JP2004322933A - Refrigerating cycle device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device for a vehicle capable of stabilizing the operation of a vapor jet type refrigerating cycle by mitigating the influence of temperature change of a heat carrier medium due to a change in a vehicle state. <P>SOLUTION: The refrigerating cycle device for a vehicle with the vapor jet type refrigerating cycle is provided with a heat storing material 35d storing the heat of cooling water of an engine 12. The vapor jet type refrigerating cycle is operated by the heat stored in the heat storing material 35d. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigeration cycle device for a vehicle including a steam injection refrigeration cycle.
[0002]
[Prior art]
For example, a vehicular refrigeration cycle device used for air conditioning of a vehicle (vehicle compartment) is generally provided with a vapor compression refrigeration cycle in which a compressor, a cooler, a decompression device, and an evaporator are connected in series. It is used for However, the vapor compression refrigeration cycle uses an engine (internal combustion engine), which is a driving power source of the vehicle, as a driving source of the compressor, and has caused a problem that fuel efficiency of the vehicle deteriorates.
[0003]
In order to solve such a problem, it is conceivable to employ a refrigeration cycle device having a steam injection refrigeration cycle (for example, see Non-Patent Document 1). FIG. 3 is a schematic configuration diagram illustrating a refrigeration cycle device including a steam injection refrigeration cycle.
[0004]
The operation of the refrigeration cycle apparatus will be described. The high-pressure refrigerant gas discharged from the ejector 91 is cooled and condensed by heat exchange with the outside air in the cooler 92. The refrigerant condensed and liquefied by the cooler 92 is decompressed by an expansion valve 93 serving as a decompression device, and then is heated and vaporized by heat exchange with air traveling toward a vehicle compartment in an evaporator 94.
[0005]
A part of the liquid refrigerant is taken out from a refrigerant flow path between the cooler 92 and the expansion valve 93 by a pump 95 and is sent to a boiler 96 under pressure. The liquid refrigerant sent to the boiler 96 is recovered by exhaust heat of an engine (not shown), is heated by the high-temperature cooling water, becomes a high-temperature and high-pressure refrigerant gas, and drives the ejector 91. It is mixed with the low-pressure refrigerant gas sucked from the 94 into the ejector 91 and discharged to the cooler 92.
[0006]
As described above, by using the ejector 91 that is driven by effectively using the exhaust heat of the engine, it is possible to suppress the deterioration of the fuel efficiency of the vehicle due to the operation of the refrigeration cycle device.
[0007]
[Non-patent document 1]
Int. J. Refrig. 1990 Vol 13 November (Page 352, FIG. 1)
[0008]
[Problems to be solved by the invention]
However, the temperature of the cooling water of the engine fluctuates under the influence of, for example, the running state of the vehicle. Therefore, the refrigeration cycle apparatus including the steam injection refrigeration cycle has a problem that the operation becomes unstable due to the influence of the temperature change of the cooling water, and the air conditioning feeling deteriorates. In particular, when the temperature of the cooling water was lowered, the driving pressure of the ejector was lowered, and sufficient cooling ability could not be exhibited.
[0009]
That is, since the state of a vehicle varies greatly compared to a building, for example, the refrigeration cycle apparatus provided with a steam injection refrigeration cycle is applied to a building in order to apply the refrigeration cycle apparatus to the vehicle. Compared to the case, more consideration is needed for stabilizing the operation of the steam injection refrigeration cycle.
[0010]
An object of the present invention is to provide a vehicular refrigeration cycle device capable of mitigating the influence of a temperature change of a heat transfer medium caused by a change in the state of a vehicle and stabilizing the operation of a steam injection refrigeration cycle. It is in.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a refrigeration cycle device for a vehicle according to the first aspect of the present invention includes heat storage means for storing heat from a heat transfer medium that has recovered exhaust heat of the vehicle, and the heat stored in the heat storage means The steam injection refrigeration cycle is operated by heating the refrigerant with the boiler. Therefore, by the heat capacity of the heat storage means, it is possible to mitigate the influence of the temperature change of the heat transfer medium due to the change of the state of the vehicle and to stabilize the drive of the ejector, that is, to stabilize the operation of the steam injection refrigeration cycle. it can.
