A novel solar-aided NOx removal system in peaking power plants

Abstract

Solar–coal hybrid power generation achieves the production of efficient, clean, and low-carbon electricity. The association between solar heat and selective catalytic reduction NOx removal (SCR de-NOx) can lead to the development of a novel solar-aided NOx removal system for peaking power plants. In this study, a novel system was proposed, in which large amount of flat-plate and small amount of trough solar energies were integrated to optimise the SCR de-NOx and energy utilisation in the boiler tail. Thermodynamic, NOx removal, and economic analyses were performed. For a typical peaking unit, the proposed system produced 14.6 MWe of solar-generated electric power and exhibited a high solar-to-electricity efficiency of 30.15%. The integrated solar heat significantly increased the SCR de-NOx temperature and NOx removal efficiency. Based on its outstanding solar conversion performance, the proposed system achieved a net annual benefit (NAB) of 24.01 million Chinese yuan (CNY) and maintained a low cost of solar-generated electricity (COEs) of 0.56 CNY/kWh. Based on cascade utilisation of solar thermal energy, the proposed system achieved high performance under all loads and significantly improved the NOx removal performance under low and medium loads, especially for peaking power plants.