me4293 geothermal heat pump with R134a and exergy calcs

[@hoseinfaramarzpour627]

I have a question. I am going to use water for the condenser section. it means that the refrigerant will warm the water, which will be stored in a storage. The ambient temperature (T0) is -15 C. Now, my question is how should I calculate the water exergy. there is no data for temperature of -15 for water. some papers calculated the air exergy instead of water. next question, could you please introduce me a reference book for the exergy topic

[@hoseinfaramarzpour627]

hello Sir. I have a very important question. if reference temperature is -10, how should we calculate the exergy of water on -10? this number for water should be 0 since it is ice.

[@maxklit1478]

Hi! I can't seem to figure out which numbers you use for the exergy destruction calculations. Since the ef1 is much larger than ef2 the exergy destruction in the compressor doesn't make sense to me. Could you please explain?

[@hoseinfaramarzpour627]

I think the properties you used are totally wrong. or the refrigerant is not r134-a

[@randallmanteufel6411]

check datum point for energy & entropy properties. Tables in Moran textbook have both enthalpy and entropy for sat liquid at -40 C = zero. This is common, but other tables/books have different datum point.