Vehicle air conditioning system

Abstract

The present invention provides a vehicle air conditioning system that achieves improved energy efficiency. The vehicle air conditioning system 10 includes a compressor 21 that compresses refrigerant; an indoor heat exchanger 55 into which the refrigerant from the compressor flows; an outdoor heat exchanger 24 into which the refrigerant from the indoor heat exchanger flows via an electronic expansion valve; and an evaporator 53. The system also includes a heat exchange unit 81 that exchanges heat between a flow path 49 that allows the refrigerant to flow from the compressor 21 to the indoor heat exchanger 55 and a flow path 42 that connects the electronic expansion valve 22 to the outdoor heat exchanger 24.

Description

Technical Field

[0001] The present invention relates to an air-conditioning device for a vehicle. Background Art

[0002] A vehicle air conditioner is known that includes a compressor, an indoor heat exchanger, and an electric expansion valve (for example, see Patent Document 1). Figure 3 As shown in FIG. 2 , as indicated by arrow A2 in the outdoor heat exchanger 24, the refrigerant, which has been vaporized by absorbing heat from the outdoor atmosphere, passes through the heating valve 32, passes through the accumulator 23, and is converted to a gas phase by the compressor 21. Furthermore, the refrigerant flows through the pipe L1, becomes a gas-liquid mixed phase in the heat exchanger 55, flows through the pipe L2, and is converted to a liquid phase by the expansion valve 22. The heat exchanger 55 heats the conditioned air blown out by the blower 52, as shown in FIG. Figure 3 As shown by arrow A1 in FIG, the air is blown into the vehicle compartment.

[0003] [Prior technical literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-75248 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] In conventional vehicle air conditioners, heat in the refrigerant pipe L1 connecting the compressor 21 and the indoor heat exchanger 55 and heat in the refrigerant pipe L2 connecting the indoor heat exchanger 55 and the expansion valve 22 are released into the air, and energy efficiency needs to be improved.

[0008] An object of the present invention is to provide a vehicle air conditioning device that achieves improved energy efficiency.

[0009] [Technical means to solve the problem]

[0010] In order to achieve the above-mentioned purpose, the present invention provides a vehicle air-conditioning device (for example, the vehicle air-conditioning device 10 described below), including: a compressor (for example, the compressor 21 described below), which compresses the refrigerant; an indoor heat exchanger (for example, the indoor heat exchanger 55 described below), into which the refrigerant from the aforementioned compressor flows; an outdoor heat exchanger (for example, the outdoor heat exchanger 24 described below), into which the refrigerant from the aforementioned indoor heat exchange flows via an electronic expansion valve (for example, the electronic expansion valve 22 described below); and an evaporator (for example, the evaporator 53 described below), into which the refrigerant from the aforementioned outdoor heat exchanger flows via the expansion valve; and includes a heat exchange portion (for example, the piping heat exchanger 81 described below), which performs heat exchange between a flow path (for example, the outdoor pipe 49 described below) that allows the refrigerant to flow from the aforementioned compressor to the aforementioned indoor heat exchanger and a flow path (for example, the outdoor pipe 42 described below) that connects the aforementioned electronic expansion valve and the aforementioned outdoor heat exchanger.

[0011] Thus, during heating operation, heat in the pipe connecting the compressor and the indoor heat exchanger is exchanged with the pipe connecting the electronic expansion valve and the outdoor heat exchanger, and the refrigerant inside the pipe absorbs heat, thereby improving the heating effect.

[0012] In this case, the heat exchange unit is preferably located outdoors and comprises a piping heat exchanger (e.g., piping heat exchanger 81 described below). The piping heat exchanger includes piping for refrigerant to flow from the compressor to the indoor heat exchanger and piping for refrigerant to flow from the electronic expansion valve to the outdoor heat exchanger. In the piping heat exchanger, heat from the outdoor air is absorbed by the refrigerant flowing from the electronic expansion valve to the outdoor heat exchanger. Thus, by absorbing heat from the outdoor air by the refrigerant within the piping, the enthalpy of the entire heating refrigerant circuit can be increased.

[0013] (Effects of the Invention)

[0014] According to the present invention, it is possible to provide a vehicle air conditioning device that achieves improved energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a block diagram showing a vehicle air conditioning system according to an embodiment of the present invention.

