Discussion on the entransy expressions of the thermodynamic laws and their applications

•The entransy expressions of the three thermodynamic laws are discussed.•The Clausius inequality is proved with the entransy expressions of the laws.•The concept of entransy loss is defined with the entransy expressions of the laws.•Entransy loss can be used to analyze heat transfer and heat-work conversion.

In this paper, the entransy expressions of the three thermodynamic laws are discussed. The entransy expression of the first law is that the entransy of any thermodynamic system is in balance. For the second law, the entransy expression for heat transfer is that the entransy flow will never be transported from a low temperature body to a high temperature body automatically and entransy dissipation always exists. The entransy expression for heat-work conversion is that it is impossible for any device to operate in a cycle that receives heat entransy flow from a single reservoir and results in an equivalent amount of work entransy flow. The two entransy expressions of the second law are proved to be equivalent to each other. For the third law, its entransy expression is that it is impossible to achieve the zero entransy for any body through limited processes. With these expressions, the Clausius inequality is proved, and the concept of entransy loss is defined. The application of entransy loss to heat transfer and heat-work conversion is discussed.