperature sensor 95 and the pressure detected by pressure sensor 96. The specific enthalpy hc at point c is calculated from 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 that drives the compressor 10.

In step S112, the control unit 90 calculates the refrigerant circulation amount Gr1 of the refrigerant pipe L6. The refrigerant circulation amount Gr1 is calculated from the opening degree of the throttle valve 50, the pressure HP at point a, the pressure LP at point c, and the temperature detected by the temperature sensor 93.

In step S113, the control unit 90 calculates the refrigerant circulation amount Gr2 of the refrigerant pipe L5. The refrigerant circulation amount Gr2 is calculated from the opening degree of the throttle valve 40, the pressure HP at point b, the pressure LP at point c, and the temperature detected by the temperature sensor 93.

In step S114, the control unit 90 determines whether the pressure LP of the refrigerant detected by the pressure sensor 92 exceeds a predetermined pressure, and if YES, the process proceeds to step S115, and if NO, the process proceeds to step S116. proceed. The predetermined pressure is higher than the threshold pressure described above and is predetermined as a pressure suitable for hot gas heating operation.

In step S115, the control unit 90 increases the opening degree of the throttle valve 50 so that (ha-hc)×Gr1>(hc-hb)×Gr2. By doing so, the proportion of gas refrigerant in the inflow refrigerant flowing into the accumulator 30 including the refrigerant whose pressure has been reduced by the throttle valve 40 and the refrigerant whose pressure has been reduced by the throttle valve 50 is lower than that of the gas refrigerant in the outflow refrigerant flowing out from the accumulator 30. The proportion of gas refrigerant can be increased.

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

By making the proportion of gas refrigerant in the inflow refrigerant flowing into the accumulator 30 larger than the proportion of gas refrigerant in the outflow refrigerant flowing out from the accumulator 30, the liquid refrigerant stored in the accumulator 30 is reduced. Thereby, as the refrigerant flowing through the refrigeration cycle increases, the pressure of the refrigerant flowing into the compressor 10 increases, and a reduction in the power of the compressor 10 can be suppressed.

In step S116, the control unit 90 reduces the opening degree of the throttle valve 50 so that (ha-hc)×Gr1<(hc-hb)×Gr2. By doing so, the proportion of liquid refrigerant in the inflow refrigerant flowing into the accumulator 30 including the refrigerant whose pressure has been reduced by the throttle valve 40 and the refrigerant whose pressure has been reduced by the throttle valve 50 is lower than that of the liquid refrigerant in the outflow refrigerant flowing out from the accumulator 30. The proportion of liquid refrigerant can be increased. In FIG. 11, by reducing the opening degree of the throttle valve 50, the point c corresponding to the outlet side of the accumulator 30 (the suction side of the compressor 10) can be moved closer to the point d than the point e.

By making the ratio of liquid refrigerant in the inflow refrigerant flowing into the accumulator 30 larger than the ratio of liquid refrigerant in the outflow refrigerant flowing out from the accumulator 30, the liquid refrigerant stored in the accumulator 30 increases and The proportion of liquid refrigerant contained in the refrigerant flowing out from 30 decreases. Thereby, the pressure of the refrigerant flowing into the compressor 10 decreases as the refrigerant flowing through the refrigeration cycle decreases, and an increase in the torque of the compressor 10 can be suppressed.

In step S117, the control unit 90 determines whether an instruction to end the hot gas heating operation has been input, and if YES, ends the processing of this flowchart. If NO, the process from step S110 onwards is executed again.

In the hot gas heating operation described above, when reducing the power of the compressor 10, the control unit 90 controls the opening degree of the throttle valve 40 ( (first opening degree) and the opening degree (second opening degree) of the throttle valve 50. In addition, when increasing the power of the compressor 10, the control unit 90 controls the opening degree (first opening degree) of the throttle valve 40 and 50 opening degree (second opening degree).

<Dehumidifying heating operation>
The operation of the vehicle air conditioner 100 according to this embodiment during the dehumidifying and heating operation will be described with reference to FIG. 12. FIG. 12 is a refrigerant circuit diagram showing the flow of refrigerant during dehumidification/heating operation of the vehicle air conditioner 100.

The arrows shown in FIG. 12 indicate the flow direction of the refrigerant. As shown in FIG. 12, during the dehumidifying and heating operation, the refrigerant circulates in the order of the compressor 10, the heating section 20, the throttle valve 40, the outdoor heat exchanger 80, the in-vehicle 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 that circulates the refrigerant.