[0012]
In particular, even when the exhaust heat of the vehicle is small and thus it is not possible to expect heat from the heat transfer medium to heat the refrigerant in the boiler, the ejector can be driven stably for a long time by the heat capacity of the heat storage means. Therefore, it is possible to suppress increase of exhaust heat of the vehicle only for the operation of the refrigeration cycle device as much as possible.
[0013]
According to a second aspect of the present invention, in the first aspect, the vehicle is an idling stop vehicle or a hybrid vehicle. That is, in the vehicle, at least the engine is used as a traveling drive source. The boiler heats the refrigerant by the exhaust heat of the engine. Therefore, even if the exhaust heat of the engine is reduced by stopping the engine, the steam injection refrigeration cycle can be stably operated for a long time by the heat capacity of the heat storage means. Therefore, restarting the engine only for the operation of the refrigeration cycle apparatus can be suppressed as much as possible, and the fuel efficiency of the vehicle can be improved.
[0014]
A third aspect of the present invention is directed to the first or second aspect, which relates to a preferable aspect of the heat transfer medium. That is, the vehicle uses the engine as a drive source for driving, and the heat transfer medium is cooling water for the engine. Therefore, the exhaust heat of the vehicle is recovered by the cooling water and sent to the boiler, where the boiler receives heat from the cooling water to heat the refrigerant. The heat storage means stores heat from the cooling water. The temperature of the engine cooling water tends to fluctuate under the influence of the running state of the vehicle. Therefore, applying the invention of claim 1 or 2 in such an embodiment is particularly effective in stabilizing the operation of the steam injection refrigeration cycle.
[0015]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the refrigeration cycle apparatus includes a vapor compression refrigeration cycle having a compressor that draws refrigerant from an evaporator, compresses the refrigerant, and discharges the refrigerant to a cooler. I have. Further, the refrigeration cycle device includes control means for operating the steam injection refrigeration cycle when the heat storage amount of the heat storage means is large, and for operating the vapor compression refrigeration cycle when the heat storage amount of the heat storage means is small. I have. Therefore, the energy saving of the vehicle by the operation in the steam injection refrigeration cycle and the reliable refrigeration performance by the operation in the vapor compression refrigeration cycle can be achieved at a high level.
[0016]
In order to achieve the above object, according to a fifth aspect of the present invention, in a vehicle refrigeration cycle apparatus for operating a steam injection refrigeration cycle by exhaust heat of a vehicle recovered by a heat transfer medium, heat from the heat transfer medium is accumulated. A heat storage means is provided, and the operation of the steam injection refrigeration cycle is performed by heat stored in the heat storage means. Therefore, the effect of the temperature change of the heat transfer medium due to the change in the state of the vehicle can be reduced by the heat capacity of the heat storage means, and the operation of the steam injection refrigeration cycle can be stabilized.
[0017]
In particular, even when the exhaust heat of the vehicle is small and thus the heat from the heat transfer medium cannot be expected for the operation of the steam injection refrigeration cycle, the steam injection refrigeration cycle is driven stably for a long time by the heat capacity of the heat storage means. be able to. Therefore, it is possible to suppress increase of exhaust heat of the vehicle only for the operation of the refrigeration cycle device as much as possible.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a vehicle refrigeration cycle device mounted on an idling stop vehicle will be described. It should be noted that the idling stop vehicle is a vehicle having a function of automatically stopping an engine (internal combustion engine) as a driving source for driving under a certain condition (for example, after warm-up) when the engine is idling.
