Push and pull cylinder variable frequency energy-saving hydraulic elevator system of balancing load by accumulator loop

Abstract

An energy-saving hydraulic elevator system is composed of a mechanical system, a master hydraulic loop with vectorial frequency-varying volume control to regulate the rotation speed of motor, and an energy accumulator loop system for balancing the most of the weight of cage system. Said energy accumulator loop can absorb energy when cage is moving down or release energy when cage is moving up.

Description

technical field [0001] The invention relates to a control system of an elevator, in particular to a push-pull cylinder frequency conversion energy-saving hydraulic elevator system adopting an accumulator circuit to balance loads. Background technique [0002] Hydraulic elevators have the advantages of no need for a top-floor machine room, large load capacity, stable and comfortable operation, high safety and reliability, making them cheaper and easier to debug and maintain than traction elevators of the same specification. Therefore, in recent decades, hydraulic elevators have been widely promoted and applied in various countries. [0003] Because the general hydraulic elevator does not have a counterweight, the elevator completely relies on the power system to do work when it goes up, unlike the traction elevator that can rely on the counterweight to provide part of the power, and the efficiency of the hydraulic power system is not high, so the installed capacity of the hyd...

AI Technical Summary

Problems solved by technology

[0004] The patents and research results related to the reduction of installed power and energy-saving control technology of hydraulic elevators are mainly in the following aspects: ①. Energy-saving scheme with mechanical counterweight mechanism; ②. Energy-saving scheme using accumulators, mainly US patents US4761953, US4638888 and Japanese patents JA08165076 and JA08217346 respectively introduced hydraulic elevator control systems using accumulators to save energy; ③. Using variable frequency motor-driven volumetric speed regulation technology, traditional valve-controlled hydraulic elevators consume a lot of energy due to throttling speed regulation. The efficiency is low, but the use of frequency conversion volume speed regulation technology, without throttling and overflow loss, greatly reduces the energy consumption of the system, but it cannot reduce the installed power of the system

Most of the above schemes adopt the form of plunger cylinder jacking. Due to the stability requirements, the structure of the hydraulic cylinder is thick, which increases the manufacturing cost and installation space. At the same time, due to the increase of the flow rate, it is not conducive to the realization of reducing the installed power.

Although the above scheme greatly reduces the installed power and energy consumption of the hydraulic elevator, it is still difficult to reduce the installed power to that of the traction elevator.

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