A NATURAL GAS LIQUEFIER FOR VEHICLE FUEL

A GENERAL USE CRYOREFRIGERATOR WILL BE DEVELOPED DURING PHASE I FOR LIQUEFYING NATURAL GAS TO FUEL PRIVATE AND COMMERCIAL VEHICLES. THE LIQUEFIER IS A NOVEL ARRANGEMENT OF AN AIR-CHARGED STIRLING SYSTEM THAT CAN BE CONFIGURED IN EITHER AN ELECTRICALLY POWERED OR A NATURAL-GAS-POWERED VERSION. THE LIQUEFIER SYSTEM INCORPORATES SEVERAL INNOVATIVE FEATURES TO ACHIEVE A RUGGED, COMPACT ARRANGEMENT WITH HIGH THERMODYNAMIC EFFICIENCY AND LONG OPERATING LIFE. ONE SUCH FEATURE IS A DRIVE MECHANISM THAT GIVES THE PISTONS OPTIMUM PHASING WITH STRAIGHT-LINE MOTION TO MINIMIZE SIDE FORCES AND WEAR. ALSO INCORPORATED IS A NEW CONCEPT IN HEAT EXCHANGERS THAT CAN BE TAILORED PRECISELY TO THERMAL, FLOW, AND CONFIGURATION REQUIREMENTS TO OPTIMIZE THERMODYNAMIC EFFECTIVENESS. THE SYSTEM WORKINGFLUID IS AMBIENT AIR, THUS PRECLUDING ANY HAZARDS OR POLLUTION FROM REFRIGERANT LEAKAGE. THE PROTOTYPE DESIGN ISFOR A REFRIGERATION CAPACITY OF 1 KW AT 110 K, SUFFICIENT TO PRODUCE 18 GALLONS OF LIQUID METHANE DURING AN 8-HOUR OVERNIGHT REFUEL CYCLE. TO MINIMIZE OPERATOR ONVOLVEMENT, THE SYSTEM IS FULLY AUTOMATIC THROUGH THE REFUEL PROCESS EXCEPT FOR ITS COUPLING AND UNCOUPLING TO THE VEHICLE.