Modeling of a hybrid power system integrating solar radiation and syngas combustion energy

Abstract

AbstractThis study aims to model a hybrid power system that can continuously generate power by switching between two possible thermal sources: solar radiation and combustion energy from synthesis gases. The system comprised a hybrid energy receiver, solar dish, Stirling generator, fluidized‐bed gasifier, boiler, and water tank. The solar dish was a dual‐reflection solar collector that used two mirrors, namely the main and subordinate concentrators, to concentrate a broad expanse of solar radiation onto a hybrid energy receiver. The fluidized‐bed gasifier was employed for the production of synthesis gases. The synthesis gases were combusted to provide an auxiliary heat source for the Stirling generator when solar radiation was insufficient. Solar radiation or combustion energy was alternatively introduced into the hybrid energy receiver and converted to power by a 1‐kW‐scale beta‐type Stirling engine. In this manner, the Stirling generator could serve as a base‐load power plant regardless of solar conditions. In this study, a complete quantitative model was developed for a demonstration plant by incorporating thermodynamic and dynamic models of the beta‐type Stirling engine, a ray‐tracing model for the dual‐reflection solar dish, an energy model of the hybrid energy receiver, and experimental data for the fluidized‐bed gasifier. The performance response of the system during switching between solar radiation and combustion energy was predicted. The modeling results indicated that switching can result in a continuous power output ranging from 600 to 1200 W. With synthesis gas combustion as the auxiliary heat source, the hybrid Stirling power system can be operated continuously, and the overall power output is increased by 109.82% compared to a conventional concentrated solar power system that only uses solar radiation.