注蒸汽井筒隔热油管接箍散热损失

Research of Heat Loss Proportion of Heat Insulation Oil Pipe Coupling in Wellbore

蒸汽沿井筒流动过程中,蒸汽参数(压力、温度及干度等)、径向散热损失和轴向压力,沿流动过程变化。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,并进行了模拟计算。所建模型,对接箍散热量的计算没有采用估算的方式,而是采用接箍视导热系数的方法。计算结果表明,各级别的隔热油管,井筒传热中接箍散热损失所占比例差别较大,从A级到E级,散热损失所占比例12.8%～74.7%,因此接箍散热损失按30%估算是不合理的。

Steam parameter（pressure, temperature and dryness）, radial heat loss and axial pressure drop vary while it is flowing in wellbore. Wellbore mathematical models with knowledge in heat transfer, thermodynamics and hydrodynamics is established, and then the analog computation is carried out. Using the models, the heat loss of the coupling truly is calculated, instead of estimating. The calculation results show that the heat loss proportion varys greatly between heat insulation oil pipes in different grades. From grade A to grade E, the heat loss proportion varys from 12.8% to 74.7%. So,it is unreasonable to estimate the heat loss proportion of the coupling by 30%.