Novel low-energy-consumption natural gas liquefaction technology

Abstract

The invention discloses a novel low-energy-consumption natural gas liquefaction technology. The novel low-energy-consumption natural gas liquefaction technology comprises a high-efficiency natural gas precooling heat exchanger, a natural gas liquefaction cryogenic heat exchanger, a heavy-hydrocarbon separation system, a liquid expansion machine, a BOG knockout tower, namely a knockout tower of non-condensable gas in the process of natural gas liquefaction, a BOG recuperative heating cooling box, a BOG supercharger, a propylene refrigerating system and an optimized mixed refrigerant refrigerating system. According to the novel low-energy-consumption natural gas liquefaction technology, the liquid expansion machine is added to the novel low-energy-consumption natural gas liquefaction technology, and is used for recycling energy of high-pressure liquid; innovation is carried out on a heavy-hydrocarbon separation technology, the temperature of heavy-hydrocarbon separation operation is increased, and refrigerant consumption and equipment investment are reduced; a BOG separation technology is optimized, the total quantity of the BOG is reduced, and the power of a BOG compressor is reduced; recycling of BOG refrigerants is improved, and BOG high-level refrigerants are recycled. According to the novel low-energy-consumption natural gas liquefaction technology, compared with the current technology of China, the energy consumption can be reduced by 10% or so, equipment investment is small, the capacity of adapting to working conditions is good, and localized production of key equipment can be achieved.

Description

technical field [0001] The invention relates to a novel natural gas liquefaction process with low energy consumption. technical background [0002] Due to its environmental protection, natural gas has become a better material to replace other fuels, and has a wide range of applications in power generation, automobile gas, industrial gas, chemical gas and urban residential gas. With the growth of the economy, the consumption of natural gas in my country has increased rapidly. However, natural gas is not easy to transport and store. In order to meet the growing demand, liquefied natural gas is the best way to transport and store natural gas, and its demand is increasing year by year. [0003] The current natural gas liquefaction processes mainly include high-pressure throttling refrigeration, cascade refrigeration and mixed refrigerant refrigeration. The above processes have their own advantages and disadvantages. The process of high-pressure throttling refrigeration is simpl...

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Problems solved by technology

The above processes have their own advantages and disadvantages. The process of high-pressure throttling refrigeration is simple and compact, and the cost is low, but its energy consumption is high and the processing capacity is small; cascade refrigeration has a long process, complex equipment, and high energy consumption; hybrid refrigeration Although the energy consumption of the solvent refrigeration process is low, it is difficult to manufacture large-scale mixed refrigeration compressors, and it is difficult to produce locally

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