基于热泵加温系统的沼气池经济保温层厚度确定

为优化沼气工程热泵加温系统的设计,降低加温系统的初投资和运行费用,该文对经济保温层厚度进行了研究。首先采用综合传热系数法简化计算沼气池围护结构散热负荷,并借助逐时气象参数获得沼气池全年动态热负荷的计算方法。在此基础上,利用费用年值法建立了经济保温层厚度的数学模型,并将其应用到工程实例,得到了经济保温层厚度简化计算公式,在上海地区气候前提下,确定了沼气池经济保温层厚度为0.05～0.07m。同时得到当热泵年均性能系数(coefficient of performance,COP)为3.5时,膨胀聚苯乙烯、挤塑聚苯乙烯、酚醛树脂、聚氨酯、聚氯乙烯5种保温材料所对应的经济保温层厚度分别为0.092、0.063、0.054、0.048和0.046m。

Determination of economical insulation thickness for fordigester based on heat pump heating system

In order to optimize the design of heat pump heating system for biogas engineering and reduce the initial investment and operating cost, economical insulation thickness (EIT) of anaerobic digester was studied in this study. Firstly, the comprehensive heat transfer coefficient theory was applied to simplify the calculation of thermal dissipation load for the digester. The calculation method of the annual dynamic load was obtained by means of hourly meteorological parameters. Then the mathematical model of EIT was developed by annul-cost method. The simplified computational formula of EIT was applied to a project in Shanghai, and the values of EIT were determined between 0.05 and 0.07 m. With 3.5 of performance coefficient of heat pump, the EIT of five insulation materials including expanded polystyrene, extruded polystyrene, phenol resin, polyurethane, polyvinyl chloride were 0.092, 0.063, 0.054, 0.048 and 0.046 m, respectively.