EXPERIMENTAL INVESTIGATION ON THE BOILING HEAT TRANSFER OF WATER IN VERTICAL UPWARD SMOOTH TUBES AT SUB-CRITICAL AND NEAR CRITICAL PRESSURES
Under sub-critical and near critical pressure, the heat transfer characteristics of water in a vertical upward smooth tube with the diameter of φ 32 ?? 3mm were researched experimentally. The experiments were performed under conditions of the pressure p=13~21.5Mpa, the mass velocity G=600~1200kg/(m<2>s) and the internal wall heat flux q=200~600kW/m2. Based on the experiments, it was found that the effect of the pressure on the heat transfer deterioration in sub-critical pressure region was different from that in near critical pressure region. The departure from nucleate boiling (DNB) mainly occurred when the critical heat flux (CHF) was high and the dryness was low. The increasing of the mass velocity was favorable to eliminate DNB, and the design mass velocity must surpass the critical mass velocity under the corresponding work condition in the engineering design. Correlations of the critical mass velocity, CHF and the minimum heat transfer coefficient have been provided and can be used as the reference for the design of the engineering practice.
boiling heat transfer sub-critical pressure near critical pressure vertical upward smooth tube
Huixiong LI Fei YIN Shuweng SUN Li HAO Tingkuan CHEN
State Key Laboratory of Multiphase Flow in Power Engineering, Xian Jiaotong University,Xian 710049 State Key Laboratory of Multiphase Flow in Power Engineering, Xian Jiaotong University, Xian 71004 Basic Department, Beijing Institute of Civil Engineering and Architecture, Beijing 100044, China
国际会议
上海
英文
407-412
2007-03-12（万方平台首次上网日期，不代表论文的发表时间）