Effect of blade pitch in an axial fan on the energy characteristics of an air cooler

The effect of the pitch of the blades in an axial fan with an UK-2M impeller 2.8 m in diameter on the characteristics of a horizontal three-section air cooler (AC), the six-tier heat-exchange sections of which consist of bimetallic finned tubes with rolled aluminum fins (tube-finning factor of 20.4; medium cooled – gasoline) is analytically investigated. It is found that for the same power consumed by the fan drive, the pitch of the fan blades in the interval from 15 to 25° will not affect the thermal flux of the AC. Recommendations are given for selection of energy-expedient pitches of the blades during AC operation, and also for thermal analyses of units under design.