JP7279246B1 - Air conditioner - Google Patents

Abstract

An object of the present invention is to exhibit a stable heating capacity while preventing an increase in the size of an apparatus and an increase in manufacturing costs. A compressor that compresses a refrigerant, a heating section that heats an object to be heated by the refrigerant discharged from the compressor, an accumulator that separates liquid from the refrigerant sucked by the compressor, and a heating section. a circulation passage for guiding the discharged refrigerant to the accumulator; a bypass passage for joining the refrigerant discharged from the compressor without passing through the heating unit at a first junction JP1 of the circulation passage; A throttle valve 40 for decompressing the refrigerant flowing out from the heating section and a throttle valve for decompressing the refrigerant discharged from the compressor are provided in the bypass flow path. Provided is a vehicle air conditioner that is arranged on the accumulator side of the valve 40 and in the first spray area SA1 of the refrigerant by the throttle valve 40. - 特許庁[Selection drawing] Fig. 4

Description

The present disclosure relates to air conditioners.

Conventionally, there has been disclosed a refrigeration cycle device in which refrigerants having different enthalpies are mixed and sucked into a compressor (see, for example, Patent Document 1). In Patent Document 1, in order to homogeneously mix the bypass side refrigerant and the decompression section side refrigerant having different enthalpies, the bypass side refrigerant and the decompression section side refrigerant are heat-exchanged in a laminated heat exchanger and then merged. is disclosed. In Patent Literature 1, a bypass-side refrigerant and a pressure-reducing portion-side refrigerant, which have different enthalpies, are homogeneously mixed so that the refrigeration cycle device can exhibit stable heating capacity.

JP 2021-156567 A

However, in Patent Literature 1, a heat exchanger is required to exchange heat before two types of refrigerants having different enthalpies are merged, so the size of the apparatus is increased and the manufacturing cost is increased.

The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide an air conditioner that can exhibit stable heating capacity while preventing an increase in the size of the device and an increase in manufacturing costs. and

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 unit that heats an object to be heated with the refrigerant discharged from the compressor, and a liquid component in the refrigerant sucked by the compressor. a circulation passage for guiding the refrigerant that has passed through the heating portion to the accumulator; a bypass flow path for joining; a first throttle mechanism arranged in the circulation flow path for decompressing the refrigerant flowing out from the heating unit; and a first throttle mechanism arranged in the bypass flow path for reducing the refrigerant discharged from the compressor a second throttling mechanism for reducing pressure, wherein the first merging portion is arranged on the accumulator side of the circulation flow path relative to the first throttling mechanism and in a first spray region of the refrigerant by the first throttling mechanism. ing.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide an air conditioner capable of exhibiting stable heating capacity while preventing an increase in the size of the device and an increase in manufacturing costs.

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

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

The vehicle air conditioner 100 of the present embodiment is a device that generates warm air with a heating unit 20 installed inside the vehicle, or generates cool air with an in-vehicle heat exchanger 85 installed inside the vehicle, and blows the air into the vehicle. . The vehicle air conditioner 100 operates the outdoor heat exchanger 80 as an evaporator during the heat pump heating operation, and operates the outdoor heat exchanger 80 as a condenser during the cooling operation. Further, the vehicle air conditioner 100 performs heating only by the power of the compressor 10 without passing the refrigerant through the outdoor heat exchanger 80 when the outside air 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 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 unit 20 via the refrigerant pipe L3 and the refrigerant pipe L4.

The heating unit 20 is a device that heats air (an object to be heated) blown by the indoor blower 86 with 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 exchanged heat with the air in the heating unit 20 is guided to the throttle valve 40 arranged in the upstream pipe L5a of the refrigerant pipe L5.

The accumulator 30 is a device that separates at least part of the liquid in the refrigerant sucked by 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.

The throttle valve 40 is a mechanism that is arranged in the refrigerant pipe L<b>5 and decompresses the refrigerant that has flowed out from the heating unit 20 . The opening degree of the throttle valve 40 is controlled by the controller 90 . The refrigerant decompressed 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 for reducing the pressure of the refrigerant discharged from the compressor 10 . The opening degree of the throttle valve 50 is controlled by the controller 90 . The refrigerant decompressed by the throttle valve 50 is guided from the refrigerant pipe L6 to the accumulator 30 via the refrigerant pipe L7. Refrigerant pipe L7 is a pipe that connects in-vehicle heat exchanger 85 and accumulator 30 .

The on-off valve 61 is arranged in the refrigerant pipe L8 and is a device that 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 through the refrigerant pipe L8. The refrigerant pipe L8 is a pipe that connects the refrigerant pipe L5 and the refrigerant pipe L9. The refrigerant pipe L9 is a pipe that connects the refrigerant pipe L10 and the refrigerant pipe L7. The refrigerant pipe L10 is a pipe that connects the outdoor heat exchanger 80 and the vehicle interior heat exchanger 85 .

The on-off valve 62 is arranged in the refrigerant pipe L6 and is a device that 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 through the refrigerant pipe L6.
The on-off valve 63 is arranged in the refrigerant pipe L11 and is a device that 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 through the refrigerant pipe L11.

