Dynamic modelling and performance analysis of compressor-assisted thermochemical sorption for seasonal solar thermal energy storage

The present paper investigates the dynamic thermal behaviour of novel seasonal solar thermal energy storage using compressor-assisted thermochemical sorption technology to supply domestic space heating demands. The proposed compressor-assisted thermochemical sorption energy storage that used the working pair of strontium chloride-ammonia was incorporated with flat-plate solar thermal collectors (CATSES-FPSC). The potential dynamic thermal performance of charging and discharging processes of such a seasonal energy storage system for a typical UK dwelling in the city of Newcastle Upon Tyne has been evaluated through a comprehensive numerical model, which integrates the validated models of solar thermal collector, compressor, and chemisorption processes as well as a domestic space heating demand model using real weather data. The results demonstrate that integrating a compressor unit with thermochemical sorption energy storage can significantly improve the system dynamic thermal performance by reducing the operating temperature, enhancing solar collector efficiency, and increasing ammonia transfer and storage capacity. It was found that integrating a mechanical vapour compression unit into the thermochemical sorption energy storage coupled with 40 m² FPSC can boost the solar fraction of the domestic space heating demand of a typical UK dwelling using the conventional water radiator in winter from 29.57 % to 93.62 %. The study shows that, depending on the temperature of space heating facilities and the area of flat-plate solar collectors, the CATSES-FPSC system can achieve up to a 100 % solar fraction for winter heating, eliminating the need for non-renewable energy sources. This makes it a promising solution for sustainable space heating in residential buildings, even in high-latitude regions like the UK.