JP2014037169A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong cooling duration time of an air conditioner for a vehicle which is made favorable in respect of cost and energy consumption, by using a fluid pump.SOLUTION: As a fluid pump, in a refrigeration cycle A of the air conditioner for a vehicle, for sucking a refrigerant from a storage regenerator 70 provided at a downstream side of an evaporator 50, and discharging the refrigerant to the evaporator 50, there is used a jet pump 80 having: a diffuser 82 whose end part on a small diameter side is connected to a suction flow path 13; and a nozzle 84 for jetting, from an intermediate part of the diffuser 82, a high pressure refrigerant flowing in from a drive flow route 12, converting pressure energy of the high pressure refrigerant into speed energy, and decompressing and expanding the refrigerant. The jet pump sucks the refrigerant from the suction flow path 13 by drive flow formed by a spout of the refrigerant from the nozzle 84, and can discharge the refrigerant from a discharge port 81 provided on a large diameter side of the diffuser 82.

Description

  The present invention relates to a vehicle air conditioner capable of continuing cooling by an evaporator even when a compressor is stopped.

  2. Description of the Related Art Conventionally, a vehicle air conditioner is known that can continue cooling even when the engine is stopped by idling stop control and the operation of the compressor is stopped (see, for example, Patent Document 1).

  This conventional vehicle air conditioner includes a cold storage heat exchanger in the refrigerant passage between the condenser and the evaporator, stores liquid refrigerant in the cold storage heat exchanger while traveling (during operation of the compressor), and stores cold. To do. In addition, when the vehicle stops (while the compressor is stopped), an ejector is provided that supplies the high-pressure refrigerant of the compressor to the evaporator while mixing the refrigerant of the cold storage heat exchanger.

  In this prior art, when the compressor is stopped, liquid refrigerant is circulated by the ejector, the cold storage heat of the cold storage material is maintained, and the cooling can be continued while there is a high-low pressure difference in the refrigeration cycle. In addition, by using an ejector for transporting the refrigerant when the vehicle is stopped, cost and energy consumption can be reduced as compared with those using an electric pump.

JP 2005-271906 A

However, in the above-described prior art, when the refrigerant is transferred when the compressor is stopped, the ejector, which is a fluid pump, is used to generate a driving flow for transferring the refrigerant. Therefore, the pressure in the nozzle portion in the ejector is increased. There was a need.
For this reason, when cooling is continued while the compressor is stopped, the pressure in the evaporator is originally kept at a low pressure as much as possible to suppress the rise in the evaporator's direct temperature. It is difficult to maintain the pressure in the evaporator at a low pressure, leading to a reduction in cooling duration.

  The present invention has been made paying attention to the above-described conventional problems, and aims to extend the cooling duration in a vehicle air conditioner that is advantageous in cost and energy consumption using a fluid pump. To do.

In order to achieve the above object, the present invention
A refrigeration cycle with a compressor, condenser, decompressor, and evaporator in the refrigerant path;
A regenerator heat exchanger provided with a regenerator material provided downstream of the evaporator in the refrigeration cycle and cooled by a low-pressure refrigerant from the evaporator when the compressor is movable;
A drive flow path branched from the discharge side of the compressor;
Driving flow path opening / closing means for opening and closing the driving flow path;
A suction flow path connected to the cold storage heat exchanger;
A diffuser having a small-diameter end connected to the suction flow path, and a high-pressure refrigerant flowing from the drive flow path is ejected from an intermediate portion of the diffuser, and the pressure energy of the high-pressure refrigerant is converted into velocity energy to generate a refrigerant. A nozzle that decompresses and expands the refrigerant, sucks the refrigerant from the suction flow path by a driving flow formed by jetting the refrigerant from the nozzle, and can discharge the refrigerant from a discharge port connected to the large-diameter side of the diffuser A jet pump,
A discharge flow path for supplying the refrigerant discharged from the discharge port to the evaporator;
A means for executing cooling continuation control for continuing the cooling operation by the evaporator when the compressor is stopped, and during non-cooling continuation control, the drive flow path opening / closing valve is closed, and during the cooling continuation control, Control means for opening the drive flow path opening / closing valve and driving the jet pump to supply refrigerant from the discharge flow path to the evaporator;
It was set as the vehicle air conditioner characterized by providing.