[0016] Figure 2 This is a diagram illustrating the state of the refrigerant in the vehicle air conditioning system according to one embodiment of the present invention.

[0017] Figure 3 1 is a diagram showing the configuration of a conventional vehicle air conditioning device. DETAILED DESCRIPTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 1 is a diagram showing the configuration of the vehicle air conditioning device 10 .

[0019] The vehicle air conditioner 10 of this embodiment is mounted on a vehicle and performs a heating operation using a heat pump cycle 12. The vehicle air conditioner 10 includes an air conditioning unit 11, a heat pump cycle 12 in which a refrigerant circulates, and a control device (not shown).

[0020] The air conditioning unit 11 includes a duct 51 through which conditioned air flows, a blower 52 housed in the duct 51 , an evaporator 53 serving as an indoor condenser for cooling, an air mix door 54 , and an indoor heat exchanger 55 serving as an indoor condenser for heating.

[0021] The duct 51 includes an air intake port 57 located upstream of the air-conditioning air flow direction and an air outlet port 58 located downstream. The blower 52, evaporator 53, air mix door 54, and indoor heating heat exchanger 55 are arranged in this order from upstream to downstream of the air-conditioning air flow direction.

[0022] The blower 52 is driven by a driving voltage applied under the control of a control device (not shown), for example, to blow conditioned air (at least one of inside air and outside air) sucked into the duct 51 through the air intake 57 toward the downstream side of the duct 51 .

[0023] The evaporator 53 performs heat exchange between the low-pressure refrigerant flowing into the interior and the air-conditioned air flowing through the pipe 51 and passing around the evaporator 53 , and cools the air-conditioned air passing around the evaporator 53 by absorbing heat when the refrigerant evaporates.

[0024] The heating indoor heat exchanger 55 can dissipate heat using the high-temperature and high-pressure refrigerant passing through the interior thereof, thereby heating the conditioned air passing around the heating indoor heat exchanger 55 .

[0025] The air mixing door 54 is rotated by a driving device (not shown) driven under the control of a control device (not shown). Specifically, the air mixing door 54 rotates between a heating position and a cooling position. In the heating position, the air mixing door 54 rotates between a heating position and a cooling position. Figure 1 As shown, the ventilation path (heating path) in the duct 51 toward the indoor heat exchanger 55 for heating is opened, and in the cooling position, the air mixing door 54 bypassing the heating path and the ventilation path (cooling path) on the lower side of the indoor heat exchanger 55 are opened and cover the indoor heat exchanger 55.

[0026] The heat pump cycle 12 includes the above-mentioned evaporator 53 and the indoor heat exchanger 55 for heating, as well as the compressor 21, the expansion valve 22 for heating, the outdoor heat exchanger 24, the storage tank 25, the refrigeration valve 26, the sub-condenser 27, the check valve 28, the refrigeration expansion valve 29, the refrigeration auxiliary heat exchanger 31, the heating valve 32, the accumulator 33, the dehumidification valve 34, and the evaporation capacity control valve 35. The above-mentioned components are connected via a refrigerant flow path.

[0027] The suction port of the compressor 21 is connected to the accumulator 33, and the discharge port is connected to the heating indoor heat exchanger 55. The compressor 21 is driven by the power of an electric motor (not shown) under the control of a control device (not shown). The compressor 21 draws the main gas component of the refrigerant from the accumulator 33, pressurizes the refrigerant, and then discharges it as high-temperature and high-pressure refrigerant through the outdoor pipe 49 to the heating indoor heat exchanger 55.

[0028] The expansion valve 22 is a throttle valve whose opening degree can be adjusted under the control of a control device (not shown). During heating operation, the refrigerant discharged from the heating indoor heat exchanger 55 is decompressed and expanded, then supplied to the outdoor pipe 42 as a low-temperature, low-pressure gas-liquid two-phase (liquid-rich) spray refrigerant. The refrigerant is then discharged through the outdoor pipe 42 to the outdoor heat exchanger 24. The passage from the discharge of the compressor 21, through the heating indoor heat exchanger 55, to the expansion valve 22 constitutes the high-pressure side flow path 41.

