JP6481824B2 - Heat pump air conditioner - Google Patents

Description

  The present invention relates to a heat pump air conditioner that uses a heat pump cycle during heating operation.

  In a vehicle or the like that does not include an engine such as an electric vehicle, an air conditioner that performs a heating operation using a heat pump cycle may be used.

  Many heat pump air conditioners used in vehicles and the like have a heating refrigerant circuit and a cooling refrigerant circuit, and both refrigerant circuits share a compressor and an outdoor heat exchanger. In addition, a gas-liquid separator shared by the heating refrigerant circuit and the cooling refrigerant circuit may be provided on the upstream side (suction side) of the compressor. This gas-liquid separator separates the low-pressure refrigerant sucked into the compressor into a gas component and a liquid component, and prioritizes the gas component to flow into the compressor (see, for example, Patent Document 1).

  In the gas-liquid separator used in the heat pump air conditioner described in Patent Document 1, a suction passage of a compressor is connected above a staying chamber in which a liquid component stays.

JP 2006-3022 A

  In the heat pump air conditioner as described above, the flow rate of the refrigerant circulating in the refrigerant circuit is adjusted by appropriately retaining the liquid component of the refrigerant in the retention chamber of the gas-liquid separator during heating operation or cooling operation. The During heating operation, a relatively large amount of refrigerant liquid stays in the storage chamber and the amount of refrigerant circulating in the refrigerant circuit decreases, and during cooling operation, almost no refrigerant liquid stays in the storage chamber. The amount of refrigerant circulating inside increases.

  By the way, the refrigerant circulating in the refrigerant circuit is usually mixed with lubricating oil to lubricate sliding portions of equipment in the refrigerant circuit such as a compressor. The lubricating oil mixed in the refrigerant circulates in the refrigerant circuit together with the refrigerant, and partially stays in the storage chamber together with the refrigerant liquid in the gas-liquid separator.

  In the heat pump air conditioner, since the outdoor heat exchanger must exchange heat with the outside air in a low temperature environment during heating operation, the refrigerant is compressed to a high pressure by the compressor, and the refrigerant compressed to the high pressure is the outdoor heat exchanger It must be expanded rapidly on the entrance side. For this reason, in a heat pump air conditioner, when the compressor is operated at a high speed during heating operation, the flow rate of the lubricating oil circulating in the refrigerant circuit must be increased so as to sufficiently withstand the high speed.

  However, in the heat pump air conditioner, if the amount of lubricating oil mixed in the refrigerant is increased, the flow rate of the lubricating oil circulating in the refrigerant flow path during the cooling operation also increases, so that the heat exchange efficiency during the cooling operation is increased. It will decline. That is, if the flow rate of lubricating oil circulating in the refrigerant circuit during cooling operation increases more than necessary, a large amount of lubricating oil adheres to the inner wall of the indoor heat exchanger or outdoor heat exchanger, and the attached lubricating oil The heat transfer efficiency of the exchanger and the outdoor exchanger is likely to be reduced, and the amount of refrigerant fed into the compressor is substantially reduced due to an increase in the amount of mixed lubricating oil. The heat exchange efficiency during the cooling operation is lowered due to these causes.

  Therefore, the present invention intends to provide a heat pump type air conditioner that can circulate a sufficient amount of lubricating oil in the refrigerant circuit during heating operation and that can maintain high heat exchange efficiency during cooling operation. It is.

In order to solve the above-described problems, the heat pump air-conditioning apparatus according to the present invention uses an indoor heat exchanger for heating (for example, the indoor heat exchange for heating according to the embodiment) obtained by compressing the refrigerant compressed by a compressor (for example, the compressor 21 according to the embodiment) After the heat is exchanged with the room air in the heater 55), the pressure is reduced by the heating expansion valve (for example, the heating expansion valve 22 in the embodiment), and the refrigerant is cooled to the outdoor heat exchanger (for example, the outdoor heat exchanger 24 in the embodiment). The refrigerant circuit for heating which returns to the compressor via a gas-liquid separator (for example, the gas-liquid separator 33 of the embodiment) after heat exchange with the outside air and the refrigerant compressed by the compressor with the outside air by the outdoor heat exchanger After the heat exchange, the pressure is reduced by the cooling expansion valve (for example, the cooling expansion valve 29 in the embodiment), and the refrigerant is emptied by the cooling indoor heat exchanger (for example, the evaporator 53 in the embodiment). And a cooling refrigerant circuit that returns to the compressor via a gas-liquid separator after exchanging heat with the heating circuit, and the heating refrigerant circuit and the cooling refrigerant circuit share the compressor and the gas-liquid separator. In the heat pump air conditioner, the gas-liquid separator is disposed so as to be substantially along a vertical direction in a retention chamber (for example, the retention chamber 71 of the embodiment) in which the separated liquid is retained, and the retention chamber. A guide pipe (for example, guide pipe 72 in the embodiment) that guides the gas content of the refrigerant to flow into the inside from above, and a lead-out hole that is arranged inside the guide pipe and mainly returns the gas content to the compressor (e.g., lead-out hole 70a of the embodiment) and has a, wherein the residence chamber, the guide pipe and the first chamber is not disposed of the lead-out hole (e.g., the first chamber 75 of the embodiment) and the Idopaipu and the second chamber disposed in the lead-out hole (e.g., the second chamber 76 of the embodiment) and the隔成to partition walls (e.g., partition wall 74 of the embodiment), the cooling operation, mixed in the refrigerant A lubricating oil introduction part (for example, the inner peripheral surface 65a of the embodiment) for introducing the lubricating oil into the first chamber in the gas-liquid separator, and the height of the partition wall is The height of the outlet hole was set higher.