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

The throttle valve 70 is a mechanism that is arranged in the refrigerant pipe L<b>10 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 controller 90 . The refrigerant decompressed by the throttle valve 70 is guided to the in-vehicle heat exchanger 85 through the refrigerant pipe L10.

The outdoor heat exchanger 80 is a device that is installed outside the vehicle and exchanges heat between the outside air and the refrigerant. The outdoor heat exchanger 80 operates as an evaporator during the heat pump heating operation, and evaporates the refrigerant to cool the outside air. Also, the outdoor heat exchanger 80 operates as a condenser during cooling operation, condenses the refrigerant, and heats 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 the air by evaporating the refrigerant that has passed through the outdoor heat exchanger 80 and has been decompressed by the throttle valve 70 . The indoor blower 86 blows air toward the in-vehicle heat exchanger 85 to guide the air cooled or dehumidified in the in-vehicle heat exchanger 85 into the vehicle interior via the heating unit 20 .

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

The refrigerant heater 91 is a device that is arranged downstream of the on-off valve 61 in the refrigerant pipe L8 and heats the refrigerant that flows into the accumulator 30 . For example, when the hot gas 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 .

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. As shown in FIG. 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. As shown in FIG.

<Heat pump heating operation>
The operation of the vehicle air conditioner 100 according to the present embodiment during the heat pump heating operation will be described with reference to FIG. FIG. 2 is a refrigerant circuit diagram showing the refrigerant flow during the heat pump heating operation of the vehicle air conditioner 100. As shown in FIG. 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 below a predetermined temperature (eg, -20°C).

Arrows shown in FIG. 2 indicate the flow direction of the refrigerant. As shown in FIG. 2, the refrigerant circulates through the compressor 10, the heating section 20, the throttle valve 40, the outdoor heat exchanger 80, the accumulator 30, and the compressor 10 in this order during the heat pump heating operation. Refrigerant pipes L1, L2, L3, L4, L5a (L5), L5b (L5), L9, and L7 form a circulation flow path for circulating the refrigerant.

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 controller 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 the hot gas heating operation will be described with reference to FIG. FIG. 3 is a refrigerant circuit diagram showing refrigerant flow during hot gas heating operation of the vehicle air conditioner 100 . Arrows shown in FIG. 3 indicate the flow direction 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 (eg, -20°C).

As shown in FIG. 3, part of the refrigerant circulates through the compressor 10, the heating section 20, the throttle valve 40, the accumulator 30, and the compressor 10 in this order during the hot gas heating operation. Refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, and L7 form a circulation flow path for circulating the refrigerant. Refrigerant pipes L<b>5 , L<b>8 , L<b>9 and L<b>7 guide the refrigerant that has passed through heating unit 20 to accumulator 30 .

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 that joins the refrigerant discharged from the compressor 10 without passing through the heating section 20 at the first junction JP1 of the circulation flow path.

When performing the 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 the circulation formed by the refrigerant pipes L1, L2, L3, L4, L5a, L8, L9, and L7. A coolant is circulated in the flow path. In the vehicle air conditioner 100 of the present embodiment, the amount of refrigerant enclosed 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 up to allow air heating.

Here, the liquid phase or gas-liquid two-phase refrigerant that passes through the heating unit 20 and circulates in the circulation flow path (upstream pipe L5a) and the gas phase that is guided from the bypass flow path (refrigerant pipe L6) to the circulation flow path A description will be given of a configuration for good mixing with the refrigerant. FIG. 4 is a cross-sectional view of the circulation flow path (upstream pipe L5a) and the bypass flow path (refrigerant pipe L6) in the vicinity of the first junction JP1, as seen along a direction orthogonal to the central axis Z1 of the circulation flow path. be. The throttle valve 40 shown in FIG. 4 is schematically shown by omitting the details of the mechanism for depressurizing the refrigerant.

As shown in FIG. 4, the first junction JP1 is located on the side of the accumulator 30, which is downstream of the throttle valve 40 in the circulation flow path (upstream pipe L5a) in the direction of flow of the refrigerant, and the first flow 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 decompressed 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 along the central axis Z1 shown in FIG. 4 to the end of the first spray area SA1 is within 10D.

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

The central axis Z1 of the circulation flow path (upstream pipe L5a) shown in FIG. 4 is preferably arranged along the vertical direction at the first junction JP1. By arranging the central axis Z1 along the vertical direction, the refrigerant is not biased due to gravity in the circulation passage, and the refrigerant guided to the circulation passage and the refrigerant guided from the bypass passage are properly mixed. be done.