During the dehumidifying and heating operation, the outdoor heat exchanger 80 operates as an evaporator to evaporate the refrigerant and cool the outside air. During the dehumidifying 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 indoor blower 86 to guide the air dehumidified by the in-vehicle heat exchanger 85 to the heating unit 20, thereby dehumidifying the moisture contained in the air, heating the air in the heating unit 20, and blowing the air. can do.

<Cooling operation>
The operation of the vehicle air conditioner 100 according to this embodiment during cooling operation will be described with reference to FIG. 13. FIG. 13 is a refrigerant circuit diagram showing a refrigerant flow during cooling operation of the vehicle air conditioner 100.

The arrows shown in FIG. 13 indicate the flow direction of the refrigerant. As shown in FIG. 13, during cooling operation, the refrigerant circulates through the compressor 10, the outdoor heat exchanger 80, the in-vehicle heat exchanger 85, the accumulator 30, and the compressor 10 in this order. The refrigerant pipes L1, L2, L11, L5b, L10, and L7 form a circulation flow path that circulates the refrigerant.

During cooling operation, the outdoor heat exchanger 80 operates as a condenser to condense the refrigerant and 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 indoor blower 86 to blow air cooled by the outdoor heat exchanger 80 into the vehicle interior.

The functions and effects of the vehicle air conditioner 100 of this embodiment described above will be described.
According to the vehicle air conditioner 100 of the present embodiment, a part of the high-temperature, high-pressure refrigerant discharged from the compressor 10 is supplied to the heating section 20, and the heating section 20 heats the air (the object to be heated). The refrigerant that has passed through the heating section 20 is depressurized by the throttle valve 40 and guided to the accumulator 30 through refrigerant pipes L5, L8, L9, and L7. Further, another part of the high-temperature, high-pressure refrigerant discharged from the compressor 10 is guided to the refrigerant pipe L6 (bypass passage), and the pressure is reduced by the throttle valve 50. The refrigerant whose pressure has been reduced by the throttle valve 50 joins the refrigerant flowing through the refrigerant pipe L7, and is guided to the accumulator 30.

According to the vehicle air conditioner 100 of the present embodiment, the first confluence part JP1 is located closer to the accumulator 30 than the throttle valve 40 in the circulation flow path (upstream pipe L5a) and the first spray area SA1 of the refrigerant by the throttle valve 40. It is located in While the refrigerant flowing through the circulation flow path (upstream pipe L5a) is depressurized by the throttle valve 40 and becomes atomized, increasing the specific surface area, the high-temperature and high-pressure refrigerant guided from the bypass flow path (refrigerant pipe L6) Since the refrigerant joins the circulation flow path, mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path is promoted. The vehicle air conditioner 100 can exhibit stable heating ability while preventing the device from increasing in size and manufacturing cost.

According to the vehicle air conditioner 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 at the first merging portion JP1, the air is guided from the bypass flow path to the circulation flow path. The refrigerant forms a swirling flow that swirls around the central axis Z1 of the circulation channel. Since the refrigerant guided from the bypass flow path to the circulation flow path becomes a swirling flow, mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path is further promoted.

According to the vehicle air conditioner 100 of the present embodiment, the angle θ between 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. Compared to the case where the temperature is less than promoted.

According to the vehicle air conditioner 100 of the present embodiment, since the convex portion L5a2 is formed on the inner circumferential surface L5a1 of the circulation flow path at the first confluence portion JP1, the refrigerant guided from the bypass flow path to the circulation flow path is The flow of the refrigerant is disturbed when it collides with the inner circumferential surface L5a1 of the circulation flow path, and this disturbance promotes mixing of the refrigerant guided into the circulation flow path and the refrigerant guided from the bypass flow path.

According to the vehicle air conditioner 100 of the present embodiment, when the inner diameter of the upstream pipe L5a from the orifice 41 is D, the bypass flow path is By merging the refrigerants, mixing of the refrigerant introduced into the circulation channel and the refrigerant introduced from the bypass channel is appropriately promoted.

[Second embodiment]
Next, a vehicle air conditioner 100A according to a second embodiment of the present disclosure will be described. This embodiment is a modification of the first embodiment, and is the same as the first embodiment except when specifically explained below, and the explanation below will be omitted.

In the vehicle air conditioner 100A of the first embodiment, the circulation flow path (refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, L7) during hot gas heating operation is located closer to the accumulator 30 than the throttle valve 40. No other pressure reducing mechanism was installed. In contrast, in the vehicle air conditioner 100A of the present embodiment, an orifice (third throttle mechanism) 41, which is a pressure reducing mechanism, is arranged closer to the accumulator 30 than the throttle valve 40 in the circulation flow path during hot gas heating operation. It is something.

