Indications of presence of air in refrigeration system
>High condenser pressure
>Small bubbles in the sight glass
>Compressor discharge pressure high/running hot
>More super heat
>Pressure fluctuations
>Inefficient working
Must Read:>Refrigerant Leak Detection Methods In A/C and Refrigeration System Onboard
PROCEDURE FOR PURGING AIR
a. In the normal operation of the system, measure the liquid refrigerant pressure, temperature at the outlet of the condenser/reservoir
b. Check the corresponding saturation temperature for the recorded pressure of the liquid refrigerant from the P-T chart for the same refrigerant
c. Compare the measured temperature with the determined saturation temperature for any sub-cooling and adjust the flow of the cooling water through the condenser to achieve near saturation condition inside the condenser,
Then,
d. With the condenser liquid refrigerant outlet valve closed, circulate cooling water, start the compressor and pump down the liquid to the condenser/reservoir, checking the pressure in the suction line. If this pressure is allowed to drop down below the atmospheric pressure then there could be chances of air ingress into the system
e. Circulate the cooling water till the cooling water outlet and the inlet temperatures equal, a check to ensure complete pump down operation
f. Check the condenser sea water out let temperature, check the refrigerant pressure corresponding to its temperature from the P-T chart of same refrigerant
g. Due to the presence of air it wont match with the P-H chart
h. Release air from the condenser, through the vent cock until the pressure of the refrigerant in the condenser corresponds to the saturation pressure at the sea water outlet temperature
>High condenser pressure
>Small bubbles in the sight glass
>Compressor discharge pressure high/running hot
>More super heat
>Pressure fluctuations
>Inefficient working
Must Read:>Refrigerant Leak Detection Methods In A/C and Refrigeration System Onboard
PROCEDURE FOR PURGING AIR
a. In the normal operation of the system, measure the liquid refrigerant pressure, temperature at the outlet of the condenser/reservoir
b. Check the corresponding saturation temperature for the recorded pressure of the liquid refrigerant from the P-T chart for the same refrigerant
c. Compare the measured temperature with the determined saturation temperature for any sub-cooling and adjust the flow of the cooling water through the condenser to achieve near saturation condition inside the condenser,
Then,
d. With the condenser liquid refrigerant outlet valve closed, circulate cooling water, start the compressor and pump down the liquid to the condenser/reservoir, checking the pressure in the suction line. If this pressure is allowed to drop down below the atmospheric pressure then there could be chances of air ingress into the system
e. Circulate the cooling water till the cooling water outlet and the inlet temperatures equal, a check to ensure complete pump down operation
f. Check the condenser sea water out let temperature, check the refrigerant pressure corresponding to its temperature from the P-T chart of same refrigerant
g. Due to the presence of air it wont match with the P-H chart
h. Release air from the condenser, through the vent cock until the pressure of the refrigerant in the condenser corresponds to the saturation pressure at the sea water outlet temperature