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Hi everyone.I am an engineering student in bangladesh doing an undergraduate thesis.My thesis topics is to construct a refrigerator based on the principle of vapor compression refrigeration system.I have calculated the total cooling load.But i cannot figure it out how to calculate the length of the condenser and evaporator length based on the cooling load.Please some one help me.My designed compressor is .2 hp.Using capillary tube as expansion device and using R-12 refrigerant.
R-12 refrigerant! wow thats a lot of money to wast.
I think you need to ask Gary this Author of TECH Method Troubleshooting books.
Hey Tony, remember he is only doing a thesis not actually constructing a machine.
A lot of text books always have an R12 data sheet.
Why you said lenght? Did you mean capacity?Quote:
Originally Posted by tanveerkuet
In order to size any heat exchanger u fristly u need to know under what catogary the HE is calssified/. Anyhow there are five equations derived form mass/energy conservations are used to calculate the condenser/evaportor size.
1- Q = U A LMTD
2- Q = m CP DT for a hot side
3- Q = m CP DT for a cold side
4- m = density * Ac * veocity for hot side
5- m = density * Ac * veocity for a cold side
AC = area cross section
DT = temperture differnce
LMTD = log.mean temperture differnence
Too often, u can find five unknowns in those equations if they are more that u have to assume a pratical value for unknow parameter.
Cheers
Is it air cooled or water cooled. You have to assume some parameters & that can be worked out. I know what it means at the time of writing a thesis. If you are considering air cooled condenser,
1. Max ambient temp
2. Heat rejection
3. Velocity acorss the coil.
Should be the parameters of assumption.
Same for water cooled.
There you shall have to consider the optimum veloecity for water & refer to Rheem charts etc to work out the Length.
But the capacity what you are working on is too small for all these.
I would suggest instead you should take some concrete example so that you can also mention the practical values based on some company catalogue. That shall have more weightage in the thesis that going in for only theoritical work.