[0019]
(Circuit configuration and peripheral configuration of vehicle refrigeration cycle device)
FIG. 1 is a schematic configuration diagram showing an engine 12 of a vehicle and a vehicle refrigeration cycle device (hereinafter simply referred to as a refrigeration cycle device) 11 for air-conditioning the vehicle (vehicle compartment). As shown in the figure, the refrigeration cycle apparatus 11 includes an ejector 21 for discharging a high-temperature and high-pressure refrigerant (for example, R134a) gas. The outlet side of the ejector 21 is connected to the inlet side of the cooler 25 via a pipe 22.
[0020]
The cooler 25 is disposed in an engine room of the vehicle and is exposed to outside air. The high-temperature and high-pressure refrigerant gas flowing from the ejector 21 into the cooler 25 is condensed and liquefied by being cooled by heat exchange with the outside air. The outlet side of the cooler 25 is connected to the inlet side of the evaporator 30 via a pipe 29. An expansion valve 31 as a pressure reducing device for reducing the pressure of the liquid refrigerant from the cooler 25 is provided in the middle of the pipe 29.
[0021]
The evaporator 30 is arranged in the middle of an air outlet duct (not shown) toward the passenger compartment. The liquid refrigerant that has been decompressed by the expansion valve 31 is heated and evaporated by heat exchange with the air heading toward the passenger compartment in the evaporator 30 to become a low-pressure refrigerant gas. The outlet side of the evaporator 30 and the low pressure side of the ejector 21 are connected via a pipe 32.
[0022]
In the pipe 29, an inlet side (suction side) of a pump 34 is connected between the cooler 25 and the expansion valve 31 via a branch pipe 33. The pump 34 is composed of an electromagnetic pump. The outlet side (discharge side) of the pump 34 is connected to the inlet side of the heat absorber 35a of the boiler 35 via a pipe 36. The pump 34 takes out a part of the liquid refrigerant from the pipe 29 and sends it to the heat absorber 35a. And pump.
[0023]
The cooling water passage (not shown) in the engine 12 has an inlet connected to the outlet of the radiator 13 and an outlet connected to the inlet of the radiator 13 via pipes 14 and 15. The operation causes the cooling water to circulate between the engine 12 and the radiator 13.
[0024]
Cooling water that has cooled the engine 12 and has become high temperature is sent to the radiator 35 b of the boiler 35 via the branch pipe 16. In the boiler 35, the liquid refrigerant of the heat absorber 35a is heated by heat exchange with the high-temperature cooling water of the radiator 35b, and the liquid refrigerant becomes high-temperature and high-pressure refrigerant gas. In the present embodiment, exhaust heat recovery means (pipes 14 and 15, radiator 13, water pump 17, branch pipe 16) that recovers exhaust heat of engine 12 and sends the recovered heat to boiler 35 remote from engine 12. , Cooling water, etc.), the cooling water forms the heat transfer medium.
[0025]
The boiler 35 includes a heat absorber 35a and a radiator 35b housed in a closed container 35c. A heat storage material 35d as heat storage means is accommodated in the closed container 35c. Heat transfer between the heat absorber 35a and the radiator 35b is performed via the heat storage material 35d. The heat storage material 35d includes, for example, barium hydroxide hydrate, magnesium nitrate hydrate, lithium chloride hydrate, and the like.
[0026]
The outlet side of the heat absorber 35 a of the boiler 35 and the high pressure side of the ejector 21 are connected via a pipe 37. Therefore, the ejector 21 sucks the low-pressure refrigerant gas from the evaporator 30 by using the high-pressure refrigerant gas from the heat absorber 35a of the boiler 35 as a driving flow, and mixes these refrigerant gases, in other words, the low-pressure refrigerant from the evaporator 30. The gas is pressurized and discharged to the cooler 25 side. The high-temperature and high-pressure refrigerant gas discharged from the ejector 21 is sent to the cooler 25 to repeat the above-described vapor injection refrigeration cycle.
