Experimental Study on the Thermal-Hydraulic Performance of Louvered Fin and Flat Tube Heat Exchangers

Abstract In this study, the air side heat transfer and pressure drop characteristics of flat tube with louvered fins compact heat exchangers have been experimentally investigated. Three samples of heat exchangers, i.e., one without fins, one with flat louver fins and one with corrugated louver fins are studied. The louvers in the present samples have small louver pitch (Lp = 0.8mm) and high louver angle (θl = 37°) due to the space constraints in automotive applications. The performance tests were conducted in a high standard test facility which are composed of an evaporator chamber, condenser chamber and auxiliary units. In our study, only evaporators are tested and hence the condenser section is the same during the tests. Experimental results under the wet surface conditions show that the cooling capacity and pressure drop performances of evaporator with flat louver fins (HX2) is higher than the one with corrugated louver fins (HX3) while the evaporator without fins has the minimum heat transfer due to no interruptions. This can be due to higher number of tubes in the case of HX2 having small tube pitch. However, the overall performance (ratio of heat transfer per unit volume to pressure drop per unit volume) of HX2 is better than HX3 which signifies the importance of corrugated louver fins.