垂直螺旋管内超临界CO_(2)传热特性的数值研究  

Numerical Study of Supercritical Carbon Dioxide Heat Transfer Characteristics in a Vertical Spiral Tube

作　　者：高思雨 郝小红[1] 张森 笪雄志 GAO Siyu;HAO Xiaohong;ZHANG Sen;DA Xiongzhi(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《工程热物理学报》2025年第2期475-485,共11页Journal of Engineering Thermophysics

摘　　要：超临界CO_(2)传热对发电系统的设计和运行具有重要意义,其常应用于非均匀加热的情况下,例如对于S-CO_(2)锅炉的应用。本文通过半侧加热、半侧绝热的方式,在压力8~15 MPa、进口温度305~325 K、质量流量835.27~2892.58 kg·m^(-2)·s^(-1)的工况下,采用RNG k-ε模型、伪瞬态对超临界CO_(2)在垂直螺旋管内的传热进行数值研究。进行了热流密度、质量流速、入口温度、压力、浮力以及流动加速度对传热系数的影响分析。研究结果显示,随着热流密度的增加,传热恶化程度加剧;增大质量流量可以显著提高传热系数。随着压力的增加,使流体的密度增加并且流体中的压力梯度更大,导致重力和剪切力的作用增强,使Ri数减小。最后,为了准确预测半侧加热条件下垂直螺旋管内超临界CO_(2)的传热情况,提出了一个新的传热关联式。The heat transfer of supercritical carbon dioxide is of great significance for the design and operation of power generation systems,and it is often used in cases of non-uniform heating,such as in the application of S-CO_(2)boilers.In this study,a numerical investigation of heat transfer of supercritical carbon dioxide in vertical helical tubes was conducted using the RNG k-εmodel under the conditions of semi-side heating,semi-side adiabatic,at pressures of 8~15 MPa,inlet temperatures of 305~325 K,and mass flow of 835.27~2892.58 kg·m^(-2)·s^(-1).The impact of heat flux,mass flow,inlet temperature,pressure,buoyancy,and flow acceleration on the heat transfer coefficient was analyzed.The research results indicate that the severity of heat transfer deterioration increases with the increase of heat flux;increasing the mass flow significantly improves the heat transfer coefficient;as the pressure increases,the fluid density increases,and the pressure gradient in the fluid becomes larger,resulting in enhanced gravitational and shear forces,leading to a decrease in the Richardson number.Finally,in order to accurately predict the heat transfer of supercritical carbon dioxide in vertical helical tubes under semi-side heating conditions,a new heat transfer correlation is proposed.

关 键 词：超临界二氧化碳 螺旋管 伪瞬态 非均匀加热 数值模拟 

分 类 号：TK121[动力工程及工程热物理—工程热物理]