JP3358303B2 - Automotive air conditioners - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for improving the condensation capacity of an automotive air conditioner.

[0002]

2. Description of the Related Art In recent years, in automobiles, there is a tendency to reduce the size of an engine room to increase the living space in the vehicle interior. In response to this trend, it is required to reduce the size of the condenser of the automotive air conditioner installed in the engine room, but on the other hand, it is also required to increase the air conditioning capacity in order to improve the comfort of the cabin. Have been.

In order to satisfy the above two conflicting requirements, it is necessary to improve the performance of a refrigeration cycle of an automotive air conditioner. As one method of improving the performance of this cycle,
Although the performance of the condenser can be improved, as described above, the demand for downsizing of the engine room requires a compact and high-performance condenser. Conventionally, Japanese Unexamined Utility Model Publication No. Sho 63-168215 discloses a radiator for cooling engine cooling water, in which a condenser is built in an outlet side tank through which cooling water cooled in a heat exchange section flows. The thing which cools a condenser is proposed.

[0004]

In the above-mentioned publication, the refrigerant is cooled and condensed by the engine cooling water, so that the engine cooling water is constantly cooled by the condensing temperature of the refrigerant. 40 ° C. to 55 for 13a
It is necessary to cool down to a temperature of about (.degree. C. or less). For this purpose, the performance of the radiator must be remarkably improved, and it is unavoidable to increase the size of the radiator, which is not practical.

According to the present invention, in a refrigeration cycle of an automotive air conditioner, the temperature of a superheated refrigerant gas immediately after discharge of a compressor is:
Special high temperature (80 ° C to 130 ° C for refrigerant R-13a)
Focusing on the fact that the temperature difference for heat exchange between the engine cooling water at the radiator outlet side (about 60 ° C. to 100 ° C. in summer) is easy to take, and the compressor discharge The objective is to improve the performance of the refrigeration cycle of an automotive air conditioner by using a small condenser by effectively cooling only the immediately superheated refrigerant gas with the engine cooling water at the radiator outlet side. .

[0006]

In order to achieve the above object, the present invention employs the following technical means. According to the first aspect of the present invention, in the refrigeration cycle of the automotive air conditioner, the compressor (1) has a heat exchange means (3, 13) on the discharge side thereof for cooling the superheated refrigerant gas immediately after the discharge of the compressor (1). ,
This heat exchange means is used to cool the radiator after it has been cooled by the radiator.
The engine cooling water on the eta outlet side, and
A bypass for engine cooling water that bypasses the radiator
Engine cooling water and the superheated refrigerant gas before merging with the
The air-conditioning system is characterized in that it is configured to exchange heat with heat and to allow the refrigerant cooled by the heat exchange means (3, 13) to flow into the condenser (4).

According to a second aspect of the present invention, in the vehicle air conditioner according to the first aspect, the heat exchange means is contained in an outlet tank (8d) of the radiator (8), and the superheated refrigerant gas and the superheated refrigerant gas are connected to each other. The radiator (8) is a superheated gas cooler (3) for exchanging heat with engine cooling water at the outlet side. According to a third aspect of the present invention, in the vehicle air conditioner according to the first aspect, the heat exchange means includes an outlet-side water pipe (8h) through which engine cooling water flows out of an outlet tank (8d) of the radiator (8). A superheated gas cooler (3) arranged in the middle of the heat exchanger for exchanging heat between the superheated refrigerant gas and engine cooling water at the outlet of the radiator (8).
It is characterized by being.

According to a fourth aspect of the present invention, in the vehicle air conditioner according to the first aspect, the heat exchanging means is arranged so as to exchange heat with engine cooling water at an outlet side of the radiator (8). (13a) and a heat pipe (13) having a heat absorbing portion (13b) arranged so as to be able to exchange heat with the superheated refrigerant gas. Note that the reference numerals in parentheses of the above-mentioned units indicate the correspondence with specific units described in the embodiments described later.

