JPH0459542B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION -Field of Industrial Application- The present invention relates to a cooling system for an automobile, and more particularly to an evaporator structure used in a cooling system for a motor vehicle having a bypass conduit that bypasses the evaporator.

-Prior art- In a typical automobile cooling system, as shown in Fig. 2, refrigerant that has become superheated steam in an evaporator A is transferred to a compressor B driven by an engine.
A refrigeration cycle is performed in which the refrigerant liquid is compressed and sent to the condenser C to be liquefied, and the refrigerant liquid is adiabatically expanded by the expansion valve D and recirculated to the evaporator A.

By the way, in such an automobile cooling system, consideration is given to the fact that the compression capacity of compressor B varies greatly depending on the operating state of the engine, and that compressor B may be damaged if liquefied refrigerant flows into compressor B. Therefore, the position of the compression start point α of the refrigeration cycle shown in FIG. 3 is usually set as deep as possible in the superheated steam region, that is, at a position to the right of the saturated liquid line. Therefore, the refrigerant that has already become superheated vapor flows through most of the flow path inside the evaporator A of the automobile cooling system, but the refrigerant that is in the superheated vapor state loses heat between it and the cooling air. Exchange efficiency is poor and cooling capacity may become a problem.

For this reason, recently, as shown in Fig. 4, a bypass pipe E is provided immediately after the expansion valve D to bypass the evaporator A, and by returning the refrigerant vapor from the bypass pipe E to the compressor B, liquid refrigerant is reduced as much as possible. Attempts have been made to guide only the air into the evaporator A to improve the efficiency of heat exchange with cooling air. Of course, in order to put this type of automotive cooling system into practical use, it is necessary to completely separate the refrigerant liquid and refrigerant vapor, but it is difficult to install a new gas-liquid separator in a narrow engine room. is unreasonable due to increased vehicle weight and space constraints.

-Object of the Invention- The object of the present invention is to overcome the above-mentioned conventional situation and to obtain an evaporator structure that can put into practical use an automobile cooling system using a bypass pipe by only slightly improving the existing evaporator. It is in.

-Structure of the Invention- In order to achieve this object, the present invention divides the inside of an evaporator into a plurality of spaces so as to form a meandering refrigerant flow path, and the refrigerant is placed on one side of the refrigerant flow path inside the evaporator. An intake port is provided and a refrigerant outlet is provided on the other side to allow the refrigerant to flow in a meandering manner within the evaporator, and a steam extraction pipe is arranged above the interior of the evaporator to connect the vapor extraction pipe to a low pressure side pipeline to the compressor. Continuing on from the above, we propose an evaporator for an automobile cooling system in which the steam extraction pipe has intake holes open to the upper part of each space of the evaporator.

-Example- Hereinafter, details of an example of the present invention will be explained with reference to FIG.

Fig. 1 shows an embodiment in which the present invention is applied to a laminated evaporator.The inside of the evaporator A1, which has a refrigerant intake port 2 at the upper left end and a refrigerant outlet 3 at the upper right end, has a meandering refrigerant flow. 3 by two partition plates 3A and 3B so as to form a path.
The space is divided into individual spaces X, Y, and Z. The interiors of these spaces X, Y, and Z are subdivided into flat refrigerant passages by a plurality of laminated plates 5 having communication holes 4 formed at predetermined ends, and fins 6 are provided on the outer surfaces of these laminated plates 5. By installing it, heat exchange with the cooling air is performed.

Further, in the illustrated embodiment, a steam extraction pipe 7 extending substantially horizontally from the space X to the space Z is disposed above the interior of the evaporator. The inlet portion 7a of this steam extraction pipe 7 is open into the first space X in a state facing the refrigerant intake port 2, and the other end portion 7b of the steam extraction pipe 7 is connected to the bypass pipe E. Thus, the refrigerant air evaporated in the first space X is returned to the compressor B through the bypass pipe E. And the steam extraction pipe 7
A plurality of intake holes 8 which are open into the spaces Y and Z are formed in the middle of the space Y and Z, so that the refrigerant vapor evaporated in the spaces Y and Z is discharged to the bypass pipe E.

Since the evaporator A1 of the illustrated embodiment has the above-described structure, the refrigerant vapor contained in the refrigerant fed into the evaporator A1 from the refrigerant intake port 2 through the expansion valve D as well as the first space The evaporated refrigerant vapor flows into the vapor extraction pipe 7 from the inlet portion 7a of the vapor extraction pipe 7, and is discharged from the bypass pipe E to the outside of the evaporator A1. Therefore, the first
By discharging the refrigerant vapor in the space X to the bypass pipe E, only the liquid refrigerant that has flowed down the first space
Since the refrigerant vapor evaporated in Z can be discharged from the intake hole 8 to the bypass pipe E, gas-liquid separation in the evaporator A1 is promoted and heat exchange efficiency can be improved.
Of course, the steam extraction pipe 7 can be added by simply modifying the existing evaporator, so there is no increase in weight and there is no need to worry about installation space.

- Effects of the Invention - As is clear from the above description, according to the evaporator structure of the present invention, refrigerant liquid and refrigerant vapor can be reliably separated and the refrigerant liquid can flow into the evaporator. In addition to being able to improve heat exchange efficiency, the steam extraction pipe according to the present invention has the following features:
Since it can be easily expanded by simply modifying the existing evaporator, there is no increase in weight and there is no need to worry about installation space.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the evaporator structure according to the first embodiment of the present invention, Fig. 2 is a conceptual diagram of a conventional automobile cooling system, Fig. 3 is an absolute pressure-enthalpy diagram of the cooling system, and Fig. 4 FIG. 1 is a conceptual diagram of an improved conventional automobile cooling system. A... Evaporator, B... Compressor, D
...Expansion valve, E...Bypass pipe, X, Y, Z...
...space, 7...steam extraction pipe, 8... (steam extraction pipe) intake hole.

Claims (1)

[Claims] 1. The inside of the evaporator is divided into a plurality of spaces so as to form a meandering refrigerant flow path, and a refrigerant intake port is provided on one side of the refrigerant flow path inside the evaporator, and a refrigerant outlet is provided on the other side, The refrigerant is made to flow through the evaporator in a meandering manner, and a steam extraction pipe is disposed above the inside of the evaporator, and the steam extraction pipe is connected to a low pressure side pipeline to the compressor, and the vapor extraction pipe is connected to the upper part of each space of the evaporator. An evaporator for a cooling device for an automobile, characterized in that an air intake hole is opened to the air.