Water Cooled Machine IC81W
Water Cooled Machine IC81W
(OP)
Hi guys can anyone please give a estimation or rule of thumb for determining the heat loss fron a water cooled motor ( Heat Exchanger )For example we hae a 1Mw 4p motor with efficiency at FL of 95.8%, Water inlet is 33 Deg C , and oulet approx 39 Deg C, Water flow rate is 9.4 m3/h





RE: Water Cooled Machine IC81W
1,000,000 x 0.042=42,000 Watt-sec = 42,000 Joule
Based on the water flow and temperature rise
100 cm^3 x 9.4 m^3/hr x 6 deg C / 3600 sec/hr = 15,666 cal
15,666 cal x 4.18 J/cal = 65,000 Joule
The difference between the two calculations could be caused by
Motor less efficient
Motor overloaded
Flow or temperature rise errors.
RE: Water Cooled Machine IC81W
Since 9.4 cum/hr = 2.611 liters/sec, and delta T = 39-33 °C = 6 C
kWloss = 2.611 x 6 / 0.24 = 65.275 kilowatts.
RE: Water Cooled Machine IC81W
What we are trying to establish is the heat loss of this water cooled machine into the pump room. The water circuit will take a certain amount away, ( 65.275 kw ? )but some heat will still be transferred through the frame ( sides )maybe small but their will be 10 of these motors in this pump room
RE: Water Cooled Machine IC81W
There are two possibilities;
1> The motor is running at a lower temperature than the room and is actually cooling the room.
2> The data is in error.
respectfully
RE: Water Cooled Machine IC81W
The water temperature rise is pretty straight to measure the energy it removes from the heat source.
It takes 1 calorie (4.184 joules) to increase 1 gram of water 1 °C.
RE: Water Cooled Machine IC81W
There will also be cooling effects from the room walls and air leaks that are usually present.
RE: Water Cooled Machine IC81W
I was once told a rule of thumb that the heat loss was the centre height (in mm)/100. ie for a 710 machine it is approx 7.1kW. Its arbitrary and surprising how many times it comes close. Any want want to bet the centre height of this generator is 450mm?