In the vehicle air conditioner of the present invention, during the cooling continuation control, in the jet pump, the pressure of the high-pressure refrigerant supplied from the driving flow path is ejected from the nozzle in the middle part of the diffuser to generate a driving flow, and from this nozzle, The refrigerant in the suction channel is sucked into the diffuser by the pressure difference due to the speed difference between the refrigerant injected by converting the pressure energy into velocity energy and the refrigerant in the suction channel connected to the diffuser, and the evaporator is discharged from the discharge port. Is discharged.
As described above, since the jet pump does not have a boosting unit, it is possible to suppress the pressure increase in the evaporator and to extend the cooling duration time as compared with the conventional case where the pressure is increased using the ejector. Can be achieved.
In addition, since a gas refrigerant having a density lower than that of the liquid refrigerant is used to form the driving flow in the jet pump, the required volume when converted at the same mass flow rate is several times that of the liquid refrigerant. The outlet flow velocity of the nozzle is increased and the pump suction amount is increased as compared with the case of using the refrigerant. Therefore, the refrigerant flow rate in the evaporator increases, and the cooling performance when the compressor is stopped can be improved.

FIG. 3 is a circuit diagram illustrating a refrigeration cycle of the vehicle air conditioner according to the first embodiment. It is sectional drawing which shows typically the jet pump used for the vehicle air conditioner of Embodiment 1. FIG. It is sectional drawing which shows typically the ejector of an example of the prior art compared with Embodiment 1. FIG.

Below, the vehicle air conditioner of Embodiment 1 is demonstrated based on FIG. 1 and FIG.
(Configuration of Embodiment 1)
First, the structure of the vehicle air conditioner of Embodiment 1 is demonstrated.
As shown in FIG. 1, the vehicle air conditioner of Embodiment 1 includes a refrigeration cycle A in which a compressor 20, a condenser 30, a decompressor 40, and an evaporator 50 are sequentially arranged in a refrigerant passage 10.
Further, a storage regenerator 70 as a regenerator heat exchanger provided with a regenerator material cooled by a low-pressure refrigerant is provided on the outlet side of the evaporator 50 in the refrigerant passage 10.

The compressor 20 is disposed in an engine room (not shown) of the vehicle and driven by the engine (not shown), and compresses and discharges the refrigerant to high temperature and high pressure.
The condenser 30 is disposed in an engine room (not shown), and cools and liquefies the refrigerant compressed to high temperature and high pressure by the compressor 20 by heat exchange with the outside air. The condenser 30 is provided with a liquid tank 30a, and a filter (not shown) for filtering the refrigerant is provided therein.
The decompressor 40 decompresses the high-pressure liquid refrigerant by passing it through an orifice or a pressure-reducing valve to obtain a low-temperature / low-pressure liquid refrigerant.

  The evaporator 50 is disposed in an air conditioning unit (not shown) disposed in the passenger compartment, and performs heat exchange with the passenger compartment air flowing in the air conditioning unit, thereby evaporating the low-temperature and low-pressure liquid refrigerant and reducing the temperature. -It is a low-pressure gas refrigerant, which cools the passenger compartment air and cools the passenger compartment.

A storage regenerator 70 capable of storing refrigerant is provided in the middle of the flow path 11 connecting the evaporator 50 and the compressor 20.
The storage regenerator 70 includes a cylindrical tank main body 71 capable of storing a refrigerant, and a regenerator 72 provided on the outer periphery of the tank main body 71 and capable of exchanging heat with the refrigerant stored in the tank main body 71. Yes. In addition, as the cool storage material 72, what contains water and a highly water-absorbent resin (sodium polyacrylate), and well-known things, such as a paraffin, are used.
Further, as shown in the figure, the pipe 11 a on the evaporator 50 side of the flow path 11 is opened at the upper part of the tank main body 71, while the pipe 11 b on the downstream side of the flow path 11 is opened at the upper end of the tank main body 71. Is extended downward from the upper portion of the tank body 71 and is led out to the outside.

  Further, in the refrigeration cycle A, the refrigerant stored in the storage regenerator 70 is sucked from the suction flow path 13 by the driving flow formed by the high-temperature and high-pressure refrigerant on the discharge side of the compressor 20 supplied from the driving flow path 12. A jet pump 80 that discharges upstream of the evaporator 50 via the discharge flow path 14 is provided.

An outline of the structure of the jet pump 80 will be described with reference to FIG. 2. The jet pump 80 has a discharge port 81 provided at one end and gradually contracts along the axial direction from the discharge port 81 toward the inside. A diameter diffuser 82 is formed.
A suction hole 83 is formed along the axial direction continuously to the minimum diameter portion of the diffuser 82, and the suction hole 83 is connected to the suction flow path 13.

  A nozzle 84 is formed along the entire inner periphery of the diffuser 82 in the axial direction, and the nozzle 84 is connected to the drive flow path 12. Further, in the diffuser 82, the downstream portion of the nozzle 84 is a mixing portion 85 of the refrigerant ejected from the nozzle 84 and the refrigerant sucked from the suction hole 83.

  An opening / closing switching valve 90 as a driving flow path opening / closing valve that opens and closes the driving flow path 12 is provided at a connection portion between the driving flow path 12 and the refrigerant path 10. The open / close switching valve 90 is normally in a closed state in which the refrigerant passage 10 and the drive flow path 12 are blocked, and communicates the refrigerant passage 10 and the drive flow path 12 during valve opening operation.

Switching of the open / close switching valve 90 is controlled by an air conditioning control circuit (control means) 100 that controls the operation of the vehicle air conditioner.
The air conditioning control circuit 100 is provided with a so-called idling stop in addition to well-known control in which detection values related to the cabin temperature necessary for controlling the vehicle air conditioner are input from various sensors (not shown) to control the air temperature. Thus, in the state where the engine (not shown) is stopped and the compressor 20 is stopped, the cooling continuation process is performed in which the cooling in the evaporator 50 is continued using the liquid refrigerant stored in the storage regenerator 70. During this cooling continuation process, the normally opened / closed switching valve 90 is opened, and when a preset condition for ending the cooling continuation is satisfied, the opening / closing switching valve 90 is returned to the closed state.
Satisfaction of the end condition of the cooling continuation process means that the idling stop is completed, the preset time has elapsed, the liquid refrigerant in the storage regenerator 70 is exhausted, or the evaporator 50 has passed. This is the case when the blower temperature becomes higher than the control target temperature. At least one of these may be set as an end condition, or a plurality of these may be set as end conditions, and the process may be ended when one of them is satisfied.

  The idling stop is to stop the engine while parked or waiting for a signal, stop the engine by detecting a temporary stop, detect the start operation and detect the engine (not shown). This is a well-known control for restarting. In the first embodiment, it is assumed that the control unit that executes the idling stop outputs the idling stop signal sst toward the air conditioning control circuit 100 while the idling stop is being performed.

(Operation of Embodiment 1)
Next, the operation of the first embodiment will be described.
<During normal driving (non-idling stop)>
During normal travel, the open / close switching valve 90 is in a normal state, that is, a state in which the refrigerant passage 10 is communicated.
Therefore, in such a control state, a general cooling operation is performed in the vehicle air conditioner, and the refrigerant is circulated through the refrigerant passage 10 along the path indicated by the solid line arrow in FIG.
That is, the compressor 20 compresses and discharges the refrigerant to a high temperature and a high pressure. The high-temperature and high-pressure refrigerant is liquefied by heat exchange (cooling) with the outside air in the condenser 30 and sent to the decompressor 40. In the decompressor 40, the refrigerant is depressurized to become a low-temperature / low-pressure liquid. Further, in the evaporator 50, the refrigerant exchanges heat with the air in the passenger compartment, cools the air in the passenger compartment, and evaporates to lower the temperature / low pressure. And is sucked into the compressor 20 through the storage regenerator 70.
In the storage regenerator 70, the refrigerant that has evaporated in the evaporator 50 into a low-temperature / low-pressure gaseous state absorbs heat from the regenerator 72 and cools the regenerator 72 when passing through the storage regenerator 70. .
Then, when the air conditioning in the passenger compartment is stabilized and the load on the evaporator 50 is reduced, and the cool storage material 72 is cooled and the amount of heat absorbed by the cool storage material 72 is reduced, the refrigerant is liquefied in the tank body 71 of the storage cool storage device 70. And stored.

<When idling is stopped>
When idling stop control is executed based on the control of a general controller (not shown) when the vehicle is stopped, the drive of the compressor 20 is stopped as the drive of the engine Eng is stopped. The discharge of the high-pressure refrigerant from is stopped.

  At this time, the air conditioning control circuit 100 receives the idling stop signal sst, switches the open / close switching valve 90, and connects the discharge side of the compressor 20 to the nozzle 84 of the jet pump 80.

  Accordingly, in the jet pump 80, the high-temperature and high-pressure refrigerant on the discharge side of the compressor 20 indicated by an arrow C12 in FIG. 2 is ejected from the nozzle 84 to the intermediate portion in the axial direction of the diffuser 82. Then, it is decompressed and expanded to generate a driving flow indicated by an arrow DF in FIG. At this time, since the gas refrigerant having a density lower than that of the liquid refrigerant is ejected from the nozzle 84, the outlet flow velocity of the nozzle 84 increases as compared with the case where the liquid refrigerant is used. In this case, the speed is about several times, for example, about four times that when the liquid refrigerant is used.

