Pump Efficiencies
At high pressures, liquid is compressible. At 40,000 psi, water is about 10 percent compressible. That means the plunger must move enough to fill 10 percent of the chamber volume before the pressure reaches 40,000 psi. At that point the outlet check will open against the pressure in the output line. At the end of the stroke, when the plunger reverses and the outlet check closes, any water that’s trapped in the cylinder expands, pushing on the plunger until the plunger has moved far enough to drop the pressure to the inlet pressure and open the inlet check valve. The energy put into the plunger motion by this expanding water can be recovered or not depending upon the drive type.
In the crank pump this expansion energy is recovered in the same way that it is recovered from the expanding hot gasses in an internal combustion engine: it goes back into the kinetic energy of the rotating components. In the intensifier pump it gets dumped into the oil of the hydraulic circuit, which causes heating. That heat must then be removed, usually by an oil to water heat exchanger. As a result, intensifiers operate at about 70 percent efficiency whereas crank drive pumps operate at efficiencies of 95 percent and higher. Intensifiers also require extra water for cooling purposes, resulting in significantly higher electric and water costs to pay for energy wasted as heat.
回复 1# chunpan 的帖子
可是FLOW的机器的压力表是设在刀头组上啊.他的工作压力就可以开到380兆帕.只是FLOW的客户在实际应用当中大多数都开到350兆帕左右.这样他的零配件使用寿命延长/直驱泵工作时没有压力波动.在切割精细切割占很大的优势.缺点是:所有的高压配件的使用寿命很短(与增压器比较).用直驱泵算起来切割成本高 其实我早就计算过2个机的使用成本, 楼上说的对, 在高压水泵的零件更换成本上计算是比增压泵高 15%, 但是从总切割成本上计算, 用同样的材料, 质量要求和厚度, 直驱泵的速度快 30%, 成本低 25%.
问题是你要的是单成本还是实在切割一个工件要用的总成本. 我们是国内最早做直驱泵的,11年了
直驱泵目前应用最广的是水射流清洗行业
直驱泵虽然看似简单,但其制造精度难度远大于增压器式 请问你现在的直驱泵是多少 MPA的? 现在推出是压力300MPA .流量23升.用在清洗行业的直驱泵
年底或明年年初推工作压力380MPA的小直驱泵.应用于切割
都是进口 我们的直驱泵工作压力330-350MPA(刀头的） ，最大切割厚度80mm钢板，切面质量很好。 在水里加入化学品降低流体动力学阻力，不是也可以起到提高效率、降低磨损的作用吗？现在有在使用？