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

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

As shown in FIGS. 4 to 6, the angle θ between the central axis Z1 of the circulation flow path (upstream piping L5a) and the central axis X1 of the bypass flow path (refrigerant piping L6) is, for example, 90 degrees or 135 degrees. , or 180 degrees. Also, the angle θ may be set to any angle between 90 degrees and 180 degrees. Compared to when the angle θ is less than 90 degrees, the relative velocity between the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path increases, and the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path increase. can promote mixing of

FIG. 7 is a cross-sectional view of the circulation flow path (upstream pipe L5a) and the bypass flow path (refrigerant pipe L6) shown in FIG. 4, taken along line AA. The upstream pipe L5a of the present embodiment is a pipe having a circular cross section. As shown in FIG. 7, in the first junction JP1, when the circulation flow path (upstream pipe L5a) is viewed along the central axis Z1, the bypass flow path (refrigerant piping L6) extends along the central axis X1 of the bypass flow path. and the central axis Z1 of the circulation channel are connected to the circulation channel so as not to cross 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 D/8 or more and D/3 or less, for example. In this embodiment, the central axis X1 of the bypass channel and the central axis Z1 of the circulation channel are prevented from intersecting, but the central axis X1 of the bypass channel and the central axis Z1 of the circulation channel intersect You may connect a bypass flow path to a circulation flow path like this.

As shown in FIG. 7, the upstream pipe L5a of the present embodiment has a circular inner peripheral surface L5a1 without irregularities at the first confluence JP1, but may be in another form. For example, at the first junction JP1, the inner peripheral surface L5a1 of the upstream pipe L5a may be uneven. 8 is a cross-sectional view showing a modification of the circulation channel and the bypass channel shown in FIG. 7. FIG.

As shown in FIG. 8, in the first confluence portion JP1, the inner peripheral surface L5a1 of the circulation flow path (upstream pipe L5a) is formed with a plurality of projections L5a2 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 the refrigerant guided to the circulation flow path and the bypass flow are caused by this disturbance. Mixing with the coolant directed from the channel is promoted. The convex portion L5a2 may be formed so as to extend parallel to the central axis Z1, or may be formed so as to spirally turn around the central axis Z1.

Here, the operation of the vehicle air conditioner 100 during the hot gas heating operation will be described with reference to FIGS. 9 to 11 . 9 and 10 are flowcharts showing the operation of the vehicle air conditioner 100 during the 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 the hot gas heating operation.

In step S101, the controller 90 controls the on-off valves 61, 63, 64, 65 to be closed.
In step S102, the control unit 90 determines whether or not the refrigerant pressure LP detected by the pressure sensor 92 exceeds the threshold pressure. If YES, the process proceeds to step S108, and if NO, the process proceeds to step S103. proceed.

In step S103, the controller 90 controls the on-off valve 62 to open. By opening the on-off valve 62 and operating the compressor 10, the control unit 90 circulates the entire amount of the refrigerant discharged from the compressor 10 so as to be guided to the accumulator 30 via the refrigerant pipe L6. Thus, 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 is guided to the refrigerant pipe L6.

In step S<b>104 , the control unit 90 controls the opening degree of the throttle valve 50 to be adjusted. Step S104 is executed when NO is determined in step S102, when the pressure LP of the refrigerant detected by the pressure sensor 92 is equal to or lower than the threshold pressure and the hot gas heating operation using the heating unit 20 cannot be performed. be.

Therefore, in step S104, in order to enable the hot gas heating operation using the heating unit 20, the opening degree of the throttle valve 50 is adjusted, and the amount of refrigerant circulating through the refrigerant pipe L6 to the accumulator 30 is adjusted. to adjust. The controller 90 controls the opening 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 of the throttle valve 50 . By doing so, it is possible to shorten the start-up time required to make the hot gas heating operation using the heating unit 20 executable.

In step S105, the control unit 90 determines whether or not the refrigerant pressure LP detected by the pressure sensor 92 exceeds the threshold pressure. If YES, the process proceeds to step S106. The adjustment of the degree of opening of the valve 50 is performed again.

In step S106, the control unit 90 adjusts the opening degree of the throttle valve 40 prior to 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 controller 90 controls the on-off valve 61 to open. By opening the on-off valve 61, part of the refrigerant discharged from the compressor 10 circulates through the compressor 10, the heating section 20, the throttle valve 40, the accumulator 30, and the compressor 10 in this order.

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 is guided to the refrigerant pipe L6. Switching to the second operation mode in which the refrigerant is led to both the heating unit 20 and the refrigerant pipe L6. The on-off valve 61 functions as a switching unit that switches between the first operation mode and the second operation mode. The control unit 90 controls the on-off valve 61 to switch the first operation mode to the second operation mode when the pressure of the refrigerant sucked by the compressor 10 exceeds the threshold pressure.

In step S108, the controller 90 controls the on-off valve 62 to open. In step S109, the controller 90 controls the on-off valve 62 to open. Control unit 90 opens on-off valve 62 and on-off valve 61 and operates compressor 10 , whereby part of the refrigerant discharged from compressor 10 is guided to heating unit 20 and discharged from compressor 10 . Another part of the refrigerant is guided to the accumulator 30 from the refrigerant pipe L6 without passing through the heating unit 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 a 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 subcooling degree SC, which is the difference between the refrigerant temperature at point b and the refrigerant temperature at point b' shown in FIG. 11, becomes a predetermined value. The controller 90 calculates the supercooling degree 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 of points a, b, and c shown in FIG. 11, respectively. The specific enthalpy ha of the point a is calculated from the temperature detected by the temperature sensor 94 and the pressure detected by the pressure sensor 96 . The specific enthalpy hb of the point b is calculated from the temperature detected by the temperature sensor 95 and the pressure detected by the pressure sensor 96 . The specific enthalpy hc at the 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 .

