| 摘要 |
PURPOSE:To raise the digestive gas generating efficiency, by controlling the waste heat recovering rate on the basis of the deviation between the temperature in a digesting tank and a prescribed optimum temperature in a waste heat recovering apparatus for a power plant utilizing a digestive gas. CONSTITUTION:A digestive gas 2 such as methane gas generated in a digesting tank 1 of a sewage disposal plant or the like is stored in a tank 3 and supplied to a gas engine 5 via a pipe 4. A secondary coil 14 of an exhaust-gas heat exchanger 12 and a secondary coil 15 of a cooling-water heat exchanger 7 are connected in series to each other for recovering waste heat of the gas engine 5, and the waste heat thus recovered is supplied to the digesting tank 1 via a sludge heat exchanger 16. The temperature in the digesting tank 1, detected by a temperature ditector 21 disposed in the tank 1, is applied to a controller 22 and compared with an optimum temperature to obtain the deviation between them. A correcting control signal for reducing above deviation to zero is applied to a motor-driven valve 11 of a three-way valve provided in an exhaust-gas pipe 10 so as to control the opening of the motor-driven valve 11. |