[0027]
An intermediate part of a pipe 22 connecting the ejector 21 and the cooler 25 and an intermediate part of a pipe 32 connecting the evaporator 30 and the low pressure side of the ejector 21 are connected via a bypass pipe 27. A compressor 23 driven by the engine 12 is provided in the middle of the bypass pipe 27. An electromagnetic clutch 26 is provided on a power transmission path between the engine 12 and the compressor 23. The electromagnetic clutch 26 permits power transmission from the engine 12 to the compressor 23 when turned on, and shuts off power transmission when turned off.
[0028]
In the pipe 32, a check valve 39 for preventing a backflow of the refrigerant from the ejector 21 side to the evaporator 30 side is disposed between the connection position of the bypass pipe 27 and the low pressure side of the ejector 21. A check valve 38 is disposed on the pipe 37 to prevent the refrigerant from flowing backward from the ejector 21 to the boiler 35.
[0029]
(Control configuration of refrigeration cycle device)
As shown in FIG. 1, an air conditioner ECU 41 that controls the entire refrigeration cycle apparatus 11 is a computer-like control unit including a CPU, a ROM, a RAM, and an I / O interface. An information detecting means 42 is connected to an input terminal of the I / O of the air conditioner ECU 41. The information detecting means 42 includes an air conditioner switch 43 which is an on / off switch of the refrigeration cycle apparatus 11, a temperature sensor 44 for detecting the temperature of the heat storage material 35d of the boiler 35, and various kinds of information necessary for air conditioning control. A sensor (not shown) is provided.
[0030]
The electromagnetic clutch 26 and the pump 34 are connected to the I / O output terminals of the air conditioner ECU 41 via drivers (not shown). The air conditioner ECU 41 is communicably connected to an engine ECU 51 which controls the entire control of the engine 12. The air conditioner ECU 41 controls the electromagnetic clutch 26 and the pump 34 based on various information obtained from the information detecting means 42.
[0031]
(Operation of air conditioner ECU)
The air conditioner ECU 41 as a control means starts the arithmetic processing shown in the flowchart of FIG. 2 according to a program stored in advance when the refrigerant circulation is required under the ON state of the air conditioner switch 43.
[0032]
In step (hereinafter abbreviated as S) 101, the heat storage amount Q (x) of the heat storage material 35d is calculated (estimated) based on information from the information detecting means 42 and the like. That is, in S101, for example, the heat storage amount Q (x) of the heat storage material 35d is calculated (estimated) based on the heat storage efficiency of the heat storage material 35d stored in advance, detection information from the temperature sensor 44, and the like.
[0033]
The process proceeds from S101 to S102. In S102, it is determined whether the heat storage amount Q (x) of the heat storage material 35d calculated in S101 is large or small, that is, whether the heat storage amount Q (x) is equal to or more than a predetermined value Q (set). . S102: Yes, that is, when the heat storage amount Q (x) of the heat storage material 35d is secured to a certain level or more, and the ejector 21 can be suitably driven even in this state and the engine 12 is stopped. , The process proceeds to S103. In S103, the electromagnetic clutch 26 is turned off and the pump 34 is turned on (operated), and the refrigeration cycle apparatus 11 is operated by the above-described steam injection refrigeration cycle.
[0034]
If the determination in S102 is No, that is, it is difficult to say that the heat storage amount Q (x) of the heat storage material 35d is sufficient. If the ejector 21 cannot be suitably driven in this state and the engine 12 is stopped, the process proceeds to S104. Will be migrated to. In S104, the pump 34 is turned off (stopped), and the electromagnetic clutch 26 is turned on to operate the compressor 23. Therefore, the low-pressure refrigerant gas from the evaporator 30 is sucked into the compressor 23, compressed, and discharged to the cooler 25. The high-pressure refrigerant gas discharged from the compressor 23 is returned to the compressor 23 via the cooler 25, the expansion valve 31, and the evaporator 30. That is, the refrigeration cycle apparatus 11 is operated by a vapor compression refrigeration cycle.
