JP2019100644A - Refrigeration cycle device - Google Patents

Abstract

To provide a refrigeration cycle device improved in degree of freedom of a loading position of a charging port without degrading durability of an evaporation pressure regulation valve.SOLUTION: A refrigeration cycle device 10 includes an outdoor evaporator 16 exchanging heat between a refrigerant flowing out of a condenser 12 and cooling water, an indoor evaporator 18 exchanging heat between a refrigerant flowing out of the outdoor evaporator 16 and outside air, an evaporation pressure regulation valve 19 disposed on a refrigerant outlet side of the indoor evaporator 18 to regulate the refrigerant evaporation pressure in the indoor evaporator 18, a low pressure-side charging port 23 disposed on a downstream side of the evaporation pressure regulation valve 19 for charging the refrigerant, and an accumulator 20 disposed between the evaporation pressure regulation valve 19 and the low pressure-side charging port 23 to exert a role to suppress sudden fluctuation of an interna pressure in charging the refrigerant from the low-pressure charging port 23.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a refrigeration cycle apparatus.

  Patent Document 1 includes a compressor, an outdoor evaporator, and an indoor evaporator, and has a function of adjusting the refrigerant evaporation pressure in the indoor evaporator to a frosting suppression pressure or more in order to suppress frost formation in the indoor evaporator. A refrigeration cycle apparatus equipped with an evaporating pressure control valve is disclosed. The evaporation pressure control valve regulates the valve opening degree by a mechanical mechanism.

  In such a refrigeration cycle apparatus, on the downstream side of the compressor, a charging port on the high pressure side for charging the refrigerant before shipment is disposed, and on the downstream side of the low pressure side evaporator, the refrigerant is charged after shipment. The low-side charging port for this purpose is arranged.

JP, 2012-225637, A

  Here, the evaporation pressure control valve of the refrigeration cycle apparatus of Patent Document 1 is configured to change the valve opening degree by the pressure difference between the refrigerant pressure on the upstream side and the refrigerant pressure on the downstream side. Furthermore, when the refrigerant pressure on the downstream side of the evaporation pressure control valve becomes higher than the refrigerant pressure on the upstream side of the evaporation pressure adjustment valve and the reverse pressure acts on the evaporation pressure adjustment valve, the evaporation pressure adjustment valve is durable There is a risk of deterioration. For this reason, the charging port on the low pressure side is generally disposed upstream of the evaporation pressure control valve.

  As described above, it is difficult to arrange the charging port on the low pressure side downstream of the evaporating pressure regulating valve, and the degree of freedom of the mounting position of the charging port on the low pressure side is limited. For this reason, even if the charging port on the low pressure side is disposed downstream of the evaporation pressure control valve, a refrigeration cycle apparatus that does not deteriorate the durability of the evaporation pressure control valve has been desired.

  An object of the present invention is to provide a refrigeration cycle apparatus in which the degree of freedom of the mounting position of the charging port is improved without deteriorating the durability of the evaporation pressure control valve.

  In order to achieve the above object, the refrigeration cycle apparatus according to claim 1 is a heat exchange target fluid by using a compressor (11) for compressing and discharging a refrigerant and a refrigerant discharged from the compressor (11) as a heat source Heating unit (25) for heating the outdoor evaporator (16) for heat exchange between the refrigerant flowing out of the heating unit and the outside air, and indoor evaporation for heat exchange between the refrigerant flowing out of the outdoor evaporator and the heat exchange target fluid (18), a first refrigerant passage (14a) for guiding the refrigerant flowing out of the heating unit to the inlet side of the outdoor evaporator, and a first refrigerant passage, the opening area of the first refrigerant passage can be changed 1 Decompression unit (15a), a second refrigerant passage (14b) for guiding the refrigerant flowing out of the outdoor evaporator to the suction side of the compressor via the indoor evaporator, and an outdoor evaporator and indoor evaporation in the second refrigerant passage Between the second refrigerant passage and the Potential pressure reducing portion (15b), an evaporation pressure regulating valve (19) disposed downstream of the indoor evaporator in the second refrigerant passage and adjusting the refrigerant evaporation pressure in the indoor evaporator, and the evaporation pressure at the end Opening and closing the third refrigerant passage (14c) connected to the second refrigerant passage between the adjustment valve and the compressor and leading the refrigerant flowing out of the outdoor evaporator to the suction side of the compressor, and opening and closing the third refrigerant passage Part (21), a charging port (23) disposed downstream of the evaporation pressure control valve in the second refrigerant passage, for charging the refrigerant, and the evaporation pressure control valve and charging in the second refrigerant passage Pressure fluctuation suppressing portion disposed between the port and the buffer space (20a, 51a) which is a space for suppressing a rapid fluctuation of the internal pressure of the second refrigerant passage when the refrigerant from the charging port is charged (20, 51, 52) It has a.

  According to this, since the pressure fluctuation suppressing portion is provided, when the refrigerant is charged from the charging port to the refrigeration cycle apparatus, the rapid fluctuation of the internal pressure of the second refrigerant passage in which the evaporation pressure adjusting valve is disposed is suppressed. be able to. For this reason, pressure fluctuation on the outlet side of the evaporating pressure regulating valve can be suppressed. Therefore, even if the charging port is disposed on the downstream side of the evaporation pressure control valve, the deterioration of the durability of the evaporation pressure control valve can be suppressed.

  That is, according to the first aspect of the present invention, the degree of freedom of the mounting position of the charging port can be improved without deteriorating the durability of the evaporation pressure control valve.

  In addition, the code | symbol in the parenthesis of each means described by this column and the claim is an example which shows the correspondence with the specific means as described in embodiment mentioned later.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the air conditioner provided with the refrigerating-cycle apparatus which concerns on 1st Embodiment. It is a whole block diagram of the air conditioner provided with the refrigerating-cycle apparatus which concerns on 2nd Embodiment. It is a whole block diagram of the air conditioner provided with the refrigerating-cycle apparatus which concerns on 3rd Embodiment.

First Embodiment
An air conditioner 1 provided with the refrigeration cycle apparatus 10 of the first embodiment will be described using FIG. 1. The air conditioner 1 includes a refrigeration cycle apparatus 10, a heating unit 25, and an indoor air conditioning unit 30. In the present embodiment, the refrigeration cycle apparatus 10 according to the present invention is applied to an air conditioner 1 for a vehicle mounted on an electric vehicle which obtains driving force for traveling the vehicle from a traveling electric motor. The refrigeration cycle apparatus 10 has a function of cooling or heating the air which is blown into the vehicle compartment, which is the space to be air conditioned, in the air conditioner 1. Therefore, the heat exchange target fluid of this embodiment is blowing air.

