The refrigerant pressure gauge goes round and round, like growth rings, which makes our heads very confused!
Finding the pattern is actually very simple.
Let’s first look at the high pressure gauge
Taking R22 refrigerant as the representative
We can see that when the value of black circle R22 is 40 (here is the high pressure, corresponding to the condensation temperature), the corresponding value of the outermost white ring pressure is 1.4 MPa .
is also the most commonly used high-pressure value for cold dryers!
Let’s look at the low pressure gauge
which also uses R22 as the representative
. We can see that when the value of green circle R22 is 0 (here is the low pressure, corresponding to the evaporation temperature), the corresponding white pressure value in the outermost circle is 0.4 MPa .
We will try our best to keep the high and low pressure of the cold dryer using R22 around these two values.
What if it is air-cooled?
If the condensation method of the refrigerated dryer is air-cooled, the condensation temperature should be more than 15 degrees higher than the ambient temperature.
The ambient temperature in southern cities in summer is mostly close to 40 degrees!
At this time, you need to work hard on the selection of compressor . If you choose a compressor that matches the condensing temperature of 55 degrees, you can easily control the pressure gauge within a reasonable range.
Summary
Of course, the selection of evaporation temperature and condensation temperature will undergo various changes based on the working conditions, which requires technicians to have enough experience to deal with it. What truly reflects the technology is often the changing working conditions.
