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Naddy
12-09-2013, 06:37 PM
hey, i am working on a 12 V refrigeration system.

What are the calculations that are need to be done for designing the refrigeration system.?
What are the parameters?
How to calculate the power?
How to calculate the COP ? What are the different parameters need to consider in designing ?

Rob White
13-09-2013, 10:38 AM
hey, i am working on a 12 V refrigeration system.

What are the calculations that are need to be done for designing the refrigeration system.?
What are the parameters?
How to calculate the power?
How to calculate the COP ? What are the different parameters need to consider in designing ?



A fridge is a fridge.

You design the thing like you would any other, the 12v compressor
makes no real difference to the design of the refrigeration system.

You need to know what your product is.
You need to know whether you are removing the heat
from the product or just storing the product at a set temperature.
You need to know how long you want to take to achieve
the desired temperature.

Start with the product......


Once you know that you can calculate how much heat you will
be moving and then you can calculate how you are going to move the heat.

Rob

.

Naddy
13-09-2013, 02:54 PM
i want to store the product at a set temperature of 2C to 5c.
and time to achieve this temperature is 20 minutes.
Can you help me how can i do this two thing?

Rob White
13-09-2013, 08:52 PM
.

No, not really.

To do that we need to know how much of what product?

If you are talking about a domestic fridge, a common house
fridge, that is used for storing general produce then you could
measure the heat load in 100's of watts. If you are wanting to cool
half a sheep in 20 mins you would need many, many kilowatts of
cooling capacity.

If you are asking these questions maybe this project is too much for you

Rob

.

Naddy
14-09-2013, 03:29 AM
i want to store .5lbs (250gram) of vegetables.
the volume of storage area is 16litre. Generally a home freeze is 100litre but here the area of storage is also small.
the size of storage area is 10*8*5 inchs.

Rob White
14-09-2013, 05:41 PM
.

Get an old small domestic fridge and use that.
You can fit your 12v comp to the system.

Regards

Rob

.

The Viking
14-09-2013, 07:31 PM
Or cheaper still, as you are asking these questions and we therefore can assume that you are not a time-served fridge guy, buy a small domestic fridge and an inverter to run it of.

To design a system from scratch takes a lot of specialist knowledge and even to "just" change a compressor you will need to know exactly what you are doing, none of this knowledge is something you would be able to pick up from the internet.
Your DIY option is likely to cost you way more just in tools and parts (not to mention a few scrapped compressors) than you would have to pay for standard, of the shelf, equipment like an inverter and a domestic fridge.

:cool:

The Viking
14-09-2013, 07:34 PM
Or, another completely different option...

Buy an of the shelf marine or leisure fridge (normally used in boats, caravans and camper vans) as these are generally fairly small and designed to be run on 12V or even propane.

:cool: