METHODS OF SERVICING MOBILE AIR CONDITIONING SYSTEMS
The present invention relates to methods and systems for introducing one or more hydrohalocarbon refrigerants into a heat transfer system from a vessel by recovering the one or more hydrohalocarbon refrigerants from the heat transfer system; monitoring the vapor pressure in the vessel and if the vapor pressure in the vessel becomes greater than 3 psi over the expected saturation pressure for the one or more hydrohalocarbon refrigerants then releasing vapor from the vessel; and returning said one or more hydrohalocarbon refrigerants to the heat transfer system by drawing liquid refrigerant from the vessel.
1 . A method for introducing one or more hydrohalocarbon refrigerants into a heat transfer system comprising:
recovering from a heat transfer system one or more hydrohalocarbon refrigerants and providing the one or more hydrohalocarbon refrigerants to a vessel;
monitoring the vapor pressure in the vessel and if the vapor pressure in the vessel becomes greater than 3 psi over the expected saturation pressure for the one or more hydrohalocarbon refrigerants then releasing vapor from the vessel; and
returning the one or more hydrohalocarbon refrigerants to the heat transfer system by drawing liquid refrigerant from the vessel.
2 . The method of claim 1 wherein the one or more hydrohalocarbon refrigerants are selected from the group consisting of HFC-134a, HFO-1234yf, and combinations thereof.
3 . The method of claim 1 wherein the vapor pressure is released from the vessel when it becomes at least 5 psi greater than the expected saturation pressure for the one or more hydrohalocarbon refrigerants.
4 . The method of claim 1 wherein the vapor pressure is released from the vessel when it becomes at least 6 psi greater than the expected saturation pressure for the one or more hydrohalocarbon refrigerants.
5 . The method of claim 1 wherein the vapor pressure is released from the vessel when it becomes between 7 psi and 8 psi greater than the expected saturation pressure for the one or more hydrohalocarbon refrigerants.
6 . The method of claim 1 wherein the one or more hydrohalocarbon refrigerants are stored in the vessel as both a liquid phase and a vapor phase.
7 . The method of claim 6 wherein the vapor phase further comprises one or more non-condensable gases.
8 . The method of claim 7 wherein the non-condensable gas comprises CO 2 .
9 . A method for introducing one or more hydrohalocarbon refrigerants selected from the group consisting of HFC-134a, HFO-1234yf, and combinations thereof, to a heat transfer system from a vessel comprising:
releasing vapor pressure from within the vessel when the vapor pressure becomes greater than 3 psi over the expected saturation pressure for the one or more hydrohalocarbon refrigerants; and
providing the one or more hydrohalocarbon refrigerants to the heat transfer system by drawing liquid refrigerant from the vessel.
10 . The method of claim 9 wherein the one or more hydrohalocarbon refrigerants comprise a combination of HFC-134a and HFO-1234yf.
11 . The method of claim 9 wherein the vapor pressure is released from the vessel when the vapor pressure becomes at least 5 psi greater than the expected saturation pressure for the one or more hydrohalocarbon refrigerants.
12 . The method of claim 9 wherein the vapor pressure is released from the vessel when the vapor pressure becomes at least 6 psi greater than the expected saturation pressure for the one or more hydrohalocarbon refrigerants.
13 . The method of claim 9 wherein the vapor pressure is released from the vessel when the vapor pressure becomes between 7 psi and 8 psi greater than the expected saturation pressure for the one or more hydrohalocarbon refrigerants.
14 . The method of claim 9 wherein the one or more hydrohalocarbon refrigerants are stored in the vessel in both a liquid phase and a vapor phase.
15 . The method of claim 14 wherein the vapor phase further comprises one or more non-condensable gases.
16 . The method of claim 15 wherein the non-condensable gas comprises CO 2 .
17 . A system for introducing one or more hydrohalocarbon refrigerants into a heat transfer system comprising:
a vessel for storing one or more hydrohalocarbon refrigerants;
an automatic purge valve assembly set to release vapor pressure in the vessel when it becomes greater than 3 psi over the expected saturation pressure for the one or more hydrohalocarbon refrigerants;
an input line for providing the one or more hydrohalocarbon refrigerants from the heat transfer system to the vessel; and
an output line for returning liquid refrigerant from the vessel to the heat transfer system.
18 . The system of claim 17 wherein the one or more hydrohalocarbon refrigerants are selected from the group consisting of HFC-134a, HFO-1234yf, and combinations thereof.
19 . The system of claim 17 wherein the automatic purge value assembly comprises a purge line, a purge valve, and a control system.
20 . The system of claim 19 wherein the automatic purge value assembly further comprises a pressure transducer and, optionally, a temperature transducer.