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

As shown in FIG. 14, the orifice 41 is arranged closer to the accumulator 30 than the throttle valve 40 in the circulation flow path (upstream pipe L5a, refrigerant pipe L8). The branch flow path branches a part of the refrigerant from the bypass flow path (refrigerant pipe L6) at the branch part BP, and is closer to the accumulator 30 than the first confluence part JP1 of the circulation flow path (upstream pipe L5a, refrigerant pipe L8). It is made to merge with the circulation flow path at the second merging part JP2.

Here, the gas-liquid two-phase refrigerant passes through the heating unit 20 and the throttle valve 40 and flows through the circulation flow path (upstream pipe L5a, refrigerant pipe L8), and the refrigerant flows from the branch flow path (refrigerant pipe L12) to the circulation flow path. A configuration for properly mixing the gas-phase refrigerant introduced into the refrigerant will be described. FIG. 15 is a cross-sectional view of the circulation flow path, the bypass flow path, and the branch flow path as seen along the direction orthogonal to the central axis Z1 of the circulation flow path in the vicinity of the first merge portion JP1 and the second merge portion JP2. be. In FIG. 15, the vicinity of the first merging portion JP1 is the same as that in the first embodiment, so the description below will be omitted.

As shown in FIG. 15, the second merging portion JP2 is located on the accumulator 30 side, which is downstream of the orifice 41 in the circulation flow path (upstream pipe L5a, refrigerant pipe L8) in the refrigerant flow direction, and the refrigerant flow through the orifice 41. It is arranged so as to include the second spray area SA2. The second spray area SA2 is an area where the gas-liquid two-phase refrigerant whose pressure has been reduced by the orifice 41 is sprayed. The second spray area SA2 is, for example, an area within 10D from the orifice 41, where D is the inner diameter of the refrigerant pipe L8 forming the circulation flow path. The distance Dis2 from the orifice 41 to the end of the second spray area SA2 along the central axis Z1 shown in FIG. 15 is within 10D.

As shown in FIG. 15, in the second confluence part JP2, when the circulation flow path (refrigerant pipe L8) is viewed from a predetermined direction orthogonal to the central axis Z1, the central axis Z1 of the circulation flow path (refrigerant pipe L8) and the branch flow The angle α formed by the central axis X2 of the pipe (refrigerant pipe L12) is 90 degrees. Note that the angle α may be an angle other than 90 degrees, and is preferably set to an arbitrary angle of 90 degrees or more and 180 degrees or less.

Although illustration is omitted, when the circulation flow path (refrigerant pipe L8) is viewed along the central axis Z1 in the second confluence part JP2, the bypass flow path (refrigerant pipe L6) is aligned with the central axis X1 of the bypass flow path. It is connected to the circulation flow path so that it does not intersect with the center axis Z1 of the flow path.

It is preferable that the central axis Z1 of the circulation flow path (refrigerant pipe L8) shown in FIG. 15 is arranged along the vertical direction at the second merging portion JP2. By arranging the central axis Z1 along the vertical direction, the refrigerant is not biased due to gravity in the circulation flow path, and proper mixing of the refrigerant guided into the circulation flow path and the refrigerant guided from the bypass flow path is promoted. be done.

As shown in FIG. 15, when the circulation flow path (upstream pipe L5a) is viewed from a predetermined direction perpendicular to the central axis Z1 of the circulation flow path, the circulation flow from the bypass flow path (refrigerant pipe L6) at the first confluence part JP1. A first inflow direction ID1 in which the refrigerant flows into the flow path (upstream pipe L5a), and a second inflow direction in which the refrigerant flows from the branch flow path (refrigerant pipe L12) into the circulation flow path (refrigerant pipe L8) at the second confluence JP2. Direction ID2 is facing. Here, facing means that the first inflow direction ID1 and the second inflow direction Direction ID2 is 180 degrees or within a predetermined angle (for example, 10 degrees) from 180 degrees.

FIG. 16 is a sectional view taken along the line BB of the circulation flow path shown in FIG. 15. As shown in FIG. 16, the orifice 41 of this embodiment is a throttling mechanism in which the cross-sectional area of a part of the pipe forming the circulation flow path (refrigerant pipe L8) is reduced compared to other parts. The orifice 41 shown in FIG. 16 is a plate-shaped member formed in an annular shape around the central axis Z1, has an outer diameter D that is the same as the inner diameter of the refrigerant pipe L8, and has an opening hole 41a formed in the center.

