Heat conduction modeling and calculating method for natural circulation vapor generator

Abstract

The invention discloses a heat conduction modeling and calculating method for a natural circulation vapor generator. On the basis of a cylinder wall no-internal-heat-source one-dimensional heat conduction differential equation, distribution of the temperature in a heat transfer pipe in the natural circulation vapor generator and distribution of the temperature in dirt are expressed as a function of the primary side wall temperature and a function of the secondary side wall temperature of the heat transfer pipe, and a function of the outer surface temperature of the dirt, it is supposed that the heat transfer pipe and the dirt are in a quasi stable state in the dynamic process, and the problem of solving a partial differential equation is converted into the problem of solving an ordinary differential equation; in addition, when heat conduction and fluid thermotechnical hydraulic power are coupled, a loose coupling calculation method is adopted, on the basis of ensuring the model precision, the workloads of simulating calculation are greatly reduced, heat conduction of the natural circulation vapor generator is calculated fast, and the method is beneficial for achieving high-precision real-time simulating calculation of the natural circulation vapor generator and a nuclear power unit device, and has the great significance in guiding a nuclear power plant unit to operate safely and reliably.

Description

technical field [0001] The invention belongs to the technical field of steam generators, and more specifically relates to a heat conduction modeling and calculation method of a natural circulation steam generator. Background technique [0002] The natural circulation steam generator is the hub of the heat exchange of the primary and secondary circuits of the power plant of the nuclear power plant. After passing through the descending section, the heat transfer tube is flushed, and then flows longitudinally along the outside of the heat transfer tube. Under the heating of the primary side fluid, it experiences single-phase water and two-phase vapor-liquid, and finally passes through the steam-water separator to obtain saturated steam, and finally passes through the steam turbine. Work drives the generator to generate electricity. [0003] As the key equipment for energy exchange in nuclear power plants, realizing the real-time simulation of natural circulation steam generato...

AI Technical Summary

Problems solved by technology

In the calculation of steam generator heat conduction and fluid thermal-hydraulic coupling, the Gill algorithm with high calculation accuracy can also be used, but because it is an implicit algorithm, the amount of calculation in dynamic simulation is very large, and it cannot meet the needs of real-time simulation

Therefore, accuracy and calculation speed have become a pair of difficult contradictions for high-precision real-time simulation of natural circulation steam generators

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