Method for power generation by utilizing low-concentration gas or ventilation air methane (VAM)

The invention discloses a method for power generation by utilizing low-concentration gas or ventilation air methane (VAM). The method comprises the steps of: introducing the low-concentration gas into a fuel gas internal combustion engine through an air inlet of the fuel gas internal combustion engine directly or after mixing the low-concentration gas with air, to serve as the air for the fuel gas internal combustion engine, mixing the air and fuel gas entering the fuel gas internal combustion engine through a fuel gas inlet, introducing a mixture gas into an air cylinder, compressing, combusting, swelling, pushing a piston and driving a crank shaft to do work and generate power. According to the invention, not only the low-concentration gas or the VAM can be directly utilized, but also the methane gas with the explosion limit concentration of 5-15% can be utilized after being mixed with the air. The application technology disclosed by the invention can be used for reducing the fuel amount of the internal com