The orifice 41 shown in FIG. 16 may be the orifice 41 of the first modification shown in FIG. 17. FIG. 17 is a diagram showing a first modification of the orifice 41 shown in FIG. 16. The orifice 41 shown in FIG. 17 has an opening hole 41a formed in the center and a plurality of opening holes 41b having a smaller diameter than the opening hole 41a.

The orifice 41 shown in FIG. 16 may be a second modified orifice 41 shown in FIG. 18. FIG. 18 is a diagram showing a second modification of the orifice 41 shown in FIG. 16. The orifice 41 shown in FIG. 18 does not have an opening hole formed in the center, but has opening holes 41b having a smaller diameter than the opening hole 41a formed at multiple locations other than the center.

As shown in FIGS. 16 to 18, in the upstream piping L5a of the present embodiment, the inner peripheral surface L8a at the second confluence part JP2 is circular with no irregularities, but other shapes may be used. . For example, in the second merging portion JP2, the inner circumferential surface L8a of the refrigerant pipe L8 may have an uneven shape. FIG. 19 is a sectional view taken along the line CC of the circulation channel shown in FIG. 15.

As shown in FIG. 19, in the second merging portion JP2, convex portions L8b are formed at a plurality of locations on the inner peripheral surface L8a of the circulation flow path (refrigerant pipe L8) along the circumferential direction around the central axis Z1. . Therefore, 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, the flow of the refrigerant is disturbed by the convex portion L8b, and this disturbance causes Mixing of the refrigerant introduced into the circulation channel and the refrigerant introduced from the bypass channel is promoted. The convex portion L8b may be formed to extend parallel to the central axis Z1, or may be formed to spiral around the central axis Z1.

In addition, in this embodiment, one branch flow path (refrigerant pipe L12) and one orifice 41 are each provided in the vehicle air conditioner 100A, but the number is not limited to the above-mentioned number, and the number may be increased. may further promote mixing. For example, one or more branch parts BP different from the branch part BP shown in FIG. 14 are provided, a branch flow path is connected to the other branch part BP, and a circulation flow path (refrigerant pipe L8) is formed at a plurality of merging parts. It is also possible to merge the two. In this case, it is preferable to arrange the orifice 41 at each of the upstream sides of the plurality of merging parts of the circulation flow path (refrigerant pipe L8).

In addition, in the present embodiment, the orifice 41 is arranged upstream of the second confluence part JP2 of the circulation flow path (refrigerant pipe L8), but there is a mode in which the orifice 41 is not arranged in the circulation flow path (refrigerant pipe L8). You can also use it as Even if the orifice 41 is not arranged in the circulation flow path (refrigerant pipe L8), the circulation flow path can be maintained by flowing the refrigerant from the branch flow path (refrigerant pipe L12) into the circulation flow path (refrigerant pipe L8). can promote mixing of the refrigerant flowing through it.

The functions and effects of the vehicle air conditioner 100A of this embodiment described above will be explained.
According to the vehicle air conditioner 100A of the present embodiment, the central axis X1 of the branch flow path (refrigerant pipe L12) and the central axis Z1 of the circulation flow path (upstream pipe L5a) do not intersect at the second confluence part JP2. The refrigerant guided from the branch channel to the circulation channel forms a swirling flow that swirls around the central axis Z1 of the circulation channel. Since the refrigerant guided from the branch flow path to the circulation flow path becomes a swirling flow, mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the branch flow path is further promoted.

According to the vehicle air conditioner 100A of the present embodiment, since the angle between 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, this angle is less than 90 degrees. Compared to the case of , the relative velocity between the refrigerant flowing through the circulation flow path and the refrigerant guided from the branch flow path is increased, and the mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the branch flow path is further promoted. Ru.

According to the vehicle air conditioner 100A of the present embodiment, since the first inflow direction ID1 and the second inflow direction ID2 are opposed to each other, the refrigerant flowing from the bypass flow path in the first inflow direction ID1 forms a circulation flow path. Even if the refrigerant is biased toward one side in the radial direction of the piping, the bias can be reduced by the refrigerant flowing from the branch flow path in the second inflow direction ID2.

According to the vehicle air conditioner 100A of the present embodiment, since the convex portion L5a2 is formed on the inner circumferential surface L5a1 of the circulation flow path at the second merging portion JP2, the refrigerant guided from the branch flow path to the circulation flow path is The flow of the refrigerant is disturbed when it collides with the inner circumferential surface L5a1 of the circulation flow path, and this disturbance promotes mixing of the refrigerant guided into the circulation flow path and the refrigerant guided from the branch flow path.

