户用小型沼气采暖锅炉的设计计算

在高寒地区农户仅将沼气作为炊事用能,冬季采暖方式主要还以直接燃烧秸秆、薪柴等生物质为主。为了实现冬季取暖和炊事都利用沼气,设计小型户用沼气锅炉,并参照大中型锅炉的设计方法,提出适用于小型户用沼气锅炉的热力计算方法。通过理论计算和选取相应参数,利用炉膛出口温度和排烟温度先假设与后校核的方法,对沼气锅炉辐射换热面和对流换热面进行理论设计计算,并设计出沼气锅炉的整体结构。通过试验对锅炉性能进行测试,平均热效率为92.76%,完全符合锅炉的设计要求。

Design of small domestic biogas boiler

In the cold area farmers only use biogas for cooking,while heating is mainly generated by directly combustion of straw,firewood and other biomass.In order to use the biogas as fuel for both heating and cooking in winter,a small domestic biogas boiler is designed.Basing on the design method of large and medium-sized boiler,this paper puts forward a set of suitable thermodynamic calculation method for small domestic biogas boiler.During theoretical calculation,the radiation heat transfer surface and convective heat transfer surface were optimized to make the calculated outlet temperature of the combustion chamber and smoke discharging temperature accorded with assuming values,and then the overall structure of the methane boiler was designed.The performance of the boiler was tested,and average thermal efficiency of 92.76% was achieved,which could meet the requirements of the design of boiler.