Experimental Study on the Optimization of Thermal Performance in a Solar Steam Generator

Abstract

SOEC (Solid Oxide Electrolysis Cell) require high temperature steam, but generating steam with electricity is very energy intensive. Concentrated solar power can be a good substitute for electricity to generate high temperature steam. In this paper, the thermal performance of a solar steam generator is researched. The steam generator improves the heat transfer capacity by installing porous ceramic material inside and using spray cooling technique. Due to the limited heat transfer capacity of previous steam generators, other types of steam generators can only produce steam with a temperature below 700°C. The steam generator in this paper has a high thermal efficiency depending on the nozzle characteristics. Therefore, the steam generator has obvious advantages in terms of generating high-temperature steam. The experimental results show that the instantaneous thermal efficiency of the steam generator with a new nozzle can reach a maximum of 58% when the solar irradiation power is 2.26 kW and the inlet water flow rate is 1.23 kg/h. At this time, the steam generator can produce high temperature water vapour at a maximum temperature of 715.4°C. The optimized solar steam generator was also coupled with the SOEC system, and hydrogen production was successfully achieved by experimental means. The solar SOEC system has great potential for hydrogen production.