According to the vehicle air conditioner 100A of this embodiment, since the central axis Z1 of the circulation channel is arranged along the vertical direction, the refrigerant is not biased due to gravity in the circulation channel, and Mixing of the guided refrigerant and the refrigerant introduced from the branch flow path is appropriately promoted.

According to the vehicle air conditioner 100A of the present embodiment, when the inner diameter of the upstream pipe L5a from the orifice 41 is D, the branch flow path is connected to the second confluence part JP2 located in the second spray area SA2 within 10D. By merging the refrigerants, mixing of the refrigerant introduced into the circulation channel and the refrigerant introduced from the branched channel is appropriately promoted.

The air conditioner described in each embodiment described above can be understood, for example, as follows.
An air conditioner (100) according to a first aspect of the present disclosure includes a compressor (10) that compresses a refrigerant, a heating section (20) that heats an object to be heated with the refrigerant discharged from the compressor, and 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 that has passed through the heating section to the accumulator; a bypass flow path (L6) that allows the refrigerant discharged from the compressor to join together at a first merging part (JP1) of the circulation flow path (L5, L8, L7) without causing any , a first throttle mechanism (40) that reduces the pressure of the refrigerant flowing out from the heating section, and a second throttle mechanism (50) that is disposed in the bypass flow path and reduces the pressure of the refrigerant discharged from the compressor; The first merging section is disposed closer to the accumulator than the first throttle mechanism in the circulation flow path and in a first spray area (SA1) of the refrigerant by the first throttle mechanism.

According to the air conditioner according to the first aspect of the present disclosure, a portion of the high-temperature, high-pressure refrigerant discharged from the compressor is supplied to the heating section, and the object to be heated is heated by the heating section. The refrigerant that has passed through the heating section is depressurized by the first throttle mechanism and guided to the accumulator through the circulation channel. Further, another part of the high-temperature, high-pressure refrigerant discharged from the compressor is guided to the bypass flow path, and the pressure is reduced by the second throttle mechanism. The refrigerant whose pressure has been reduced by the second throttling mechanism joins with the refrigerant flowing through the circulation channel at the first merging section, and is guided to the accumulator.

According to the air conditioner according to the first aspect of the present disclosure, the first merging section is disposed closer to the accumulator than the first throttle mechanism in the circulation flow path and in the first spray area of the refrigerant by the first throttle mechanism. The refrigerant flowing through the circulation channel is depressurized by the first throttling mechanism, becomes atomized, and has an increased specific surface area, and the high-temperature, high-pressure refrigerant guided from the bypass channel joins the circulation channel. Mixing of the refrigerant flowing through the circulation channel and the refrigerant guided from the bypass channel is promoted. The air conditioner can exhibit stable heating ability while preventing the device from increasing in size and manufacturing cost.

The air conditioner according to the second aspect of the present disclosure, in the first aspect, further includes a third throttle mechanism (41) disposed closer to the accumulator than the first throttle mechanism in the circulation flow path.
According to the air conditioner according to the second aspect of the present disclosure, the third throttling mechanism reduces the pressure of the refrigerant flowing through the circulation channel and turns it into a spray. Therefore, the mixing of the refrigerant flowing into the third throttle mechanism can be further promoted and guided to the accumulator.

The air conditioner according to the third aspect of the present disclosure further includes the following configuration in the first aspect or the second aspect. That is, a branch flow path is provided in which a part of the refrigerant is branched from the bypass flow path and merged into the circulation flow path at a second merge portion closer to the accumulator than the first merge portion of the circulation flow path.
According to the air conditioner according to the third aspect of the present disclosure, a part of the refrigerant branched from the bypass flow path joins the circulation flow path at the second merging portion, thereby improving the mixing of the refrigerant flowing through the circulation flow path. can be promoted.

The air conditioner according to the fourth aspect of the present disclosure further includes the following configuration in the first aspect. That is, a third throttling mechanism disposed closer to the accumulator than the first throttling mechanism in the circulation flow path, and a third throttling mechanism that branches part of the refrigerant from the bypass flow path to the first confluence of the circulation flow path. a branch flow path that joins the circulation flow path at a second merging portion that is closer to the accumulator than the second merging portion, the second merging portion being closer to the accumulator than the third throttling mechanism of the circulation flow path; The refrigerant is disposed in a second spray area of the refrigerant by the third throttle mechanism.