  The refrigeration cycle apparatus 10 is configured to be able to switch between a refrigerant circuit in the heating mode, a refrigerant circuit in the cooling mode, a refrigerant circuit in the series dehumidifying heating mode, and a refrigerant circuit in the parallel dehumidifying heating mode.

  In the air conditioner 1, the heating mode is an operation mode in which the blowing air is heated and blown out to a vehicle compartment which is a space to be air conditioned. The series dehumidifying and heating mode and the parallel dehumidifying and heating mode are operation modes for reheating the cooled and dehumidified blowing air and blowing it out to a vehicle compartment which is an air conditioning target space. The cooling mode is an operation mode in which the blowing air is cooled and blown out to a vehicle compartment which is a space to be air conditioned.

  In FIG. 1, the flow of the refrigerant in the refrigerant circuit in the heating mode is indicated by a solid arrow, the flow of the refrigerant in the refrigerant circuit in the parallel dehumidifying heating mode is indicated by a hatched hatched arrow, and the series dehumidification mode and the cooling mode are further provided. The flow of the refrigerant in the refrigerant circuit is indicated by a white arrow.

  In the refrigeration cycle apparatus 10, a HFC refrigerant (specifically, R134a) is employed as the refrigerant, and the vapor compression subcritical refrigeration cycle in which the high-pressure refrigerant pressure Pd does not exceed the critical pressure of the refrigerant is used. Configured. Of course, an HFO-based refrigerant (for example, R1234yf) or the like may be adopted as the refrigerant. Furthermore, the refrigeration oil for lubricating the compressor 11 is mixed in the refrigerant, and a part of the refrigeration oil circulates the cycle together with the refrigerant.

  The refrigeration cycle apparatus 10 includes a compressor 11, a condenser 12, a first pressure reducing valve 15a (first pressure reducing unit), a second pressure reducing valve 15b, an outdoor evaporator 16, a check valve 17, an indoor evaporator 18, and an evaporation pressure adjustment. A valve 19, an accumulator 20 (pressure fluctuation suppression unit), a first open / close valve 21 (open / close unit), a second open / close valve 22, a low pressure side charging port 23, and a high pressure side charging port 24 are provided.

  The compressor 11 sucks, compresses and discharges the refrigerant in the refrigeration cycle apparatus 10. The compressor 11 is disposed in the hood of the vehicle. The compressor 11 is configured as an electric compressor that drives, by an electric motor, a fixed displacement type compression mechanism whose discharge displacement is fixed. As this compression mechanism, various compression mechanisms such as a scroll-type compression mechanism and a vane-type compression mechanism can be adopted.

  The operation (rotational speed) of the electric motor is controlled by a control signal output from the air conditioning control device, and either type of AC motor or DC motor may be adopted. Then, the refrigerant discharge capacity of the compression mechanism is changed by the air conditioning control device controlling the number of rotations of the electric motor.

  The refrigerant inlet side of the condenser 12 is connected to the discharge port of the compressor 11. The condenser 12 heats the cooling water by heat exchange between the high-temperature high-pressure discharge refrigerant discharged from the compressor 11 and the cooling water that is the heat exchange fluid flowing through the heating unit 25 at least in the heating mode. Heat exchanger. The high pressure refrigerant condenses when the heat of the high pressure refrigerant is dissipated to the cooling water.

  The heating unit 25 includes a condenser 12, a cooling water circulation circuit 26, a heater core 27, and a cooling water pump 28. The heating unit 25 heats the blown air, which is a heat exchange fluid, using the high-pressure refrigerant discharged from the compressor 11 as a heat source.

  As the cooling water flowing in the cooling water circulation circuit 26, a liquid containing at least ethylene glycol, dimethylpolysiloxane or a nanofluid, or an antifreeze liquid is used.

  The cooling water circulation circuit 26 is an annular flow path for circulating the cooling water between the condenser 12 and the heater core 27. In the cooling water circulation circuit 26, the condenser 12, the heater core 27, and the cooling water pump 28 are arranged in this order.

  The cooling water pump 28 circulates the cooling water in the cooling water circulation circuit 26 by sucking the cooling water and discharging it to the condenser 12 side. The cooling water pump 28 is an electric pump, and is a cooling water flow rate adjustment unit that adjusts the flow rate of the cooling water circulating in the cooling water circulation circuit 26.

  The heater core 27 is disposed in a casing 31 described later. The heater core 27 heats the blowing air by heat exchange between the cooling water heated by the condenser 12 and the blowing air which is a fluid for heat exchange. Thus, the condenser 12 heats the blowing air through the heater core 27.

  One inlet / outlet side of the first three-way joint 13 a is connected to the refrigerant outlet of the condenser 12. Such a three-way joint may be formed by joining a plurality of pipes, or may be formed by providing a plurality of refrigerant passages in a metal block or a resin block. Furthermore, in the refrigeration cycle apparatus 10, second to fourth three-way joints 13b to 13d are provided as described later. The basic configuration of the second to fourth three-way joints 13b to 13d is the same as that of the first three-way joint 13a.

  These three-way joints function as branches or junctions. For example, in the first three-way joint 13a in the parallel dehumidifying and heating mode, one of the three inlets and outlets is used as an inlet, and the remaining two are used as outlets. Therefore, the first three-way joint 13a in the parallel dehumidifying and heating mode functions as a branch unit that branches the flow of the refrigerant flowing from one inlet and flows out from the two outlets.

  Also, for example, in the fourth three-way joint 13d in the parallel dehumidifying and heating mode, two of the three inflows and outlets are used as an inlet, and the remaining one is used as an outlet. Therefore, the fourth three-way joint 13d in the parallel dehumidifying and heating mode functions as a joining portion which joins the refrigerants flowing from the two inlets and causes the refrigerant to flow out from one outlet.

  A first refrigerant passage 14a for guiding the refrigerant flowing out of the condenser 12 to the refrigerant inlet side of the outdoor evaporator 16 is connected to another inflow / outlet of the first three-way joint 13a. Further, at the other inflow / outlet of the first three-way joint 13a, the inlet side of the second pressure reducing valve 15b disposed in the second refrigerant passage 14b described later (specifically, A fourth refrigerant passage 14d leading to one inflow / outlet of the third three-way joint 13c is connected.

