Air-conditioning method and air-conditioning system

Abstract

An air-conditioning method comprises the steps of performing a refrigerator operation using a refrigerator to which cooling water cooled in a plurality of cooling towers is supplied as a cold heat source, and performing a free cooling operation using at least some of the plurality of cooling towers as a cold heat source, wherein at a time of the free cooling operation, the number of the cooling towers which are operated is controlled.

1 . An air-conditioning method comprising the steps of:
 performing a refrigerator operation using a refrigerator to which cooling water cooled in a plurality of cooling towers is supplied as a cold heat source, and   performing a free cooling operation using at least some of the plurality of cooling towers as a cold heat source,   wherein at a time of the free cooling operation, the number of the cooling towers which are operated is controlled.   
     
     
         2 . The air-conditioning method according to  claim 1 ,
 wherein an intermediate operation which uses at least some of the plurality of cooling towers as a cold heat source in combination with the refrigerator is performed, and at a time of the intermediate operation, the number of the cooling towers which are operated to be the cold heat source is controlled.   
     
     
         3 . The air-conditioning method according to  claim 1 ,
 wherein switching of the operation is performed in accordance with an outside air temperature and an air-conditioning load condition.   
     
     
         4 . The air-conditioning method according to  claim 1 ,
 wherein a plurality of the refrigerators are provided, and the number of the cooling towers which are operated is controlled for each of the plurality of refrigerators.   
     
     
         5 . The air-conditioning method according to  claim 1 ,
 wherein the refrigerator is a turbo refrigerator, and inverter control is performed for the refrigerator.   
     
     
         6 . The air-conditioning method according to  claim 1 ,
 wherein by controlling a rotational speed of a pump which circulates the cooling water cooled in the plurality of cooling towers or the refrigerator, a flow rate of the cooling water is controlled.   
     
     
         7 . An air-conditioning system, comprising:
 a plurality of cooling towers that cool cooling water;   a refrigerator having a condenser and an evaporator;   a circulation line for a refrigerator operation that circulates the cooling water cooled in the cooling tower into the condenser, and circulates the cooling water cooled in the evaporator into an air-conditioning load part;   a circulation line for a free cooling operation that circulates the cooling water cooled in the cooling tower into the air-conditioning load part;   a line switching device that switches the circulation line for the refrigerator operation and the circulation line for the free cooling operation, and regulates the number of cooling towers to be connected to the circulation line for the free cooling operation; and   a control device that controls the line switching device and individually controls operation and stoppage of the plurality of cooling towers.   
     
     
         8 . The air-conditioning system according to  claim 7 , further comprising a circulation line for an intermediate operation that connects the plurality of cooling towers in series to the evaporator of the refrigerator,
 wherein the line switching device switches the lines including the circulation line for the intermediate operation, and changes the number of cooling towers to be connected to the circulation line for the intermediate operation.   
     
     
         9 . The air-conditioning system according to  claim 7 ,
 wherein a plurality of the refrigerators are provided, and the number of the cooling towers which are connected to each of the refrigerators is changed by the line switching device.