HYBRID CYCLE FOR THE PRODUCTION OF LIQUEFIED NATURAL GAS

摘要

REFRIGERATION PROCESS FOR GAS LIQUEFACTION WHICH UTILIZES ONE OR MORE VAPORIZING REFRIGERANT CYCLES TO PROVIDE REFRIGERATION BELOW ABOUT -40 °C AND A GAS EXPANDER CYCLE TO PROVIDE REFRIGERATION BELOW ABOUT -100 °C. EACH OF THESE TWO TYPES OF REFRIGERANT SYSTEMS IS UTILIZED IN AN OPTIMUM TEMPERATURE RANGE WHICH MAXIMIZES THE EFFICIENCY OF THE PARTICULAR SYSTEM. A SIGNIFICANT FRACTION OF THE TOTAL REFRIGERATION POWER REQUIRED TO LIQUEFY THE FEED GAS (TYPICALLY MORE THAN 5 AND OFTEN MORE THAN 10OF THE TOTAL) CAN BE CONSUMED BY THE VAPORIZING REFRIGERANT CYCLES. THE INVENTION CAN BE IMPLEMENTED IN THE DESIGN OF A NEW LIQUEFACTION PLANT OR CAN BE UTILIZED AS A RETROFIT OR EXPANSION OF AN EXISTING PLANT BY ADDING GAS EXPANDER REFRIGERATION CIRCUIT TO THE EXISTING PLANT REFRIGERATION SYSTEM. (FIGURE 1)