| 摘要 |
PURPOSE:To control the level of a fluid for a container to the best level invariably without reference to operation conditions of a plant by giving priority levels to transportation destinations of the fluid according to the operation conditions. CONSTITUTION:In a large load region, three-way solenoid valves 53, 54 and 55 each provide conduction from the port A to C by the on signal of a pressure switch 51 and when a pressure switch 52 is turned on, on the other hand, a four-way solenoid valve 56 provides conduction from A to C and from B to D. Therefore, signals for control levels NWL, HNWL and DWL from level setting means 61, 62 and 63 are supplied as set levels to recording controllers 34, 35 and 36, which correspond to a deaerator, a low-pressure water feeding and heating device, and a condenser, through an operating device 67. Namely, the deaerator, low-pressure water feeding and heating device, and condenser are given priority in this order. As a plant load decreases, the pressure switches 51 and 52 turn off in order and the priority is changed accordingly. |
