Steam Absorption Chiller Efficiency 2

[dat66]

Does anyone know where I can find information on absorption chiller efficiency based on *non* design conditions? I'm looking to estimate (calculate) the energy benefit of implementing a condenser water reset routine.

It loos like I'm getting full capacity out of the unit on the CHW side but I want to optimize the cooling tower operation.

(600-T unit, 2-speed fans on the CT, P/S CHW)

 

[quark]

The best thing to do is an energy balance. Steam input and the actual refrigerating effect become the heat input to the system and heat absorbed by cooling water becomes heat output from the system. Ideally heat input should equal heat output. I did this type of calculation in the past and reduced cooling water flowrates without problem.

However, care should be taken and your observation is critical for, absorption systems are not good for capacity control and lower cooling water flowrates result in flooding of evaporator. This is a trial and error method worth giving a try.

 

[dat66]

Thanxs quark, that makes sense but what if I don't have steam flow? Are there any 'generally accepted' rules-of-thumb?

 

[quark]

Collect the condensate from economizer or from any suitable place. This will give you a fair idea about steam flowrate. You can ignore inaccuracy due to flashing.

 

[TBP]

A couple of outfits manufacture condensate meters - Cadillac, and Lincoln. If you're anywhere near a district heating operation, they frequently have a bunch of old condenate meters laying around. You could likely borrow/rent/buy one. The technology has been around forever but it's dead accurate with literally an infinite turndown, and very simple.