Method and system for metering gas flow in multiphase flow, multiphase flow distribution device

Abstract

The invention provides a method and system for measuring gas flow in multiphase flow, and a multiphase flow distribution device. The method comprises the following steps: shunting a sample multiphase flow from a first laminar flow; separating all gases in the sample multiphase flow as sample gases, wherein the sample gases do not contain steam; measuring the flows of the sample gases; and calculating the total flow of all of the gases contained in the first laminar flow before shunting according to the flows of the sample gases. The multiphase flow distribution device comprises a main pipeline (21) which allows the multiphase flow having the first laminar flow to flow in, a first shunting pipe (24) which is used for shunting the sample multiphase flow from the first laminar flow and is communicated with the main pipeline (21) to form a branch pipe of the main pipeline (21), and a first return pipe (260 which allows the sample gases shunted from the sample multiphase flow to flow back to the main pipeline (21) and is communicated with the main pipeline (21). The measuring system comprises the multiphase flow distribution device, and a flow meter (7) arranged at the first return pipe (26). The method and system provided by the invention can reduce the measurement cost.

Description

technical field [0001] The invention relates to a method and system for metering gas flow in a multiphase flow, and a distribution device for the multiphase flow. Background technique [0002] Taking underground coal gasification as an example, underground coal gasification refers to the technology of converting underground coal into combustible gas in situ through thermochemical reactions. The export gas composition of underground coal gasification not only contains hydrogen, methane, carbon monoxide, carbon dioxide, but also contains a large amount of water vapor, water mist, tar, and even a small amount of coal slag. The above-mentioned export gas of underground coal gasification belongs to multiphase When the multiphase flow of underground coal gasification is directly measured, the cost of measurement and operation cost are relatively high. Moreover, the above solid and liquid impurities contained in the multiphase flow of underground coal gasification will interfere w...

AI Technical Summary

Problems solved by technology

[0007] (1) The coal gas at the outlet of underground coal gasification contains a large amount of impurities, and the prior art slag removal device is too simple to meet the technical requirements of underground coal gasification;

[0008] (2) The outlet gas temperature is relatively high, and the existing technology 1 has not done relevant design

[0010] (1) Since the impurities and water content in the coal gas vary greatly during the gas production cycle of the underground coal gasification underground gasifier, there must be a large error when using this technology, especially in the case of a small flow rate. more obvious;

[0011] (2) The temperature of the main pipe at the outlet of underground coal gasification is high, and the existing technology 2 cannot meet the requirements of practical application

Due to the large amount of gasified gas in the main pipe, if the traditional method is used for purification, it is necessary to set up a huge condenser and separation and purification equipment, which not only increases the investment, but also has very high operation and maintenance costs, and will cause damage to the surrounding environment Pollution

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