JPS61191834A - Evaporator structure of chilling unit for automobile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

1. Prior art 1. In general automotive cooling systems.

As shown in Figure 3, the refrigerant that has become superheated vapor in the evaporator A is compressed by the compressor B, which is driven once by the engine, and sent to the condenser C where it is liquefied, and the refrigerant liquid is adiabatically expanded by the expansion valve. A refrigeration cycle is performed in which the water is recirculated to 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. 4 is usually set as deep as possible within the superheated steam region, that is, at a position to the right of the saturated liquid line. Therefore, the refrigerant that has become superheated vapor is already flowing through most of the flow path inside the evaporator A of the automobile cooling system, but the refrigerant in the superheated vapor state has a high heat exchange efficiency with the cooling air. There are cases where the cooling capacity becomes a problem.

For this reason, recently, as shown in Fig. 5, a bypass pipe E is installed to bypass the evaporator A immediately after the expansion valve.
By returning the refrigerant vapor to the compressor B from the bypass line E, only the liquid refrigerant is transferred to the evaporator A.
Attempts have been made to improve the efficiency of heat exchange between cooling air and cooling air. Of course, in order to put this type of automotive cooling system into practical use, it is necessary to completely separate the liquid refrigerant and refrigerant vapor, but it is difficult to install a new gas-liquid separator in a narrow engine room. , which is unreasonable due to increased vehicle weight and space constraints.

1. Purpose of the Invention 1. The purpose of the present invention is to obtain an evaporator structure that can put an automobile cooling system using a bypass pipe into practical use by slightly improving the existing evaporator, in view of the above-mentioned conventional circumstances. be.

Structure of the Invention In order to achieve this object, the present invention provides an automobile cooling system that provides a bypass line that bypasses the evaporator and returns refrigerant vapor immediately before the evaporator to the compressor, and that receives refrigerant from an expansion valve. The present invention proposes an evaporator structure in which a gas-liquid separation chamber is formed at the inlet of the evaporator, and the upper part of the gas-liquid separation chamber is connected to the bypass pipe.

An embodiment of the present invention will now be described in detail with reference to FIGS. 1 and 2.

Figure 1 shows a first embodiment in which the present invention is applied to a Teminate type evaporator. The space is divided into three spaces x, y, and z by two partition plates 3A and 3B so as to form a coolant flow path. And these spaces X.

The insides of 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 heat exchange with the cooling air is achieved by attaching fins 6 to the outer surfaces of these laminated plates 5. In addition, in the illustrated embodiment, a small cup-shaped tank 7 is added to the upper part of the first space The refrigerant vapor that has flowed into the first space X through the bypass pipe E connected to the evaporator side of the gas-liquid separation chamber 8 is returned to the compressor B.

Since the evaporator A1 of the first embodiment has one or more structures, the refrigerant vapor contained in the refrigerant sent into the evaporator structure from the refrigerant intake port through the expansion valve as well as the first space The evaporated refrigerant vapor collects in the gas-liquid separation chamber 8. Therefore, by discharging the refrigerant vapor in the gas-liquid separation chamber 8 to the bypass pipe E, only the liquid refrigerant that has flowed down the first space X can be introduced into the second space Y. Exchange efficiency can be improved. Of course, this gas-liquid separation chamber 8 can be easily formed by simply modifying the existing evaporator, so there is no increase in weight and there is no need to worry about installation space.

FIG. 2 shows a second embodiment in which the present invention is applied to a fin tube type evaporator A2. part is used as the gas-liquid separation chamber 8A. That is, a small partition wall 11 that opens only the lower part into the distributor 10 is fixed to the inner side of the distributor 10, and the space 8 within the partition wall 11 is fixed.
Bypass pipe E is connected facing A. Therefore, the refrigerant sent from the expansion valve is transferred to the distributor l.
While passing through O, the refrigerant is separated into liquid refrigerant and refrigerant vapor, and the liquid refrigerant is preferentially flowed into each cooling tube 9. Therefore,
Since a liquid refrigerant with a large specific heat flows into the cooling tube 9 of the evaporator A2, heat exchange efficiency is improved, and
Since the outer shape and weight of the distributor 10 according to the present invention are almost the same as those of conventional distributors, there is no increase in weight or space constraints.

Effects of the Invention As is clear from the above description, the evaporator structure of the present invention reliably separates liquid refrigerant and refrigerant vapor and allows the liquid refrigerant to flow into the evaporator, thereby improving heat exchange efficiency in the evaporator. Furthermore, in the present invention,
A gas-liquid separation chamber can be created at the inlet of the evaporator 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 an evaporator structure according to a first embodiment of the present invention, Fig. 2 is a cross-sectional view of the main part of an evaporator according to a second embodiment of the present invention, and Fig. 3 is a conceptual diagram of a conventional automobile cooling system. , FIG. 4 is an absolute pressure car enthalpy diagram of the cooling system, and FIG. 5 is a conceptual diagram of an improved conventional cooling system for automobiles. A: Evaporator, B: Compressor, D: Expansion valve, E: Bypass pipe, 8.8A: Gas-liquid separation chamber, 10: Distributor. Patent applicant: Nissan Motor Co., Ltd.

Claims (1)

[Claims] 1) There is an automobile cooling system in which a bypass pipe is provided to bypass the evaporator and refrigerant vapor immediately before the evaporator is returned to the compressor, and a gas-liquid separation is provided at the inlet of the evaporator that receives refrigerant from the expansion valve. An evaporator structure for an automobile cooling system, characterized in that a chamber is formed, and an upper part of the gas-liquid separation chamber is connected to the bypass pipe.