I was wondering if anyone could help me with a math problem. I tried it but my answer doesn't seem right? Here's the Question. What is the capacity in tonnes of refrigeration of a system in which 1200 kg of the refrigerant are circulated per hour? The enthalpy of the vaporized refrigerant leaving the evaporator is 181 kj/kg and the enthalpy of the liquid refrigerant entering the expansion valve is 64.66 kj/kg.
Here's how i did it. The refrigerating effect is calculated by subtracting enthapy of liquid refrigerant enetering the expansion valve from the enthapy of the vaporized refrigerant leaving the evaporator. Thus i have 181 kj/kg - 64.66 kj/kg = 116.34 kj/kg( refrigerating effect)
I now need to calculate the heat of fusion. I get
1200 kg of refrigerant x 334 kj(which is the amount of heat required to melt 1 kg of a substance, of ice)= 400800 kj per 24 hrs or 400800 divided by 24 = 16700 kj/hr. I then divided further 16700 kj/hr by 60 to get 278.33 or 278 kj/min.
Therfore to get Tons of refrigeration i divided 116.34 by 278 and the answer i get is 0.418 tonnes.
For some reason this doesn't seem right. Could someone assist me with this math.
Happy New Year