  A first pressure reducing valve 15a is disposed in the first refrigerant passage 14a. The first pressure reducing valve 15 a is a first pressure reducing portion capable of changing the opening area of the first refrigerant passage 14 a and reducing the pressure of the refrigerant flowing out of the condenser 12 at least in the heating mode. The first pressure reducing valve 15a is a variable throttle mechanism having a valve body configured to be able to change the throttle opening degree, and an electric actuator including a stepping motor that changes the throttle opening degree of the valve body.

  Furthermore, the first pressure reducing valve 15a is configured as a variable throttle mechanism with a fully open function that functions as a simple refrigerant passage without exerting the refrigerant pressure reducing function by fully opening the throttle opening degree. The operation of the first pressure reducing valve 15a is controlled by a control signal (control pulse) output from the air conditioning controller.

  The refrigerant inlet side of the outdoor evaporator 16 is connected to the outlet side of the first pressure reducing valve 15a. The outdoor evaporator 16 exchanges heat between the refrigerant flowing out of the first pressure reducing valve 15a (the condenser 12) and the outside air blown from a blowing fan (not shown). The outdoor evaporator 16 is disposed on the front side of the vehicle in the vehicle bonnet. The blower fan is an electric blower whose rotational speed (blowing capacity) is controlled by a control voltage output from the air conditioning control device.

  The second refrigerant passage 14 b is connected to the refrigerant outlet side of the outdoor evaporator 16. The second refrigerant passage 14 b is a passage that leads the refrigerant flowing out of the outdoor evaporator 16 to the suction side of the compressor 11 via the indoor evaporator 18. In the second refrigerant passage 14b, the second three-way joint 13b, the check valve 17, the third three-way joint 13c, and the second pressure reducing valve 15b, the indoor evaporator 18, the evaporation pressure adjusting valve 19, the fourth three-way joint 13d, and the accumulator 20 and the low pressure side charging port 23 are arranged in this order with respect to the refrigerant flow. The end of the second refrigerant passage 14 b is connected to the suction port of the compressor 11.

  The third refrigerant that guides the refrigerant that has flowed out of the outdoor evaporator 16 to the inlet side of the accumulator 20 (specifically, one inlet / outlet of the fourth three-way joint 13d) to the inlet / outlet of the second three-way joint 13b The passage 14c is connected. The fourth refrigerant passage 14d described above is connected to the third three-way joint 13c.

  The check valve 17 only allows the refrigerant to flow from the second three-way joint 13 b side (outside evaporator 16 side) to the indoor evaporator 18 side.

  The second pressure reducing valve 15 b is disposed between the outdoor evaporator 16 and the indoor evaporator 18 in the second refrigerant passage 14 b. In the present embodiment, the second pressure reducing valve 15 b is disposed between the third three-way joint 13 c and the indoor evaporator 18 in the second refrigerant passage 14 b. The second pressure reducing valve 15 b is a second pressure reducing portion capable of changing the opening area of the second refrigerant passage 14 b and reducing the pressure of the refrigerant flowing out of the outdoor evaporator 16 and flowing into the indoor evaporator 18. The basic configuration of the second pressure reducing valve 15b is the same as that of the first pressure reducing valve 15a. Furthermore, the second pressure reducing valve 15b of the present embodiment is configured by a variable throttle mechanism with a fully closing function that closes the refrigerant passage when the throttle opening degree is fully closed.

  Therefore, in the refrigeration cycle apparatus 10 of the present embodiment, the refrigerant circuit can be switched by fully closing the second pressure reducing valve 15b and closing the second refrigerant passage 14b. In other words, the second pressure reducing valve 15b has a function as a refrigerant pressure reducing unit and also has a function as a refrigerant circuit switching device that switches the refrigerant circuit of the refrigerant circulating in the cycle.

  The indoor evaporator 18 is in the cooling mode, in the series dehumidifying and heating mode, and in the parallel dehumidifying and heating mode, before the heater core 27 which is a heat exchange fluid with the refrigerant flowing out from the second pressure reducing valve 15b (outdoor evaporator 16). It is a heat exchanger for cooling which exchanges heat with air. In the indoor evaporator 18, the blown air is cooled by evaporating the refrigerant decompressed by the second pressure reducing valve 15b to exhibit an endothermic effect. The indoor evaporator 18 is disposed in the casing 31 of the indoor air conditioning unit 30 on the upstream side of the air flow of the heater core 27.

  The inlet side of the evaporating pressure adjusting valve 19 is connected to the second refrigerant passage 14 b on the refrigerant outlet side of the indoor evaporator 18. The evaporation pressure control valve 19 has a function of adjusting the refrigerant evaporation pressure Pe in the indoor evaporator 18 to be equal to or higher than the frost formation suppression pressure APe in order to suppress frost formation of the indoor evaporator 18. In other words, the evaporation pressure control valve 19 functions to adjust the refrigerant evaporation temperature Te in the indoor evaporator 18 to the frost formation suppression temperature ATe or more.

  In the present embodiment, R134a is employed as the refrigerant, and the frost formation suppression temperature ATe is set to a value slightly higher than 0 ° C. Therefore, the frost formation suppression pressure APe is set to a value slightly higher than 0.293 MPa, which is the saturation pressure of R134a at 0 ° C.

  A fourth three-way joint 13 d is connected to the second refrigerant passage 14 b on the outlet side of the evaporation pressure adjusting valve 19. The third refrigerant passage 14c described above is connected to the fourth three-way joint 13d. That is, the terminal end of the third refrigerant passage 14c is connected to the fourth three-way joint 13d which is a joining portion disposed in the second refrigerant passage 14b between the evaporation pressure adjusting valve 19 and the compressor 11.

  The inlet side of the accumulator 20 is connected to still another inflow / outlet of the fourth three-way joint 13d. That is, the accumulator 20 is disposed between the evaporation pressure control valve 19 and the low pressure side charging port 23 in the second refrigerant passage 14b. In the present embodiment, the accumulator 20 is provided on the downstream side of the fourth three-way joint 13d, which is a junction portion of the third refrigerant passage 14c with the second refrigerant passage 14b.

  The accumulator 20 has a buffer space 20a formed therein. The accumulator 20 is a gas-liquid separator that separates the gas and liquid of the refrigerant that has flowed into the inside in the buffer space 20a and stores the surplus refrigerant in the cycle. As described above, the buffer space 20 a of the accumulator 20 also functions as a liquid storage unit that stores the excess refrigerant in the cycle.

  The volume of the flow path between the low pressure side charging port 23 and the evaporation pressure control valve 19 is increased by the buffer space 20 a of the accumulator 20 as compared with the case where the buffer space 20 a is not provided. Therefore, the buffer space 20a of the accumulator 20 has a function as a pressure fluctuation suppressing portion that suppresses a rapid fluctuation of the internal pressure of the second refrigerant passage 14b when the refrigerant is charged into the refrigeration cycle apparatus 10 from the low pressure side charging port 23. Play.

