Numerical Study and Geometric Structure Optimization on Casing Tube for R290 Using Response Surface Method

Abstract

Three types of casing tube heat exchangers for R290 are studied in this paper. Based on CFD, an investigation is conducted into the heat transfer and pressure drop of R290 during flow boiling, and the performance evaluation criteria (PEC) serves to assess the performance of the tube. The results show that PEC value of the corrugated tube with grooves is higher than that of both smooth tube and circular corrugated tube. The performance of corrugated tube with grooves are further studied in this paper, and the influence of three geometric structure parameters (groove number, corrugation height and corrugation spacing) on heat transfer and pressure drop is explored. By using the response surface method (RSM), the significance of the three parameters is obtained. The results reveal that the groove number has the most significant impact on PEC of the corrugated tube with grooves. Under the given working conditions, with constant parameters, the optimal geometric parameters are obtained: the groove number A=10, the corrugation height B=0.3 mm, and the corrugation spacing C=5 mm. And the PEC value of the optimized tube can be up to 1.848. The RSM applied in this paper could be used in structure optimization of other heat exchanger.

Keywords: corrugated tube with grooves, R290, CFD, PEC, response surface method