样例视频记录
以下是本模块提供的视频样本的文字记录:
可以肯定的是，你已经知道什么是泵以及它的作用。但您可能不知道的是，许多类型的泵输送流体，它们的结构和操作是由它们所输送的流体类型决定的。泵的根本定义只是一种利用机械动作移动流体的装置。有两种类型的泵:正排量泵和旋转动力泵。容积式泵“抓着走着”，固定数量的流体被转子、齿轮、活塞或其他一些设备捕获，在泵进口产生一个真空。然后它被机械地移动(置换)到泵的排出物。无论系统中的压力如何，排量泵都能以给定的速度提供恒定的流量。这些基本泵的一个例子就是你汽车引擎里的油泵和水泵。虽然正排量泵很容易理解，但旋转动力泵有点不直观。旋转动力泵通过旋转将动能传递给水而“抛来抛去”。 The fluid is thrown within the pump, and in turn, kinetic energy transfers to the fluid as its velocity increases. As the pump discharges, the velocity reduces, and the energy converts to potential energy in the form of increased pressure. Note that centrifugal pumps do not “suck” water in. They create conditions where the pressure of the system at the pump inlet (the suction head), pushes the water into the pump. Specifically, as the fluid leaves the pump, system pressure at the pump inlet pushes fluid into the void left behind the discharged fluid. There are numerous types of rotodynamic pumps, but the most common in commercial buildings are the centrifugal type.
