A combined thermal system of ejector refrigeration and Organic Rankine cycles for power generation using a solar parabolic trough

Abstract

The present work investigates the implementation of low-grade solar energy in combined ejector refrigeration and an Organic Rankine cycle for cooling and power generation. In such systems, the solar radiation intensity determines the cooling path and the power produced. The proposed solar thermal system consists of two cycles, namely: the solar collector and the combined cycles. The solar thermal cycle is a parabolic trough collector, whereas the combined cycles are ejector refrigeration and an Organic Rankine cycles. The latter consists of an ejector, evaporator, condenser, expansion valve, preheater, turbine, pumps and generator. In this context, a mathematical model of the solar thermal system is established to determine and control the outlet temperature of the working fluid and the temperatures of the absorber, and the glass cover of the parabolic trough receiver. In the proposed model, the effects of the solar intensity, inclination angle and ambient conditions are included. The performance of the parabolic solar collector is evaluated depending on the meteorological data and concentrator-related parameters. The hourly-calculated results of this model for the thermal solar receiver are introduced into the simulation program of the proposed combined cycle. The fluids R601a, R123, R245fa, and R141b are used as refrigerants. In addition, the effects of the thermodynamic parameters on the system performance are investigated. The obtained numerical data are compared to experimentally obtained and published data. A good agreement is found between these data.