  The suction port side of the compressor 11 is connected to the gas phase refrigerant outlet of the accumulator 20. Therefore, the accumulator 20 suppresses the suction of the liquid-phase refrigerant into the compressor 11 and functions to prevent the liquid compression in the compressor 11.

  A first on-off valve 21 is disposed in a third refrigerant passage 14c connecting the second three-way joint 13b and the fourth three-way joint 13d. The first on-off valve 21 is an electromagnetic valve as a refrigerant circuit switching device that switches the refrigerant circuit that circulates the refrigerant by opening and closing the third refrigerant passage 14c. The first open / close valve 21 is an open / close unit whose operation is controlled by a control signal output from the air conditioning control device.

  A second on-off valve 22 is disposed in a fourth refrigerant passage 14d that connects the first three-way joint 13a and the third three-way joint 13c. The second on-off valve 22 is an electromagnetic valve as a refrigerant circuit switching device that switches the refrigerant circuit that circulates the refrigerant by opening and closing the fourth refrigerant passage 14d. The basic configuration of the second on-off valve 22 is the same as that of the first on-off valve 21.

  The low pressure side charging port 23 is disposed in the second refrigerant passage 14 b downstream of the evaporating pressure adjusting valve 19. In the present embodiment, the low pressure side charging port 23 is disposed between the accumulator 20 and the compressor 11 in the second refrigerant passage 14 b. The low pressure side charging port 23 is for charging the refrigerant into the refrigeration cycle apparatus 10 while operating the compressor 11 after the vehicle (the refrigeration cycle apparatus 10) is shipped.

  The high pressure side charging port 24 is disposed in the first refrigerant passage 14 a downstream of the condenser 12. In the present embodiment, the high pressure side charging port 24 is disposed in the first refrigerant passage 14a between the first three-way joint 13a and the first pressure reducing valve 15a. The high pressure side charging port 24 is for charging the refrigerant into the refrigeration cycle apparatus 10 before shipment of the vehicle (refrigeration cycle apparatus 10).

  Next, the indoor air conditioning unit 30 will be described. The indoor air conditioning unit 30 is for blowing out the blowing air whose temperature has been adjusted by the refrigeration cycle apparatus 10 into the vehicle interior which is the space to be air conditioned. The indoor air conditioning unit 30 is disposed inside the instrument panel at the foremost part of the vehicle interior. The indoor air conditioning unit 30 is configured by housing a blower 32, an indoor evaporator 18, and a heater core 27 in a casing 31 forming the outer shell thereof.

  The casing 31 is an air passage forming portion that forms an air passage for blowing air blown into a vehicle compartment, which is a space to be air conditioned. The casing 31 has a certain degree of elasticity and is molded of a resin (for example, polypropylene) which is excellent in strength. Inside / outside air switching as an inside / outside air switching unit to switch and introduce inside air (air in the air conditioning target space) and outside air (air outside the air conditioning target space) into the casing 31 on the most upstream side of the blown air flow in the casing 31 A device 33 is arranged.

  An air blower (blower) 32 for blowing the air taken in through the inside / outside air switching device 33 into the space to be air-conditioned is disposed downstream of the air flow of the inside / outside air switching device 33. The blower 32 is an electric blower that drives a centrifugal multi-blade fan (sirocco fan) by an electric motor, and the number of rotations (air flow amount) is controlled by a control voltage output from the air conditioning control device.

  An indoor evaporator 18 is disposed downstream of the air flow of the blower 32 in the air passage formed in the casing 31. Furthermore, the downstream side of the indoor evaporator 18 of the air passage formed in the casing 31 is bifurcated, and the indoor condenser passage 35 and the cold air bypass passage 36 are formed in parallel.

  A heater core 27 is disposed in the indoor condenser flow passage 35. That is, the indoor condenser flow passage 35 is a flow passage through which the blown air which exchanges heat with the refrigerant in the heater core 27 flows. The indoor evaporator 18 and the heater core 27 are disposed in this order with respect to the blowing air flow. In other words, the indoor evaporator 18 is disposed upstream of the heater core 27 in the flow of the blown air.

  The cold air bypass passage 36 is a flow passage for flowing the blown air, which has passed through the indoor evaporator 18, to the downstream side by bypassing the heater core 27.

  On the downstream side of the blown air flow of the indoor evaporator 18 and on the upstream side of the blown air flow of the heater core 27, a heater core of the blown air after passing through the indoor evaporator 18 by the control signal output from the air conditioning control device An air mix door 34 is arranged to adjust the air volume ratio for passing 27.

  A mixing channel 37 is formed in the casing 31 on the downstream side of the merging portion of the indoor condenser channel 35 and the cold air bypass passage 36. In the mixing flow path 37, the blowing air heated by the heater core 27 and the blowing air not passing through the cold air bypass passage 36 and not heated by the heater core 27 are mixed.

  Furthermore, a plurality of opening holes are disposed at the most downstream portion of the air flow of the casing 31 for blowing the air (air-conditioned air) mixed in the mixing flow path 37 into the vehicle compartment which is the air conditioning target space. There is.

  The temperature of the conditioned air mixed in the mixing channel 37 is adjusted by adjusting the ratio of the air volume ratio of the air volume passing through the heater core 27 to the air volume passing through the cold air bypass passage 36 by the air mix door 34. The temperature of the conditioned air blown out from the opening hole into the vehicle compartment which is the space to be conditioned is adjusted.

  That is, the air mix door 34 functions as a temperature control unit that adjusts the temperature of the conditioned air blown into the vehicle compartment, which is the space to be conditioned. The air mix door 34 is driven by an electric actuator for driving the air mix door. The operation of the electric actuator is controlled by a control signal output from the air conditioning controller.

  Further, the air mix door 34 switches to a flow path in which the blowing air flows in the order of the indoor evaporator 18 → the heater core 27 in the heating mode, in the series dehumidifying heating mode, and in the parallel dehumidifying heating mode. It plays a role as an air passage switching device which switches the flow to the flow passage to the indoor evaporator 18 by bypassing the heater core 27.

  Next, the operation of the air conditioner 1 of the present embodiment will be described. In the air conditioner 1 of the present embodiment, the operation of the heating mode, the cooling mode, the series dehumidifying heating mode, and the parallel dehumidifying heating mode can be switched. The switching of each operation mode is performed by executing an air conditioning control program stored in advance in the air conditioning control device.