According to the air conditioner according to the fourth aspect of the present disclosure, the second merging section is disposed closer to the accumulator than the third throttle mechanism in the circulation flow path and in the second spray area of the refrigerant by the third throttle mechanism. The refrigerant flowing through the circulation channel is depressurized by the third throttling mechanism, becomes atomized, and has an increased specific surface area, and the high-temperature, high-pressure refrigerant guided from the branch channel joins the circulation channel. Mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the branch flow path is further promoted.

The air conditioner according to the fifth aspect of the present disclosure further includes the following configuration in the second aspect or the fourth aspect. That is, the third throttle mechanism is an orifice in which a cross-sectional area of a portion of the piping forming the circulation flow path is smaller than that of the other portion.
According to the air conditioner according to the fifth aspect of the present disclosure, by arranging a relatively simple orifice in the circulation flow path, the specific surface area of the refrigerant flowing through the circulation flow path is increased to promote mixing of the refrigerant. Can be done.

The air conditioner according to the sixth aspect of the present disclosure further includes the following configuration in the first aspect or the second aspect. That is, in the first confluence section, when the circulation flow path is viewed along the central axis of the circulation flow path, the bypass flow path is located between the center axis (X1) of the bypass flow path and the center of the circulation flow path. It is connected to the circulation flow path so as not to intersect with the axis (Z1).

According to the air conditioner according to the sixth aspect of the present disclosure, the central axis of the bypass channel and the central axis of the circulation channel do not intersect at the first merging section, so that the refrigerant is guided from the bypass channel to the circulation channel. forms a swirling flow that swirls around the central axis of the circulation channel. Since the refrigerant guided from the bypass flow path to the circulation flow path becomes a swirling flow, mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path is further promoted.

The air conditioner according to the seventh aspect of the present disclosure further includes the following configuration in the third aspect. That is, in the second confluence section, when the circulation flow path is viewed along the central axis of the circulation flow path, the branch flow path is such that the central axis of the bypass flow path and the center axis of the circulation flow path are It is connected to the circulation flow path so as not to intersect.

According to the air conditioner according to the seventh aspect of the present disclosure, the central axis of the branch channel and the central axis of the circulation channel do not intersect at the second merging section, so that the refrigerant is guided from the branch channel to the circulation channel. forms a swirling flow that swirls around the central axis of the circulation channel. Since the refrigerant guided from the branch flow path to the circulation flow path becomes a swirling flow, mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the branch flow path is further promoted.

The air conditioner according to the eighth aspect of the present disclosure further includes the following configuration in the first aspect or the second aspect. That is, in the first merging section, when the circulation flow path is viewed from a predetermined direction perpendicular to the central axis of the circulation flow path, the angle between the center axis of the circulation flow path and the center axis of the bypass flow path is The bypass flow path is connected to the circulation flow path at an angle of 90 degrees or more and 180 degrees or less.

According to the air conditioner according to the eighth aspect of the present disclosure, since the angle between the central axis of the circulation channel and the central axis of the bypass channel is 90 degrees or more and 180 degrees or less, this angle is less than 90 degrees. Compared to the case, the relative speed between the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path is increased, and the mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path is further promoted. .

The air conditioner according to the ninth aspect of the present disclosure further includes the following configuration in the third aspect. That is, in the second merging section, when the circulation flow path is viewed from a predetermined direction perpendicular to the central axis of the circulation flow path, the angle between the center axis of the circulation flow path and the center axis of the branch flow path is The branch flow path is connected to the circulation flow path at an angle of 90 degrees or more and 180 degrees or less.

According to the air conditioner according to the ninth aspect of the present disclosure, since the angle between the central axis of the circulation channel and the central axis of the branch channel is 90 degrees or more and 180 degrees or less, this angle is less than 90 degrees. Compared to the case, the relative velocity between the refrigerant flowing through the circulation channel and the refrigerant guided from the branch channel is increased, and the mixing of the refrigerant flowing through the circulation channel and the refrigerant guided from the branch channel is further promoted. .

The air conditioner according to the tenth aspect of the present disclosure further includes the following configuration in the third aspect. That is, when the circulation flow path is viewed from a predetermined direction perpendicular to the central axis of the circulation flow path, a first inflow direction in which the refrigerant flows from the bypass flow path to the circulation flow path at the first merging portion; Second inflow directions in which the refrigerant flows from the branch flow path to the circulation flow path are opposite to each other at the second merging portion.

According to the air conditioner according to the tenth aspect of the present disclosure, since the first inflow direction and the second inflow direction are opposite to each other, the refrigerant flowing from the bypass flow path in the first inflow direction forms the circulation flow path in the piping. Even if the refrigerant is biased toward one side in the radial direction, the bias can be reduced by the refrigerant flowing from the branch flow path in the second inflow direction.

