| 摘要 |
Variable air volume cooling system for a building which utilizes changes in the diameter of the belt (3) going around a two piece driver pulley (4) and a follower two piece driven pulley (2) to effect changes in fan speed and, accordingly, the air volume supplied. A control means (11) to operate a servo-motor (5) connected to the driver pulley (4) provides for separating the two piece driver pulley (4) to slow the fan (1), driving the two pieces of the driver pulley (4) together to speed up the fan (1), and for maintaining the same speed should a desired temperature range be obtained. The control (11) compares the temperature (16) of the area to be cooled with the speed (24) of the fan (1) to produce its outputs. Deadband operation (28) is provided to eliminate toggling and other excesses of output reversals. |