Thereby, at the time of heating operation, the refrigerant that has been compressed by the compressor and becomes high temperature and high pressure exchanges heat by the indoor heat exchanger for heating to warm indoor air, and the refrigerant is decompressed by the expansion valve for heating. The refrigerant that has passed through the heating expansion valve and has become low temperature and low pressure is partially vaporized by taking in the heat of the outside air in the outdoor heat exchanger, and then flows into the gas-liquid separator. The refrigerant that has flowed into the gas-liquid separator is retained in the first chamber and the second chamber in the retention chamber together with the lubricating oil mixed in the refrigerant. Then, the gas component of the refrigerant in the gas-liquid separator is sucked into the compressor through the outlet hole together with the liquid component of the refrigerant remaining in the retention chamber and the lubricating oil. Lubricating oil sucked up from the outlet hole circulates in the heating refrigerant circuit.
Further, during the cooling operation, the refrigerant compressed to a high temperature and high pressure by the compressor exchanges heat with the outside air by the outdoor heat exchanger, and is then decompressed by the cooling expansion valve. The refrigerant that has passed through the cooling expansion valve and has become low-temperature and low-pressure is partially vaporized by taking in the heat of the room air in the room heat exchanger for cooling, and then cools the room air. The refrigerant that has passed through the indoor heat exchanger for cooling flows into the gas-liquid separator. At this time, the lubricating oil that has flowed into the gas-liquid separator together with the refrigerant stays in the first chamber through the lubricating oil inlet, fills the first chamber, and then flows over the partition wall and flows into the second chamber. Also stay in. Then, the gas component of the refrigerant in the gas-liquid separator is sucked into the compressor through the outlet hole together with a part of the lubricating oil staying in the second chamber. The lubricating oil sucked up from the outlet hole circulates in the cooling refrigerant circuit, but the flow rate of the lubricating oil circulated at this time is limited by the amount of lubricating oil remaining in the first chamber of the gas-liquid separator.

  It is desirable that the partition wall be set to a height at which the partition wall is immersed in the mixed liquid of the refrigerant and the lubricating oil that has flowed into the staying chamber during the heating operation.

  In this case, during the heating operation, the refrigerant flowing into the gas-liquid separator and the liquid component of the lubricating oil are mixed in a wide space in the staying chamber. For this reason, during the heating operation, the refrigerant and the lubricating oil are sucked into the compressor in a sufficiently mixed state. Therefore, the flow rate of the lubricating oil flowing in the refrigerant circuit during the heating operation is stabilized.

  The lubricating oil introduction part is configured by an inner peripheral surface of the staying chamber, and the partition wall is configured by a cylindrical body that partitions the bottom side of the staying chamber in the radial direction inside and outside, and the staying partitioned by the partition wall. The inside portion of the room may be the first chamber and the inside portion may be the second chamber.

In this case, the lubricating oil that has flowed into the gas-liquid separator together with the refrigerant during the cooling operation stays in the first chamber outside the cylinder through the inner peripheral surface of the retention chamber , and after filling the first chamber, the cylinder Over the upper end of the gas and flows into the second chamber inside. Only the lubricating oil staying in the second chamber inside the cylinder is sucked into the compressor.
In this configuration, the lubricating oil can be reliably retained in the first chamber during the cooling operation while having an extremely simple structure.

  The heating refrigerant circuit and the cooling refrigerant circuit share the compressor, the outdoor heat exchanger, and the gas-liquid separator, and in the downstream portion of the outdoor heat exchanger, the cooling expansion valve and the A cooling main passage (for example, the cooling main passage 43 of the embodiment) connected to the gas-liquid separator via a cooling indoor heat exchanger, the cooling expansion valve, and the cooling indoor heat exchanger. A heating bypass passage (for example, the heating bypass passage 44 of the embodiment) that is connected to the gas-liquid separator so as to be switchable, and is connected to the discharge section of the compressor in the heating chamber. A heating main passage (for example, the heating main passage 94 in the embodiment) connected to the upstream portion of the outdoor heat exchanger via the exchanger and the heating expansion valve, the heating indoor exchanger, and the By bypassing the heating expansion valve, the outdoor heat exchanger Cooling bypass passage connected to the flow portion (e.g., a bypass passage 96 for cooling the embodiment) and, may be is switchably connected.

  In this case, during the cooling operation, the refrigerant discharged from the compressor discharge portion flows into the gas-liquid separator through the cooling bypass passage and the cooling main passage, and is discharged from the compressor discharge portion during the heating operation. The refrigerant flows into the gas-liquid separator through the heating main passage and the heating bypass passage. During the cooling operation, the refrigerant bypasses the heating indoor heat exchanger through the cooling bypass passage, so that unnecessary heat loss is not caused in the heating indoor heat exchanger during the cooling operation. In addition, since the refrigerant does not flow into the heating indoor heat exchanger during the cooling operation, heat is radiated in the heating indoor heat exchanger during the cooling operation, thereby preventing the liquefied refrigerant and lubricating oil from staying inside. be able to. Further, during the cooling operation, since the refrigerant bypasses the heating indoor heat exchanger through the cooling bypass passage, the pipe through which the refrigerant passes becomes short. For this reason, the pressure loss in the cooling refrigerant circuit can be reduced.

  The compressor discharge section may be provided with a three-way valve (for example, the three-way valve 95 of the embodiment) that selectively switches between the heating main passage and the cooling bypass passage.

  According to this invention, in the gas-liquid separator shared by the heating refrigerant circuit and the cooling refrigerant circuit, the lubricating oil is retained in the first chamber in the retention chamber during the cooling operation, and the flow rate of the lubricating oil sucked into the compressor A partition wall is provided to limit this. For this reason, a sufficient amount of lubricating oil can be circulated in the refrigerant circuit during the heating operation, and the flow rate of the lubricating oil circulated in the refrigerant circuit can be limited during the cooling operation to maintain high heat exchange efficiency.