The air conditioner according to the eleventh aspect of the present disclosure further includes the following configuration in the first aspect or the second aspect. That is, in the first merging portion, convex portions (L5a2) are formed at a plurality of locations on the inner circumferential surface of the circulation flow path along the circumferential direction around the central axis of the circulation flow path.

According to the air conditioner according to the eleventh aspect of the present disclosure, since the convex portion is formed on the inner circumferential surface of the circulation flow path at the first merging portion, the refrigerant guided from the bypass flow path to the circulation flow path flows into the circulation flow path. The flow of the refrigerant is disturbed when it collides with the inner peripheral surface of the passage, and this turbulence promotes mixing of the refrigerant introduced into the circulation passage and the refrigerant introduced from the bypass passage.

The air conditioner according to the twelfth aspect of the present disclosure further includes the following configuration in the third aspect. That is, in the second merging portion, convex portions are formed at a plurality of locations on the inner circumferential surface of the circulation flow path along the circumferential direction around the central axis of the circulation flow path.

According to the air conditioner according to the twelfth aspect of the present disclosure, since the convex portion is formed on the inner circumferential surface of the circulation channel at the second merging section, the refrigerant guided from the branch channel to the circulation channel flows into the circulation flow path. The flow of the refrigerant is disturbed when it collides with the inner circumferential surface of the channel, and this turbulence promotes mixing of the refrigerant introduced into the circulation channel and the refrigerant introduced from the branch channel.

The air conditioner according to the thirteenth aspect of the present disclosure further includes the following configuration in the first aspect or the second aspect. That is, in the first merging section, the central axis of the circulation flow path is arranged along the vertical direction.
According to the air conditioner according to the thirteenth aspect of the present disclosure, since the central axis of the circulation flow path is arranged along the vertical direction, the refrigerant is not biased due to gravity in the circulation flow path. Mixing of the guided refrigerant and the refrigerant introduced from the bypass flow path is appropriately promoted.

The air conditioner according to the fourteenth aspect of the present disclosure further includes the following configuration in the third aspect. That is, in the second merging section, the central axis of the circulation flow path is arranged along the vertical direction.
According to the air conditioner according to the fourteenth aspect of the present disclosure, since the central axis of the circulation channel is arranged along the vertical direction, the refrigerant is not biased due to gravity in the circulation channel, and Mixing of the guided refrigerant and the refrigerant guided from the branch flow path is promoted appropriately.

The air conditioner according to the fifteenth aspect of the present disclosure further includes the following configuration in the first aspect or the second aspect. That is, the first spray area is an area within 10D from the first throttle mechanism, where D is the inner diameter of the pipe forming the circulation flow path.
According to the air conditioner according to the fifteenth aspect of the present disclosure, by merging the refrigerant from the bypass flow path at the first merging portion disposed in the first spray region within 10D from the first throttle mechanism, the refrigerant is added to the circulation flow path. Mixing of the guided refrigerant and the refrigerant introduced from the bypass flow path is appropriately promoted.

The air conditioner according to the sixteenth aspect of the present disclosure further includes the following configuration in the fourth aspect. That is, the second spray area is an area within 10D from the third throttle mechanism, where D is the inner diameter of the pipe forming the circulation flow path.
According to the air conditioner according to the 16th aspect of the present disclosure, by merging the refrigerant from the branch flow path at the second merging section disposed in the second spray region within 10D from the third throttle mechanism, the refrigerant is added to the circulation flow path. Mixing of the guided refrigerant and the refrigerant introduced from the branch flow path is appropriately promoted.

10 Compressor 20 Heating section 30 Accumulator 40 Throttle valve (first throttle mechanism)
41 Orifice (third aperture mechanism)
41a, 41b Opening hole 50 Throttle valve 61, 62, 63 On-off valve 64 On-off valve (first on-off valve)
65 On-off valve (second on-off valve)
70 Throttle valve 80 Outdoor heat exchanger 81 Outdoor fan 85 In-vehicle heat exchanger (evaporator)
86 Indoor blower 90 Control unit 91 Refrigerant heaters 92, 96 Pressure sensors 93, 94, 95 Temperature sensors 100, 100A Vehicle air conditioner Dis1, Dis2 Distances Gr1, Gr2 Refrigerant circulation amount ID1 First inflow direction ID2 Second inflow direction JP1 First confluence part JP2 Second confluence part L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, L12 Refrigerant pipe L5a Upstream pipe L5a1 Inner peripheral surface L5a2 Convex part L5b Downstream pipe SA1 First spray area SA2 Second spray area SC Supercooling degree X1, X2, Z1 Central axis ha, hb, hc Specific enthalpy θ, α Angle

