集热式太阳能污泥干化系统能效评估与适应性分析

Evaluation of Sludge Drying Using Solar Collector by Costs and Application

污泥集热式太阳能干化技术改变了太阳能利用形式，采用恒定的加热温度，相对于温室型太阳能干化技术能够提高干燥效率，保证系统稳定运行。文章通过对该系统的物料和热量衡算得出，在不采用辅助能源时，干化时间、单位面积处理能力、干化床占地面积均与太阳能辐射强度成反比例函数关系，集热器占地面积随着污泥处理量增加而增大，且均大于干化床的占地面积。结合系统投资与运行成本分析，随着干化时间延长处理费用增加，当干化时间为10-15天时，可使污泥日处理费用达到最低。因此，考虑到干化床和集热器的占地面积，该系统适用于处理规模小且所在地区太阳能辐射强度大的污水处理厂。

Sludge drying using solar collector can provide a constant heating temperature, thus offering better drying efficiency and stability than traditional sludge solar drying. Based on the principle of mass balance and energy conservation, calculation of the mass and energy flow of this system demonstrated that with no auxiliary energy added to the system, the drying time, as well as the processing capacity per unit area or the dry bed area, is inversely proportional to the solar radiation intensity. The area of solar collectors is always larger than that of dry bed, and grows with the increase of the sludge treatment capacity. The investment and running costs analysis shows that the treatment costs of sludge increase when the dry time is prolonged, and the optimum drying time is 10-15 d with the lowest costs. Therefore, taking the relatively larger dry bed and solar collector area needed per ton sludge into consideration, this system is suitable for the small-scale sewage treatment plants located in the regions with high intensity of solar radiation.