It is a lineblock diagram of the heat pump type air-conditioner concerning one embodiment of this invention. It is operation | movement explanatory drawing of the heat pump type air conditioner which concerns on one Embodiment of this invention. It is operation | movement explanatory drawing of the heat pump type air conditioner which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view of the gas-liquid separator which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view of the gas-liquid separator which concerns on one Embodiment of this invention. It is a block diagram of the heat pump type air conditioner which concerns on other embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a configuration diagram of a heat pump air conditioner 10 according to this embodiment.
A heat pump air conditioner 10 (hereinafter referred to as “air conditioner 10”) according to this embodiment is mounted on, for example, an electric vehicle that does not include an engine (internal combustion engine) as a vehicle drive source. Specifically, the air conditioner 10 mainly includes an air conditioning unit 11, a heat pump cycle 12 in which a refrigerant can circulate, and a control device 13.

The air conditioning unit 11 includes a duct 51 through which conditioned air circulates, a blower 52 accommodated in the duct 51, an evaporator 53 (an indoor heat exchanger for cooling), an air mix door 54, an indoor heat exchanger 55 for heating, And a heater core 56.
The duct 51 has an air intake port 57 located on the upstream side in the flow direction of the conditioned air, and an air outlet 58 located on the downstream side. The blower 52, the evaporator 53, the air mix door 54, the heating indoor heat exchanger 55, and the heater core 56 described above are arranged in this order from the upstream side to the downstream side in the flow direction.

  The blower 52 is driven in accordance with, for example, a drive voltage applied under the control of the control device 13, and the conditioned air (at least one of the inside air and the outside air) taken into the duct 51 through the air intake port 57 is downstream. Send out.

  The evaporator 53 performs heat exchange between the low-pressure refrigerant flowing into the interior and the vehicle interior atmosphere (in the duct 51), and cools the conditioned air passing through the evaporator 53 by, for example, heat absorption when the refrigerant evaporates.

  The heating indoor heat exchanger 55 can dissipate heat with a high-temperature and high-pressure refrigerant flowing into the inside, and heats conditioned air passing through the heating indoor heat exchanger 55, for example.

  The heater core 56 is disposed downstream of the indoor heat exchanger 55 for heating in the duct 51. The heater core 56 is connected to a water heating electric heater 62 and a water pump 63 through a pipe 61. Water is circulated between the heater core 56 and the water heating electric heater 62 by the operation of the water pump 63. Then, the water heated by the water heating electric heater 62 is supplied to the heater core 56 to heat the conditioned air passing through the heater core 56.

  The air mix door 54 can be rotated by driving means (not shown) that is driven under the control of the control device 13, for example. Specifically, the air mix door 54 bypasses the heating position (see FIG. 2) that opens the ventilation path (heating path) toward the indoor heat exchanger 55 for heating and the heater core 56 in the duct 51 and the heating path. And a cooling position (see FIG. 3) that opens the ventilation path (cooling path).

  The heat pump cycle 12 includes, for example, the evaporator 53 and the heating indoor heat exchanger 55, the compressor 21, the heating expansion valve 22, the bypass valve 23, the outdoor heat exchanger 24, the cooling valve 26, the receiver tank 25, and the sub capacitor. 27, a check valve 28, a cooling expansion valve 29, a cooling auxiliary heat exchanger 31, a heating valve 32, a gas-liquid separator 33, a dehumidifying valve 34, and an evaporation capability control valve 35, each of these components Are connected via a refrigerant flow path.

  The compressor 21 is connected between the gas-liquid separator 33 and the indoor heat exchanger 55 for heating. The compressor 21 is driven by, for example, a driving force of a driving unit that is driven by the control of the control device 13. The compressor 21 mainly sucks a gas component from the gas-liquid separator 33 and compresses the refrigerant. It discharges to the indoor heat exchanger 55 for heating mentioned above as a refrigerant.

The heating expansion valve 22 is a so-called throttle valve, and expands the refrigerant discharged from the heating indoor heat exchanger 55, and then expands the gas-liquid two-phase (liquid-phase rich) spray at low temperature and low pressure. It discharges to the outdoor heat exchanger 24 as a refrigerant.
A passage from the protruding portion of the compressor 21 to the heating expansion valve 22 via the heating indoor heat exchanger 55 is a high-pressure side main passage 41.

The bypass valve 23 is provided on a bypass passage 42 that bypasses the heating expansion valve 22 of the high-pressure main passage 41 and is connected to the outdoor heat exchanger 24 in the downstream portion of the heating indoor heat exchanger 55, for example, Opening and closing is controlled by the control device 13. The bypass valve 23 is closed when the heating operation is performed, and is opened when the cooling operation is performed.
Thereby, for example, when the heating operation is performed, the refrigerant flowing out of the heating indoor heat exchanger 55 passes through the heating expansion valve 22 and flows into the outdoor heat exchanger 24 at a low temperature and a low pressure.
On the other hand, when the cooling operation is performed, the refrigerant flowing out of the heating indoor heat exchanger 55 passes through the bypass valve 23 and flows into the outdoor heat exchanger 24 in a high temperature state.

  The outdoor heat exchanger 24 performs heat exchange between the refrigerant flowing into the interior and the outdoor atmosphere. A fan 24 a that can blow air toward the outdoor heat exchanger 24 is disposed in front of the outdoor heat exchanger 24. The fan 24a is driven by the control of the control device 13, for example.

