PURPOSE: To improve the reliability of a compressor and expand an available range of the outside temperature for saving energy by a method wherein the range of change in the condensing pressure is decreased by means of a combination of a fan group control method and a water spray control method of an air-cooled condenser.
CONSTITUTION: Water spray is carried out on an air-cooled condenser 2 and the total number of fans 1 are opearted during normal operation. When the outside temperature falls below the set point, the operating number of the fans 1 is reduced to raise the condensing pressure. When the outside temperature falls further and the condensing pressure drops below the set point, water spray is stopped, and in addition, two or more or all the number of the fans are brought in operation to raise the condensing pressure. In the case the outside temperature drops while the water spray is stopped, causing the condensing temperature to drop below a set point, the operating number of fans 1 is reduced with water spray kept stopped, and the air flow rate is reduced for adjusting the condensing pressure. By this control, a sharp drop of the condensing pressure is restrained and the reliability of a compressor 4 is improved with saving energy.
AMO GIICHI
IZUSHI MINETOSHI
AOYAMA MITSUGI
AIYAMA MASAYUKI
HITACHI SHIMIZU ENG KK