Why is it said that when a circulation pump is operating, the pressure at points before the constant-pressure point increases, while the pressure at points after the constant-pressure point decreases? ?
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Why is it said that when a circulation pump is operating, the pressure at points before the constant-pressure point increases, while the pressure at points after the constant-pressure point decreases? ? Should the pressure of the circulation pump in this case be: the height difference between the pump and the expansion tank, plus the resistance losses and pressure differences in the piping system, as well as the height difference from the expansion tank? ?
The pump only provides the resistance loss in the circulation loop. No ones with height differences. Before the constant-pressure point, the pressure at all points increases, and after the constant-pressure point, the pressure decreases.
Why not those with a height difference? Does a height difference not require a pump to provide head? ? Otherwise, can it flow through?
The Bernoulli equation should be able to explain it. Law of conservation of energy. One unit of water starts from a point, goes around in a circle, and returns to that same point. If the height difference remains unchanged, the potential energy changes by 0; if the velocity remains unchanged, the kinetic energy also changes by 0. What’s left then is frictional resistance. As long as the pump provides the energy required to overcome frictional resistance, this value is also 0. So, the moon is still that same moon, and the stars are still those same stars; nothing has changed: lol. What you can’t figure out is how water can reach such a high level; the answer is that it goes up, but then it has to come back down again. The upward movement and the downward movement cancel each other out.