[0009]

According to the first to fourth aspects of the present invention,
Because of the above technical means, in the refrigeration cycle of the automotive air conditioner, heat is generated between the high-temperature superheated refrigerant gas immediately after discharge from the compressor (1) and the engine cooling water at the outlet of the radiator (8). By performing the replacement, only the superheated refrigerant gas immediately after the discharge of the compressor (1) can be effectively cooled by the engine cooling water on the outlet side of the radiator (8). Therefore, since the cooled refrigerant flows into the condenser (4), the required condensation capacity can be sufficiently exhibited even if a small condenser (4) is used. Moreover, since the condenser (4) itself is not cooled by the engine cooling water as in the prior art, it is not necessary to increase the size of the radiator (8).

Therefore, it is possible to improve the performance of the refrigeration cycle of the automotive air conditioner without increasing the size of the condenser (4) and the radiator (8), which is extremely useful in practice. According to the fourth aspect of the present invention, in addition to the above-described effects, the heat pipe (13) is used, so that during a high-load operation such as a hill running in summer,
Even if the condition that the discharge superheated gas temperature is lower than the radiator (8) outlet side cooling water temperature occurs, the heat pipe (1
From the operation characteristic of 3), there is an advantage that heat does not flow backward from the cooling water on the outlet side of the radiator (8) to the superheated discharge gas, so that there is no adverse effect on the refrigeration cycle.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. (First Embodiment) FIG. 2 shows a refrigerating cycle of an air conditioner for a vehicle to which the present invention is applied, and 1 is a compressor, which is driven by a vehicle engine (drive source, not shown) via an electromagnetic clutch 2. It is driven. Reference numeral 3 denotes a superheated gas cooler that cools a high-temperature, high-pressure superheated refrigerant gas immediately after being discharged from the compressor 1, and heat-exchanges the supercooled refrigerant gas with the engine cooling water at the radiator outlet side, which will be described in detail later. This is for cooling the superheated refrigerant gas.

Reference numeral 4 denotes a condenser for exchanging heat with the air blown by a cooling fan (not shown) to cool and condense the gas refrigerant cooled by the superheated gas cooler 3. 5 is a liquid receiver that collects the liquid refrigerant condensed in the condenser 4 and draws only the liquid refrigerant downstream of the cycle, 6 is a temperature-operated expansion valve that constitutes a pressure reducing means for the refrigerant, and 7 is a refrigerant evaporator. The refrigerant is evaporated by exchanging heat with air-conditioned air blown by an air-conditioning blower, which is cooled by the latent heat of evaporation of the refrigerant, and is blown out into the passenger compartment as cool air.

FIG. 1 shows an example of an arrangement of the superheated gas cooler 3, the condenser 4 and the radiator 8 which constitute a main part of the present invention. There is provided an inlet tank 8b having an inlet pipe 8a into which the cooling water from 9 flows. An outlet tank 8d having an outlet pipe 8c through which the cooling water flows is provided below the radiator 8.
Between the upper and lower tanks 8b and 8d, a tube 8e having a flat cross section and a core (heat exchange portion) 8g composed of corrugated fins 8f are provided. Reference numeral 10 denotes a water pump driven by the engine 9 for circulating cooling water in an engine cooling water circuit.

Reference numeral 11 denotes a thermostat for opening and closing a cooling water circuit to the radiator 8 according to the temperature of the cooling water, and 12 denotes a bypass circuit for engine cooling water. In the first embodiment, the above-described superheated gas cooler 3 is installed in the outlet tank 8d of the radiator 8, and heat exchange between the engine cooling water and the superheated refrigerant gas at the radiator outlet side cools the superheated refrigerant gas. It is like that. 3a is a superheated gas inlet from the compressor 1 to the superheated gas cooler 3, and 3b is its outlet.

