Hi

I'm new here and was hoping for some guidance. As part of my engineering course I have been asked to carry out some analysis of the performance of refrigeration plant incorporating a water cooled condensor. I logged 5 sets of data based on varying heat loads on the evaporator using R134a refrigerant noting that my pressures are Gauge not Abs.

My problem really is how to start my p-h chart. I somewhat understand the process involved in my own head but am struggling to convey it in chart form. For example, if I take t4 and t2 as my evaporator and condensor temperatures respectively why are my recorded pressures not matching my temperatures on the p-h chart for R134a (t2=57.9degC does not equate to 11.6bar nor t4=12.7degC does not equate to 3.6bar.) Also worth noting although I waited 5mins after every alteration to heat load for stabilization no-one verified results.

If anyone can get me started in particular with the plotting of these results I'm pretty sure I can calculate COP, CC, Power absorbed, etc.

Thanks



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