At step S112, the controller 90 calculates the refrigerant circulation amount Gr1 in the refrigerant pipe L6. The refrigerant circulation amount Gr<b>1 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 controller 90 calculates the refrigerant circulation amount Gr2 in the refrigerant pipe L5. The refrigerant circulation amount Gr2 is calculated from the opening degree of the throttle 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.

In step S114, the control unit 90 determines whether or not the refrigerant pressure LP detected by the pressure sensor 92 exceeds a predetermined pressure. 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 aforementioned threshold pressure and predetermined as a pressure suitable for the hot gas heating operation.

At step S115, the controller 90 increases the opening of the throttle valve 50 so that (ha-hc)×Gr1>(hc-hb)×Gr2. By doing so, the ratio of the gaseous refrigerant in the inflowing refrigerant flowing into the accumulator 30 containing the refrigerant decompressed by the throttle valve 40 and the refrigerant decompressed by the throttle valve 50 is reduced to the outflowing refrigerant outflowing from the accumulator 30. It can be higher than the proportion of gas refrigerant.

In FIG. 11, by increasing the opening 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 brought closer to the point e than to the point d. Point d corresponds to the downstream side of throttle valve 40 and point e corresponds to the downstream side of throttle valve 50 .

By making the ratio of the gas refrigerant in the refrigerant flowing into the accumulator 30 higher than the ratio of the gas refrigerant in the refrigerant flowing out of the accumulator 30, the amount of liquid refrigerant stored in the accumulator 30 is reduced. As a result, the pressure of the refrigerant flowing into the compressor 10 increases as the amount of refrigerant flowing through the refrigerating cycle increases, and a decrease in the power of the compressor 10 can be suppressed.

In step S116, the controller 90 reduces the opening of the throttle valve 50 so that (ha-hc)×Gr1<(hc-hb)×Gr2. By doing so, the ratio of the liquid refrigerant in the inflowing refrigerant flowing into the accumulator 30 containing the refrigerant decompressed by the throttle valve 40 and the refrigerant decompressed by the throttle valve 50 is reduced to that in the outflowing refrigerant flowing out of the accumulator 30. It can be higher than the proportion of liquid refrigerant. In FIG. 11, by decreasing 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 brought closer to the point d than to the point e.

By making the ratio of the liquid refrigerant in the inflow refrigerant that flows into the accumulator 30 higher than the ratio of the liquid refrigerant in the outflow refrigerant that flows out from the accumulator 30, the liquid refrigerant stored in the accumulator 30 increases and the accumulator The proportion of liquid refrigerant contained in the refrigerant flowing out from 30 is reduced. As a result, the pressure of the refrigerant flowing into the compressor 10 decreases as the amount of refrigerant flowing through the refrigerating cycle decreases, and an increase in the torque of the compressor 10 can be suppressed.

In step S117, the control unit 90 determines whether or not an instruction to terminate the hot gas heating operation has been input, and if YES, terminates the processing of this flowchart. If NO, the process after step S110 is executed again.

In the hot gas heating operation described above, when the power of the compressor 10 is reduced, the controller 90 controls the opening of the throttle valve 40 ( first degree of opening) and the degree of opening of the throttle valve 50 (second degree of opening). Further, 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 (second opening) is controlled.

<Dehumidification and heating operation>
The operation of the vehicle air conditioner 100 according to the present embodiment during the dehumidifying and heating operation will be described with reference to FIG. 12 . FIG. 12 is a refrigerant circuit diagram showing the refrigerant flow during the dehumidifying and heating operation of the vehicle air conditioner 100. As shown in FIG.

Arrows shown in FIG. 12 indicate the flow direction of the refrigerant. As shown in FIG. 12, the refrigerant circulates through 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 in this order during the dehumidifying and heating operation. Refrigerant pipes L1, L2, L3, L4, L5a, L5b, L10, and L7 form a circulation flow path for circulating 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 dehumidification and heating operation, the controller 90 opens the on-off valve 64 and closes the on-off valves 61, 62, 63, and 65. FIG. 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 heating the air by the heating unit 20 while dehumidifying the moisture contained in the air. can do.

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

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 vehicle interior heat exchanger 85, the accumulator 30, and the compressor 10 in this order. Refrigerant pipes L1, L2, L11, L5b, L10, and L7 form a circulation flow path for circulating the refrigerant.

During cooling operation, the outdoor heat exchanger 80 operates as a condenser to condense the refrigerant and heat the outside air. During the cooling operation, the controller 90 opens the on-off valve 63 and closes the on-off valves 61, 62, 64, and 65. FIG. The controller 90 can drive the indoor blower 86 to blow the air cooled by the outdoor heat exchanger 80 into the vehicle interior.