When the heating operation is performed, the outdoor heat exchanger 24 can absorb heat from the outdoor atmosphere by a low-temperature and low-pressure refrigerant flowing into the interior, and vaporizes the refrigerant by, for example, heat absorption from the outdoor atmosphere.
On the other hand, when the cooling operation is performed, the outdoor heat exchanger 24 can dissipate heat to the outdoor atmosphere by the high-temperature refrigerant flowing into the interior, and cools the refrigerant by, for example, heat radiation to the outdoor atmosphere and blowing of the fan 24a.

  The cooling valve 26 is installed on the cooling main passage 43 connected to the downstream portion of the outdoor heat exchanger 24 in the refrigerant flow path, and is controlled to be opened and closed by, for example, the control device 13. The cooling valve 26 is opened when the cooling operation is performed, and is closed when the heating operation is performed.

  The receiver tank 25 is installed on the downstream side of the cooling valve 26 in the cooling main passage 43. The receiver tank 25 collects a gas-phase refrigerant (gas component of the refrigerant) among the refrigerant that has passed through the outdoor heat exchanger 24 and has flowed into the cooling main passage 43. That is, the receiver tank 25 circulates only the liquid-phase refrigerant (liquid component of the refrigerant) out of the refrigerant flowing into the cooling main passage 43 to the downstream side of the cooling main passage 43.

  The sub condenser 27 is installed in the cooling main passage 43 on the downstream side of the receiver tank 25 and exchanges heat between the refrigerant flowing into the interior and the outdoor atmosphere.

  The check valve 28 is installed on the downstream side of the sub condenser 27 in the cooling main passage 43. The check valve 28 circulates the refrigerant that has passed through the sub-capacitor 27 toward the downstream side when the cooling operation is performed, and is more than the check valve 28 in the cooling main passage 43 when the dehumidifying operation is performed. This prevents the refrigerant from flowing backward to the upstream side (sub capacitor 27 side).

  The cooling expansion valve 29 is a so-called throttle valve, and is connected between the check valve 28 and the inlet of the evaporator 53 in the cooling main passage 43. The cooling expansion valve 29 expands the refrigerant that has passed through the check valve 28 according to the valve opening controlled by the control device 13, for example, and then expands the gas-liquid two-phase (gas-phase rich) at low temperature and low pressure. It discharges to the evaporator 53 as an atomized refrigerant.

The cooling auxiliary heat exchanger 31 straddles between an upstream portion located upstream of the cooling expansion valve 29 and a downstream portion located downstream of the evaporator 53 in the cooling main passage 43. Are arranged as follows. The cooling auxiliary heat exchanger 31 performs heat exchange between the upstream portion and the downstream portion described above during the cooling operation, and cools the refrigerant in the upstream portion before flowing into the evaporator 53.
In this embodiment, the cooling main passage 43 is provided with the cooling valve 26, the receiver tank 25, the sub condenser 27, the check valve 28, the cooling auxiliary heat exchanger 31, and the cooling expansion from the downstream portion of the outdoor heat exchanger 24. This is a passage connected to the gas-liquid separator 33 via the valve 29, the evaporator 53, and the evaporation capacity control valve 35.

  The heating valve 32 is installed on a heating bypass passage 44 that bypasses the cooling main passage 43 and connects the downstream portion of the outdoor heat exchanger 24 and the gas-liquid separator 33. The heating valve 32 is controlled to be opened and closed by the control device 13, for example. The heating valve 32 is opened when the heating operation is performed, and is closed when the cooling operation is performed.

  The gas-liquid separator 33 is connected between the merging portion 46 connecting the downstream end of the cooling main passage 43 and the downstream end of the heating bypass passage 44 and the compressor 21 described above. The gas-liquid separator 33 separates the gas-liquid refrigerant flowing out from the merging portion 46 and causes the compressor 21 to mainly suck the gas-phase refrigerant.

  The dehumidifying valve 34 connects a portion of the cooling main passage 43 that is located downstream of the check valve 28 and a portion of the high-pressure side main passage 41 that is located downstream of the heating indoor heat exchanger 55. Installed on the dehumidifying channel 48 to be opened and closed, for example, and controlled to be opened and closed by the control device 13. The dehumidifying valve 34 is opened when the dehumidifying operation is performed, and is closed when the other operations (cooling operation and heating operation) are performed.

  The evaporation capacity control valve 35 is installed between the evaporator 53 and the cooling auxiliary heat exchanger 31 in the cooling main passage 43 and is controlled to be opened and closed by the control device 13, for example. The evaporation capacity control valve 35 is controlled so that the opening degree is smaller when the dehumidifying operation is performed than when the cooling operation is performed.

Here, in this embodiment, a heating refrigerant circuit in which the refrigerant circulates in the interior during the heating operation and a cooling refrigerant circuit in which the refrigerant circulates in the interior during the cooling operation are provided. The outdoor heat exchanger 24 and the gas-liquid separator 33 are shared.
The heating refrigerant circuit includes a high-pressure side main passage 41 that connects the discharge portion of the compressor 21 and the upstream portion of the outdoor heat exchanger 24 via the heating indoor heat exchanger 55 and the heating expansion valve 22, and the cooling circuit. A heating bypass passage 44 that bypasses the main passage 43 and connects the downstream portion of the outdoor heat exchanger 24 and the gas-liquid separator 33 is provided. The cooling refrigerant circuit includes a cooling main passage 43 connecting the downstream portion of the outdoor heat exchanger 24 and the gas-liquid separator 33 via the cooling expansion valve 29 and the evaporator 53, and a heating indoor heat exchanger. 55, which includes a part of the high-pressure side main passage 41 passing through 55 and the bypass passage 42, and bypasses the heating expansion valve 22 to connect the discharge portion of the compressor 21 and the upstream portion of the outdoor heat exchanger 24. doing.

