Study on Endoreversible Trigeneration Cycles Design Based on Finite Physical Dimensions Thermodynamics

Abstract

This paper focuses on the finite physical dimensions thermodynamics (FPDT) based design of combined endoreversible power and refrigeration cycles (CCHP). Four operating schemes were analyzed, one for summer season and three for winter season. These basic CCHP cycles should define the reference ones, having the maximum possible energy and exergy efficiencies considering real restrictive conditions. The FPDT design is an entropic approach because it is defining and using the dependences between the reference entropy and the control operational parameters characterizing the external energy interactions of CCHP subsystems. The FPDT introduces a generalization of CCHP systems design, due to the particular influences of entropy variations of the working fluids are substituted with influences of four operational finite dimensions control parameters, i.e. two mean log temperature differences between the working fluids and external heat sources and two dimensionless thermal conductance inventories. Two useful energy interactions, power and cooling rate were used as operational restrictive conditions. It was assumed that there are consumers required for the supplied heating rates depending on the energy operating scheme. The FPDT modeling evaluates main thermodynamic and heat transfers performances. The FPDT model presented in this paper is a general one, applicable to all endoreversible trigeneration cycles. The FPDT design model of the trigeneration component endoreversible cycles emphasizes the cycle internal relationships between the operational functions and the restrictive imposed variable finite physical dimension parameters.