Due to the driving flow from the nozzle 84, the liquid refrigerant in the storage regenerator 70 is sucked into the diffuser 82 from the suction hole 83 as shown by an arrow C 13 in FIG. 2 and is discharged from the discharge port 81 to the evaporator 50 as indicated by an arrow C14 in FIG. Thereby, the refrigerant stored in the storage regenerator 70 follows the path indicated by the dotted arrow in FIG. 1, that is, the storage regenerator 70 → the suction flow path 13 → the jet pump 80 → the evaporator 50 → the storage regenerator 70. It is circulated in the route.
This discharge operation can be executed until there is no pressure difference between the discharge side of the compressor 20 and the evaporator 50 side.
Therefore, in the evaporator 50, the refrigerant is supplied even after the compressor 20 is stopped, and the refrigerant is evaporated, so that the air can be cooled.

Here, to explain the conventional problems, the conventional ejector 01 shown in FIG. 3 converts the pressure energy of the high-pressure refrigerant flowing from the driving flow path on the pressure reducing valve side into velocity energy, and decompresses and expands the refrigerant. A mixing unit 04 for mixing the refrigerant from the nozzle 02 and the refrigerant from the suction unit 03 downstream of the nozzle 02 and the suction unit 03 for sucking the refrigerant from the cold storage heat exchanger, and a diffuser 05 for increasing the pressure of the refrigerant And are provided in series.
Thus, in the ejector 01, the refrigerant injected toward the evaporator is pressurized in the nozzle 02 and the diffuser 05, and the refrigerant pressure in the evaporator becomes relatively high.

  On the other hand, in the jet pump 80 used in the first embodiment, the refrigerant is sucked from the suction hole 83 based on the flow velocity of the driving flow (arrow DF) by the gas-phase refrigerant from the nozzle 84 in the diffuser 82, as in the conventional case. Therefore, the evaporator 50 can be kept at a low pressure as compared with the conventional one having a boosting portion. Therefore, the temperature rise of the evaporator 50 can be suppressed.

(Effect of Embodiment 1)
The vehicle air conditioner of Embodiment 1 described above has the effects listed below.
a) The vehicle air conditioner of Embodiment 1 is
Refrigeration cycle A provided with a compressor 20, a condenser 30, a decompressor 40, and an evaporator 50 in the refrigerant passage 10, and
In this refrigeration cycle A, a storage regenerator 70 as a regenerator heat exchanger provided on the downstream side of the evaporator 50 and provided with a regenerator 72 that is cooled by a low-pressure refrigerant from the evaporator 50 when the compressor 20 is movable; ,
A drive flow path 12 branched from the discharge side of the compressor 20;
An open / close switching valve 90 as a drive flow path opening / closing means for opening and closing the drive flow path 12;
A suction flow path 13 connected to a storage regenerator 70 as a regenerative heat exchanger;
A diffuser 82 whose end on the small diameter side is connected to the suction flow path 13 and a high-pressure refrigerant flowing from the drive flow path 12 are ejected from an intermediate portion of the diffuser 82, and the pressure energy of the high-pressure refrigerant is converted into velocity energy to generate a refrigerant. Is provided with a nozzle 84 that decompresses and expands the refrigerant, and the refrigerant is sucked from the suction flow path 13 by the driving flow formed by the ejection of the refrigerant from the nozzle 84 and discharged from the discharge port 81 provided on the large-diameter side of the diffuser 82. A possible jet pump 80;
A discharge flow path 14 for supplying the refrigerant discharged from the discharge port 81 to the evaporator 50;
A means for executing cooling continuation control for continuing the cooling operation by the evaporator 50 when the compressor 20 is stopped. During the non-cooling continuation control, the switching valve 90 as a drive flow path opening / closing valve is closed to cool the cooling. An air-conditioning control circuit 100 as a control means for opening the opening / closing switching valve 90 as a driving flow path opening / closing valve and driving the jet pump 80 to supply the refrigerant from the discharge flow path 14 to the evaporator 50 during continuous control;
It is characterized by having.
Therefore, in the jet pump 80, the high-temperature and high-pressure refrigerant on the discharge side of the compressor 20 is ejected from the nozzle 84 to the intermediate portion in the axial direction of the diffuser 82, and a driving flow indicated by an arrow DF in FIG. With this driving flow, the liquid refrigerant in the storage regenerator 70 is sucked into the diffuser 82 from the suction hole 83 through the suction flow path 13 and discharged from the discharge port 81 to the evaporator 50. Therefore, in the evaporator 50, the refrigerant is supplied even after the compressor 20 is stopped, and the refrigerant is evaporated, so that the air can be cooled.
At this time, since the gas refrigerant having a density lower than that of the liquid refrigerant is ejected from the nozzle 84, the outlet flow velocity of the nozzle 84 is increased as compared with the case where the liquid refrigerant is used, and the refrigerant flow rate is increased accordingly. High cooling performance can be obtained in the evaporator 50.
Further, the jet pump 80 has a structure in which the refrigerant is sucked from the suction hole 83 based on the flow velocity of the driving flow (arrow DF) by the gas-phase refrigerant from the nozzle 84 in the diffuser 82 and does not have a pressure increasing portion as in the conventional case. Therefore, the evaporator 50 can be kept at a low pressure as compared with the conventional one having a booster. Therefore, the temperature rise of the evaporator 50 can be suppressed.

