In order to solve the problems of high heat loss, low fermentation temperature and low gas production in biogas engineering in winter. In this paper, the annual thermal energy loss of biogas project is systematically analyzed, and a regenerative mass recovery device with solid-liquid separation is developed. Finally, the heating effect of the device at different temperatures is tested through experiments. The results showed that under the condition of good heat preservation measures, the heat loss of the fermentation tank accounted for 89.3% 93.2% of the total heat loss of the anaerobicfermentation system. Under the ambient temperatureof 18 ℃, the feed at 16.2 ℃can be heated to 26.6 ℃by regeneration and mass recovery. The waste heat ofthe biogas slurry recovered accounted for 51.9% of theheat required for constant temperature fermentation.At ambient temperature of 0 ℃, the feed at 2.5 ℃can be heated to 18.9 ℃ by regeneration and massrecovery. The waste heat of the biogas slurry recoveredaccounted for 47.2% of the heat required for constanttemperature fermentation. The remaining heat issupplied by a collector array consisting of 14 groups ofsolar collectors, which can ensure the constanttemperature fermentation of biogas engineering at37 ℃ in winter. And the system has good economicand environmental benefits.
Keywords small and medium-sized biogas project, solid-liquid separation, heat and mass recycle, solarheating area, economic benefits