A nuclear power plant capacity control box purging system and method

Abstract

The invention provides a purging system and a purging method for a nuclear power plant volume control box. The purging system comprises a lower discharge pipeline, an upper filling pipeline, a volumecontrol box, an air intake pipeline, an exhaust pipeline, an injected gas pipeline and a gas concentration online detection bypass. The invention improves the gas-liquid mass transfer coefficient through the ejector in the lower discharge pipeline, the filler in the volume control box and the bubbler. In addition, in the nitrogen purging process, the amount of oxygen precipitated from the gas in the volume control box is much larger than that in the prior art; in addition, the nitrogen purging mode can remove a large amount of dissolved oxygen in water, reduce the usage amount of hydrazine, and reduce the operation cost due to the consumption of desalting bed resin by using hydrazine. In the hydrogen purging process, the dissolved amount of hydrogen is much higher than that of the prior art, the concentration of hydrogen in water is improved, the inhibition effect on oxygen generated by irradiation decomposition of water is further improved, the concentration of dissolved oxygen in water is further lower, and the inhibition effect on oxygen corrosion of nuclear power plants is improved.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor thermal hydraulics, in particular to a nuclear power plant capacity control box purging system and method. Background technique [0002] Nuclear energy is clean, competitive, and can replace fossil fuels on a large scale. However, the accidents at the Three Mile Island nuclear power plant in the United States, the Chernobyl nuclear power plant in the Soviet Union, and the Fukushima nuclear power plant in Japan have all sounded the alarm for nuclear safety. It is the top priority of nuclear energy development. Oxygen corrosion produced by nuclear power plants is one of the important factors affecting the safety and service life of nuclear power plants. Therefore, nuclear power plants must use various oxygen removal technologies to ensure that the oxygen content of the working fluid is low, thereby inhibiting oxygen corrosion. [0003] The working principle of the nuclear power plant is: th...

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Problems solved by technology

However, in the original system, both nitrogen and hydrogen directly enter the air space of the volume control box 4, and water is only atomized into the air space of the volume control box 4 through the atomizing nozzle 5. The gas-liquid contact time and the gas-liquid contact area are very low. As a result, the oxygen precipitation rate is very low during the nitrogen purging process, the hydrogen dissolution rate is very low during the hydrogen purging process, and the purging effect of the capacity control box is poor; The oxygen content in the air space of the control box 4 will also increase due to the oxygen brought in by the downflow, resulting in the need for repeated purging

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