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

According to the vehicle air conditioner 100 of the present embodiment, the first junction JP1 is 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. are placed in In a state in which the refrigerant flowing through the circulation flow path (upstream pipe L5a) is decompressed by the throttle valve 40 and becomes atomized and has an increased specific surface area, the high-temperature, high-pressure refrigerant is introduced 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 a stable heating capacity while preventing an increase in the size of the device and an increase in the 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 junction JP1, the air is guided from the bypass flow path to the circulation flow path. A swirling flow is formed in which the refrigerant is swirled around the central axis Z1 of the circulation flow path. Since the refrigerant guided from the bypass flow path to the circulation flow path becomes a swirling flow, the 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. The relative velocity between the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path increases compared to the case of less than 100 degrees, and the mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path further increases. Promoted.

According to the vehicle air conditioner 100 of the present embodiment, since the convex portion L5a2 is formed on the inner peripheral surface L5a1 of the circulation flow path at the first junction JP1, the refrigerant guided from the bypass flow path to the circulation flow path The flow of the coolant is disturbed when it collides with the inner peripheral surface L5a1 of the circulation flow path, and the turbulence promotes mixing of the refrigerant guided to 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 first junction JP1 is arranged in the first spray area SA1 within 10D from the bypass flow path. By merging the refrigerants, mixing of the refrigerant guided to the circulation flow path and the refrigerant guided from the bypass flow path 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 modified example of the first embodiment, and is assumed to be the same as the first embodiment except for the case where it will be particularly described below, and the description below will be omitted.

100 A of vehicle air conditioners of 1st Embodiment are the accumulator 30 side rather than the throttle valve 40 in the circulation flow path (refrigerant piping L1, L2, L3, L4, L5a, L8, L9, L7) at the time of hot gas heating operation. No other decompression mechanism was placed in the On the other hand, in the vehicle air conditioner 100A of the present embodiment, the orifice (third throttle mechanism) 41, which is a decompression mechanism, is arranged closer to the accumulator 30 than the throttle valve 40 in the circulation flow path during the hot gas heating operation. It is.

FIG. 14 is a refrigerant circuit diagram of a vehicle air conditioner 100A according to the second embodiment of the present disclosure. As shown in FIG. 14, a 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 of the circulation flow path (upstream pipe L5a, refrigerant pipe L8). The branch flow path is formed by branching a portion of the refrigerant from the bypass flow path (refrigerant pipe L6) at the branch portion BP, and connecting the circulation flow path (upstream pipe L5a, refrigerant pipe L8) to the accumulator 30 side of the first junction JP1. merges into the circulation flow path at the second junction JP2.

Here, the gas-liquid two-phase refrigerant that passes through the heating unit 20 and the throttle valve 40 and circulates in the circulation flow path (upstream side piping L5a, refrigerant piping L8) and the circulation flow path from the branch flow path (refrigerant piping L12) A description will be given of a configuration for favorably mixing the refrigerant with the gas-phase refrigerant that is led to. FIG. 15 is a cross-sectional view of the circulation channel, the bypass channel, and the branch channel in the vicinity of the first junction JP1 and the second junction JP2, as seen along the direction orthogonal to the central axis Z1 of the circulation channel. be. In FIG. 15, the vicinity of the first junction JP1 is the same as in the first embodiment, and thus the description thereof will be omitted.

As shown in FIG. 15, the second junction JP2 is on the side of the accumulator 30, which is downstream of the orifice 41 in the circulation flow path (the upstream pipe L5a and the refrigerant pipe L8) in the direction of refrigerant flow, and the orifice 41 flows the refrigerant. 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 decompressed 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 that forms the circulation flow path. The distance Dis2 from the orifice 41 along the central axis Z1 shown in FIG. 15 to the end of the second spray area SA2 is within 10D.

As shown in FIG. 15, when the circulation flow path (refrigerant pipe L8) is viewed from a predetermined direction perpendicular to the central axis Z1 at the second junction JP2, the central axis Z1 of the circulation flow path (refrigerant pipe L8) and the branch flow The angle α between the path (refrigerant pipe L12) and the central axis X2 is 90 degrees. Note that the angle α may be an angle other than 90 degrees, and is preferably set to any angle between 90 degrees and 180 degrees.

Although not shown, when the circulation flow path (refrigerant pipe L8) is viewed along the central axis Z1 at the second junction JP2, the bypass flow path (refrigerant pipe L6) is aligned with the central axis X1 of the bypass flow path for circulation. It is connected to the circulation channel so as not to intersect with the central axis Z1 of the channel.

The central axis Z1 of the circulation flow path (refrigerant pipe L8) shown in FIG. 15 is preferably arranged along the vertical direction at the second junction JP2. By arranging the central axis Z1 along the vertical direction, the refrigerant is not biased due to gravity in the circulation passage, and the refrigerant guided to the circulation passage and the refrigerant guided from the bypass passage are properly mixed. be done.

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

16 is a cross-sectional view of the circulation flow path shown in FIG. 15, taken along line BB. As shown in FIG. 16, the orifice 41 of this embodiment is a throttle mechanism in which a portion of the pipe forming the circulation flow passage (refrigerant pipe L8) has a smaller cross-sectional area than the other portion. The orifice 41 shown in FIG. 16 is a plate-shaped member that is annularly formed 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 modified example shown in FIG. FIG. 17 shows a first modification of the orifice 41 shown in FIG. 16. FIG. 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 the orifice 41 of the second modified example shown in FIG. FIG. 18 is a diagram showing a second modification of the orifice 41 shown in FIG. 16. As shown in FIG. The orifice 41 shown in FIG. 18 does not have an opening hole in the center, and has opening holes 41b smaller in diameter than the opening hole 41a at a plurality of locations other than the center.

