变频驱动的闭式回路节能型液压升降系统

VVVF controlled closed-circuit energy-saving hydraulic lift system

为进一步降低液压升降系统的装机功率和能耗,提出了一种新式的节能型液压升降系统,其原理是将变转速容积调速、活塞拉缸和蓄能器作液压配重技术结合在一起,构成变频驱动的闭式回路液压系统.研究了该原理在液压电梯中的典型应用,给出了系统装机功率的计算公式,得到了系统装机功率、蓄能器容积与蓄能器工作压力比(最低工作压力与最高工作压力之比)的关系.试验研究了在不同负载工况下电梯轿厢的速度运行性能,并对比分析了该系统与阀控等系统的节能性能.结果表明,采用此新型节能方案不仅能够大幅降低液压电梯系统的装机功率和能耗,使系统平均总效率提高至70%,而且具有良好的速度运行性能.

A variable voltage variable frequency （VVVF） controlled closed-circuit energy-saving hydraulic lift system was proposed to decrease the installed power and energy consumption of hydraulic lift systems, which based on a combination of the technologies of VVVF control, pull-cylinder and hydraulic accumulator acting as hydraulic counterweight. The application of the energy-saving principle in a typical hydraulic elevator system was investigated. The mathematical relationships of installed power, accumulator volume and accumulator pressure-ratio （the ratio of minimum to maximum of working pressure） were presented. Then the running characteristics of the system were tested under different load working conditions. And the energy-saving performance was contrastively analyzed between the closed-circuit system and the valve-controlled system and so on. The results showed that the closed-circuit system ran steadily and comfortably. Comparing with the other hydraulic elevators system, the efficiency of the system with closed circuits increased to 70%.