Refrigeration system superheat is the actual temperature of the refrigeration valve or other media that is a few degrees higher than the saturation temperature corresponding to the actual stresses, called superheat.
For example 1atm atmospheric pressure, 110 overheated water vapor its superheat degree is 10 degrees.
The superheat of the refrigeration system and air conditioner system is mainly controlled by the throttling device.
The return gas temperature is calculated by means of a temperature-sensitive part placed in the compressor return line or at the evaporator outlet.
The temperature difference between the return gas temperature and the saturation temperature is the suction superheat.
And set the superheat degree as the basis to adjust the throttling device opening.
From another point of view, this method adjusts the amount of liquid supplied to the evaporator.
Therefore, it achieves the regulation of cooling and will be the air conditioning system suction superheat.
Of course, different systems of superheat adjustment are not the same, the specific superheat also needs to refer to the instructions of the refrigeration equipment.
Degree of Superheat in Refrigeration
In refrigeration systems, the actual temperature of the evaporator outlet and the compressor discharge port work mass is higher than the saturation temperature corresponding to the actual pressure.
Therefore, the concept of superheat degree needs to appear.
The superheat degree is mainly controlled by the expansion throttle device, in general, the superheat degree of the throttle valve or expansion valve factory already has the conditions for normal use.
The superheat of the refrigeration throttling device before installation into the system is called static assembly superheat, the value is about 3 degrees.
The range of superheat required from the start of the refrigeration throttle (expansion valve) to the set opening level is called the effective superheat of the expansion valve or variable superheat.
Usually, the effective superheat is about 2 to 5℃
The working superheat of the refrigeration system is the sum of the static assembly superheat and the effective superheat of the thermal expansion valve, and this value is 5 to 8 degrees.
This is the superheat degree we often say.
Read more: refrigeration valve.
The Role of Superheat
In the refrigeration system, if the compressor suction is complete without superheating, it is possible to produce back gas with liquid.
Even caused by the wet stroke liquid shock damage to the compressor.
To avoid this phenomenon, a certain degree of suction superheat is required to ensure that only dry steam enters the compressor.
There is also a reasonable operating interval for the superheat of the refrigeration system.
Therefore, the superheat of the refrigeration system should not be too high.
High superheat will cause the discharge temperature of the HVAC&R compressor to increase, resulting in overload operation of the compressor.
So, The correct superheat of the cooling system is very important.