Experiments On The Solid Heat Storage Materials And Solar-Hybrid Co-generation System Using Chemical-Looping Combustion

Solar thermal energy storage technology is a key technology of solar thermal power plant, but solar-to-electricity efficiency is low due to the temperature limitation of the thermal energy storage material. Also the required heat storage devices lead to the high cost, which hampers the utilization of the solar thermal power plants.Based on our previous research in the chemical-looping combustion (CLC) and solar thermal utilization, we propose a new power generation system with integration of the solar thermal energy storage material and the fuel for power generation. We mainly focus on the research of the materials, trying to find a most suitable solar thermal energy storage material for utilization in middle-and-low solar thermal power system. Besides, we devise a new solar thermochemical hybrid trigeneration system with CO2capture using dimethyl ether-fueled chemical-looping combustion integrated power, heating and cooling system (CCHP), expanding the application of the chemical looping combustion in the solar Hybrid distributed systems.We prepare six kinds of materials by dissolution method, with Fe2O3, NiO, and CoO as solid reactants and Al2O3, MgAl2O4, and YSZ as binders compare their reactivity with (DME) on the TGA reactor.Also we study the key parameters such as the reaction temperature, materials particle size, the reaction gas concentration on the performance of materials response, and examine the carbon deposition and cycle stability of the CoO/CoAl2O4material. Then we come to a preliminary judgment that the CoO/CoAl2O4material is a promising solid thermal energy storage material. Besides, in order to further reduce the reduction reaction temperature, increase the reaction rate, improve the response properties of the material, we carry out some experiments on the effect of different additives on the reactivity of the material CoO/CoAl2O4. THe results show that the material (CoO+PtO21%)/CoAl2O4could make a better performance of the reaction with low reduction temperature and high reaction rate. So it is a promising solid thermal energy storage material, which can be used in the mid-temp solar thermal power system.In addition, based on the principle of energy cascade utilization, a new solar thermochemical hybrid trigeneration system with CO2capture using dimethyl ether-fueled chemical-looping combustion integrated CCHP system is proposed. A thermodynamic physical model is constructed, and the analytical expression of solar thermal efficiency is developed. The thermodynamic performance and the effects of the key parameters of the proposed cycle are studied, and the irreversibility of the key energy conversion is analyzed using the energy utilization diagram (EUD) method. The results show that when the solar radiation intensity is800W/m2, the system of solar thermal efficiency is up to61.6%, at a turbine inlet temperature (Ⅲ) of1000℃.This paper presents a new method of solar thermal energy storage and a new kind of solar thermal energy storage material. Meanwhile, a new system with high solar thermal efficiency is proposed providing a new way of solar thermal utilization.