Multi-energy complementary system based on biogas

The system comprises a power grid, a photovoltaic power generation device, a storage battery, an electric refrigerator, an air source heat pump, a gas turbine combined supply unit, a gas-fired boiler, a waste heat recovery boiler, a heat exchange device and the like to meet the requirements of users on three aspects of cooling, heating and power. Biogas generated by anaerobic fermentation treatment of garbage and sewage is utilized to drive a biogas generator set to generate power and photovoltaic power generation capacity to meet electric load, insufficient power is supplemented by a power grid, an electric refrigerator supplies cold load to the system, and waste heat of a gas-fired boiler and a co-production unit meets heat requirements of users through a heat exchange device. The air source heat pump utilizes a small amount of electric energy to convert low-grade energy in the air into available heat or cold at a proper time so as to supplement a part of load requirements. The system can be arranged in an