Cooling air for blower station on WWTP? 2

[MartinLe]

At a wwtp, we will be installing a new cogeneration plant and adsorption chiller. Because adsorption chillers don't com in abritrary sizes, we may have 10 or 20 extra kW cooling power (in the form of cold water, ~ 5°C/15°C).

Now the plant operator has the idea to cool the air inflow into the blower station - the rationale beeing the blowers need cooling anyway & that the blowers are more efficient when working on cooler air.

Has anyone ever done this? Does it make sense from a process standpoint? The electrical power uptake of the combined blowers is up to 65kW (actually measured, not nameplate capacity)

tbh I don't know the exact airflow regime of the blower station - the blowers draw from the room, there's no extra ducts for cooling air, I presume the room has forced ventilation.

Even if the idea makes sense from a process perspective, the installation will be a hassle. The operators idea was to use the heating network pipes for cooling water during the summer, I have my doubts this is really feasible but I havent put much thought into it yet.

I'm of two minds about this: On one hand, the idea is intriguing and I'd like to at least investigate the possibility, OTOH this is no project where I can afford to sink too much time into any dead ends.

 

[bimr]

The blower intakes should be ducted to the building exterior. It is probably less expensive to install the intake ducts than install the chilled air system.

 

[ashtree]

Blowers are more efficient on cooler air but the amount of air you need to cool is very large. With 65kw demand my guess would be that your blowers would be pulling through 2-2500m3/hr. I doubt whether the 10-20kw of "cooling power" will make a big enough difference to be worth the extra expoense of what you are doing. Bringing the air from outside as bimr suggest will likely reduce the air temperature a couple of degrees at least anyway.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[MartinLe]

My ballpark estimate is that the blowers have an efficiency of about 60% and that half of the heat goes into the room, the other half goes into the process air ~ 13 kW.

But the point you, ashtree, raise is very valid - the airflow to operate on is fairly huge, only a small diff. in temperature can be expected so only a small benefit can be expected.