管道内脉冲式热源参数对流动传热的影响研究

Influence of Pulsed Heat Source Parameters on the Flow and Heat Transfer in the Pipe

引用流固耦合的热传导数学模型,运用有限元多物理场耦合分析软件COMSOL Multiphysics建立流道和热源物理模型,在内径为37mm的水平圆形管道内,放置不同形状、不同尺寸、不同加热功率、不同加热脉冲宽度的热源进行流固耦合的热传导数值模拟研究,数值模拟分析流道内沿管道中心不同位置处的温升变化情况。模拟结果显示,几何形状为长方体型且长度较小的热源对流体加热温升效果比较好,流体的最大温升值随热源功率增大而线性增大;热源长度越大,获得的最大温升值越小;当流量达到15m^3/d时温升值不受长方体型热源长度的影响。当热源功率达到400 W以上,加热脉冲宽度为1s时可以在0~15m^3/d流量段内获得较好的温升效果,用铂电阻式温度传感器进行准确测量,为优化基于热示踪方法的测试类仪器设计提供了理论支持和指导意义。

At the present time, the thermal tracing flowmeter has an initial application in flow measurement of low production horizontal well. Research on influence of horizontal pipe pulsed source parameters on the flow and heat transfer process has great practical significance to improve the performance of thermal tracing flowmeter. In this paper, the heat conduction mathematical model of fluid-structure interaction is derived, and a physical model of the flow channel and heat source is built by using multi-physics coupling finite element analysis software COMSOL Multiphysics. Under different flow, Changing the geometry, size, heating time and heating power pulse, the temperature at different locations along the center line of the pipe fluid flow direction is analyzed through numerical simulation. The numerical simulation results show that rectangle heat source with low depth for heating the fluid temperature effect is better and the maximum temperature rise of the fluid increases linearly with increasing heat power. When the heat source power is more than 400 W and a pulse width is 1 s, the better temperature is obtained. The results of dynamic experiments provide a theoretical support and guidance for optimizing the design of test instrument based on heat tracing method.