Claims (16)

1. a compressor that compresses refrigerant;
   a heating unit that heats an object to be heated 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 that has passed through the heating section to the accumulator;
   a bypass flow path in which the refrigerant discharged from the compressor is merged at a first merging portion of the circulation flow path without passing through the heating section;
   a first throttle mechanism disposed in the circulation flow path and reducing the pressure of the refrigerant flowing out from the heating section;
   a second throttle mechanism disposed in the bypass flow path and reducing the pressure of the refrigerant discharged from the compressor;
   In the air conditioner, the first merging section is disposed closer to the accumulator than the first throttle mechanism in the circulation flow path and in a first spray area of the refrigerant by the first throttle mechanism.
2. The air conditioner according to claim 1, further comprising a third throttle mechanism arranged closer to the accumulator than the first throttle mechanism in the circulation flow path.
3. Claim 1, further comprising a branch flow path that branches part of the refrigerant from the bypass flow path and joins the circulation flow path at a second merge portion closer to the accumulator than the first merge portion of the circulation flow path. Or the air conditioner according to claim 2.
4. a third throttle mechanism disposed closer to the accumulator than the first throttle mechanism in the circulation flow path;
   a branch flow path that branches part of the refrigerant from the bypass flow path and joins the circulation flow path at a second merge portion closer to the accumulator than the first merge portion of the circulation flow path;
   The air conditioner according to claim 1, wherein the second merging section is disposed closer to the accumulator than the third throttle mechanism in the circulation flow path and in a second spray area of the refrigerant by the third throttle mechanism.
5. The air conditioner according to claim 2 or 4, wherein the third throttle mechanism is an orifice in which a cross-sectional area of a part of the piping forming the circulation flow path is smaller than that of the other part.
6. In the first merging section, when the circulation flow path is viewed along the central axis of the circulation flow path, the bypass flow path is such that the central axis of the bypass flow path and the central axis of the circulation flow path do not intersect. The air conditioner according to claim 1 or 2, wherein the air conditioner is connected to the circulation flow path in such a manner that the air conditioner is connected to the circulation flow path.
7. In the second confluence section, when the circulation flow path is viewed along the central axis of the circulation flow path, in the branch flow path, the central axis of the bypass flow path and the central axis of the circulation flow path do not intersect. The air conditioner according to claim 3, wherein the air conditioner is connected to the circulation flow path in such a manner.
8. In the first merging section, when the circulation flow path is viewed from a predetermined direction perpendicular to the center axis of the circulation flow path, the angle between the center axis of the circulation flow path and the center axis of the bypass flow path is 90 degrees. The air conditioner according to claim 1 or 2, wherein the bypass flow path is connected to the circulation flow path so that the angle is greater than or equal to 180 degrees.
9. In the second confluence section, when the circulation flow path is viewed from a predetermined direction perpendicular to the center axis of the circulation flow path, the angle between the center axis of the circulation flow path and the center axis of the branch flow path is 90 degrees. The air conditioner according to claim 3, wherein the branch flow path is connected to the circulation flow path so that the angle is greater than or equal to 180 degrees.
10. When the circulation flow path is viewed from a predetermined direction perpendicular to the central axis of the circulation flow path, a first inflow direction in which the refrigerant flows from the bypass flow path to the circulation flow path at the first merging portion; The air conditioner according to claim 3, wherein second inflow directions in which the refrigerant flows from the branch flow path to the circulation flow path are opposite to each other at the two confluence portions.
11. According to claim 1 or 2, in the first merging portion, convex portions are formed at a plurality of locations on the inner circumferential surface of the circulation flow path along the circumferential direction around the central axis of the circulation flow path. air conditioner.
12. The air conditioner according to claim 3, wherein in the second merging section, convex portions are formed at a plurality of locations on the inner circumferential surface of the circulation flow path along the circumferential direction around the central axis of the circulation flow path.
13. The air conditioner according to claim 1 or 2, wherein in the first merging section, the central axis of the circulation flow path is arranged along the vertical direction.
14. The air conditioner according to claim 3, wherein in the second merging section, the central axis of the circulation flow path is arranged along the vertical direction.
15. The air conditioner according to claim 1 or 2, wherein the first spray area is an area within 10D from the first throttle mechanism, where D is the inner diameter of the piping forming the circulation flow path.
16. The air conditioner according to claim 4, wherein the second spray area is an area within 10D from the third throttle mechanism, where D is the inner diameter of the piping forming the circulation flow path.

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