b) The vehicle air conditioner of Embodiment 1 is characterized in that the storage regenerator 70 as a regenerator heat exchanger includes a tank body 71 as a storage unit that liquefies and stores the refrigerant from the evaporator 50. And
Therefore, the liquid refrigerant can be stored in the tank main body 71 in advance while the compressor 20 is being driven, and the cooling performance during the cooling continuation control can be improved as compared with the case where the liquid refrigerant is not stored.

c) Since the vehicle air conditioner of the first embodiment uses the jet pump 80 having the nozzle 84 in the middle in the axial direction of the diffuser 82, the mixing unit 04 and the diffuser 05 are provided downstream of the nozzle 02 as in the prior art. Compared with the ejectors 01 arranged in series, the axial dimension of the jet pump 80 can be shortened.
Therefore, there are few dimensional restrictions when the jet pump 80 is provided integrally with the evaporator 50, and the degree of design freedom is increased accordingly.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to this embodiment. Included in the invention.

For example, the power source of the compressor is not limited to the engine, and other power sources such as an electric motor may be used. For example, even in an electric vehicle or the like, it is possible to continue cooling the evaporator while the compressor is stopped.
In the embodiment, the driving flow path opening / closing means is provided at the connection portion of the driving flow path 12 to the refrigerant passage 10. However, the installation position is not limited to this position, and the driving flow path 12 is provided. It may be in the middle. Alternatively, when the driving flow path opening / closing means is provided at the connection portion of the driving flow path 12 to the refrigerant passage 10 as in the embodiment, a three-way valve structure can be used instead of a simple opening / closing valve structure.

DESCRIPTION OF SYMBOLS 10 Refrigerant path 12 Drive flow path 13 Suction flow path 14 Discharge flow path 20 Compressor 30 Condenser 40 Decompressor 50 Evaporator 70 Reservoir cooler 80 Jet pump 81 Discharge port 82 Diffuser 83 Suction hole 84 Nozzle 85 Mixer 90 Open / close switching Valve (Drive flow path opening / closing means)
100 Air-conditioning control circuit (control means)
A Refrigeration cycle

Claims (2)

A refrigeration cycle with a compressor, condenser, decompressor, and evaporator in the refrigerant path;
A regenerator heat exchanger provided with a regenerator material provided downstream of the evaporator in the refrigeration cycle and cooled by a low-pressure refrigerant from the evaporator when the compressor is movable;
A drive flow path branched from the discharge side of the compressor;
Driving flow path opening / closing means for opening and closing the driving flow path;
A suction flow path connected to the cold storage heat exchanger;
A diffuser having a small-diameter end connected to the suction flow path, and a high-pressure refrigerant flowing from the drive flow path is ejected from an intermediate portion of the diffuser, and the pressure energy of the high-pressure refrigerant is converted into velocity energy to generate a refrigerant. A nozzle that decompresses and expands the refrigerant, sucks the refrigerant from the suction flow path by a driving flow formed by jetting the refrigerant from the nozzle, and can discharge the refrigerant from a discharge port connected to the large-diameter side of the diffuser A jet pump,
A discharge flow path for supplying the refrigerant discharged from the discharge port to the evaporator;
A means for executing cooling continuation control for continuing the cooling operation by the evaporator when the compressor is stopped, and during non-cooling continuation control, the drive flow path opening / closing valve is closed, and during the cooling continuation control, Control means for opening the drive flow path opening / closing valve and driving the jet pump to supply refrigerant from the discharge flow path to the evaporator;
A vehicle air conditioner characterized by comprising: In the vehicle air conditioner according to claim 1,
The cold storage heat exchanger includes a storage unit that liquefies and stores the refrigerant from the evaporator.