Design method for heptafluoropropane gas fire-extinguishing system

Abstract

The invention relates to a design method for a heptafluoropropane gas fire-extinguishing system. The fire-extinguishing system is mainly composed of a high-pressure fire-extinguishing agent storage bottle group, a fire-extinguishing agent conveying pipe network and nozzles which are sequentially connected, wherein the fire-extinguishing agent conveying pipe network comprises a main pipe, an ascending pipe and a high-pressure hose which are connected with the high-pressure fire-extinguishing agent storage bottle group, and branch pipes connecting the main pipe with the nozzles; and the high-pressure hose is connected to the main pipe through a follow collection pipe. According to the design method disclosed by the invention, a dynamic design and calculation method is adopted, during a process of spraying a high-pressure liquid onto the nozzles in each protection area through the fire-extinguishing agent conveying pipe network from the high-pressure fire-extinguishing agent storage bottle group, the process of continuous changes of the pressure and the flow speed of the liquid at each point in the fire-extinguishing agent conveying pipe network is subjected to discretization processing, one continuous process is discretized to be formed by superposing a plurality of time slices with a time step Delta t, the pressure and the flow speed in each time step are regarded as constant, and the pressure and the speed of the liquid at each node in the pipe network in each time step are calculated respectively.

Description

technical field [0001] The invention relates to a design method of a gas fire extinguishing system, and is mainly aimed at the design method of a heptafluoropropane gas fire extinguishing system. Background technique [0002] Heptafluoropropane gas fire extinguishing agent, also known as HFC-227ea, FM-200, is stored in a liquid state under a certain pressure. It is a colorless, odorless, non-conductive, and non-secondary pollution gas. It has the characteristics of cleanness, low toxicity, good electrical insulation, and high fire extinguishing efficiency. In particular, it has no damage to the ozone layer and has a relatively long residual time in the atmosphere. Short, its environmental protection performance is obviously better than halon, it is a kind of clean gas fire extinguishing agent that has been successfully researched and developed so far, and it is considered to be one of the most ideal products to replace halon 1301 and 1211. Heptafluoropropane gas fire exting...

AI Technical Summary

Problems solved by technology

The important and difficult point of the design method of this patent is: due to the nature of the heptafluoropropane gas fire extinguishing agent itself, the spraying time of the fire extinguishing agent must be controlled within 10s, which has always been a difficult point in the design and calculation process, and it must also be guaranteed; Also, the calculation of the maximum working pressure on the nozzle has not been very clear, but this is an important parameter of the system; in addition, there has been no calculation method for the length of time for the initial liquid level to reach the nozzle

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