| 摘要 |
A fluid heating or cooling system installation 101 comprises a side-stream filtration vessel having an inlet 103, outlet 104 and air vent port 105. A first valve apparatus 115, ideally an isolating valve 118, is located upstream of the inlet and controls system liquid flow into the vessel. A second valve apparatus 116 is located downstream of the outlet and a pump 106 and controls system liquid flow through the outlet of the vessel. A controller 117 co-ordinates degassing system liquid by: (a) using the isolation valve to stop system liquid flowing into the vessel through the inlet to place the vessel in an operating pressure condition; (b) deactivating the pump after a period of delay from step (a) and using the second valve apparatus to restrict system liquid flow from the outlet to place the vessel in a degassing pressure condition, in which pressure in the vessel is lower than when under the operating pressure condition; (c) using the isolation valve or the second valve apparatus to introduce system liquid into the vessel, after step (b), to restore the operating pressure condition; and reactivating the pump after a period of delay from step (c). |