[0035]
When the refrigeration cycle apparatus 11 is operated in the vapor compression refrigeration cycle, most of the heat released from the cooling water of the engine 12 by the radiator 35b of the boiler 35 is stored in the heat storage material 35d. Therefore, the heat storage amount Q (x) of the heat storage material 35d increases quickly.
[0036]
When the vehicle is in the idling stop state (the engine 12 is stopped), if the determination in S102 is No, the operation of the engine 12 is requested to the engine ECU 51. The request for operating the engine 12 is canceled if the subsequent S102 determination becomes Yes. If the request to operate the engine 12 to the engine ECU 51 is canceled, the vehicle is again shifted to the idling stop.
[0037]
The present embodiment having the above configuration has the following effects.
(1) The refrigeration cycle device 11 includes a heat storage material 35d that stores heat from the cooling water of the engine 12, and operates the steam injection refrigeration cycle by using the heat stored in the heat storage material 35d. Therefore, by the heat capacity of the heat storage material 35d, the influence of the temperature change of the cooling water (for example, the temperature drop of the cooling water at the time of high-speed running or the temperature rise of the cooling water at the time of traffic congestion) caused by the fluctuation of the running state of the vehicle is reduced. In addition, the operation of the steam injection refrigeration cycle can be stabilized. This leads to an improvement in air conditioning feeling.
[0038]
Further, even if the temperature of the cooling water of the engine 12 tends to decrease due to the idling stop (stop of the engine 12) of the vehicle, the ejector 21 can be stably driven for a long time by the heat capacity of the heat storage material 35d. Therefore, when idling is stopped, restarting the engine 12 only for air conditioning can be suppressed as much as possible, and the fuel efficiency of the vehicle can be further improved.
[0039]
(2) The refrigeration cycle apparatus 11 includes a vapor compression refrigeration cycle in addition to the vapor injection refrigeration cycle. When the heat storage amount Q (x) of the heat storage material 35d is equal to or more than the predetermined value Q (set), the air conditioner ECU 41 operates the steam injection refrigeration cycle, and sets the heat storage amount Q (x) of the heat storage material 35d to the predetermined value Q (x). If it is less than (set), the vapor compression refrigeration cycle is operated. Therefore, it is possible to achieve, at a high level, both improvement in the fuel efficiency of the vehicle by the operation in the steam injection refrigeration cycle and the reliable cooling performance by the operation in the vapor compression refrigeration cycle.
[0040]
When the heat storage amount Q (x) of the heat storage material 35d is less than the predetermined value Q (set) during the operation of the engine 12, the vapor compression refrigeration cycle is operated to store the heat storage amount Q (x) of the heat storage material 35d. It can be said that raising the pressure quickly) is suitable as preparation for idling stop of the vehicle.
[0041]
It should be noted that, for example, the following embodiments can be implemented without departing from the spirit of the present invention. In the above embodiment, the compressor 23 uses the engine 12 as a drive source. This is changed, and the drive source of the compressor 23 is a dedicated electric motor. Alternatively, the engine 12 and the electric motor are used together as a drive source of the compressor 23. In the latter case, for example, when the engine 12 is in operation, the engine 12 is used as a drive source for the compressor 23, and when the engine 12 is stopped, the electric motor is used as a drive source for the compressor 23. .
[0042]
In the above embodiment, the boiler 35 is configured to heat the refrigerant by the cooling water of the engine 12. By changing this, the boiler 35 is configured to heat the refrigerant using the exhaust gas of the engine 12 as a heat source. That is, the exhaust gas is grasped as a heat carrier medium that collects the exhaust heat of the engine 12 and sends it to the boiler 35. Alternatively, the boiler 35 is configured to heat the refrigerant using the lubricating oil of the engine 12 as a heat source. That is, the lubricating oil is grasped as a heat transfer medium that collects the exhaust heat of the engine 12 and sends it to the boiler 35.
