Device and method for producing liquefied natural gas using pipeline pressure energy to generate electricity and refrigerate

Abstract

The invention discloses a liquefied natural gas producing device and method for using pipeline pressure energy for power generation and refrigeration. The liquefied natural gas producing device comprises a pressure adjusting system, a natural gas liquefying system and a control system, wherein the pressure adjusting system comprises an expansion machine and a heat exchanger which are connected in series; the natural gas liquefying system comprises a natural gas pretreating system, a heat exchanger and a natural gas liquefying cold box, the natural gas pretreating system, the heat exchanger and the natural gas liquefying cold box are connected in sequence, and besides the natural gas liquefying system further comprises a mixed refrigerant circulating system; an output shaft of the expansion machine is connected with a double-output clutch, a first output end of the double-output clutch is connected with a generator, and a second output end of the double-output clutch is connected with a refrigerant compressor in the mixed refrigerant circulating system; an input shaft of the refrigerant compressor is connected with a double-input clutch, a first input end of the double-input clutch is connected with a motor, and a second input end of the double-input clutch is connected with the second output end of the double-output clutch. The liquefied natural gas producing device and method have the advantage of using the pressure energy sufficiently.

Description

Technical field [0001] The invention relates to a liquefied natural gas production device and method, in particular to a liquefied natural gas production device and method that utilizes pipeline pressure energy to generate electricity and refrigerate. Background technique [0002] As one of the three major fossil energy sources, natural gas will account for an increasing proportion of energy consumption. Natural gas is not only a large reserve, but also a high-quality clean energy. In developing countries like China, it plays a pivotal role in improving the energy structure and solving environmental problems and energy crises. [0003] At present, large-scale land transportation of natural gas at home and abroad is mainly pipeline transportation. The use of high-pressure transportation in long-distance pipelines is a development trend in various countries in the world, and the transportation pressure of many natural gas pipelines abroad is above 10MPa. my country's long-distance ...

AI Technical Summary

Problems solved by technology

[0006] The above-mentioned patented technologies are aimed at improving the pressure regulating process of the pressure regulating station itself. Through certain equipment and processes, the recovery of pressure energy and the liquefaction of natural gas in pipelines are realized, and there are generally limitations in the production of liquefied natural gas.

And each process only utilizes the pressure energy of the high-pressure pipe network at the first level, while the mechanical energy generated during the utilization process is wasted in vain.

Chinese invention patent application CN102538390A discloses a new type of natural gas liquefaction system and its method. The patent application scheme points out that during the process of expansion and refrigeration by using the pressure energy of the high-pressure pipe network, the expansion work of the expander can be recovered for power generation or used for other purposes. However, no further specific utilization plan was given, especially no specific plan on how to fully and rationally utilize this mechanical energy

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