Performance investigation of a new distributed energy system integrated a solar thermochemical process with chemical recuperation

A new distributed energy system that integrates a solar thermochemical process with chemical recuperation cycle is proposed. The methanol is converted into synthesis fuel through the endothermic decomposition reaction using the mid-and-low temperature solar energy in solar receivers/reactors, and the solar thermal energy is upgraded into the chemical energy of the synthesis fuel. The synthesis fuel releases its chemical energy in a micro gas turbine to drive a distributed energy system to output cooling, heating and power. A part of the flue heat from the synthesis fuel is stored and drives the methanol decomposition in a fixed bed reactor to replenish the synthesis fuel. Energy analysis and exergy analysis are implemented to evaluate the thermodynamics performances of the proposed system. Results indicate that the proposed system achieves a primary energy ratio of 75.42%, and the net efficiency of solar to electricity is 23.26% on the design condition. Due to the interaction of the thermochemical process and the energy storage, the power generation is insensitive to the variations of solar radiations, and has a good performance under varying user's load demands. The promising results can provide an efficient and stable utilization approach of the solar energy in distributed energy systems. (C) 2017 Elsevier Ltd. All rights reserved.