As shown in FIGS. 16 to 18, the upstream pipe L5a of the present embodiment has a circular inner peripheral surface L8a without unevenness at the second junction JP2. . For example, at the second junction JP2, the inner peripheral surface L8a of the refrigerant pipe L8 may be uneven. 19 is a cross-sectional view of the circulation flow path shown in FIG. 15, taken along line CC.

As shown in FIG. 19, in the second junction JP2, convex portions L8b are formed at a plurality of locations along the circumferential direction around the central axis Z1 on the inner peripheral surface L8a of the circulation flow path (refrigerant pipe L8). . 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. Mixing of the refrigerant guided to the circulation channel and the refrigerant guided from the bypass channel is promoted. The convex portion L8b may be formed so as to extend parallel to the central axis Z1, or may be formed so as to spirally turn around the central axis Z1.

In the present embodiment, one branch flow path (refrigerant pipe L12) and one orifice 41 are provided in the vehicle air conditioner 100A, respectively. may further promote mixing. For example, one or more branching portions BP different from the branching portion BP shown in FIG. 14 are provided, branch flow paths are connected to the other branching portions BP, and circulation flow paths (refrigerant piping L8) are provided at a plurality of confluence portions. You may make it merge with . In this case, it is preferable to dispose the orifice 41 on each of the upstream sides of the plurality of confluence portions of the circulation flow path (refrigerant pipe L8).

In the present embodiment, the orifice 41 is arranged upstream of the second junction JP2 of the circulation flow path (refrigerant pipe L8). may be Even in a mode in which the orifice 41 is not arranged in the circulation flow path (refrigerant pipe L8), the circulation flow path (refrigerant pipe L8) is allowed to flow into the circulation flow channel (refrigerant pipe L8) from the branch flow channel (refrigerant pipe L12). can promote mixing of the refrigerant flowing through.

The operation and effects of the vehicle air conditioner 100A of the present embodiment described above will be described.
According to the vehicle air conditioner 100A of the present embodiment, the center axis X1 of the branch flow path (refrigerant pipe L12) and the center axis Z1 of the circulation flow channel (upstream pipe L5a) do not intersect at the second junction JP2. , the refrigerant guided from the branch flow path to the circulation flow path forms a swirl flow in which the refrigerant swirls around the central axis Z1 of the circulation flow path. Since the refrigerant guided from the branch flow path to the circulation flow path becomes a swirling flow, the mixture 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, 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. 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. be.

According to the vehicle air conditioner 100A of the present embodiment, since the first inflow direction ID1 and the second inflow direction ID2 face each other, the refrigerant flowing from the bypass channel in the first inflow direction ID1 forms a circulation channel. Even if the refrigerant is biased toward one side of the pipe in the radial direction, 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 peripheral surface L5a1 of the circulation flow path at the second junction JP2, the refrigerant guided from the branch flow path to the circulation flow path The flow of the coolant is disturbed when it collides with the inner peripheral surface L5a1 of the circulation flow path, and the turbulence accelerates the mixing of the refrigerant guided to the circulation flow path and the refrigerant guided from the branch flow path.

According to the vehicle air conditioner 100A of the present embodiment, since the central axis Z1 of the circulation passage is arranged along the vertical direction, the refrigerant is not biased due to gravity in the circulation passage. Mixing of the introduced refrigerant and the refrigerant introduced from the branch channel 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 second confluence portion JP2 is arranged in the second spray area SA2 within 10D from the branch flow path. By merging the refrigerants, mixing of the refrigerant guided to the circulation flow path and the refrigerant guided from the branch flow path is appropriately promoted.

For example, the air conditioner described in each embodiment described above is understood 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 liquid from the refrigerant sucked by the compressor, a circulation flow path (L5, L8, L7) that guides the refrigerant that has passed through the heating unit to the accumulator, and passes through the heating unit a bypass flow path (L6) for merging the refrigerant discharged from the compressor without allowing the refrigerant to merge at a first junction (JP1) of the circulation flow path (L5, L8, L7); a first throttle mechanism (40) for reducing the pressure of the refrigerant flowing out of the heating unit; a second throttle mechanism (50) arranged in the bypass flow path for reducing the pressure of the refrigerant discharged from the compressor; and the first merging portion is arranged in the first spraying area (SA1) of the refrigerant by the first throttle mechanism on the accumulator side of the circulation flow path with respect to the first throttle mechanism.

According to the air conditioner according to the first aspect of the present disclosure, part of the high-temperature, high-pressure refrigerant discharged from the compressor is supplied to the heating unit, and the heating target is heated by the heating unit. The refrigerant that has passed through the heating section is depressurized by the first throttle mechanism and guided to the accumulator through the circulation flow path. Further, another part of the high-temperature and high-pressure refrigerant discharged from the compressor is guided to the bypass channel and decompressed by the second throttle mechanism. The refrigerant decompressed by the second throttle mechanism joins the refrigerant flowing through the circulation flow path at the first junction and is led to the accumulator.

