Device for recovering heat energy by coupling biothermal energy to low-temperature thermal energy through circulating sewage evaporation

The invention provides a device for recovering heat energy by coupling biothermal energy to low-temperature thermal energy through circulating sewage evaporation. The device comprises a solar water heater (1), a fermentation body percolate collection device, a negative pressure fan (6), a spray condenser (7), a water source water-water heat pump (8), a first water source water-gas heat pump (10),a low-temperature condensate storage tank (14), a high-temperature condensate collection tank (17), a high-pressure fan (26), a thermal insulation water tank (29), and a second water source water-gasheat pump (32). By means of the device in the embodiment of the invention, the fermentation of a fermentation body is prompted by coupling thermal energy, sewage is evaporated by fermented biothermalenergy and exposed hot air, the fermentation body adsorbs non-volatile substances to ferment into an organic fertilizer, condensed water is used for reclaiming water or irrigation water, and surplus hot water is supplied to the