蒸汽沿井筒流动过程中,蒸汽参数(压力、温度及干度等)、径向散热损失和垂向压力能损失,均沿流动过程变化。本文运用传热学、热力学及流体力学等学科知识,建立了井筒数值模拟综合计算模型,给出了求解方法,并进行了模拟计算。本文所建模型,综合考虑了蒸汽流动过程中压力、温度、干度和热损与压降的相互影响,给出了更为精确的无因次时间函数的表达式,通过试验确定了接箍对总传热系数的影响,同时也通过试验修正了隔热管性能变化对隔热性能的影响。
Steam parameters (pressure, temperature and dryness), heat losses and pressure drop are changing while steam is injected down the wellbore. This paper presents the numerical simulation and calculation model of steam injection, which was set up based on the knowledge of heat transfer, thermodynamics and fluid dynamics. The pressure, temperature, dryness and the interaction between heat losses and pressure drop are concerned in this model, thus it gives the dimensionless time-dependent function precisely. By means of experiments to ascertain the influence of collar on the coefficient of global heat transfer, it can give more accurate results. Meanwhile based on the tests, the influence on the characteristic of heat insulation due to the variation of the characteristic of heat insulation tub is modified.