[0043]
From the viewpoint of effective use of the exhaust heat, the heat source capable of heating the refrigerant in the boiler 35 is not limited to the exhaust heat of the engine 12, but may be, for example, the exhaust heat of the transmission (for example, lubrication as a heat transfer medium). The refrigerant may be heated by utilizing heat of oil). Further, a system that recovers heat from a plurality of heat-dissipating locations using a heat transfer medium and sends it to the boiler 35 may be configured on the vehicle.
[0044]
O The driving source of the vehicle includes an electric motor in addition to the engine 12. That is, a refrigeration cycle device for a vehicle mounted on an electric vehicle using an electric motor as a drive source for driving, or a vehicle mounted on a hybrid vehicle that uses the electric motor and the engine as a drive source for driving and may run only with the electric motor. Embodiment of the present invention in a refrigeration cycle apparatus. In this case, the boiler 35 may be configured to heat the refrigerant by cooling water that collects the exhaust heat of the electric motor and the exhaust heat of the control circuit (inverter) that controls the electric motor.
[0045]
The present invention is embodied in a refrigeration cycle apparatus using carbon dioxide as a refrigerant.
[0046]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention of the said structure, it becomes possible to reduce the influence of the temperature change of the heat transfer medium resulting from the fluctuation | variation of the state of a vehicle, and to stabilize operation | movement of a steam injection refrigeration cycle.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a refrigeration cycle device for a vehicle.
FIG. 2 is a flowchart illustrating control by an air conditioner ECU.
FIG. 3 is a schematic configuration diagram of a refrigeration cycle device according to the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Refrigeration cycle apparatus for vehicles, 12 ... Engine, 21 ... Ejector, 23 ... Compressor, 25 ... Cooler, 30 ... Evaporator, 31 ... Expansion valve as a pressure reducing device, 34 ... Pump, 35 ... Boiler (35d ... Heat storage) 41. Air-conditioning ECU as control means.

Claims (5)

An ejector that discharges a refrigerant, a cooler that cools the refrigerant from the ejector, a decompression device that decompresses the refrigerant cooled by the cooler, an evaporator that heats the refrigerant depressurized by the decompression device, and the evaporator The refrigerant heated in is ejected to the ejector, a suction side is connected to a refrigerant flow path between the cooler and the decompression device, and a refrigerant flows from the refrigerant flow path between the cooler and the decompression device. A pump that takes out a part, a boiler that heats the refrigerant pumped from the pump, a heat transfer medium that collects exhaust heat of the vehicle and sends it to the boiler, and a refrigerant that is heated in the boiler by the heat transfer medium Is driven by the ejector, and by this driving, is mixed with the refrigerant sucked from the evaporator into the ejector and discharged to the cooler side. In vehicle refrigeration cycle apparatus having a formula refrigeration cycle,
A refrigeration cycle device for a vehicle, comprising: heat storage means for storing heat from the heat transfer medium, wherein the heat stored in the heat storage means heats a refrigerant by the boiler. The vehicle refrigeration cycle apparatus according to claim 1, wherein the vehicle is an idling stop vehicle or a hybrid vehicle, and the boiler heats the refrigerant by exhaust heat of an engine that is a driving source of the vehicle. The refrigeration cycle device for a vehicle according to claim 1, wherein the vehicle uses an engine as a driving drive source, and the heat transfer medium is cooling water for the engine. A vapor compression refrigeration cycle having a compressor that sucks and compresses refrigerant from the evaporator and discharges the refrigerant to the cooler;
Control means for operating the steam injection refrigeration cycle when the heat storage amount of the heat storage means is large, and operating the steam compression refrigeration cycle when the heat storage amount of the heat storage means is small. The refrigeration cycle device for a vehicle according to any one of claims 1 to 3. In a vehicle refrigeration cycle device that operates a steam injection refrigeration cycle by exhaust heat of a vehicle recovered by a heat transfer medium,
A refrigeration cycle apparatus for a vehicle, comprising: heat storage means for storing heat from the heat transfer medium; and operating the steam injection refrigeration cycle by the heat stored in the heat storage means.

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