Thermoeconomic design and analysis of a sensible-heat thermal energy storage system with Joulean heating of the storage element

Abstract

A second-law-based thermoeconomic model of a sensible heat-storage system with Joulean heating is derived and discussed in which the storage element is cooled by flowing stream of gases. In this analysis, unit cost values are attached to the irreversible losses caused by the finite-temperature difference heat transfer and pressure drop during the heat removal process. Important dimensionless parameters are identified and the results are presented in terms of the optimum number of heat transfer units (NTU_opt) as a function of the dimensionless unit cost per unit heat conductance (γ_UA) and dimensionless temperature difference (τ) of the storage systems. The storage systems studied are optimized by introducing a new performance criterion described as the cost rate number $\text{(Γ}{}^{\mathrm{\ast }}\text{)}$. Performance results of low- and high-temperature storage systems are also examined and the results are compared with that obtained from Krane's analysis to illustrate the usefulness of the present approach. The influence of important unit cost parameters on NTU_opt and $\text{Γ}{}_{\mathrm{<mtext>opt</mtext>}}{}^{\mathrm{\ast }}$ are also studied in somewhat more detail.