Parametric analysis of a solar-driven trigeneration system with an organic Rankine cycle and a vapor compression cycle

Abstract

The objective of this paper is the parametric analysis of a solar-fed trigeneration system ideal for the building sector that produces useful heat, electricity and cooling. The examined unit is driven by 100 m2 of parabolic trough collectors which are combined with a sensible storage tank with thermal oil. An organic Rankine cycle is fed by solar useful heat production and it produces electricity while a part of its power drives a vapor compression cycle with R290. Heating is also produced by separate heat exchangers in the solar loop. The parametric analysis is conducted in steady-state conditions with a developed model in Engineering Equation Solver. The examined parameters are the following: superheating degree in the turbine inlet, cooling production, heating production, solar beam irradiation intense, sun angle, pressure level in the turbine inlet and heat source temperature level. For the nominal scenario of 10 kW cooling production at 5°C and 10 kW heating production at 60°C, the system produces 6.14 kW electricity, while the exergy and energy efficiencies are found 12.14% and 37.34% respectively. Assuming that the system operates 2500 h yearly, the simple payback period of the investment is calculated at 8.5 years. The maximum examined values for both heating and cooling production are at 20 kW.