According to the air conditioner according to the first aspect of the present disclosure, the first merging portion is arranged on the accumulator side of the first throttle mechanism of the circulation flow path and in the first spray region of the refrigerant by the first throttle mechanism. Since the high-temperature and high-pressure refrigerant led from the bypass flow path joins the circulation flow path in a state where the refrigerant flowing through the circulation flow path is decompressed by the first throttle mechanism and atomized to increase the specific surface area, Mixing of the refrigerant flowing through the circulation channel and the refrigerant guided from the bypass channel is promoted. In addition, the air conditioner can exhibit a stable heating capability while preventing an increase in the size of the device and an increase in the 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) arranged closer to the accumulator than the first throttle mechanism of the circulation flow path.
According to the air conditioner according to the second aspect of the present disclosure, the refrigerant flowing through the circulation flow path is decompressed by the third throttle mechanism and becomes atomized. Therefore, it is possible to further promote the mixing of the refrigerant flowing into the third throttle mechanism and lead it to the accumulator.

An air conditioner according to a third aspect of the present disclosure, in the first aspect or the second aspect, further includes the following configuration. That is, a branch flow path is provided in which a part of the refrigerant is branched from the bypass flow path and joins the circulation flow path at a second junction on the accumulator side of the first junction of the circulation flow path.
According to the air conditioner according to the third aspect of the present disclosure, by allowing part of the refrigerant branched from the bypass flow path to join the circulation flow path at the second junction, the refrigerant flowing through the circulation flow path can be mixed. can be promoted.

An air conditioner according to a fourth aspect of the present disclosure, in the first aspect, further includes the following configuration. That is, a third throttling mechanism arranged closer to the accumulator than the first throttling mechanism of the circulation flow path; a branch flow path that joins the circulation flow path at a second confluence section on the accumulator side of the circulation flow path, and the second confluence section is closer to the accumulator than the third throttle mechanism of the circulation flow path, and It is arranged in the 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 confluence section is arranged in the second spray region of the refrigerant by the third throttle mechanism on the accumulator side of the circulation flow path and by the third throttle mechanism. In a state where the refrigerant flowing through the circulation channel is decompressed by the third throttling mechanism and atomized to increase the specific surface area, the high-temperature and 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.

An air conditioner according to a fifth aspect of the present disclosure, in the second aspect or the fourth aspect, further includes the following configuration. In other words, the third throttle mechanism is an orifice in which the cross-sectional area of a part of the piping forming the circulation flow path is made smaller than the other part.
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.

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

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

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

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

An air conditioner according to an eighth aspect of the present disclosure, in the first aspect or the second aspect, further includes the following configuration. That is, in the first junction, when the circulation channel is viewed from a predetermined direction perpendicular to the central axis of the circulation channel, the angle formed by the central axis of the circulation channel and the central axis of the bypass channel 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, the angle between the central axis of the circulation flow path and the central axis of the bypass flow path is 90 degrees or more and 180 degrees or less. The relative velocity between the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path increases compared to the case, and the mixing of the refrigerant flowing through the circulation flow path and the refrigerant guided from the bypass flow path is further promoted. .

An air conditioner according to a ninth aspect of the present disclosure, in the third aspect, further includes the following configuration. That is, when the circulation channel is viewed from a predetermined direction orthogonal to the central axis of the circulation channel in the second confluence portion, the angle formed by the central axis of the circulation channel and the central axis of the branch channel is The branch channel is connected to the circulation channel so as to be 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 formed by 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 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. .

An air conditioner according to a tenth aspect of the present disclosure, in the third aspect, further includes the following configuration. 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 into the circulation flow path at the first junction; A second inflow direction in which the refrigerant flows from the branch flow path to the circulation flow path is opposed at the second confluence 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 face each other, the refrigerant flowing from the bypass flow path in the first inflow direction forms a circulation flow path. , the deviation 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, in the first aspect or the second aspect, further includes the following configuration. 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 channel along the circumferential direction around the central axis of the circulation channel.

According to the air conditioner according to the eleventh aspect of the present disclosure, since the protrusion is formed on the inner peripheral surface of the circulation flow path at the first junction, the refrigerant guided from the bypass flow path to the circulation flow path circulates. The flow of the coolant is disturbed when it collides with the inner peripheral surface of the passage, and this turbulence promotes mixing of the refrigerant guided to the circulation flow path and the refrigerant guided from the bypass flow path.

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

According to the air conditioner according to the twelfth aspect of the present disclosure, since the convex portion is formed on the inner peripheral surface of the circulation flow path at the second junction, the refrigerant guided from the branch flow path to the circulation flow path circulates. When the coolant collides with the inner peripheral surface of the passage, the flow of the coolant is disturbed, and this turbulence promotes the mixing of the coolant led to the circulation channel and the coolant led from the branch channel.

The air conditioner according to the thirteenth aspect of the present disclosure, in the first aspect or the second aspect, further includes the following configuration. That is, in the first confluence portion, 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 introduced refrigerant and the refrigerant introduced from the bypass channel is appropriately promoted.