  In addition, the refrigerant circuit including the heating refrigerant circuit and the cooling refrigerant circuit is filled with refrigerant that circulates inside, and the refrigerant lubricates the sliding portions of the devices in the circuit such as the compressor 21. Lubricating oil is mixed. The amount of the lubricating oil that can sufficiently lubricate the compressor 21 during the heating operation is mixed in the refrigerant assuming that it is during the heating operation that requires the compressor 21 to operate at a high speed.

  The control device 13 controls the operation of the air conditioner 10 based on, for example, a command signal input by an operator via a switch (not shown) disposed in the passenger compartment, for example. Furthermore, the control device 13 switches and controls the operation of the air conditioner 10 to a heating operation, a cooling operation, a dehumidifying operation, or the like.

  Next, the operation of the above-described air conditioner 10 will be described. FIG. 2 is an explanatory diagram illustrating the operation of the air conditioner 10 during the heating operation, and FIG. 3 is an explanatory diagram illustrating the operation of the air conditioner 10 during the cooling operation. In the drawing, the chain line indicates the high-pressure state of the refrigerant, the solid line indicates the low-pressure state of the refrigerant, and the broken line indicates a portion where the refrigerant does not flow.

(Heating operation)
At the time of heating operation, as shown in FIG. 2, the air mix door 54 is set to a heating position for opening the heating path, and the heating valve 32 is opened. During the heating operation, the bypass valve 23, the cooling valve 26, the dehumidifying valve 34, and the evaporation capacity control valve 35 are closed.

In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 21 heats the conditioned air in the duct 51 by heat radiation in the heating indoor heat exchanger 55.
Then, the refrigerant that has passed through the heating indoor heat exchanger 55 is expanded by the heating expansion valve 22 to form a liquid-rich gas-liquid two-phase spray, and then, from the outdoor atmosphere in the outdoor heat exchanger 24. It absorbs heat and becomes a vapor-phase rich gas-liquid two-phase spray. The refrigerant that has passed through the outdoor heat exchanger 24 flows into the gas-liquid separator 33 through the heating bypass passage 44 and the junction 46. The refrigerant that has flowed into the gas-liquid separator 33 is gas-liquid separated inside, and mainly gas-phase refrigerant (liquid component of the refrigerant) is sucked into the compressor 21.

  At this time, the conditioned air flowing in the duct 51 of the air conditioning unit 11 passes through the evaporator 53 and then passes through the heating indoor heat exchanger 55 and the heater core 56 in the heating path. The conditioned air is heated when passing through the heating indoor heat exchanger 55 and the heater core 56, and then supplied to the vehicle interior through the outlet 58 as heating.

(Cooling operation)
During the cooling operation, as shown in FIG. 3, the air mix door 54 is set to a cooling position in which the conditioned air that has passed through the evaporator 53 passes through the cooling path, and the bypass valve 23, the cooling valve 26, and the evaporation capacity control valve 35. Is opened. The heating expansion valve 22, the heating valve 32, and the dehumidifying valve 34 are closed.

In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 21 passes through the heating indoor heat exchanger 55 and the bypass valve 23 and is radiated to the outdoor atmosphere in the outdoor heat exchanger 24, and then is used for cooling. It flows into the main passage 43. The refrigerant is radiated again to the outdoor atmosphere in the sub-capacitor 27 after the gas-phase refrigerant is collected in the receiver tank 25. Thereafter, the refrigerant is expanded by the cooling expansion valve 29 to form a liquid-rich gas-liquid two-phase spray, and then the conditioned air in the duct 51 is cooled by heat absorption in the evaporator 53.
The gas-phase gas-liquid two-phase refrigerant that has passed through the evaporator 53 is heat-exchanged in the cooling auxiliary heat exchanger 31 and then flows into the gas-liquid separator 33. The gas-phase rich refrigerant that has flowed into the gas-liquid separator 33 is gas-liquid separated inside, and mainly gas-phase refrigerant (gas component of the refrigerant) is sucked into the compressor 21.

  At this time, the conditioned air flowing in the duct 51 of the air conditioning unit 11 is cooled when passing through the evaporator 53, and then bypasses the heating indoor heat exchanger 55 and is supplied as cooling from the outlet 58 to the vehicle interior. The

It continues and demonstrates the gas-liquid separator 33 used with the air conditioner 10 of this embodiment.
4 and 5 are longitudinal sectional views of the gas-liquid separator 33, FIG. 4 shows the inside of the gas-liquid separator 33 during the cooling operation, and FIG. 5 shows the gas-liquid separation during the heating operation. The inside of the vessel 33 is shown.
In the gas-liquid separator 33, a housing 65 is constituted by a cylindrical cylindrical container, and an introduction side connection port 66 connected to the cooling main passage 43 and the heating bypass passage 44 is formed on the upper wall of the housing 65; A lead-out side connection port 67 connected to the suction portion of the compressor 21 is provided.

  A guide wall 68 that guides the refrigerant that has flowed into the housing 65 through the introduction-side connection port 66 toward the inner peripheral surface 65 a of the housing 65 is installed in the upper portion of the housing 65. The guide wall 68 is formed in a substantially circular shape when viewed from above, and a guide flange 68a that is bent downward is provided at the outer peripheral edge. The guide flange 68a is opposed to the inner peripheral surface 65a of the housing 65 with a gap so that the lubricating oil easily adheres to the inner peripheral surface 65a of the housing 65 when the refrigerant and the lubricating oil pass through the gap. Is set to In this embodiment, the inner peripheral surface 65a of the housing 65 constitutes a lubricating oil introducing portion.

