摘要：
Temperature is the critical factor affecting biogas production rate.Anaerobic digester is the heating object in biogas engineering,the heat load of fermentation tank is the basis of biogas project design and selection of heating system,which is related to the stability of anaerobic digest system and economy of heating system.Therefore,it is vital to define the heat load characteristics of the fermentation tank.The average temperature of the fermentation tank was calculated,and then the digester's heating load was figured out,the maximum value was regarded as the system's thermal load.This method was simple,however,which made the result deviated practical situation greatly.To accurately calculate the heat load of the fermentation tank,it was advantageous to match the heating system with the fermentation tank,and explore the optimal system configuration and operation strategy of the heating system in order to reduce the energy consumption and cost.The hourly meteorological parameters of special meteorological data set for analysis of thermal environment of building in China in the Shanghai area was used,based on the analysis of physical and mathematical model of fermentation of biogas project,the hourly accumulation of fermentation pool enclosure structure heat dissipation was calculated,and annual dynamic changes of fermentation pool heat load was obtained,which can be used to guide the design of heating system of fermentation tank.The essence of this method was to make steady algorithm time step shortened from a month to 1 h,which enhanced the calculation precision obviously.Results showed that under the three different conditions,the relative errors of heat load model and experimental measurement were -5.98％,3.93％ and 5.39％,respectively.Thus,dynamic heat load model was of high precision,and it was acceptable to be applied to guide engineering design and operation,avoid the long time operation of the system under partial load,which had theoretical significance and reference value for the design and operation of biogas engineering.%温度是影响沼气发酵产气率的关键因素,发酵池的热负荷是沼气工程加温系统设计与选型的基础,关系到发酵系统的稳定运行与加温系统的经济性.精确计算出发酵池热负荷,有利于将加温系统供能侧与发酵池需能侧匹配,并探索出加温系统的最佳系统配置和运行策略,以降低能耗和成本.在分析沼气工程发酵设备物理和数学模型基础上,采用逐时累加法计算发酵池围护结构散热量,得到发酵池热负荷的全年动态变化规律,将稳态算法的时间步长由1个月缩短到1h,提高了计算精度.研究结果表明,在(25±1)°C、(30±1)°C和(35 ±1)°C3种不同工况下,热负荷的模型计算结果与试验测量结果相对误差分别为-5.98％、3.93％和5.39％,对于沼气工程保温和增温设计具有一定的理论意义和参考价值.
