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SkyWalker
20-10-2010, 08:51 PM
Hello everyone,

If a TEV is overfeeding liquid into the evaporator due to bad bulb mounting or broken valve the result would be little or no superheat. Now with this (if i have read correctly) also comes lack of cooling.?

is this statement above correct? if so, is the lack of cooling because the refrigerant isnt changing state (latent heat) thus isnt gaining enough heat from the "refrigerated space?"

really im asking for a small explanation on the reasoning for the lack of cooling even though there is "too much" liquid refrigerant in the evap, so much infact that it marches out of the evap and into the comp, Doh! :/

I thank anyone in advance as any info is greatly appreciated and soaked up by my "eager to learn brain", lol

mikeref
20-10-2010, 11:31 PM
Hi Skywalker, the lack of cooling is the result of insufficient pressure difference from high to low side, so firing refrigerant unchecked into the evaporator will flood it but without the significant pressure drop to boil off liquid refrigerant, your liquid will walk right on through and find something else to do like damage the compressor..mike.

SkyWalker
24-10-2010, 08:46 AM
thanks for that mike, makes sense :)

Peter_1
24-10-2010, 12:23 PM
If a TEV is overfeeding liquid into the evaporator due to bad bulb mounting or broken valve the result would be little or no superheat. Now with this (if i have read correctly) also comes lack of cooling.?....

Decreasing SH will increase evaporator capacity because more surface is used to use the effect from the change of state of the liquid. All surface taken to superheat is lost evaporator capacity.
Second, overfeeding will increase LP of compressor, so better compression efficiency and lower compression ratio (=higher COP).