Study on mechanical stress of semicircular and rectangular channels in printed circuit heat exchangers

Abstract

Recuperator and precooler are key components of supercritical CO2 Brayton cycle. One of promising candidates is printed circuit heat exchanger (PCHE) due to its high compactness and heat transfer performance. However, both of them operate at high pressure, which is a great challenge for their safety. Therefore, accurate and quick mechanical stress analysis is important for PCHE design. In this work, a simplified mechanical stress method based on homogenization method is proposed for PCHE. An optimized rectangular channel, which has the same mechanical characteristics with a semicircular channel is proposed. Then the PCHE numerical model is constructed, and the mechanical stress of PCHEs with semicircular and rectangular channels is examined by elastic stress analysis. The results show that the maximum stresses of the semicircular channel, simplified rectangular channel and optimized rectangular channel are 151.6 MPa, 253.0 MPa and 184.3 MPa, respectively. The mechanical characteristics of the optimized rectangular channel are close to the corresponding semicircular channel, which can improve the design accuracy and is benefit for the weight and volume reduction of PCHE.