Heat generation in the pump st006


No pump is 100% efficient. If a pump is rated 60% efficient that means that 40% of the power is being converted to heat and vibration. In a normal temperature stabilized pump, running at its best efficiency point (BEP) the temperature rise within the pump is calculated from the following formulas:

BHP = Brake Horsepower (you get his number from the pump curve supplied by the manufacturer).

42.41 = Conversion of HP to Btu. /min.8.33 = Weight of one gallon of water (U.S.)

lbs./ min. = Gpm. x 8.33 x Specific Gravity

S.H. = Specific Heat (1 for water)

BKW = Brake Kilowatts (From the pump curve)

1434 = Conversion of Kilowatts to Kilocalories

A temperature rise across the pump of 18 degrees Fahrenheit or 10 degrees Centigrade is considered excessive. This can occur if the pump is run with a shut, or excessively throttled discharge. If you would like to calculate the temperature rise of the liquid in a running pump when the discharge is shut, use the following formulas:

Temperature rise in degrees Fahrenheit per minute equals:

BHP. = Brake Horsepower at shut off42.4 = Conversion from Brake Horse Power (B.H.P.) to BTU/ minute

W = Net weight of the liquid, in the pump, in pounds (lbs.)

C = Specific Heat of the liquid

Temperature rise in degrees Centigrade per minute equals:

BKW. = Brake Kilowatt at shut off7.97 = Conversion from Brake Kilowatts (BKW) to Kilo calories/ minute

W = Net weight of the liquid, in the pump, in kilograms (Kg.)

C = Specific Heat of the liquid.