In this embodiment, the condenser 4 is arranged in parallel with the radiator 8 so as to be in direct contact with the side of the radiator 8, and the condenser 4 and the radiator 8 are integrated in advance and have an integral structure. It is designed to be installed in the engine room of a car. The cooling air is blown to the cooling air 4 and the cooling air 8 by a common blowing fan (not shown).

In the condenser 4, an inlet header 4b having a refrigerant inlet 4a is provided at a lower portion thereof, and an outlet header 4d having a refrigerant outlet 4c is provided at an upper portion thereof.
Between the upper and lower headers 4b and 4d, a tube 4e having a flat cross section and a core (heat exchange portion) 4g composed of corrugated fins 4f are provided. Next, the operation of the first embodiment in the above configuration will be described.
FIG. 3 shows the running pattern and time of the automobile on the horizontal axis.
The temperature of each part is shown on the vertical axis. During normal running of the car, the amount of cooling water to the radiator 8 is reduced by the action of the thermostat 11, so that the cooling water is sufficiently cooled by the radiator 8, and 60 ° as shown in 3
The temperature is low enough around C.

On the other hand, in the air conditioning refrigeration cycle, the compressor 1
Since the superheated refrigerant gas immediately after the discharge of the superheated gas has a high temperature of about 80 to 100 ° C.,
It is cooled by heat exchange with low-temperature engine cooling water around C. Then, the refrigerant gas whose temperature has dropped after cooling flows into the condenser 4, so that even if the condenser 4 is small, it is possible to exhibit a sufficient condensing capacity.

In the case of extremely rare high load operation such as running uphill in summer, the temperature of the superheated gas on the discharge side of the compressor rises to about 100 to 130 ° C., but the radiator outlet water temperature also rises to 100 ° C. As a result, the temperature difference between the two decreases, and the cooling effect of the superheated gas also decreases. However, since the high-load operation rarely continues for a long time, it does not pose a significant problem in practical use.

Further, since the radiator outlet water temperature is low when the engine is started, it can sufficiently contribute to the improvement of the cooling capacity (cool down performance) at the time of starting the air conditioner. (Second Embodiment) FIG. 4 shows a second embodiment, in which a radiator 8 is provided.
Unlike the first embodiment in which the condensers 4 are arranged in parallel on the sides of the radiator 8, the condensers 4 are arranged in series on the air upstream side of the radiator 8. The present invention can be similarly implemented in this configuration.

In the second embodiment, the superheated gas cooler 3 is arranged in the outlet water pipe 8h for returning the low-temperature cooling water from the outlet tank 8d of the radiator 8 to the engine 9.
The heat exchange between the superheated gas and the low-temperature cooling water is performed. (Third Embodiment) FIGS. 5 and 6 show a third embodiment in which a heat pipe 13 is provided as a means for exchanging heat between the cooling water at the radiator outlet side and the superheated refrigerant gas immediately after discharge from the compressor 1. .

That is, the heat pipe 13 extends from the outlet tank 8d of the radiator 8 to the inlet header 4b of the condenser 4, and is disposed so as to penetrate both of them. The heat radiating portion 13a of the heat pipe 13 is disposed in the outlet tank 8d of the radiator 8, while the heat absorbing portion 1a
3b is disposed in the inlet header 4b of the condenser 4. Here, the through-portions of the outlet tank 8d of the radiator 8 and the inlet-side header 4b of the condenser 4 are sealed to prevent leakage of refrigerant and cooling water.

In the third embodiment, the superheated refrigerant gas discharged from the compressor 1 and rising to a high temperature of, for example, 80 ° C. to 130 ° C. is cooled by the heat absorbing portion 13b of the heat pipe 13, and The amount of heat absorbed by the pipe 13 is relatively low at the radiator outlet (60
(° C to 100 ° C). In this way, the refrigerant gas cooled by the heat absorbing portion 13b of the heat pipe 13 flows into the condenser 4, so that even if the condenser 4 is small, the necessary condensing ability can be sufficiently exhibited. .