[0029] A portion of the outdoor piping 42 and a portion of the outdoor piping 49 are disposed within a pipe heat exchanger 81, which is located outdoors. During heating operation, the pipe heat exchanger 81 absorbs heat from the outdoor atmosphere using the low-temperature, low-pressure refrigerant passing through the outdoor piping 42. Furthermore, it absorbs heat released from the outdoor piping 49. This absorption of heat from the outdoor atmosphere raises the temperature of the low-temperature, low-pressure, gas-liquid two-phase (liquid-rich) spray refrigerant within the outdoor piping 42. The refrigerant flowing out of the heating indoor heat exchanger 55 passes through the expansion valve 22 and flows into the outdoor heat exchanger 24 in a low-temperature, low-pressure state.

[0030] like Figure 1 As shown by arrow A2 in FIG, the outdoor heat exchanger 24 exchanges heat between the refrigerant flowing into the outdoor heat exchanger 24 and the outdoor air. The outdoor heat exchanger 24 can absorb heat from the outdoor air by the low-temperature, low-pressure refrigerant passing through the outdoor heat exchanger 24, and vaporize the refrigerant by absorbing heat from the outdoor air.

[0031] The cooling valve 26 is provided in the cooling flow path 43 connected to the downstream portion of the outdoor heat exchanger 24 in the refrigerant flow path and is opened and closed by a control device (not shown). The cooling valve 26 is open during cooling operation and closed during heating operation.

[0032] The accumulator tank 25 is provided downstream of the outdoor heat exchanger 24 and upstream of the cooling valve 26 in the cooling flow path 43. During cooling operation, the accumulator tank 25 accumulates the remaining refrigerant flowing into the cooling flow path 43 through the outdoor heat exchanger 24.

[0033] The subcondenser 27 is provided on the downstream side of the cooling valve 26 in the cooling flow path 43 , and heat exchange is performed between the refrigerant flowing into the subcondenser 27 and the outdoor atmosphere.

[0034] The check valve 28 is provided on the downstream side of the subcondenser 27 in the cooling flow path 43. During cooling operation, the check valve 28 directs the refrigerant passing through the subcondenser 27 to the downstream side. During dehumidification operation, the check valve 28 prevents the refrigerant from flowing back to the upstream side of the check valve 28 (the subcondenser 27 side) in the cooling flow path 43.

[0035] The refrigeration expansion valve 29 is a so-called throttle valve and is disposed in the refrigeration flow path 43 between the check valve 28 and the inlet of the evaporator 53. The refrigeration expansion valve 29 decompresses and expands the refrigerant passing through the check valve 28, according to a valve opening controlled by a control device (not shown), and then discharges the refrigerant into the evaporator 53 as a low-temperature, low-pressure gas-liquid two-phase (gas-rich) spray refrigerant.

[0036] The auxiliary cooling heat exchanger 31 is arranged across the upstream portion of the cooling flow path 43, upstream of the cooling expansion valve 29, and the downstream portion, downstream of the evaporator 53. During cooling operation, the auxiliary cooling heat exchanger 31 exchanges heat between the upstream and downstream portions, cooling the refrigerant in the upstream portion before it flows into the evaporator 53.

[0037] Here, the cooling flow path 43 in this embodiment is a channel connected to the accumulator 33 from the downstream part of the outdoor heat exchanger 24 through the storage tank 25, the cooling valve 26, the sub-condenser 27, the check valve 28, the cooling auxiliary heat exchanger 31, the cooling expansion valve 29, the evaporator 53, and the evaporation capacity control valve 35.

[0038] The heating valve 32 is provided in the refrigerant flow path that bypasses the cooling flow path 43 and connects the downstream portion of the outdoor heat exchanger 24 to the accumulator 33. The heating valve 32 is opened and closed by a control device (not shown).

[0039] The accumulator 33 is disposed between the confluence portion 46 connecting the downstream end of the cooling flow path 43 and the downstream end of the outdoor heat exchanger 24, and the suction portion of the compressor 21. The accumulator 33 separates the refrigerant flowing in from the confluence portion 46 into gas and liquid, stores the remaining liquid component (liquid phase) of the refrigerant internally, and draws the main gas component (gas phase) of the refrigerant into the compressor 21.

[0040] Dehumidification valve 34 is provided on dehumidification flow path 48, and its opening and closing are controlled by a control device (not shown). Dehumidification flow path 48 connects the portion of cooling flow path 43 downstream of check valve 28 with the portion of high-pressure flow path 41 downstream of heating indoor heat exchanger 55. Dehumidification valve 34 is open during dehumidification operation and closed during other operations (cooling and heating).

