Indian Journal of Science and Technology

Abstract

Objectives: The main task of the estimation of power processes of any technical system is to define the efficiency of the consumed energy usage. Method: The most often used efficiency criterion is the ratio of the useful energy to the consumed energy defined from the power flow balances and the environmental losses. This criterion is defined primarily on the basis of the energy conservation law (more often on the primary case, i.e., on the basis of the 1st law of thermodynamics) and is generally called the coefficient of efficiency (COE). Findings: The article presents the entropy coefficient of efficiency. The entropy efficiency of a building depends on the inside and outside temperatures and the heat carrier temperature in the heating system, but only to the extent to which the heat emission and the heat conductivity coefficients depend on these temperatures. Taking these values to be constant, one can determine that the building efficiency depends only on the thermo physical properties of the radiators, walls and heat carriers. The method can be applied to obtain a common criterion of efficiency of complex heating or/and cooling buildings. If thermal energy converts into work, then entropy efficiency is equal to ratio of real cycle efficiency to thermal efficiency of Carnot cycle both for power and heat pump cycles. Also this method works for endoreversible cycles. Improvements: Entropy efficiency EnEf is the universal parameter of thermodynamic efficiency including COE and COP. EnEf criterion can be applied even in the cases when COE and COP have no sense.

Keywords: Entropy Efficiency, Heat Pump Cycle, Heating a Building, Power Cycle, Thermal Energy