Study Of Heat Transfer In Chemical Solar Storage System

The energy density of solar radiation is about lkW/m2, which is urgently needed to develop. Its substantial effective use will significantly reduce the dependence on fossil fuels and the environmental pollution caused by using fossil fuels. In this way, the human living environment can be improved. However, the energy of solar radiation is intermittent. So we need to transfer it to continuous energy and store it to satisfy the requirements of users. Heat storage technology is an quite important part in academic research of the solar energy use. And the heat energy density is one of the keys to constrain thermal storage technology. Therefore, it has a practical significance on the solar thermal storage. In this paper, an organic working fluid is used as a chemical heat storage to simulate the catalytic chemical reaction exothermic process. Due to the explorage about the exothermic reaction process of heat and mass transfer regularity by numerical methods, which is used to obtain the dynamics of this exothermic reaction, research chemical refrigerants and catalyst, and provide reference data of reactor development and design. The method of the photo-chemical reactions by transforming convert solar energy into chemical energy, and using catalytic chemical energy into heat to satisfy the user’s thermal requirements in this paper.The catalytic reactor bed will be setted as cylinder, which is worked up a kinetic model of catalytic reaction process by catalytic reaction process theoretical analysis. This model is used to solve problems related to the flow, heat and mass transfer of Multi-physics coupling. This article uses COMSOL software to calculate model.According to the numerical results, the change does not affect the reaction to release heat and reactant concentration after the catalytic region increases to a critical peak. When the porosity comes smaller, the specific surface area of the catalyst is greater and the reaction can be proceed sufficiently. But due to the increase of flow resistance coefficient, the effect on the blockage of the flow is greater. The increase of porosity will increase the amount of reactant material in the catalytic zone residence time pipe segment. At the same time, the promotion of reforming reaction can also increase the porosity of the catalyst and weaken the effect of heat transfer area. When the temperature was decreased inhibition reforming reaction, which can make interacting factors lead to the presence of chemical reactions catalyzed exothermic peak.The flow rate of the chemical heat storage can not be too fast in the reactor, if not the chemical reaction will be not yet reacted completly through the catalyst zone. And the reaction will result in a small release of heat. The maximum temperature of the exothermic catalytic reactor pipe section will be increased at first. Then reduced with the increased rate of reactant inlet. At that time, we will have a peak data.The reacted outlet temperature will increase with the increased heat of reaction under the reaction solution flow rate and inlet concentration certain circumstances,and both of them are Linear correlated. Obviously, the high reaction heat will produce a higher reaction temperature, and it is not safe use. Therefore, the photo-chemical working fluid must be considered when pursuit the high energy density and high exothermic temperature.The heat balance calculation shows that when the energy density is proportional to the concentration of the reactants, the reaction outlet temperature increases with the increased concentration of the reactants under certain reaction heat. So the reaction heat is inversely proportional to the concentration of the reaction under the premise of energy density to meet the requirements of the situation, and the photo-chemical dissolution characteristics of the working fluid need to be coordinated with the reaction heat the working fluid.