JPH0319459B

PURPOSE:To carry out the control of the number of cool and hot water apparatuses to be operated appropriately and economically by increasing the number of apparatuses to be operated when the temperature of outgoing water is changed toward the direction of increasing the quantity of heat consumed by a load apparatus, and decreasing the number of apparatuses when the temperature of return water is changed in the direction of decreasing the quantity of heat consumed. CONSTITUTION:A plurality of cool and hot water apparatuses (CHW) 21-2n are provided, and the temperature T1 of outgoing water and the temperature T2 return water are measured by temperature meters 13 and 14 provided in the vicinities of the side of a header 3 of a pipeline 4 and the side of a header 7 of a pipeline 6. At the same time, an average temperature T3 of respective return water passing through pipelines 6 and 8 is measured by a temperature meter 15 provided at the intermediate of the pipeline 6 of the header 7 and pipelines on the side of pumps 11-1n. Further, the flow quantity Q of return water is measured by a flowmeter 16 inserted into the pipeline 6, and a control unit 12 obtains the quantity of heat consumed of a load apparatus 5 based on the temperature difference between the temperatures T1 and T2 and the flow quantity Q as the quantity of the load. Based on the thus obtained result, the control unit 12 gives instructions to the cool and hot water apparatuses CHW 21-2n to control the number of apparatuses to be operated. Further, based on the temperatures T1 and T2, the CNT 12 judges the increase or decrease of the number of apparatuses to be operated and carries out the correction.