How do you determine the evaporation and condensation temperature?

1. condensation temperature:

The condensation temperature of the refrigeration system refers to the temperature when the refrigerant condenses in the condenser, and the corresponding refrigerant vapor pressure is the condensation pressure. For the water-cooled condenser, the condensing temperature is generally 3-5℃ higher than the cooling water temperature.

Condensation temperature is one of the main operating parameters in the refrigeration cycle. For practical refrigeration devices, due to the small variation range of other design parameters, condensing temperature can be said to be the most important operating parameter, which is directly related to the refrigeration effect, safety, reliability and energy consumption level of the refrigeration device.

2. Evaporation temperature: Evaporation temperature refers to the temperature when the refrigerant evaporates and boils in the evaporator, which is corresponding to the evaporation pressure. Evaporation temperature is also an important parameter in the refrigeration system. The evaporation temperature is generally 2-3℃ lower than the required water temperature.

The evaporation temperature is ideally the refrigeration temperature, but the actual refrigerant evaporation temperature is 3 to 5 degrees lower than the refrigeration temperature.

3. How to determine the evaporation temperature and condensation temperature generally: The evaporation temperature and the condensation temperature are based on the requirements, such as the air cooling unit, the condensation temperature mainly depends on the ambient temperature, and the evaporation temperature depends on what you apply to, even in some low temperature areas, the required evaporation temperature is lower. These parameters are not uniform, mainly see the practical application.

Please refer to the following data:

In general,

water cooling: evaporation temperature = cold water outlet temperature -5℃ (dry evaporator)

if full evaporator, evaporation temperature = cold water outlet temperature -2℃.

Condensation temperature = cooling water outlet temperature +5℃

air cooling: evaporation temperature = cold water outlet temperature -5 ~ 10℃,

condensation temperature = ambient temperature +10 ~ 15℃, generally 15.

Cold storage: evaporation temperature = cold storage design temperature -5 ~ 10℃.

Evaporation temperature regulation: first we need to know that the lower the evaporation pressure, the lower the evaporation temperature. Evaporation temperature regulation, in the actual operation is to control the evaporation pressure, that is, to adjust the pressure value of the low pressure gauge, the operation by adjusting the thermal expansion valve (or throttle valve) opening to adjust the low pressure. The expansion valve opening degree is big, evaporation temperature increases, the low pressure also increases, cooling capacity will increase; If the expansion valve opening degree is small, the evaporation temperature decreases, the low pressure also reduces, the cooling capacity will be reduced.