Pressure-Volume integral Expressions for Work In Irreversible Processes

摘要

The definition of pressure-volume work (PVW) in irreversible thermodynamic processes remains a contentious topic. For this reason, many authors restrict the definition of PVW to quasistatic or reversible processes (1-7). Some problems with the definition of irreversible PVW were discussed by Bauman (8) and in follow-up papers (9-12). Historically, there have been two different protocols for defining work, w, in a physico-chemical process (13-15). (In this paper we use the modern convention that w is the work done on the system by the surroundings, so the first law is written AE = q + w.) One protocol is developed from the perspective of the system and the other from the perspective of the surroundings. We fully developed (15) both protocols and showed that either one can be used to define PVW under appropriate circumstances. However, a major conclusion from our analysis was that the values of w can be different for the two protocols if the process is irreversible. This difference has not been recognized in the past.