(A) Heating mode In the heating mode, the air conditioning control device opens the first on-off valve 21 and closes the second on-off valve 22 to place the first pressure reducing valve 15a in the throttling state for exerting the pressure reducing function. Is completely closed.

  Thus, in the heating mode, as shown by the solid arrows in FIG. 1, the compressor 11 → the condenser 12 → the first pressure reducing valve 15a → the outdoor evaporator 16 → (the first on-off valve 21 →) the accumulator 20 → the compressor A vapor compression refrigeration cycle in which the refrigerant is circulated in the order of 11 is configured.

  In this cycle configuration, the air conditioning control device appropriately controls the operation of various air conditioning devices connected to the output side. For example, as for the control signal output from the air conditioning controller to the electric actuator for driving the air mix door, the air mix door 34 fully closes the cold air bypass passage 36 and the total flow rate of the blown air after passing through the indoor evaporator 18 is It is determined to pass through the air passage on the heater core 27 side.

Therefore, in the refrigeration cycle apparatus 10 in the heating mode, the high pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The refrigerant flowing into the condenser 12 exchanges heat with the cooling water flowing in the cooling water circulation circuit 26 and radiates heat. As a result, the cooling water flowing in the cooling water circulation circuit 26 is heated. Since the air mix door 34 opens the air passage on the heater core 27 side,
The air blown from the blower 32 and passed through the indoor evaporator 18 is heated by the heater core 27.

  Since the second on-off valve 22 is closed, the refrigerant flowing out of the condenser 12 flows out from the first three-way joint 13a to the first refrigerant passage 14a side and is decompressed until it becomes a low pressure refrigerant by the first pressure reducing valve 15a. Ru. Then, the low-pressure refrigerant reduced in pressure by the first pressure reducing valve 15a flows into the outdoor evaporator 16 and absorbs heat from the outside air blown from the blower fan.

  The refrigerant flowing out of the outdoor evaporator 16 flows out from the second three-way joint 13b to the third refrigerant passage 14c because the first on-off valve 21 is open and the second pressure reducing valve 15b is fully closed. It flows into the accumulator 20 through the four-way joint 13d and is separated into gas and liquid. Then, the gas phase refrigerant separated by the accumulator 20 is sucked from the suction side of the compressor 11 and compressed by the compressor 11 again.

  Therefore, in the heating mode, heating the vehicle interior can be performed by blowing the blown air heated by the condenser 12 into the vehicle interior which is the space to be air conditioned.

(B) Cooling mode In the cooling mode, the air conditioning control device closes the first on-off valve 21 and closes the second on-off valve 22 to fully open the first pressure reducing valve 15a and to narrow the second pressure reducing valve 15b. .

  Thus, in the cooling mode, as shown by the white arrow in FIG. 1, the compressor 11 → the condenser 12 → (the first pressure reducing valve 15a →) the outdoor evaporator 16 → (the check valve 17 →) the second pressure reducing valve A vapor compression type refrigeration cycle in which the refrigerant is circulated in the order of 15b → indoor evaporator 18 → evaporation pressure control valve 19 → accumulator 20 → compressor 11 is configured.

  In this cycle configuration, the air conditioning control device appropriately controls the operation of various air conditioning devices connected to the output side. For example, with regard to the control signal output from the air conditioning control device to the electric actuator for driving the air mix door, the air mix door 34 makes the cold air bypass passage 36 fully open, and the total flow of the blown air after passing through the indoor evaporator 18 is cold air. It is decided to pass the bypass passage 36.

  Therefore, in the refrigeration cycle apparatus 10 in the cooling mode, the high pressure refrigerant discharged from the compressor 11 flows into the condenser 12. At this time, since the air mix door 34 completely closes the air passage on the heater core 27 side, the cooling water flowing into the heater core 27 flows out of the heater core 27 almost without heat exchange with the blowing air.

  Since the second on-off valve 22 is closed, the refrigerant flowing out of the condenser 12 flows out from the first three-way joint 13a to the first refrigerant passage 14a side and flows into the first pressure reducing valve 15a. At this time, since the first pressure reducing valve 15a is fully open, the refrigerant flowing out of the condenser 12 flows into the outdoor evaporator 16 without being reduced in pressure by the first pressure reducing valve 15a.

  The refrigerant that has flowed into the outdoor evaporator 16 dissipates heat to the outside air blown from the blower fan by the outdoor evaporator 16. The refrigerant flowing out of the outdoor evaporator 16 flows into the second refrigerant passage 14b through the second three-way joint 13b since the first on-off valve 21 is closed, and becomes a low-pressure refrigerant at the second pressure reducing valve 15b. The pressure is reduced to

  The low pressure refrigerant decompressed by the second pressure reducing valve 15 b flows into the indoor evaporator 18, absorbs heat from the air blown from the blower 32, and evaporates. Thereby, the blowing air is cooled. The refrigerant flowing out of the indoor evaporator 18 flows into the accumulator 20 through the evaporation pressure control valve 19 and is separated into gas and liquid. Then, the gas phase refrigerant separated by the accumulator 20 is sucked from the suction side of the compressor 11 and compressed by the compressor 11 again.

  Therefore, in the cooling mode, cooling of the vehicle interior can be performed by blowing out the blown air cooled by the indoor evaporator 18 into the vehicle interior that is the space to be air conditioned.

(C) Series dehumidifying and heating mode In the series dehumidifying and heating mode, the air conditioning control device closes the first on-off valve 21, closes the second on-off valve 22, sets the first pressure reducing valve 15a in a throttling state, and the second pressure reducing valve 15b. It will be in the squeezed state. Further, the air conditioning control device displaces the air mix door 34 so that the air passage on the heater core 27 side is fully opened and the cold air bypass passage 36 side is fully closed.

  Thereby, in the refrigeration cycle apparatus 10 in the series dehumidifying and heating mode, as shown by the white arrow in FIG. 1, the compressor 11 → the condenser 12 → (first pressure reducing valve 15a) → outdoor evaporator 16 → (check valve 17) → second pressure reducing valve 15b → indoor evaporator 18 → evaporation pressure adjusting valve 19 → accumulator 20 → compressor 11 In this order, a vapor compression type refrigeration cycle in which the refrigerant circulates is configured. That is, a refrigeration cycle in which the outdoor evaporator 16 and the indoor evaporator 18 are connected in series to the refrigerant flow is configured.

