Originally Posted by
RANGER1
Liquid receiver?
The only things I can think of with your symptoms are,
- System 2 short of refrigerant.
(if so, why the suction pressure is 7,2Bar- plus it is charged with same amount of refrigerant as other identical circuit)
- no liquid receiver or low level in it. Has to have one in my opinion.
(It is not equiiped with a receiver yes, it has very small piping, i do not apply liquid receivers to small distance piping systems as the EXV is not starving)
- change filter drier to eliminate pressure drop & possible flash gas after it due to little sub cooling. (I changed the filter drier, no change on the pressure drop,)
- Expansion valve open more as starving for refrigerant.
(Applied this and gave EXV a bigger opening range- reduced superheat setpoint to 5K no change on cooling efffect)
- superheat 7 degC possibly fooling us due to it only being able to get a maximum of that, unless ambient can increase it through heat gain which does not apply in your situation on test rig.
Correct, testing rig is insulated+indoors. No effect on the superheat.
- If system short of refrigerant condenser may behave differently & condense at a higher pressure.
(Agreed, but the suction pressure is on design conditions-The discharge pressure increases when we add on refrigerant, subcooling doesnt change much.)
Does not explain higher suction pressure but running out of ideas.
(Thanks for spending your time on the issue. i am also out of ideas)
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