摘要
针对非均匀受热管管壁周向壁温和热负荷等热特性参数分布不均性,将外壁温度与外壁散热热负荷作为边界条件,建立非均匀受热管的温度场计算二维模拟数学模型,基于径向节点推进思想,采用有限容积法建立离散方程,编制求解流体换热和管壁导热耦合决定的非均匀受热管二维温度场导热反问题数值计算程序。利用程序计算了Φ32mm×3mm和Φ24mm×4mm半周加热垂直上升光管对超临界水的传热特性,计算结果都可以很好地反映非均匀加热管管壁温的分布规律,同时计算收敛性良好。计算结果表明:超临界压力下,半周加热垂直上升光管壁温及壁面热负荷周向分布不均,高热负荷侧温度高,而低热负荷侧温度低。在拟临界区,出现传热强化,管内传热系数的增大会减小热量沿管壁周向的均流作用。
In the light of the non-uniform distribution of thermodynamic parameters,such as circumferential wall temperature of the non-uniformly heated tube wall and heat load etc.,a two-dimensional mathematical model was established for simulating and calculating the temperature field of a non-uniformly heated tube with the outer wall temperature and heat-dispersion thermal load serving as boundary conditions.Based on the idea of radial node advancement,the authors have adopted a finite volume method to set up a discrete equation.A numerical calculation program was prepared to solve the reverse problem of heat conduction in the two-dimensional temperature field on the non-uniformly heated tubes determined by the coupling of the fluid heat exchange and tube wall heat conduction.By making use of the program,calculated was the heat transfer characteristics of semi-circle heated vertical riser (bare tube 32×3 mm and 24×4 mm) with respect to supercritical water.The calculation results can exceedingly well reflect the wall temperature distribution regularity of non-uniformly heated tubes and exhibit a good computation convergence.The results of calculation also indicate that at a supercritical pressure,the semi-circle heated vertical bare-riser wall temperature and wall surface heat load assume a non-uniform circumferential distribution.The side with a high heat load has a high temperature and the side with a low heat load a low temperature.In the pseudocritical zone,a heat transfer intensification occurs and an increase of in-tube heat transfer coefficient will weaken the flow-equalizing role of heat along the circumferential direction of tube walls.
出处
《热能动力工程》
EI
CAS
CSCD
北大核心
2007年第4期435-439,共5页
Journal of Engineering for Thermal Energy and Power
基金
国家自然科学基金资助项目(50323001)
关键词
温度场
导热反问题
非均匀受热管
热负荷
temperature field,reverse problem of heat conduction,heat load,non-uniformly heated tube