The guide wall 68 is attached with a lead-out pipe 69 having an upper end connected to the lead-out side connection port 67 and a lower end extending to the vicinity of the bottom wall in the housing 65. At the lower end of the outlet pipe 69, an end part 70 having a plurality of outlet holes 70 a communicating between the inside and the outside of the outlet pipe 69 is attached. A guide pipe 72 having a diameter larger than that of the outlet pipe 69 is disposed coaxially with the outlet pipe 69 on the radially outer side of the outlet pipe 69. The guide pipe 72 has a lower end fixed to the bottom surface in the housing 65 and an upper end opened to a space portion on the radially inner side of the guide flange 68 a of the guide wall 68. The refrigerant gas introduced into the housing 65 passes through the gap between the guide pipe 72 and the outlet pipe 69 from the upper end of the guide pipe 72 and passes through the outlet hole 70 a of the end part 70 and the inside of the guide pipe 72. Then, it is sucked into the suction part of the compressor 21.
A communication hole 73 described later is formed in the peripheral wall portion near the lower end of the guide pipe 72.

The bottom side in the housing 65 is a retention chamber 71 in which the liquid component of the refrigerant introduced from the introduction side connection port 66 and the lubricating oil mixed in the refrigerant stay. In addition, a partition wall 74 is provided at the bottom of the housing 65 so as to surround the outside of the guide pipe 72. In the case of this embodiment, the partition wall 74 is comprised by the circular cylinder. The partition wall 74 divides the inside of the stay chamber 71 into an annular first chamber 75 on the radially outer side and a circular second chamber 76 on the radially inner side. The outer peripheral surface of the first chamber 75 is constituted by an inner peripheral surface 65a of the housing 65 that is a lubricating oil introducing portion, and the lower ends of the guide pipe 72 and the outlet pipe 69 are disposed in the second chamber 76. ing. The height of the partition wall 74 is set to be higher than the height of the outlet hole 70 a at the lower end of the outlet pipe 69.
The refrigerant liquid and the lubricating oil that have flowed into the second chamber 76 flow into the inner region of the guide pipe 72 through the communication hole 73 near the lower end of the guide pipe 72. The liquid content of the refrigerant in the guide pipe 72 and the liquid level of the lubricating oil are the same as the liquid level in the second chamber 76.

The refrigerant liquid and the lubricating oil separated from each other in the gas and liquid in the housing 65 flow into the first chamber 75 in the stay chamber 71 along the inner peripheral surface 65a of the housing 65, and then fill the first chamber 75 before partitioning. It passes over the wall 74 and flows into the second chamber 76. Then, when the amount of liquid that is separated into gas and liquid in the housing 65 further increases, the upper end portion of the partition wall 74 is submerged in the liquid that has been subjected to gas and liquid separation.
In the case of this embodiment, the upper end portion of the partition wall 74 is set to be submerged in the gas-liquid separated liquid during the heating operation in which a large amount of the liquid component of the refrigerant is separated and stays in the stay chamber 71. . Further, during the cooling operation in which the liquid content of the refrigerant hardly stays in the stay chamber 71 and the lubricating oil in the refrigerant mainly stays in the stay chamber 71, the liquid level in the second chamber 76 is in the first chamber 75. The lubricating oil is sucked into the compressor 21 through the outlet hole 70a from the second chamber 76 having a lower liquid level.
4 and 5 is a desiccant that is installed in the housing 65 of the gas-liquid separator 33 and dries the moisture mixed in the refrigerant. 4 is the lubricating oil staying in the first chamber 75 and the second chamber 76, and the reference L2 in FIG. 5 is a mixed liquid of the refrigerant and lubricating oil staying in the staying chamber 71. It is.

Subsequently, the function of the gas-liquid separator 33 during the cooling operation and the heating operation will be described.
During the cooling operation, the refrigerant that has passed through the evaporator 53 in the cooling main passage 43 flows into the housing 65 through the inlet side connection port 66 of the gas-liquid separator 33. The refrigerant flowing into the housing 65 from the introduction side connection port 66 is guided to the guide wall 68 and proceeds along the inner peripheral surface 65a of the housing 65 in the direction of the staying chamber 71, during which the gas and liquid are separated.

  As shown in FIG. 4, the liquid component and the lubricating oil in the gas-liquid separated refrigerant flow into the first chamber 75 of the staying chamber 71 through the inner peripheral surface 65 a of the housing 65, which is a lubricating oil introducing portion. Then, after filling the inside of the first chamber 75, it passes over the partition wall 74 and flows into the second chamber 76. As a result, the liquid component and the lubricating oil in the refrigerant stay in the first chamber 75 and the second chamber 76. However, during the cooling operation, the refrigerant does not stay in a large amount in the staying chamber 71 as a liquid component, and the lubricating oil mainly stays in the staying chamber 71.

  On the other hand, the gas component in the refrigerant that has been gas-liquid separated passes through the gap on the upper side of the guide pipe 72 and the lead-out pipe 69 above the stay chamber 71 and travels below the guide pipe 72 to lead out the lower end of the lead-out pipe 69. The air passes through the hole 70 a and is sucked into the suction portion of the compressor 21 through the lead-out pipe 69 and the lead-out side connection port 67. At this time, since the outlet hole 70a at the lower end of the outlet pipe 69 is located below the liquid level mainly composed of the lubricating oil in the second chamber 76, the gas content of the refrigerant passes through the outlet hole 70a to the compressor 21. When sucked, the lubricating oil in the second chamber 76 is sucked into the compressor 21 together with the refrigerant gas.

