低温供热堆换热器的实时仿真研究

Research on Real-Time Simulation of Heat Exchanger in Low Temperature Nuclear Heating Reactor

根据200 MW低温供热堆换热器的非标准结构特点,在流体以三次叉流自然循环方式冲刷一次侧管束的情况下,建立了合理的数学物理模型.通过编制程序,应用组合的效能 传热单元数法和平均温压法 2 种方法,对各控制体进行了传热特性分析.该程序能准确地计算出换热器两侧的功率、流量、温度耦合变化的相互影响,求得换热器两侧各控制节点的温度变化规律.结果表明:求解非刚性方程的阿当姆斯数值方法的计算速度要快于求解刚性方程的吉尔方法,2种计算方法的误差不超过 5%.证明了阿当姆斯方法更适合低温供热堆的换热器实时仿真.计算仿真为200 MW低温供热堆的设计和安全运行提供了可靠依据.

The heat transfer characteristics of the heat exchanger in 200 MW low temperature nuclear heating reactor were analyzed by efficiency-number of transfer units and the mean temperature difference method, respectively. Based on the reasonable mathematic and physical model for the coupled three natural circulation cross flows, the code of the real-time simulation of the heat exchanger was developed. Compared the Adams method with Gear method adopted to solve the stiff differential equations, the temperature distributions of two sides in the heat exchanger were obtained. In addition the interrelationship of coupling change of power, flux, and temperature in two sides of the heat exchanger was investigated. The results indicate that the error of both two calculation methods is less than 5% and the Adams method is faster and more suitable for the real-time simulation process. The results could be used to the accident analysis and design for 200 MW low temperature nuclear heating reactor.