Waste heat recovery technology of internal combustion engine is of great significance to energy conservation and emission reduction. Among them

supercritical carbon dioxide(S-CO_2) power cycle system has received more and more attention due to its low cost and friendly to environment. As a key component of the S-CO_2 power circulation system

the heat transfer performance of exhaust heat exchanger directly affects the overall efficiency of the circulation. Printed circuit heat exchanger has the characteristics of high heat transfer efficiency and compact structure

but it is seldom used in waste heat recovery of internal combustion engine. Therefore

this paper carries out the structural design and optimization for printed circuit type exhaust heat exchanger. Three kinds of exhaust heat exchangers with different flow channel structures at S-CO_2 side were designed

and the effects of different flow channel structures on the internal flow and heat transfer performance of the heat exchanger were compared through numerical simulation. The results show that

the heat exchange per unit weight and Kv value of exhaust heat exchanger with hollow channel are much higher than that of the heat exchanger with right angle channel and rounded corner channel

indicating that the printed circuit heat exchanger with hollow channel can satisfy the volume requirement of small and compact.