Low drive temperature absorption chiller

[jhllt67]

Hi, I am working on designing a small ammonia - water cycle absorption chiller that runs on low grade heat, namely solar.

I have created a spreadsheet, attached, that, I think, simulates this and I have a few questions.

First, I need some more data on ammonia, namely the absorption in water at higher pressures. I have found tables online but they are only for 1 atm. If you could please point me to a website or book, I would appreciate it.

Secondly, looking at the COPs it spits out, I wonder are they really this high (I am considering the thermal energy as free)? I realize that it doesn't include flow or pump losses etc but do these machines really use such a small amount of electricity compared to compression cycle?

 

[Compositepro]

The process is used in gas refrigerators that are used in R.V.'s. They use no electricity at all so the electrical COP is infinite. So, no your results are not surprising. The cooling is done by the termal energy. The liquid pumping can be done with an electric pump or a thermally driven one but it is a small part of the energy cycle.