| 摘要 |
PURPOSE:To control the pressure of sent-out gas as well as its heating value by controlling flow rates of liquefied natural gas and liquefied petroleum gas while holding a mixing ratio corresponding to specific heating value, and holding the pressure of the sent-out gas constant. CONSTITUTION:Measured specific gravity from a specific gravity detector 14 for the sent-out gas is converted by a heating value converter 13 into a detected heating value, which is supplied to a relational computing element 3 together with a set heating value, and the element 3 calculates the mixing ratio of the liquefied natural gas (LNG) and liquefied petroleum gas (LPG) from the deviation to obtain a set value to be sent to a distributor 4. A pressure regulator 2, on the other hand, calculates the total target flow rate of LPG and LNG and this flow rate is distributed to the distributor 4; and the flow rate of the sent-out gas is regulated by an LNG flow rate regulator and flow rate control valve regulators 5 and 6, and an LPG flow rate regulator and flow rate control valve regulators 9 and 10 while the mixing ratio of LPG and LNG is maintained. The heating value and pressure are stabilized under the control which causes no mutual disturbance, thereby supplying gas of good quality. |
