Isentropic recuperative heat exchanger with regenerative work transfer

Abstract A counter-flow heat exchanger is considered to be the ideal method for recuperative heat transfer between hot and cold fluid streams. In this paper the concept of an isentropic heat exchanger with regenerative work transfer is developed. The overall effect is a mutual heat transfer between the two fluid streams without any net external heat or work transfers. The effectiveness for an isentropic heat exchanger with regenerative work transfer is derived for the case of fluid streams with constant specific heats and it is shown that it is greater than unity. The ‘isentropic effectiveness’ of a heat exchanger is defined. The relationship between the entropy generation and effectiveness for the traditional heat exchanger is also examined and compared with that of the isentropic heat exchanger. The practical realization of isentropic operation of a heat exchanger and its possible application are briefly considered.