Shutdown gas ethane pipeline restart system and method

Abstract

The invention discloses a shutdown gas ethane pipeline restart system and method. The system comprises a main line start point valve group and temperature, pressure and flow detection system, a main line tail end valve group and temperature, pressure and flow detection system and a main line tail end bypass valve group and tracing pipeline system. By means of the shutdown gas ethane pipeline restart system, operation pressure is provided by an ethane pipeline, it is allowed that liquid ethane is formed in a pipeline, and the pipe diameter is reduced; in the restart process, when gas ethane enters the upstream, ethane is exhausted through a bypass to control the ethane gas emission, heat is exchanged between new ethane and accumulated ethane, and accumulated liquid ethane is slowly gasifiedby reducing pipeline pressure within a small range; in the restart process, by means of the bypass stainless steel valve group and tracing pipeline system, throttled ethane is prevented from producing low-temperature influences on the pipeline system, the temperature is further improved at a certain degree, and throttled ethane is prevented from producing low-temperature influence on the downstream system; and in the restart process, ethane continuously exhausted in the start process can enter the downstream system.

Description

technical field [0001] The invention relates to a system and a method for restarting after the gaseous ethane pipeline is stopped and restarted. Background technique [0002] In recent years, the market demand for ethylene has become increasingly strong, and the traditional raw material naphtha cannot be met in time, and ethane is also a good ethylene raw material, so refineries have a large demand for ethane. With the advent of the shale gas revolution in the United States, a large amount of ethane can be exported and supplied to refineries after extraction; at the same time, the domestic light hydrocarbon recovery process is becoming more and more mature, and self-produced ethane can also supplement the raw material gap of refineries. Therefore, there is a huge demand for supporting the construction of ethane pipelines from the ethane source to the refinery. Ethane products, as a class of natural gas accessory products with a lighter molar mass, have a high saturated vapo...

AI Technical Summary

Problems solved by technology

Although these two methods can avoid the formation of liquid ethane in the pipeline during the shutdown process, there are certain deficiencies: in the first method, the pipeline adopts the low-pressure transportation method. Amplification has the problem of large pipe diameter, which increases pipeline investment; in the second method, the pressure relief during stoppage not only wastes a certain amount of ethane product, but also increases the pipeline pressure after the medium is filled in the restart process. Also prone to liquid ethane, causing low temperature problems

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