论文部分内容阅读
运用计算流体动力学(CFD)方法建立纸机干燥部蒸汽喷射式热泵内流体流动的三维数值模型并进行数值模拟。模拟结果表明:热泵内流体速度场并不完全呈旋转轴对称分布;热力与结构参数对热泵的工作性能影响很大,喷射系数随着引射流体压力的增大而迅速增大,在一定范围内增大工作蒸汽压力可迅速提高喷射系数,但当压力超过某一定值后,喷射系数反而随着压力的升高而逐渐降低;存在一个最优的喉嘴距可使喷射系数达到最大值。
A three-dimensional numerical model of the fluid flow in the steam jet heat pump of the drying section of a paper machine was established by numerical computational fluid dynamics (CFD) method. The simulation results show that the fluid velocity field in the heat pump is not completely symmetrical about the rotational axis. The thermal and structural parameters have a great influence on the performance of the heat pump. The injection coefficient increases rapidly with the increase of the pressure of the fluid. Increasing the working steam pressure can increase the injection coefficient rapidly, but when the pressure exceeds a certain value, the injection coefficient decreases gradually with the increase of the pressure; there is an optimum throat distance to maximize the injection coefficient.