Experimental exergy analysis of a printed circuit heat exchanger for supercritical carbon dioxide Brayton cycles

Abstract

Abstract Exergy analysis could improve the quality of energy in the printed circuit heat exchanger. However, most of the current researches were carried out based on the first law of thermodynamics, which only focus on heat transfer, pressure drop, and heat transfer rate of the heat exchanger. There are no reports about experimental analysis of the printed circuit heat exchanger using the exergy analysis. Therefore, in this study, experimental exergy analysis of a printed circuit heat exchanger used as a recuperator for the supercritical carbon dioxide Brayton cycle is introduced. In the tests, the zigzag channels are adopted for the current heat exchanger to achieve higher heat transfer capability. The maximum running temperature and pressure in the experiments are 715.2 K and 22.5 MPa, respectively. The Reynolds number varies from 3212 to 23888. Pressure drops and temperatures are measured at the inlet and outlet of both sides. The effects of the inlet temperatures and Reynolds numbers on the exergy loss and efficiency of the printed circuit heat exchanger are investigated. The results show that the low Reynolds number and high inlet temperature on the cold side have positive effects on the exergy efficiency. New Nusselt number and friction factor correlations are developed according to the test results.