  Thus, during the cooling operation, only the lubricating oil retained in the second chamber 76 is sucked into the suction portion of the compressor 21 from the gas-liquid separator 33, and a certain amount of lubricating oil is stored in the first chamber 75. It remains stagnant. For this reason, the flow rate of the lubricating oil sucked into the compressor 21 from the gas-liquid separator 33 and circulated in the refrigerant circuit is limited by the retention in the first chamber 75. Therefore, during the cooling operation, the flow rate of the lubricating oil circulating in the refrigerant circuit is appropriately adjusted, and a large amount of lubricating oil adheres to the inner wall of the evaporator 53 and the outdoor heat exchanger 24 to reduce the heat transfer efficiency. Can be suppressed. Further, since excessive lubricating oil is not sent to the compressor 21, the amount of refrigerant circulating in the refrigerant circuit is not substantially reduced.

On the other hand, during the heating operation, the refrigerant that has passed through the outdoor heat exchanger 24 flows into the housing 65 through the heating bypass passage 44 and the inlet side connection port 66 of the gas-liquid separator 33. The refrigerant that has flowed into the housing 65 from the inlet side connection port 66 is guided to the guide wall 68 together with the mixed lubricating oil, proceeds along the inner peripheral surface 65a of the housing 65 toward the residence chamber 71, The liquid is separated.
During the heating operation, a large amount of refrigerant liquid is separated in the gas-liquid separator 33. Therefore, as shown in FIG. 5, a large amount of refrigerant liquid and lubricating oil are mixed in the residence chamber 71. Stay. In particular, as shown in FIG. 5, when the liquid level of the mixed liquid of the refrigerant and the lubricating oil rises from the upper end portion of the partition wall 74, the refrigerant and the lubricating oil stay in the staying chamber 71 in a sufficiently mixed state. Further, the gas component of the refrigerant in the gas-liquid separator 33 is sucked into the suction portion of the compressor 21 through the outlet hole 70 a together with the mixed liquid of the refrigerant and the lubricating oil staying in the stay chamber 71. As a result, a large amount of lubricating oil mixed with the refrigerant is sucked into the compressor 21 from the gas-liquid separator 33. As a result, during the heating operation, a large amount of lubricating oil circulates in the refrigerant circuit, and a sufficient amount of lubricating oil is supplied to the sliding portion of the equipment such as the compressor 21.

  As described above, in the air conditioner 10 according to this embodiment, the partition wall that restricts the flow rate of the lubricating oil that is sucked into the compressor 21 by retaining the lubricating oil in the first chamber 75 in the staying chamber 71 during the cooling operation. 74 is provided in the gas-liquid separator 33. Therefore, during the heating operation, a sufficient amount of lubricating oil can be supplied to the compressor 21 to sufficiently lubricate the sliding portion of the compressor 21, and during the cooling operation, the flow rate of the lubricating oil circulating in the refrigerant circuit. And the heat exchange efficiency can be kept high.

  In particular, in the case of the air conditioner 10 according to this embodiment, the height of the upper end portion of the partition wall 74 in the gas-liquid separator 33 is within the mixed liquid of the refrigerant and the lubricating oil flowing into the staying chamber 71 during the heating operation. Since the height is set to be immersed, the refrigerant and the lubricating oil are sufficiently mixed in the wide space in the staying chamber 71 for the heating operation. Therefore, in the air conditioner 10, since the refrigerant and the lubricating oil are sucked into the compressor 21 in a sufficiently mixed state, the flow rate of the lubricating oil flowing in the refrigerant circuit during the heating operation can be stabilized.

  In the air conditioner 10 according to this embodiment, the lubricating oil introduction portion of the gas-liquid separator 33 is configured by the inner peripheral surface 65a of the housing 65 including the staying chamber 71, and the partition wall 74 of the gas-liquid separator 33. Is constituted by a cylindrical body that partitions the bottom side of the stay chamber 71 in the radial direction inside and outside, the radially outer portion of the partition wall 74 is a first chamber 75, and the radially inner portion of the partition wall 74 is a second chamber 76. ing. For this reason, the lubricating oil can be reliably retained in the first chamber 75 during the cooling operation while having an extremely simple structure that is easy to manufacture.

Next, another embodiment shown in FIG. 6 will be described.
In other embodiments, only the configuration of the refrigerant circuit is different, and the basic configuration of the devices in the circuit such as the gas-liquid separator 33 is substantially the same. In FIG. 6, the same reference numerals are given to the common parts with the above embodiment.

  The refrigerant circuit of the air conditioner 10 of this embodiment is a heating refrigerant circuit and a cooling refrigerant circuit as in the above embodiment, and shares the compressor 21, the outdoor heat exchanger 24, and the gas-liquid separator 33. .

  In the downstream portion of the outdoor heat exchanger, the cooling main passage 43 connected to the gas-liquid separator 33 via the cooling expansion valve 29 and the evaporator 53, and the cooling expansion valve 29 and the evaporator 53 are bypassed. A heating bypass passage 44 connected to the gas-liquid separator 33 is connected to be switched by the cooling valve 26 and the heating valve 32.

  The discharge section of the compressor 21 includes a heating main passage 94 connected to the upstream portion of the outdoor heat exchanger 24 via the heating indoor heat exchanger 55 and the heating expansion valve 22, and heating indoor heat. A cooling bypass passage 96 that bypasses the exchanger 55 and the heating expansion valve 22 and is connected to the upstream portion of the outdoor heat exchanger 24 can be switched via a three-way valve 95 provided in the discharge portion of the compressor 21. It is connected to the.

