Abstract: A liquefied natural gas (LNG) fueling station which does not vent natural gas vapors. Three cryogenic storage vessels alternately serve as dispensing, conditioning, and receiving vessels. A natural gas compressor transfers vapor between the vessels and evacuates vapors vented from tanker trucks and vehicles. Heat absorbed by the LNG is utilized to warm the fuel for use in vehicles by bubbling the vapors through the LNG in the conditioning vessel.

Abstract: An absorption refrigeration system with ammonia as refrigerant and a salt solution as absorbent operates with an improved margin of safety to crystallization of the salt solution by incorporating an absorber having a precooler and narrow nozzles. The precooler serves to additionally lower the temperature of the salt solution before it is caused to absorb ammonia exothermically, and the nozzles are for injecting the salt solution into ammonia gas flows, while maintaining the solution on the upstream side at relatively high pressure. The flow characteristics of the gas-liquid mixture through absorber tubes change from churn flow to slug flow and finally to bubble flow. A blower is provided for recycling a portion of the ammonia gas back to the absorber for optimizing absorption efficiency. The precooler and the absorber tubes are cooled evaporatively to reduce operating temperatures and system operating costs.