초록 ▼

This invention concerns a method and an apparatus for improving the efficiency of an open-cycle refrigeration process for LNG production by the employment of a liquid expander to recover energy associated with the flashing of a pressurized liquid stream and employing said recovered energy to compres

This invention concerns a method and an apparatus for improving the efficiency of an open-cycle refrigeration process for LNG production by the employment of a liquid expander to recover energy associated with the flashing of a pressurized liquid stream and employing said recovered energy to compress the flashed vapor streams in the open cycle.

대표청구항 ▼

[ That which is claimed is:] [1.]1. In a process wherein a LNG-bearing stream is produced at an elevated pressure and said stream is flashed in an open methane refrigeration cycle employing a multi-stage compressor via multiple stages of pressure reduction to a near-atmospheric pressure and employin

[ That which is claimed is:] [1.]1. In a process wherein a LNG-bearing stream is produced at an elevated pressure and said stream is flashed in an open methane refrigeration cycle employing a multi-stage compressor via multiple stages of pressure reduction to a near-atmospheric pressure and employing a multi-stage compression step, the improvement comprising in at least one of said pressure reduction stages:(a) flashing a pressurized LNG-bearing stream in an expander thereby generating a two-phase stream and energy;(b) separating said two-phase stream into a gas stream and lower pressure predominantly LNG-bearing stream;(c) compressing said gas stream in a compressor thereby producing a pressurized gas stream and wherein said compressor is powered at least in part by the energy of step (a); and(d) returning said pressurized gas stream to the multi-stage compression step employed in the open methane refrigeration cycle.