[0041] The evaporation capacity control valve 35 is located in the cooling flow path 43, downstream of the evaporator 53, between the cooling auxiliary heat exchanger 31 and the cooling auxiliary heat exchanger. The evaporation capacity control valve 35 is controlled to open and close by a control device (not shown). The evaporation capacity control valve 35 is controlled so that its opening degree during dehumidification operation is smaller than during cooling operation.

[0042] The system includes a cooling refrigerant circuit 19 through which refrigerant circulates during cooling operation, and a heating refrigerant circuit 20 through which refrigerant circulates during heating operation. The two refrigerant circuits 19 and 20 share a compressor 21, an outdoor heat exchanger 24, and an accumulator 33.

[0043] Next, basic operations of the vehicle air conditioner 10 during heating and cooling operations will be described.

[0044] (Heating operation)

[0045] During heating operation, the air mix door 54 becomes Figure 1 In the heating position where the heating path is open, the heating valve 32 is open. In the heating operation, the cooling valve 26, the dehumidification valve 34, and the evaporation capacity control valve 35 are closed.

[0046] The high-temperature, high-pressure refrigerant discharged from the compressor 21 heats the conditioned air in the pipe 51 by dissipating heat in the heating indoor heat exchanger 55. The refrigerant passing through the heating indoor heat exchanger 55 is then expanded by the expansion valve 22 to form a gas-liquid two-phase spray rich in liquid. This spray is then supplied to the outdoor pipe 42. The portion of the refrigerant that passes through the outdoor pipe 42 inside the piping heat exchanger 81 is then discharged to the outdoor heat exchanger 24.

[0047] At this time, in the outdoor pipe 42 portion inside the pipe heat exchanger 81, Figure 1As shown by the arrow A3 in FIG, the temperature of the low-temperature, low-pressure gas-liquid two-phase (rich in liquid phase) spray refrigerant inside the outdoor pipe 42 rises by absorbing heat from the outdoor atmosphere and absorbing heat released from the outdoor pipe 49. Figure 2 As shown, the refrigerant in the outdoor pipe 42 becomes a gas-liquid mixed phase as shown in the region GL, and absorbs heat from the outdoor atmosphere. Figure 2 As shown, the refrigerant in the outdoor pipe 49 has a higher pressure and enthalpy, and dissipates heat to the outside, but this heat is also absorbed by the refrigerant in the outdoor pipe 42, thereby increasing the enthalpy in the entire heating refrigerant circuit 20. Figure 2 1 is a diagram illustrating the state of the refrigerant in the vehicle air conditioner 10 .

[0048] The refrigerant then absorbs heat from the outdoor atmosphere in the outdoor heat exchanger 24 and becomes a gas-rich, two-phase, gas-liquid spray. The refrigerant that has passed through the outdoor heat exchanger 24 flows through the junction 46 into the accumulator 33. The refrigerant that has flowed into the accumulator 33 undergoes gas-liquid separation within the accumulator 33, and the refrigerant that is primarily in the gas phase is drawn into the compressor 21.

[0049] At this time, the conditioned air flowing through the duct 51 of the air conditioning unit 11 passes through the evaporator 53 and then passes through the indoor heat exchanger 55 for heating in the heating path. And, the conditioned air is heated when passing through the indoor heat exchanger 55 for heating. Figure 1 As shown by arrow A1 in FIG. 5 , the air is supplied into the vehicle interior through the air outlet 58 to heat the vehicle interior.

[0050] (Cooling operation)

[0051] During cooling operation, the air mix door 54 is in a position where conditioned air passing through the evaporator 53 flows through the cooling path and covers the indoor heat exchanger 55 (cooling position). The expansion valve 22, cooling valve 26, and evaporation capacity control valve 35 are open. The expansion valve 22 is fully open. The heating valve 32 and dehumidification valve 34 are closed.

[0052] At this time, similar to the heating operation, the high-temperature, high-pressure refrigerant discharged from the compressor 21 passes through the heating indoor heat exchanger 55, is supplied directly to the outdoor pipe 42 through the fully open expansion valve 22, and is discharged to the outdoor heat exchanger 24 through the portion of the outdoor pipe 42 inside the piping heat exchanger 81. The refrigerant then dissipates heat to the outdoor atmosphere in the outdoor heat exchanger 24 before flowing into the cooling flow path 43.