In addition, since the heat pipe 13 is used, during high-load operation such as when traveling uphill in summer,
Even if a condition occurs in which the temperature of the discharged superheated gas is lower than the temperature of the radiator outlet side cooling water, the reverse flow of heat from the radiator outlet side cooling water to the discharged superheated gas does not occur due to the operating characteristics of the heat pipe 13, and the refrigeration There is an advantage that no adverse effect on the cycle occurs.

(Fourth Embodiment) FIG. 7 shows a fourth embodiment in which the condenser 4 is directly integrated below the radiator 8 and the heat pipe 13 of the third embodiment is applied. is there. (Fifth Embodiment) FIG. 8 shows a fifth embodiment in which the condenser 4 is arranged in series upstream of the radiator 8 in the air flow.
This is an application of the heat pipe 13 of the third embodiment. FIG. 8 is a top view, in which an inlet header 4b of the condenser 4 and an outlet tank 8d of the radiator 8 are disposed on the upper side, and a heat pipe 13 is installed between the both 4b and 8d. I have.

The operation of the fourth and fifth embodiments is the same as that of the third embodiment and will not be described. FIG. 9 is a Mollier diagram of the refrigeration cycle, in which the refrigerant cooling action in the region of the superheated refrigerant gas indicated by T in the drawing is shown by the superheated gas cooler 3 of the first and second embodiments or the heat pipe 13 of the third to fifth embodiments. It is done in.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of the present invention.

FIG. 2 is a refrigeration cycle diagram of the first embodiment.

FIG. 3 is a characteristic diagram for explaining the operation of the first embodiment.

FIG. 4 is a schematic configuration diagram of a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a third embodiment of the present invention.

FIG. 6 is a refrigeration cycle diagram of a third embodiment.

FIG. 7 is a schematic configuration diagram of a fourth embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of a fifth embodiment of the present invention.

FIG. 9 is a Mollier diagram of a refrigeration cycle for explaining the operation of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 Superheated gas cooler 4 Condenser 8 Radiator 8d Outlet tank 13 Heat pipe

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-271518 (JP, A) JP-A-51-68048 (JP, A) JP-A-5-231147 (JP, A) 28612 (JP, U) Japanese Utility Model Showa 63-168215 (JP, U) Japanese Utility Model Showa 60-50761 (JP, U) Japanese Utility Model 2-7005 (JP, U) Japanese Utility Model 5-47756 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) B60H 1/32 F25B 1/00 F25B 40/04 B60H 1/00 F01M 5/00 F01P 3/18

Claims (4)

(57) [Claims] 1. A refrigeration cycle of an automotive air conditioner, the compressor discharge side, the superheated refrigerant gas immediately after the compressor discharge
A heat exchange means for cooling, the heat exchange means being provided with a radiator cooled by a radiator;
The engine cooling water on the eta outlet side, and
A bypass for engine cooling water that bypasses the radiator
Engine cooling water and the superheated refrigerant gas before merging with the
An air conditioner for an automobile, wherein the air conditioner is configured to exchange heat with a heat exchanger, and the refrigerant cooled by the heat exchange means is caused to flow into a condenser. 2. The superheated gas cooler, wherein the heat exchange means is built in an outlet tank of the radiator and exchanges heat between the superheated refrigerant gas and engine cooling water at the radiator outlet side. The automotive air conditioner according to claim 1. 3. The heat exchange means is disposed in the middle of an outlet water pipe through which engine cooling water flows out of an outlet tank of the radiator, and exchanges heat between the superheated refrigerant gas and the engine cooling water at the radiator outlet side. The automotive air conditioner according to claim 1, wherein the air conditioner is a superheated gas cooler. 4. A heat exchanger wherein the heat exchanging means has a radiator disposed so as to be able to exchange heat with engine cooling water at an outlet side of the radiator, and a heat absorbing section arranged so as to be able to exchange heat with the superheated refrigerant gas. The vehicle air conditioner according to claim 1, wherein the air conditioner is a pipe.