| 摘要 |
PURPOSE:To permit the stabilized supply of cold water by a method wherein the delivery valve of a cold water pump is choked and the control of the opening degree of a valve is switches so as to keep a water sending pressure at a reference value when the water sending pressure is increased to reduce the difference in flow amount of cold water between a refrigerating machine in the remaining operation time of the cold water pump and an air-conditioning load. CONSTITUTION:When an air-conditioning load is reduced, a bypass valve is opened to reduce the flow amount of air-conditioning load. An operating set control device stops one in of the refrigerating machines on a condition that the opening degree of the bypass valve is higher than the upper limit value thereof. When the air-conditioning load is reduced further, the bypass valve is fully opened to increase the sending pressure of cold water. In order to shorten a time ban in which the control of pressure is impossible, the control of the delivery valve of the cold water pump, effected by an usual constant flow amount control, is switched to a water sending pressure constant control. This switching mechanism is a cold water pump delivery valve control switching device 18 and a switching command for the device 18 is outputted from the operating set control device 17 based on the water sending pressure, the opening degree of the bypass valve and the flow amount of cold water of respective refrigerating machines. The cold water pump delivery valve is choked by the water sending pressure constant control to reduce the flow amount thereof and keep the water sending pressure at a constant reference value.
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