Advancement of distributed energy methods by a novel high efficiency solar-assisted combined cooling, heating and power system

Abstract

To improve the conversion efficiency of renewable energy use in high efficiency novel distributed energy systems, and the match between the energy donors and receivers in them, this paper proposes and analyzes a solar assisted combined cooling, heating and power system which supplies electricity, cooling and heat, with internal energy recovery and thermochemical upgrading, as their core component. The proposed system consists of a chemically recuperated gas turbine cycle, an absorption chiller and a heat exchanger, in which the reformer upgrades the absorbed turbine exhaust heat and solar heat into produced syngas chemical exergy, and rearranges the matches of energy donors and receivers both quantitatively and qualitatively. Based on well-established technologies including trigeneration, steam reforming and low/mid temperature solar heat collection, the system exhibits enhanced specific power generation and efficiency, and it commensurately reduces CO2 emissions and saves depletable fossil fuel. The net solar-to-electricity efficiency is predicted to be 26–29% for a turbine inlet temperature of 980 °C. Compared with the stand-alone power, cooling and heating generation system, the reduction potential of fossil fuel consumption has been demonstrated to be 30.4% with a solar thermal share of 26%. Moreover, this system produces 33% less CO2 emission than a conventional combined cooling, heating and power system with the same technology but without solar assistance. An excess electricity storage unit or storage of excess syngas can be considered to balance the difference between the supply and demand quantities.