太阳能平板降膜再生过程的数值模拟

针对太阳能平板集热型再生器中辐射传热和对流传热边界条件,建立了传热传质过程的数学模型,对采用氯化钙溶液的再生过程进行了数值模拟分析,对影响再生过程的各种主要因素做了较详尽的分析.模拟结果表明,较低的溶液入口质量分数和空气入口含湿量以及较高的溶液入口温度能够增大溶液表面和空气间的水蒸气压力差;而增大空气流动Re数和空气/溶液质量流量比可以提高空气、溶液间水分传质系数.采用这些措施都能够得到更好的再生效果.

Numerical simulation of heat and mass transfer for solar energy regenerator

To predict the thermal performance of solar regenerator, a numerical simulation was conducted under convective and radiation boundary conditions and a computer model has been developed using calcium chloride as the desiccant. A parametric analysis of the system has been performed to calculate the rate of evaporation of water from the solution as a function of the system variables. From the performance predictions presented in this work, it was determined that the water evaporation rate from the weak solution depends on solution concentration, air humidity and air Reynolds. Furthermore, it was found that the ratio of air to solution mass flow rate is another important controlling parameter and the regenerator performance could also be improved to a large extent by preheating the air and the solution.