Fan cooling capacity in the fan room
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For HVAC systems, it is necessary to design the ventilation in the fan rooms to maintain temperatures between 10 and 40 degrees; the cooling capacity of the fans is required in this context. However, the manufacturers contacted stated that such a requirement regarding cooling capacity was not mentioned. I was wondering, has anyone encountered this situation? I couldn’t find any clear information online regarding the heat dissipation rate; I guess it might be due to the unnecessary power consumption of the motor plus that of the fan. It’s really difficult to figure out the exact value: Q
I don’t have any experience either; although I think your idea is correct, how do you calculate the wasted power? This is not reactive power. . . In my opinion, if insurance is to provide coverage, should it be the active power of the motor minus the effective power of the fan?
(1 – Fan efficiency) * Motor output power + Motor losses. Motor losses = Motor input power * (1 – Motor efficiency). Is that correct?
We discussed it today and decided to go with this approach: use motor power multiplied by (1 – motor efficiency × fan efficiency); all losses that do not result in useful work are considered as heat losses, and this value is quite significant.
Well, I mentioned this idea first; there’s another issue. Part of the waste energy generated by the fan is used to heat the process gas, and similarly, part of the useful energy is also utilized for heating the process gas. Based on the outlet temperature specified by the manufacturer, which is 11,000 kg/h at a temperature range of 40 degrees to 120 degrees, more than 100 kW is required to raise the temperature of this process gas. So, when taking into account the heat dissipation from the fan housing, not only the waste energy portion needs to be considered – how should the useful energy portion be calculated as well? I’m dizzy just from saying it myself :dizzy:
It should be about right; there always needs to be some margin in engineering.
Heat generated (kW) – Fan room: Item, Motor, Casing. MCC2108: 12.3, 30; MCC2109: 12.3, 30; MCC2110: 6.1, 20. This information is taken from the process package, and it can be seen that the foreigners have separated the heat generation into those related to the motor and those related to the casing. This is similar to the approach used above, where motor efficiency and fan efficiency are taken into account