An air conditioner according to a fourteenth aspect of the present disclosure, in the third aspect, further includes the following configuration. That is, in the second confluence portion, 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. Mixing of the introduced refrigerant and the refrigerant introduced from the branch channel is appropriately promoted.

The air conditioner according to the fifteenth aspect of the present disclosure, in the first aspect or the second aspect, further includes the following configuration. 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 joining the refrigerant from the bypass flow path at the first confluence portion disposed in the first spray area within 10D from the first throttle mechanism, the circulation flow path is Mixing of the introduced refrigerant and the refrigerant introduced from the bypass channel is appropriately promoted.

In the fourth aspect, the air conditioner according to the sixteenth aspect of the present disclosure further includes the following configuration. 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 joining the refrigerant from the branch flow path at the second confluence portion disposed in the second spray area within 10D from the third throttle mechanism, the circulation flow path is Mixing of the introduced refrigerant and the refrigerant introduced from the branch channel is appropriately promoted.

10 compressor 20 heating unit 30 accumulator 40 throttle valve (first throttle mechanism)
41 orifice (third throttle mechanism)
41a, 41b opening hole 50 throttle valves 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 conditioners Dis1, Dis2 distances Gr1, Gr2 refrigerant circulation amount ID1 first inflow direction ID2 second inflow direction JP1 First Junction JP2 Second Junction L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, L12 Refrigerant Pipe L5a Upstream Pipe L5a1 Inner Peripheral Surface L5a2 Projection L5b Downstream Pipe SA1 First spray area SA2 Second spray area SC Degree of supercooling X1, X2, Z1 Central axis ha, hb, hc Specific enthalpy θ, α Angle

Claims (16)

a compressor that compresses a refrigerant;
a heating unit that heats an object to be heated with the refrigerant discharged from the compressor;
an accumulator that separates liquid from 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 joins the refrigerant discharged from the compressor without passing through the heating section at a first junction of the circulation flow path;
a first throttle mechanism arranged in the circulation flow path and decompressing the refrigerant flowing out from the heating unit;
a second throttle mechanism arranged in the bypass flow path for decompressing the refrigerant discharged from the compressor,
The air conditioner, wherein the first merging portion is arranged in the accumulator side of the circulation flow path with respect to the first throttle mechanism and in a first spray region of the refrigerant by the first throttle mechanism. 2. The air conditioner according to claim 1, further comprising a third throttle mechanism disposed closer to said accumulator than said first throttle mechanism of said circulation passage. 2. A branch flow path is provided for branching a portion of the refrigerant from the bypass flow path and joining the circulation flow path at a second confluence section closer to the accumulator than the first confluence section of the circulation flow path. Or the air conditioner of Claim 2. a third throttle mechanism arranged closer to the accumulator than the first throttle mechanism of 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 junction on the accumulator side of the circulation flow path rather than the first junction,
2. The air conditioner according to claim 1, wherein the second confluence portion is arranged in the circulation passage on the side of the accumulator from the third throttle mechanism and in a second spray area of the refrigerant by the third throttle mechanism. 5. The air conditioner according to claim 2, wherein said third throttle mechanism is an orifice in which a passage cross-sectional area of a portion of said piping forming said circulation passage is reduced more than the other portions. 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 does not intersect the central axis of the bypass flow path and the central axis of the circulation flow path. 3. The air conditioner according to claim 1, wherein the air conditioner is connected to the circulation flow path in such a manner as to. In the second junction, when the circulation channel is viewed along the central axis of the circulation channel, the branch channel does not intersect the central axis of the bypass channel and the central axis of the circulation channel. 4. The air conditioner according to claim 3, wherein the air conditioner is connected to the circulation flow path in such a manner. In the first confluence portion, when the circulation channel is viewed from a predetermined direction orthogonal to the central axis of the circulation channel, the angle formed by the central axis of the circulation channel and the central axis of the bypass channel is 90 degrees. 3. The air conditioner according to claim 1, wherein the bypass flow path is connected to the circulation flow path so as to be 180 degrees or more and 180 degrees or less. In the second junction, when the circulation channel is viewed from a predetermined direction orthogonal to the central axis of the circulation channel, the angle formed by the central axis of the circulation channel and the central axis of the branch channel is 90 degrees. 4. The air conditioner according to claim 3, wherein said branch flow path is connected to said circulation flow path so as to be 180 degrees or more. 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 into the circulation flow path at the first junction; 4. The air conditioner according to claim 3, wherein a second inflow direction in which the refrigerant flows from the branch flow path to the circulation flow path is opposite to each other at the two confluence portions. 3. The method according to claim 1, 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 the circumferential direction around the central axis of the circulation flow path. air conditioner. 4. The air conditioner 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 the circumferential direction around the central axis of the circulation flow path. 3. The air conditioner according to claim 1, wherein in said first confluence portion, the central axis of said circulation flow path is arranged along the vertical direction. 4. The air conditioner according to claim 3, wherein the center axis of the circulation flow path is arranged along the vertical direction in the second junction. 3. The air conditioner according to claim 1, wherein 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. 5. 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 pipe forming the circulation flow path.

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