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Wildwood LNG Demonstration Facility 40-3203 Cryogenic Cooler 70/150 -150/-200 300 40-2301 Separator Vessel 50/150 -220/-240 600 40-2207 Cold Box 70 millibar/0 psig Ambient/70 NA 5.4 Refrigeration System The refrigeration system is a closed loop nitrogen system that supplies the cooling required to liquefy the natural gas. The refrigeration system is based upon the Brayton Refrigerant Cycle. The actual methods used in cooling the nitrogen and recovering heat is proprietary information. Table 5 outlines the design information for this system. Nitrogen, compressed to approximately 300 psig using a screw compressor, is then cooled and expanded. The expansion cools the nitrogen and lowers the pressure. The cooled nitrogen is used to cool and condense the natural gas in the cryogenic cooler. The nitrogen passes through a series of heat exchangers to recover the energy from the stream. During the process, the nitrogen temperature increases. The warmed nitrogen gas is *h-n recycled to the compressor, and the cycle begins again. The compressor uses oil for internal lubrication. As part of the system, oil entrapped in the nitrogen stream during compression is recovered in an oil coalescer. The recovered oil is recirculated through a closed loop to the compressor. The only stream in this system is the nitrogen circulation loop. There are three emergency safety relief valves that may vent nitrogen into the atmosphere in the event of over pressurization. Table 5 Design Information for the Refrigeration System Equipment Equipment Name Pressure—(P SIG) . -,Temperature (T) Flow Rate Number' Operating/Design Operating/Design scfm 30-3705 Refrigerant 70/350 100/150 600 Compressor 30-3709 Refrigerant 70/350 -220/-240 600 Expander 40-3203 Cryogenic Cooler 70/150 -150/-200 300 30-2307 Oil Separator 300/350 100/150 600 AES Construction Group Page 8