  In the refrigeration cycle apparatus 10 in the series dehumidifying and heating mode, the refrigeration cycle is configured in which the condenser 12 functions as a radiator and the indoor evaporator 18 functions as an evaporator. Furthermore, when the saturation temperature of the refrigerant in the outdoor evaporator 16 is higher than the outside air temperature Tam, the outdoor evaporator 16 functions as a radiator, and the saturation temperature of the refrigerant in the outdoor evaporator 16 is lower than the outside air temperature Tam In addition, the outdoor evaporator 16 functions as an evaporator.

  In this cycle configuration, the air conditioning control device appropriately controls the operation of various air conditioning devices connected to the output side. For example, as for the control signal output from the air conditioning controller to the electric actuator for driving the air mix door, the air mix door 34 completely closes the cold air bypass passage 36 and passes the indoor evaporator 18 as in the heating mode. The total flow rate of the blown air is determined to pass through the air passage on the heater core 27 side.

  Therefore, in the series dehumidifying and heating mode, the dehumidified heating of the vehicle interior can be performed by reheating the blown air cooled and dehumidified by the indoor evaporator 18 by the heater core 27 into the vehicle interior which is the space to be air conditioned. It can be carried out. Furthermore, the heating capacity of the blowing air in the heater core 27 can be adjusted by adjusting the throttle opening degree of the first pressure reducing valve 15a and the second pressure reducing valve 15b.

(D) Parallel Dehumidifying and Heating Mode In the parallel dehumidifying and heating mode, the air conditioning control device opens the first on-off valve 21 and opens the second on-off valve 22 to make the first pressure reducing valve 15a into a throttling state, and the second pressure reducing valve 15b. It will be in the squeezed state.

  Thus, in the parallel dehumidifying and heating mode, as shown by the hatched and hatched arrows in FIG. 1, the compressor 11 → the condenser 12 → the first pressure reducing valve 15a → the outdoor evaporator 16 → the (first on-off valve 21 →) accumulator While circulating the refrigerant in the order of 20 → compressor 11, the compressor 11 → condenser 12 → (second on-off valve 22 →) second pressure reducing valve 15b → indoor evaporator 18 → evaporation pressure adjusting valve 19 → accumulator 20 → compression A vapor compression refrigeration cycle in which the refrigerant is circulated in the order of the machine 11 is configured.

  That is, in the parallel dehumidifying and heating mode, the flow of the refrigerant flowing out of the condenser 12 is branched by the first three-way joint 13a, and one branched refrigerant is divided into the first pressure reducing valve 15a → outdoor evaporator 16 → the compressor 11 While flowing in order, the refrigerant circuit of the other branched refrigerant is made to flow in the order of the second pressure reducing valve 15 b → the indoor evaporator 18 → the evaporation pressure adjusting valve 19 → the compressor 11.

  In this cycle configuration, the air conditioning control device appropriately controls the operation of various air conditioning devices connected to the output side. For example, as for the control signal output from the air conditioning controller to the electric actuator for driving the air mix door, the air mix door 34 fully closes the cold air bypass passage 36 and air is blown after passing through the indoor evaporator 18 as in the heating mode. The total flow rate of air is determined to pass through the air passage on the heater core 27 side.

  Therefore, in the refrigeration cycle apparatus 10 in the parallel dehumidifying and heating mode, the high pressure refrigerant discharged from the compressor 11 flows into the condenser 12. Since the air mix door 34 opens the air passage on the heater core 27 side, the refrigerant flowing into the condenser 12 exchanges heat with the air that has been blown from the blower 32 and passed through the indoor evaporator 18 as in the heating mode. And dissipate heat. Thereby, the blowing air is heated.

  The flow of the refrigerant flowing out of the condenser 12 is branched at the first three-way joint 13a because the second on-off valve 22 is open. One refrigerant branched at the first three-way joint 13a flows out to the first refrigerant passage 14a side, and is depressurized until it becomes a low pressure refrigerant by the first pressure reducing valve 15a. The low-pressure refrigerant decompressed by the first pressure reducing valve 15a flows into the outdoor evaporator 16 and absorbs heat from the outside air blown by the blower fan.

  On the other hand, the other refrigerant branched at the first three-way joint 13a flows out to the fourth refrigerant passage 14d side. The refrigerant flowing out to the fourth refrigerant passage 14d side does not flow out to the outdoor evaporator 16 side by the action of the check valve 17, and the second pressure reducing valve via the second on-off valve 22 and the third three-way joint 13c. It flows into 15b.

  The refrigerant flowing into the second pressure reducing valve 15b is reduced in pressure until it becomes a low pressure refrigerant. Then, the low pressure refrigerant decompressed by the second pressure reducing valve 15 b flows into the indoor evaporator 18, absorbs heat from the air blown from the blower 32, and evaporates. Thereby, the blowing air is cooled. The refrigerant flowing out of the indoor evaporator 18 is depressurized by the evaporation pressure adjusting valve 19 and has a pressure equal to that of the refrigerant flowing out of the outdoor evaporator 16.

  The refrigerant flowing out of the evaporation pressure adjusting valve 19 flows into the fourth three-way joint 13 d and merges with the refrigerant flowing out of the outdoor evaporator 16. The refrigerant joined at the fourth three-way joint 13d flows into the accumulator 20 and is separated into gas and liquid. Then, the gas phase refrigerant separated by the accumulator 20 is sucked from the suction side of the compressor 11 and compressed by the compressor 11 again.

  Therefore, in the parallel dehumidifying and heating mode, the dehumidified heating of the passenger compartment is performed by reheating the blow air cooled and dehumidified by the indoor evaporator 18 by the condenser 12 and blowing it into the vehicle compartment which is the air conditioning target space. It can be performed.

  Furthermore, in the parallel dehumidifying and heating mode of the present embodiment, the refrigerant evaporation temperature in the outdoor evaporator 16 can be made lower than the refrigerant evaporation temperature in the indoor evaporator 18. Therefore, the heat absorption amount in the outdoor evaporator 16 can be increased by expanding the temperature difference between the refrigerant evaporation temperature in the outdoor evaporator 16 and the outside air.

  Thereby, the heating capacity of the blowing air in the heater core 27 can be increased more than the refrigeration cycle apparatus in which the refrigerant evaporation temperature in the outdoor evaporator 16 is equal to the refrigerant evaporation temperature in the indoor evaporator 18.

  As described above, according to the refrigeration cycle apparatus 10 of the present embodiment, it is possible to realize comfortable heating of the vehicle interior by switching between the heating mode, the cooling mode, the series dehumidifying heating mode, and the parallel dehumidifying heating mode. it can.

  Next, a method for filling the refrigeration cycle apparatus 10 with a refrigerant will be described. Before shipping the air conditioner 1 (the refrigeration cycle apparatus 10), the first pressure reducing valve 15a and the second pressure reducing valve 15b are fully opened, and the first on-off valve 21 and the second on-off valve 22 are open. The refrigeration cycle apparatus 10 is evacuated from the side charging port 24 and the low pressure side charging port 23.

