Evaporator

Abstract

Each heat exchange tube of an evaporator is composed of two press-worked rectangular metal plates joined together in a stacked condition. The metal plates of the heat exchange tube are swelled outward whereby at least one refrigerant flow space extending in the vertical direction and having opened upper and lower ends is provided in the heat exchange tube. Insertion portions to be inserted into header sections of header tanks of the evaporator via tube insertion holes are provided on upper and lower end portions of each heat exchange tube at positions corresponding to the refrigerant flow space. A concave portion is formed in each of the insertion portions, excluding opposite ends thereof with respect to the front-rear direction, of the upper and lower end portions of each heat exchange tube, the concave portion being concaved inward with respect to a longitudinal direction of the heat exchange tube.

Description

Technical field [0001] The present invention relates to an evaporator suitable for use as a vehicle air conditioner installed in, for example, a refrigeration cycle of a motor vehicle. Background technique [0002] In this specification and claims, the downstream side of the air flowing through the ventilation gap between the adjacent heat exchange tubes ( figure 1 , figure 2 as well as Picture 10 The direction indicated by the arrow X) is called front, and the opposite side is called back, and figure 1 , figure 2 as well as Picture 10 Up and down is called up and down. [0003] In recent years, as an evaporator for vehicle air-conditioning capable of achieving smaller size, lighter weight, and higher performance, the applicant has earlier proposed the following evaporator (refer to Japanese Patent Application Laid-Open No. 2008-20098). A pair of header tanks arranged at intervals in the direction and a plurality of flat heat exchange tubes made of aluminum extruded profiles, t...

AI Technical Summary

Problems solved by technology

As a result, the liquid-phase refrigerant flowing into the refrigerant passages of the heat exchange tubes of each heat exchange tube group remains in the gas-liquid mixed-phase refrigerant in the refrigerant inlet header and the refrigerant outlet header of the upper header tank. The amount becomes relatively small, and the effect of preventing the exhaust temperature from rising sharply when the compressor stops is not ideal.

[0006] In addition, the tip of the insertion portion of the heat exchange tube becomes horizontal, and the maximum distance in the vertical direction from the tip of the insertion portion of the heat exchange tube to the inner surface of the connecting wall of the convex portion of the refrigerant inlet header and the refrigerant outlet header As the size becomes larger, the flow resistance in the refrigerant inlet header and the refrigerant outlet header increases, which may degrade performance.

In particular, if the flow path resistance in the refrigerant outlet header increases, the ratio of the gas-phase refrigerant existing in the refrigerant outlet header will increase, so performance degradation may be significant.

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