[0053] After the remaining refrigerant is recovered from the storage tank 25, it again dissipates heat to the outdoor atmosphere in the subcondenser 27. The refrigerant then expands through the cooling expansion valve 29, becoming a two-phase gas-liquid spray rich in liquid. The refrigerant then absorbs heat in the evaporator 53, cooling the conditioned air in the pipe 51.

[0054] The gas-rich gas-liquid two-phase refrigerant that has passed through the evaporator 53 then exchanges heat in the cooling auxiliary heat exchanger 31 before flowing into the accumulator 33. The gas-rich refrigerant that has flowed into the accumulator 33 undergoes gas-liquid separation within the accumulator, and the refrigerant that is primarily in the gas phase is drawn into the compressor 21.

[0055] At this time, the conditioned air flowing through the duct 51 of the air conditioning unit 11 is cooled when passing through the evaporator 53. Then, since the air mix door 54 is in the cooling position, it bypasses the indoor heat exchanger 55 for heating and is supplied to the vehicle cabin from the blow-out port 58 for cooling.

[0056] According to this embodiment, the following effects are achieved.

[0057] In this embodiment, the vehicle air conditioner 10 includes a heat exchange unit (pipe heat exchanger 81) that performs heat exchange between the outdoor pipe 49, which carries the refrigerant from the compressor 21 to the indoor heat exchanger 55, and the outdoor pipe 42, which connects the electronic expansion valve 22 to the outdoor heat exchanger 24. Thus, during heating operation, heat from the outdoor pipe 49, the pipe connecting the compressor 21 to the indoor heat exchanger 55, is exchanged to the outdoor pipe 42, the pipe connecting the electronic expansion valve 22 to the outdoor heat exchanger 24. The refrigerant in the outdoor pipe 42 absorbs heat, thereby enhancing the heating effect.

[0058] In this embodiment, the heat exchange unit is located outdoors and comprises a piping heat exchanger 81. The piping heat exchanger 81 includes an outdoor pipe 49 for flowing refrigerant from the compressor 21 to the indoor heat exchanger 55, and an outdoor pipe 42 for flowing refrigerant from the electronic expansion valve 22 to the outdoor heat exchanger 24. In the piping heat exchanger 81, heat from the outside is absorbed by the refrigerant flowing from the electronic expansion valve 22 to the outdoor heat exchanger 24. Thus, by absorbing heat from the outside by the refrigerant in the outdoor pipe 42, the enthalpy of the entire heating refrigerant circuit 20 can be increased.

[0059] The present invention is not limited to the above-described embodiment, and various design changes can be made without departing from the scope of the present invention. For example, the configuration of the vehicle air conditioner is not limited to the configuration of the vehicle air conditioner 10. For example, the heat exchange portion is not limited to the pipe heat exchanger 81.

[0060] Reference numerals

[0061] 10 Vehicle air conditioning system

[0062] 21 Compressor

[0063] 22 Expansion valve

[0064] 24 Outdoor heat exchanger

[0065] 42 Outdoor pipeline

[0066] 49 Outdoor pipeline

[0067] 53 Evaporator

[0068] 55 Indoor heat exchanger

[0069] 81 Pipe heat exchanger (heat exchange unit)

Claims

1. A vehicle air conditioning device, comprising: Compressor, which compresses the refrigerant; an indoor heat exchanger into which the refrigerant from the aforementioned compressor flows; an outdoor heat exchanger into which the refrigerant from the aforementioned indoor heat exchanger flows via an electronic expansion valve; and, an evaporator into which the refrigerant from the outdoor heat exchanger flows through the expansion valve; and The heat exchange unit includes a heat exchange portion for performing heat exchange between a flow path for allowing the refrigerant to flow from the compressor to the indoor heat exchanger and a flow path connecting the electronic expansion valve and the outdoor heat exchanger. The heat exchange unit is arranged outdoors and is composed of a pipe heat exchanger, which is internally provided with pipes for allowing the refrigerant to flow from the compressor to the indoor heat exchanger and pipes for allowing the refrigerant to flow from the electronic expansion valve to the outdoor heat exchanger, and In the pipe heat exchanger, the heat from the outdoor is absorbed into the refrigerant flowing from the electronic expansion valve to the outdoor heat exchanger.

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