地源热泵式沼气池加温系统

沼气是适合在中国农村推广利用的可再生能源。为解决冬季沼气池产气量受低温影响的问题，该文分析了现有的几种沼气池加温保温方式，提出了一种地源热泵式的新型加温保温方法，并在实际工程上进行了运行试验。结果表明：地源热泵式加温保温方法能够使沼气池的发酵温度保持在(32±2)℃范围内，池容产气率保持在0.6 m3/(m3·d)左右，有时候可以达到1.1 m3/(m3·d)。系统运行期间，地源热泵机组制热效率保持在3.6左右，系统COP为2.7左右，一次能源利用系数可达到0.84；相对于电热膜加温系统，采用地源热泵式加温系统节能率达到63%，增加投资效益净现值为40 188.5元。与化石能源热水锅炉加温方式相比无污染，具体良好的环境效益。因此，地源热泵式沼气池加温是一种经济合理、环保节能的加温方式，具有开发应用潜力。

Heating system of biogas digester by ground-source heat pump

Biogas is one of the renewable energies which is suitable for rural area in China. For improving the lower biogas production in winter, with several heating method analyzed, a heating system of biogas digester was developed, in which the heat energy was supplied by hot water from ground-source heat pump. An experiment was carried out at a medium scale pig farm. The research results showed that this system could guarantee the fermentation temperature at (32±2)℃, and the biogas productivity at 0.6 m~3/(m~3·d), sometimes even at 1.1 m~3/(m~3·d). During the experiment, the average coefficient of performance (COP) of the ground-source heat pump unit was about 3.6, the average COP of the overall heating system about 2.7, and the primary energy ratio could reach 0.84. Compared with electrothermal film heating system, it could save 63% of electricity and the present value of investment benefit was increased to 40 188.5 yuan. And compared with hot-water boiler which burns fossil fuels, a better environment could be guaranteed without pollution. Therefore this system was feasible in technology and economy, simultaneously in favor of environmental protection and energy saving. In all, this system has the potential to develop.