JP2008180504A5 - - Google Patents

Claims (6)

at least,
Multiple or single load facilities ;
A chilled water primary pump that sends return chilled water returning from the load facility to at least one refrigerator;
A chilled water secondary pump comprising a power inverter, sending chilled water cooled by the refrigerator as chilled water, and sending chilled water of the amount of water according to the operating frequency of the power inverter to the load facility;
A control valve that adjusts the amount of the fed cold water sent by the cold water secondary pump steplessly by controlling opening and closing based on the temperature of the heat medium sent to the cooling object detected by the temperature detector;
A chilled water circulation system comprising a pump operation controller that controls an operation frequency of the power inverter and adjusts the amount of the chilled water secondary pump that feeds the chilled water;
The pump operation controller is based on the detected temperature difference in a direction in which the absolute value of the difference between the detected temperature difference between the feed cold water temperature and the return cold water temperature and the rated design temperature difference of the load facility decreases. The operation frequency of the power inverter is controlled to adjust the amount of water supplied to the load facility of the feed cold water, and further, the load facility is required for the specific load facility selected in advance. A cold water circulation system having a priority control mechanism that prioritizes satisfying a function in a direction in which an absolute value of a difference between the detected temperature difference and the rated design temperature difference decreases.   2. The chilled water circulation system according to claim 1, wherein the priority control mechanism controls an operating frequency of the power inverter, or an operating frequency of the power inverter and an operating number of the chilled water secondary pumps. A cold water circulation system comprising two or more of the cold water secondary pumps,
The pump operation controller adjusts the operating frequency of the power inverter and the cold water secondary pump so that the detected temperature difference between the feed cold water temperature and the return cold water temperature approaches the rated design temperature difference of the load equipment. The chilled water circulation system according to claim 1 or 2, wherein the number of operating units is controlled.   The temperature of the feed cold water is measured by a temperature detector provided in a first collecting pipe portion such as a feed main pipe or a feed header, and the temperature of the return cold water is measured by a temperature detector provided in a second collection pipe portion such as a return main pipe or a return header. The chilled water circulation system according to any one of claims 1 to 3, wherein the detected temperature difference is obtained.   The pump operation controller is configured such that a time when the difference between the detected temperature difference and the rated design temperature difference deviates from a preset allowable value is continuously set within a preset time or within a preset time. And a frequency control mechanism that changes the operating frequency of the power inverter in a direction in which the absolute value of the difference between the detected temperature difference and the rated design temperature difference decreases. Item 4. The cold water circulation system according to any one of Items 1 to 3.   The pump operation controller increases the number of chilled water secondary pumps when the operating frequency of the power inverter reaches a preset maximum frequency, and the chilled water secondary when the operating frequency of the power inverter reaches a preset minimum frequency. The chilled water circulation system according to claim 3, further comprising a number control mechanism for reducing the number of operating next pumps.