Refrigerator test

[iranmech]

Hi

I have a problem in refrigerator test.
I want to test refrigerator in Ashrae condition, but i dont know how to define the Ashrae condition in my test state.
for example i dont know how define the Ashrae condensing temperature (54.4 c).
moreover i want to know, temperature of which place of condensor is named condensing temperature?
I will be glad if you help me.

Be happy
Hassanzadeh

[O_E]

Hi
I have a problem in refrigerator test.I want to test refrigerator in Ashrae condition, but i dont know how to define the Ashrae condition in my test state.
for example i dont know how define the Ashrae condensing temperature (54.4 c).moreover i want to know, temperature of which place of condensor is named condensing temperature?I will be glad if you help me.Be happyHassanzadeh

As I know heat-transfer processes in a typical condenser are divided into three stages: desuperheating of hot gas, condensation of liquid refrigerant, and subcooling. Desuperheating uses about 10-15 percent of the condensing surface area, condensation uses 75 to 85 percent, and subcooling uses 5 to 10 percent. fficeffice" />>>

[taz24]

Hi

I have a problem in refrigerator test.
I want to test refrigerator in Ashrae condition, but i dont know how to define the Ashrae condition in my test state.
for example i dont know how define the Ashrae condensing temperature (54.4 c).
moreover i want to know, temperature of which place of condensor is named condensing temperature?
I will be glad if you help me.

Be happy
Hassanzadeh

Hello.

54.4 c is the actual temperature that the refrigerant is changing state from a vapour to a liquid.

The discharge gas from the compressor will be considrably high than 54c (70c - 80c - 90c) in the pipe from the comp into the cond and the first part of the cond, the gas is desuperheated to 54c.

The refrigerant will then change state throughout most of the condenser and it will have changed by about the last turn in the cond. Finaly the liquid will cool in the last part of the cond and down the pipe to the reciever.

Assuming there is no pressure drop across the condenser then the 54.4 condensing temp will be for the most part throughout the whole condenser except the first turn in and the last turn out.

Any temp below 54c is subcooled liquid and any temp above 54c is superheated vapour (Azeotropic refrigerants only).

Cheers taz.

[iranmech]

Thanks everyone.

I need condensing temperature and evaporating temperature of my Refrigerator, so if i want to measure condensing temperature and evaporating temperature, where should i place my temperature sensors?

Be happy

[nike123]

Thanks everyone.

I need condensing temperature and evaporating temperature of my Refrigerator, so if i want to measure condensing temperature and evaporating temperature, where should i place my temperature sensors?

Be happy

In the middle of heat exchangers. But, it could be tricky to get correct reading. For condenser I use IC thermometer with correct emissivity setting, and for evaporator bead type probe insulated with armaflex from above.