  This vacuuming is performed to remove the air inside the refrigeration cycle apparatus 10. The reason is that when air is left inside the refrigeration cycle apparatus 10, the moisture in the air may freeze inside the refrigeration cycle apparatus 10 and interfere with the circulation of the refrigerant.

  Furthermore, after vacuuming the refrigeration cycle apparatus 10, the first pressure reducing valve 15a and the second pressure reducing valve 15b are fully opened, and the first on-off valve 21 and the second on-off valve 22 are open. The refrigerant is charged into the refrigeration cycle apparatus 10 from the port 24.

  After shipment of the air conditioner 1 (the refrigeration cycle apparatus 10), the first pressure reducing valve 15a and the second pressure reducing valve 15b are fully opened, and the first on-off valve 21 and the second on-off valve 22 are opened. In the state where the machine 11 is operated, the refrigerant cycle device 10 is filled with the refrigerant from the low pressure side charging port 23.

  As apparent from the above description, the second refrigerant at the time of charging the refrigerant from the low pressure side charging port 23 to the second refrigerant passage 14b between the evaporation pressure adjusting valve 19 and the low pressure side charging port 23 An accumulator 20, which is a pressure fluctuation suppressing portion that suppresses a rapid fluctuation of the internal pressure of the passage 14b, is disposed.

  According to this, since the accumulator 20 includes the buffer space 20a, when the refrigerant is charged from the low pressure side charging port 23 to the refrigeration cycle apparatus 10 via the second refrigerant passage 14b, the refrigerant is in the buffer space 20a. By compressing the air, it is possible to suppress the rapid change of the internal pressure of the second refrigerant passage 14b. For this reason, pressure fluctuation on the outlet side of the evaporating pressure regulating valve 19 can be suppressed. Therefore, even if the low pressure side charging port 23 is disposed on the downstream side of the evaporation pressure adjustment valve 19, the deterioration in the durability of the evaporation pressure adjustment valve can be suppressed.

  That is, according to the refrigeration cycle apparatus 10 of the present embodiment, the degree of freedom of the mounting position of the charging port can be improved without deteriorating the durability of the evaporation pressure control valve.

  The buffer space 20a is constituted by an accumulator 20 which is a liquid storage unit for storing the surplus refrigerant. According to this, since the buffer space 20a of the accumulator 20 which is a liquid storage section originally provided in the refrigeration cycle apparatus 10 is used as a pressure fluctuation suppression section, it is necessary to newly provide the pressure fluctuation suppression section in the refrigeration cycle apparatus 10 There is not. Therefore, even if the refrigeration cycle apparatus 10 is arranged at the downstream side of the evaporation pressure adjusting valve 19 without increasing the cost and without increasing the size, the evaporation pressure adjusting valve The refrigeration cycle apparatus 10 can be provided in which the durability of No. 19 does not deteriorate.

Second Embodiment
Below, the refrigerating cycle device 10 of 2nd Embodiment is demonstrated using FIG. 2 about a different point from the refrigerating cycle device 10 of 1st Embodiment. In the refrigeration cycle apparatus 10 of the second embodiment, a muffler 51 is disposed in the second refrigerant passage 14 b between the evaporation pressure adjusting valve 19 and the low pressure side charging port 23. In the present embodiment, the muffler 51 is disposed in the second refrigerant passage 14 b between the accumulator 20 and the low pressure side charging port 23.

  In the muffler 51, a buffer space 51a is formed. The buffer space 51 a is for reducing pressure pulsation accompanying discharge of the refrigerant by the compressor 11. The buffer space 51a also functions as a pressure fluctuation suppressing unit that suppresses pressure fluctuation of the second refrigerant passage 14b when the refrigerant is charged from the low pressure side charging port 23 to the second refrigerant passage 14b.

  Thus, the volume of the flow path through which the refrigerant flows between the evaporation pressure adjusting valve 19 and the low pressure side charging port 23 is increased by the buffer space 51 a of the muffler 51. For this reason, when the refrigerant is charged from the low pressure side charging port 23 to the second refrigerant passage 14b, the air in the buffer space 51a is compressed, thereby further rapidly changing the internal pressure of the second refrigerant passage 14b. It can be suppressed. Therefore, the pressure fluctuation on the outlet side of the evaporating pressure regulating valve 19 can be further suppressed.

  As is clear from the above description, the buffer space 51 a is configured by the muffler 51 for reducing pressure pulsations accompanying discharge of the refrigerant by the compressor 11. According to this, in the refrigeration cycle apparatus 10 in which the muffler 51 is provided, it is not necessary to newly provide the pressure fluctuation suppression unit in the refrigeration cycle apparatus 10. Therefore, even if the refrigeration cycle apparatus 10 is arranged at the downstream side of the evaporation pressure adjusting valve 19 without increasing the cost and without increasing the size, the evaporation pressure adjusting valve The refrigeration cycle apparatus 10 can be provided in which the durability of No. 19 does not deteriorate. Further, pressure fluctuation on the outlet side of the evaporation pressure adjusting valve 19 can be further suppressed when the refrigerant from the low pressure side charging port 23 is charged into the refrigeration cycle apparatus 10.

Third Embodiment
Below, the refrigerating cycle device 10 of 3rd Embodiment is demonstrated using FIG. 3 about a different point from the refrigerating cycle device 10 of 1st Embodiment. In the refrigeration cycle apparatus 10 of the third embodiment, a buffer space 52, which is a pressure fluctuation suppressing portion, is provided in the second refrigerant passage 14b between the evaporation pressure adjusting valve 19 and the low pressure side charging port 23. In the present embodiment, the buffer space 52 is provided in the second refrigerant passage 14 b between the accumulator 20 and the low pressure side charging port 23.

  The buffer space 52 is formed by repeatedly bending the pipe. The buffer space 52 increases the length of the flow path through which the refrigerant flows between the evaporation pressure adjusting valve 19 and the low pressure side charging port 23, and the volume of the flow path through which the refrigerant flows increases.

  The buffer space 52 may be configured by increasing the volume of the flow path through which the refrigerant flows by branching a plurality of pipes and collecting the plurality of pipes.

  Thus, the volume of the flow path through which the refrigerant flows between the evaporation pressure adjusting valve 19 and the low pressure side charging port 23 is increased by the buffer space 52. Therefore, when the refrigerant is charged from the low pressure side charging port 23 to the refrigeration cycle apparatus 10 via the second refrigerant passage 14b, the air in the buffer space 52 is compressed, whereby the refrigerant in the second refrigerant passage 14b is Abrupt changes in internal pressure can be further suppressed. Therefore, the pressure fluctuation on the outlet side of the evaporating pressure regulating valve 19 can be further suppressed.

  As apparent from the above description, the buffer space 52 is constituted by piping. According to this, a structure for suppressing pressure fluctuation on the outlet side of the evaporating pressure adjusting valve 19 can be realized at low cost.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present invention.

  Although the above-mentioned each embodiment explained the example which applied refrigeration cycle device 10 concerning the present invention to vehicles, the present invention is not limited to vehicles, and may be applied to stationary type refrigeration cycle device 10.

  Moreover, each component apparatus which comprises the refrigerating cycle apparatus 10 is not limited to what was disclosed by the above-mentioned embodiment. For example, although the above-mentioned embodiment explained the example which adopted an electric compressor as compressor 11, when applied to a vehicle travel engine, the vehicle travels via a pulley, a belt, etc. as compressor 11. An engine driven compressor driven by a rotational driving force transmitted from an engine may be employed.

  In addition, the means disclosed in each of the above embodiments may be combined as appropriate in the feasible range. For example, it may be an air conditioner in which the refrigeration cycle apparatus 10 of the second embodiment and the refrigeration cycle apparatus 10 of the third embodiment are combined.

  In addition, a restriction such as an orifice is provided in the low pressure side charging port 23 to further suppress pressure fluctuation on the outlet side of the evaporation pressure adjusting valve 19 when charging the refrigerant from the low pressure side charging port 23 to the refrigeration cycle apparatus 10 May be an embodiment.

  Moreover, the method of filling a refrigerant | coolant in the inside of the refrigerating cycle apparatus 10 with a refrigerant | coolant after shipment of the air conditioning apparatus 1 (refrigerating cycle apparatus 10) is not limited to what was disclosed by the above-mentioned embodiment. Another example will be described below.

  First, with the first pressure reducing valve 15a and the second pressure reducing valve 15b fully open, and the first on-off valve 21 and the second on-off valve 22 open, the high pressure side charging port 24 enters the refrigeration cycle apparatus 10 Fill the specified amount of refrigerant.

  Next, after the high pressure side charging port 24 is closed, the refrigerant cycle device 10 is filled with the refrigerant from the low pressure side charging port 23 in a state where the compressor 11 is operated.

  As apparent from the above description, after the refrigerant cycle device 10 is filled with a specified amount of refrigerant from the high pressure side charging port 24, the refrigerant is charged from the low pressure side charging port 23.

  According to this, when the refrigerant cycle device 10 is filled with the refrigerant from the low pressure side charging port 23, the refrigerant cycle device 10 is filled with the specified amount of refrigerant, so the refrigeration cycle device is charged from the low pressure side charging port The pressure difference between the refrigerant filled in the refrigerant and the refrigerant in the refrigeration cycle apparatus can be reduced. Therefore, when the refrigerant is charged into the refrigeration cycle apparatus from the low pressure side charging port, the reverse pressure hardly acts on the evaporation pressure regulating valve 19.

  Therefore, when the refrigerant is charged from the low pressure side charging port 23 to the refrigeration cycle apparatus 10, it is possible to further suppress the rapid fluctuation of the pressure fluctuation on the outlet side of the evaporation pressure adjusting valve 19.

  The specified amount of refrigerant charged from the high pressure side charging port 24 into the refrigeration cycle apparatus 10 is the outlet of the evaporation pressure adjusting valve 19 when the refrigerant is charged from the low pressure side charging port 23 to the second refrigerant passage 14b. It is a predetermined amount necessary to suppress the rapid fluctuation of the pressure fluctuation on the side.

11 Compressor 14a First refrigerant passage 14b Second refrigerant passage 14c Third refrigerant passage 15a First pressure reducing valve (first pressure reducing portion)
15b Second pressure reducing valve (second pressure reducing section)
16 outdoor evaporator 18 indoor evaporator 19 evaporation pressure control valve 20 accumulator (pressure fluctuation suppression unit, liquid storage unit)
21 1st on-off valve (opening and closing part)
23 Low voltage side charging port (charging port)
25 heating unit

Claims (4)

A compressor (11) that compresses and discharges a refrigerant;
A heating unit (25) configured to heat the fluid to be heat exchanged using the refrigerant discharged from the compressor (11) as a heat source;
An outdoor evaporator (16) that exchanges heat between the refrigerant flowing out of the heating unit and the outside air;
An indoor evaporator (18) for exchanging heat between the refrigerant flowing out of the outdoor evaporator and the heat exchange target fluid;
A first refrigerant passage (14a) for guiding the refrigerant flowing out of the heating unit to the inlet side of the outdoor evaporator;
A first pressure reducing portion (15a) disposed in the first refrigerant passage and capable of changing an opening area of the first refrigerant passage;
A second refrigerant passage (14b) for guiding the refrigerant flowing out of the outdoor evaporator to the suction side of the compressor via the indoor evaporator;
A second pressure reducing portion (15b) disposed between the outdoor evaporator and the indoor evaporator in the second refrigerant passage and capable of changing an opening area of the second refrigerant passage;
An evaporation pressure adjusting valve (19) disposed on the downstream side of the indoor evaporator in the second refrigerant passage and adjusting the refrigerant evaporation pressure in the indoor evaporator;
And a third refrigerant passage (14c) which is connected at the end to the second refrigerant passage between the evaporation pressure control valve and the compressor and which leads the refrigerant flowing out of the outdoor evaporator to the suction side of the compressor ,
An opening and closing portion (21) for opening and closing the third refrigerant passage;
A charging port (23) disposed downstream of the evaporation pressure control valve in the second refrigerant passage, for charging the refrigerant;
It is arranged between the evaporation pressure control valve and the charging port in the second refrigerant passage, and suppresses rapid fluctuation of the internal pressure of the second refrigerant passage when the refrigerant is charged from the charging port. And a pressure fluctuation suppressing portion (20, 51, 52) which forms a buffer space (20a, 51a, 52) which is a space for the purpose.   The refrigeration cycle apparatus according to claim 1, wherein the buffer space is constituted by a liquid storage section (20) for storing an excess refrigerant.   The refrigeration cycle apparatus according to claim 1, wherein the buffer space is constituted by a muffler (51) for reducing pressure pulsations accompanying discharge of the refrigerant by the compressor.   The refrigeration cycle apparatus according to claim 1, wherein the buffer space is configured by a pipe.

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