Using the 2nd law of thermodynamics to quantify the extra power required for each irreversible process in compression cycle heat pumps

摘要

Irreversibilities in engines result in lost work while irreversibilities in air conditioners and heat pumps result in extra work that must be supplied. First law methods allow for the calculation of the overall performance of a thermodynamic cycle but second law methods are required to demonstrate the extra work associated with each less than ideal or irreversible process. However, existing text books and literature do not provide good examples of such methods. Thus this paper provides a relevant example of such techniques for working engineers who may design or analyze heat pumps and air conditioners and also for the benefit of the authors of thermodynamic text books for possible inclusion in future texts and ultimately for future students and engineers who will learn from these improved textbooks.