| 摘要 |
PURPOSE:To eliminate an error in adjustment caused by the measurement delay of an aerometer and to reduce variation in heating value by setting a simulation program which estimates the specific gravity of natural gas and controlling an adjustment part on the basis of the arithmetic value. CONSTITUTION:The liquefied natural gas in a tank 1 is sent by a pump 2 to a carbureter 3 to become natural gas, which is passed through a supply pipe 4 and a branch pipe 6 and jetted into a mixing tank 4 from a nozzle 7. Consequently, the natural gas is mixed in the tank 5 by convection and its composition is uniformed. The natural gas jetted from the nozzle 7 stays in the tank for a time corresponding to the capacity of the tank 5 without moving its outlet immediately. An arithmetic unit 21, on the other hand, estimates the specific gravity of the natural gas whose composition is uniformed in the tank 5 by the simulation program on the basis of a specific gravity measured value inputted from the aerometer 19 and sends a control instruction based upon the estimated value to the adjustment part 12. Further, a flow rate control valve 13 or 15 is opened to a necessary extent of opening and gas for heat increase or dilution is supplied selectively to a mixing part 17 by a necessary amount. |
