System for producing liquefied natural gas by utilizing liquid nitrogen cold energy

Abstract

The invention discloses a system for producing liquefied natural gas by utilizing liquid nitrogen cold energy, which comprises purification equipment, a pre-cooling heat exchanger, a gas-liquid separator, a cryogenic tank, a main heat exchanger, a throttle valve, a cryogenic tank, a liquid nitrogen storage tank and a natural gas pipeline, wherein the purification equipment is sequentially connected with a hot fluid channel of the pre-cooling heat exchanger, the gas-liquid separator, a hot fluid channel of the heat exchanger, the throttle valve and the cryogenic tank, and the gas-liquid separator is connected with the cryogenic tank; the liquid nitrogen storage tank is connected with a cold fluid channel of the pre-cooling heat exchanger through a cold fluid channel of the main heat exchanger, and the purification equipment is connected with the natural gas channel. The invention has simple equipment, and can not only obtain LNG products but also obtain liquid light hydrocarbon and other high-added-value side products; and simultaneously, the process is easy to realize skid mounting, and the system is suitable for liquefying and transportation of more dispersedly distributed natural gas resources on land or sea and biogas resources on land.

Description

technical field [0001] The invention relates to a system for producing liquefied natural gas by utilizing the cold energy of liquid nitrogen. Suitable for liquefaction of natural gas on land or offshore. Background technique [0002] With the development of the economy, the energy crisis is becoming more and more apparent, and the environmental pollution is becoming more and more serious. Natural gas, as a high-quality clean energy with less pollution and high calorific value, is more and more favored by various countries. In recent years, the proven reserves of natural gas have increased steadily, and the production and sales volume have also continued to increase. The implementation of projects such as "West-to-East Gas Transmission", "North-to-South Gas Transfer", "Sea Gas Landing", "Imported LNG" and other projects will effectively promote the development and utilization of natural gas in my country. [0003] Since the origin of natural gas is often not located in indu...

AI Technical Summary

Problems solved by technology

However, its design is complicated, and there is no mature experience in China at present.

[0009] Existing natural gas liquefaction devices all use refrigeration cycles to provide the cooling capacity required for natural gas liquefaction, but their common disadvantages are complex process structures and equipment, and high cost

In addition, since natural gas contains a small amount of light hydrocarbon components in addition to methane, at least two stages of refrigeration are required to obtain liquid light hydrocarbon products while liquefying natural gas, which increases the complexity of equipment and processes

Images