Heating device for domestic heat supply biogas generating pit

The utility model relates to a biogas generating device and in particular relates to a heating device for a domestic heat supply biogas generating pit, which consists of a waste heat circulation part and a hot water circulation part. The waste heat circulation part is a fume heat exchanger(8) arranged on the inner wall of the biogas generating pit(12); the gas inlet of the fume heat exchanger(8)is connected with a fume exhaust pipe(13)of a hot water boiler; a blower(4)is arranged on the fume exhaust pipe(13); and the gas outlet of the fume heat exchanger(8)is communicated with a chimney(10). The hot water circulation part is a hot water heat exchanger(9)arranged at the bottom of the biogas generating pit; a water intake pipe(2)of the hot water heat exchanger(9)is connected with the water outlet of the boiler(1); and a water outlet pipe(4)of the hot water heat exchanger(9)is connected with a water intake pipe(3)of the boiler(1)through a water tank(6) and a water pump(4). The hot water circulation heating system and the waste heat utilization system work together to ensure fermentation in the biogas generating pit within the mesothermal temperature range of 25-35DEG C. The biogas generating pit is quick in fermentation speed, big in yield and high in material use ratio.