In this embodiment, during the cooling operation, the three-way valve 95 connects the discharge portion of the compressor 21 to the cooling bypass passage 96 side, and the heating valve 32 is closed and the cooling valve 26 is opened, so that the downstream portion of the outdoor heat exchanger 24 is opened. Is connected to the cooling main passage 43 side. Thus, during the cooling operation, the refrigerant discharged from the discharge portion of the compressor 21 flows into the gas-liquid separator 33 through the cooling bypass passage 96 and the cooling main passage 43.
Further, during the heating operation, the three-way valve 95 connects the discharge portion of the compressor 21 to the heating main passage 94 side, the cooling valve 26 is closed, and the heating valve 32 is opened, so that the downstream portion of the outdoor heat exchanger 24 is heated. Connect to the bypass passage 44 side. Thereby, during the heating operation, the refrigerant discharged from the discharge portion of the compressor 21 flows into the gas-liquid separator 33 through the heating main passage 94 and the heating bypass passage 44.

In the case of this embodiment, unlike the above-described embodiment, during the cooling operation, the refrigerant discharged from the compressor 21 by the switching of the passage by the three-way valve 95 does not pass through the inside of the indoor heat exchanger 55 for heating directly. It flows into the upstream part of the exchanger 24. For this reason, since an unnecessary heat loss does not occur in the heating indoor heat exchanger 55 during the cooling operation, the cooling efficiency can be further improved.
Furthermore, in the embodiment, since the refrigerant does not flow into the heating indoor heat exchanger 55 during the cooling operation, the refrigerant liquefies inside the heating indoor heat exchanger 55 due to heat radiation in the heating indoor heat exchanger 55 during the cooling operation. It is possible to prevent the accumulated refrigerant and lubricating oil from staying. In the case of this embodiment, since the refrigerant passes through the cooling bypass passage 96 having a short passage length during the cooling operation, unnecessary pressure loss due to the refrigerant flowing through the passage having a long passage length can be reduced. .

  In addition, this invention is not limited to said embodiment, A various design change is possible in the range which does not deviate from the summary.

10 ... Air conditioner (heat pump type air conditioner)
DESCRIPTION OF SYMBOLS 21 ... Compressor 22 ... Heating expansion valve 24 ... Outdoor heat exchanger 29 ... Cooling expansion valve 33 ... Gas-liquid separator 43 ... Cooling main passage 44 ... Heating bypass passage 53 ... Evaporator (cooling indoor heat exchanger)
55 ... Indoor heat exchanger for heating 65a ... Inner peripheral surface (lubricant introduction part)
70a ... Lead hole 71 ... Residence chamber
72 ... Guide pipe 74 ... Partition wall 75 ... First chamber 76 ... Second chamber 94 ... Heating main passage 95 ... Three-way valve 96 ... Cooling bypass passage

Claims (5)

After the refrigerant compressed by the compressor exchanges heat with the indoor air using the indoor heat exchanger for heating, the refrigerant is decompressed using the expansion valve for heating, and after the heat is exchanged with the outdoor air using the outdoor heat exchanger, the refrigerant passes through the gas-liquid separator. A heating refrigerant circuit to be returned to the compressor;
After the refrigerant compressed by the compressor exchanges heat with the outside air in the outdoor heat exchanger, the refrigerant is decompressed by the cooling expansion valve, and the refrigerant is heat exchanged with the indoor air in the cooling indoor heat exchanger, and then passes through the gas-liquid separator. A refrigerant circuit for cooling back to the compressor;
With
The heating refrigerant circuit and the cooling refrigerant circuit are heat pump air conditioners that share the compressor and the gas-liquid separator,
The gas-liquid separator is
A retention chamber in which the separated liquid is retained;
A guide pipe that is arranged so as to be substantially along the vertical direction in the staying chamber, and guides the gas content of the refrigerant to flow into the inside from above;
A lead-out hole disposed inside the guide pipe and mainly returning a gas component to the compressor;
In the staying chamber,
A partition wall隔成and a second chamber disposed in the guide pipe and said first chamber is not disposed of the lead-out hole guide pipe and the outlet hole,
A lubricating oil introduction section for allowing the lubricating oil mixed in the refrigerant to flow into the first chamber in the gas-liquid separator during cooling operation; and
The heat pump air conditioner characterized in that a height of the partition wall is set higher than a height of the outlet hole.   2. The heat pump air conditioner according to claim 1, wherein the partition wall is set to a height at which the partition wall is immersed in a mixed liquid of refrigerant and lubricating oil that has flowed into the staying chamber during heating operation. The lubricating oil introduction part is constituted by an inner peripheral surface of the staying chamber,
The partition wall is configured by a cylindrical body that partitions the bottom side of the stay chamber inside and outside in the radial direction,
The heat pump air conditioning system according to claim 1 or 2, wherein an outer portion of the stay chamber partitioned by the partition wall is the first chamber and an inner portion is the second chamber. apparatus. The heating refrigerant circuit and the cooling refrigerant circuit share the compressor, the outdoor heat exchanger, and the gas-liquid separator,
In the downstream part of the outdoor heat exchanger, a cooling main passage connected to the gas-liquid separator via the cooling expansion valve and the cooling indoor heat exchanger, the cooling expansion valve, and the A heating bypass passage that bypasses the indoor heat exchanger for cooling and is connected to the gas-liquid separator is connected to be switchable,
The discharge section of the compressor includes a heating main passage connected to the upstream portion of the outdoor heat exchanger via the heating indoor exchanger and the heating expansion valve, the heating indoor exchanger, and the The bypass passage for cooling bypassing the expansion valve for heating and connected to the upstream portion of the outdoor heat exchanger is connected to be switched so as to be switchable. The heat pump air conditioner described.   The heat pump air conditioner according to claim 4, wherein a three-way valve that selectively switches between the heating main passage and the cooling bypass passage is provided in a discharge portion of the compressor.

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