Development and Verification of a Transient Analysis Tool for Reactor System Using Supercritical CO2 Brayton Cycle as Power Conversion System

Supercritical CO2 Brayton cycle is a good choice ofthermal-to-electric energy conversion system, which owns a high cycle efficiency and a compact cycle configuration. It can be used in many power-generation applications, such as nuclear power, concentrated solar thermal, fossil fuel boilers, and shipboard propulsion system. Transient analysis code for Supercritical CO2 Brayton cycle is a necessity in the areas of transient analyses, control strategy study, and accident analyses. In this paper, a transient analysis code SCTRAN/CO2 is developed for Supercritical CO2 Brayton Loop based on a homogenous model. Heat conduction model, point neutron power model (which is developed for nuclear power application), turbomachinery model for gas turbine, compressor and shaft model, and PCHE type recuperator model are all included in this transient analysis code. The initial verifications were performed for components and constitutivemodels like heat transfermodel, frictionmodel, and compressormodel. The verification of integrated system transient was also conducted through making comparison with experiment data of SCO2EP of KAIST. The comparison results show that SCTRAN/CO2 owns the ability to simulate transient process for S-CO2Brayton cycle. SCTRAN/CO2 will become an important tool for further study of Supercritical CO2 Bryton cycle-based nuclear reactor concepts.

超临界二氧化碳布雷顿循环是一种热 - 电能量转换系统的良好选择，它具有较高的循环效率和紧凑的循环结构。它可用于许多发电应用，例如核能、聚光太阳能热、化石燃料锅炉以及船用推进系统。超临界二氧化碳布雷顿循环的瞬态分析程序在瞬态分析、控制策略研究以及事故分析等领域是必不可少的。本文基于均相模型为超临界二氧化碳布雷顿循环开发了一个瞬态分析程序SCTRAN/CO2。该瞬态分析程序包含热传导模型、点中子功率模型（为核能应用而开发）、燃气轮机的涡轮机械模型、压缩机和轴模型以及印刷电路板式换热器（PCHE）型回热器模型。对部件以及诸如传热模型、摩擦模型和压缩机模型等本构模型进行了初步验证。还通过与韩国科学技术院（KAIST）的超临界二氧化碳实验回路（SCO2EP）的实验数据进行比较，对集成系统瞬态进行了验证。比较结果表明，SCTRAN/CO2具备模拟超临界二氧化碳布雷顿循环瞬态过程的能力。SCTRAN/CO2将成为进一步研究基于超临界二氧化碳布雷顿循环的核反应堆概念的重要工具。