The invention discloses a lower-position water tank integrated closed 
cooling tower. The lower-position water tank integrated closed 
cooling tower comprises a 
cooling tower shell, a first spraying plate 
pipe, an 
air pump, a dustproof net, a fan, a cleaning roller, a mounting port, a second spraying 
pipe, a water outlet, a condenser, a first water conveying 
pipe, a water pump, a water inlet, a 
cooling coil, a bracket, a water collecting port, a water tank, a motor, a power frame, a slide block, a lead screw, a second water conveying pipe and an intake grid. The lower-position water tank integrated closed cooling 
tower can spray and cool the 
cooling coil through the second spraying pipe, the first water conveying pipe and the water pump; the 
air pump can timely absorb 
water vapor for coolingthrough the condenser; then, the 
water vapor is conveyed to the first spraying plate pipe for spraying by the second water conveying pipe, so that the 
cooling effect can be improved, and the influence on the fan by the 
water vapor can be prevented; the dustproof net can achieve a dustproof effect to prevent dust from falling into the cooling 
tower shell from the mounting port; and the motor, thepower frame, the slide block and the lead screw can control the cleaning roller to move back and forth to clean the dustproof net.