A test device and method for simulating metal vapor-liquid two-phase corrosion of air-cooled condenser

Abstract

The invention provides a vapor-liquid two-phase corrosion test device and method for simulating the metal pipe of an air-cooled condenser. The test device includes a deoxygenation system, a circulating water tank, a simulated corrosion tank, a circulating water treatment and a monitoring system. The circulating water tank is placed in a water bath to maintain a constant temperature, and the upper end of the water bath is covered with a foam board. A thin gas tube connected to the nitrogen cylinder is inserted into the bottom of the water tank, and the upper part of the water tank is led out with a thin tube and connected to a vacuum pump. Insert electrodes, test pieces and thermometers into the simulated corrosion tank, and connect the simulated corrosion tank to the water tank pipeline. The water tank is connected to a water treatment and monitoring device. The whole system uses glass and silicone tubes, which is an iron-free system. The whole structure is simple, easy to operate, and can more realistically simulate the on-site environment.

Description

technical field [0001] The patent of the present invention relates to an experimental system for simulating a thermal power plant, in particular to an accelerated corrosion test system for simulating a vapor-liquid two-phase flow inside a metal pipe of a direct air-cooled condenser in a thermal power plant. Background technique [0002] Thermal power generation consumes not only primary energy but also water resources, and the lack of water resources is a major problem facing the world at present. According to the statistics of the United Nations in recent years, the world's fresh water consumption has increased six to seven times since the beginning of this century, which is twice as fast as the population growth rate. At present, about 1.5 billion people in 80 countries in the world are facing insufficient fresh water resources, and about 300 million people in 26 countries are completely living in a state of water shortage. my country's per capita water consumption is onl...

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Problems solved by technology

Due to factors such as cost and operation, the current material for building air-cooled condensers is mainly carbon steel (20G). Carbon steel is severely corroded in a high-temperature dissolved oxygen water environment, especially the lack of steam in high-flow steam turbines leads to single-phase and gas in the air-cooling system. The flow-accelerated corrosion (FAC) of the liquid two-phase causes the iron content in the water-steam system of the unit to seriously exceed the standard, which in turn leads to more serious corrosion problems

[0004] At present, there is no standard to guide the chemical operation of air-cooled units, and the air-cooled units that have been put into operation are generally controlled with reference to the relevant chemical operation indicators of wet-cooled units, which leads to the common phenomenon of FAC of carbon steel components in air-cooled units

The current method for studying the corrosion characteristics of air-cooled condenser materials in the operating environment is mainly laboratory simulation research. The existing simulation experimental equipment can only simulate a single liquid phase flow environment, and the system cannot be metal-free, and the oxygen removal efficiency is low. , and it cannot be simulated under negative pressure conditions, so that the basic purpose of the simulation experiment cannot be achieved, and there is a big gap with the actual environment on site

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