Investigation on the mid-temperature solar thermochemical power generation system

Abstract

A novel mid-temperature solar thermochemical power generation system with the capacity of 1MWe is proposed in this work, which mainly consists of a parabolic trough solar collector, a solar receiver/reactor, a syngas storage tank, an internal combustion engine and heat exchange devices. The fed methanol that is evaporated and fed into the solar receiver/reactor for decomposition and producing syngas (H2 and CO), the required reaction heat is provided by the parabolic trough collector with the temperature of 200-300℃. The generated syngas can be stored or directly utilized by an internal combustion engine for the power generation. The system thermodynamic performance and the off-design operation characteristics are numerically investigated. The results indicate that the introduced solar thermal energy achieves a favorable conversion efficiency, the system annual energy efficiency and the solar-to-electric efficiency reach to 33.78% and 18.29%, respectively. The monthly averaged solar-to-electric efficiencies under system off-design conditions reach to 8.73%-26.31%, an evident improvement of the efficiency is achieved compared with the typical parabolic trough type solar power system. In addition, a small scale pilot system with the capacity of 20 kWe is constructed to achieve the operation with a full power ratio, and the developed mid-temperature solar thermochemical power concept is experimentally validated. The research findings contribute to the efficient utilization of the concentrated solar thermal energy.