Heat exchanger

Abstract

A gas cooler includes paired header tanks, and a plurality of parallel flat tubes disposed between the header tanks. Each header tank is configured such that an outside plate, an inside plate, and an intermediate plate are brazed together in layers. When the height of each flat tube is represented by T (mm), the distance between each of the opposite longitudinal end surfaces of each flat tube and an outer surface of the corresponding intermediate plate is represented by L (mm), and the width of each communication hole of the intermediate plate is represented by W (mm), relations L≧0.7 T and 1.1 T≦W≦2.5 T are satisfied. This gas cooler can minimize an increase in pressure loss when supercritical refrigerant flows from the flat tubes into first refrigerant flow sections of the outside plate and flows from the first refrigerant flow sections into the flat tubes.

1 . A heat exchanger comprising a pair of header tanks disposed apart from each other and each having at least one header section; and a plurality of flat tubes disposed in parallel between the two header tanks and having opposite end portions connected to the respective header tanks, wherein each of the two header tanks is configured such that an outside plate, an inside plate, and an intermediate plate intervening between the outside and inside plates are brazed together in layers; the outside plate has at least one outwardly bulging portion extending in the longitudinal direction of the header tank and having an opening closed by the intermediate plate, the interior of the outwardly bulging portion serving as a first refrigerant flow section; the inside plate has a plurality of tube insertion holes in the form of through-holes formed in a region corresponding to the outwardly bulging portion and spaced apart from one another along the longitudinal direction of the inside plate; opposite end portions of the flat tubes are inserted through the respective tube insertion holes of the inside plates of the two header tanks, and are brazed to the inside plates; the intermediate plate has communication holes in the form of through-holes formed for allowing the tube insertion holes of the inside plate to communicate with the first refrigerant flow section of the outside plate, the communication holes communicating with one another via communication portions, each of which is formed between adjacent communication holes of the intermediate plate; the communication portions and portions of the communication holes which correspond to the communication portions form a second refrigerant flow section in the intermediate plate, the second refrigerant flow section communicating with the first refrigerant flow section of the outside plate and allowing refrigerant to flow therethrough in the longitudinal direction of the header tank; the header section is formed by portions of the three plates which constitute the corresponding header thank and which correspond to the outwardly bulging portion; and the longitudinal opposite ends of the flat tubes are positioned within the second refrigerant flow sections of the intermediate plates of the two header tanks, wherein
 when the height of each flat tube is represented by T (mm), the distance between each of the opposite longitudinal end surfaces of each flat tube and an outer surface of the corresponding intermediate plate is represented by L (mm), and the width of each communication hole of the intermediate plate is represented by W (mm), relations L≧0.7 T and 1.1 T≦W≦2.5 T are satisfied.   
   
   
       2 . A heat exchanger according to  claim 1 , wherein a relation L≦2.5 T is satisfied. 
   
   
       3 . A heat exchanger according to  claim 1  or  2 , wherein the first header tank includes a plurality of header sections arranged in the longitudinal direction of the header tank; the second header tank includes a header section(s), the number of which is one fewer than the number of the header sections of the first header tank and which faces adjacent two header sections of the first header tank; a header section at one end portion of the first header thank is an inlet header section having a refrigerant inlet, and a header section at the other end portion of the first header thank is an outlet header section having a refrigerant outlet. 
   
   
       4 . A heat exchanger according to  claim 3 , wherein the first header tank includes two header sections, and the second header tank includes a single header section.