Maximum work configuration for irreversible finite-heat-capacity source engines by applying averaged-optimal-control theory

A finite-heat-capacity source irreversible engine with irreversibility losses of bypass-thermal-leak and heat-resistances is investigated. Comprehensively considering that source heat-capacity is function of its temperature and bypass-thermal-leak and heat-resistance obey generalized form, optimality condition for the maximum work output is obtained by utilizing averaged-optimal-control theory. Detailed mathematical ex-pressions of source heat-capacity, heat-transfer rates and bypass-thermal-leak rate are not prescribed. Generalized result is obtained. Effects of heat-capacity characteristic of the finite-heat-capacity source, heat-resistance models and bypass-thermal-leak on the optimal cycle configuration for maximum work output are analyzed. Finite-heat-capacity source heat-capacity not only has effect on the optimal temperature relationship be-tween working substance and finite-heat-capacity source at high-temperature side of the irreversible engine, but also has effects on optimal profiles of temperatures of finite-heat-capacity source and working substance versus the time. Bypass-thermal-leak affects the optimal temperature relationship between finite-heat-capacity source and working substance at high-temperature side, and the maximum work configurations with and without bypass-thermal-leak are different from each other significantly. The results obtained her ein include those in some previous related literatures.& COPY; 2023 Elsevier B.V. All rights reserved.