【作者】 赵斌；

【导师】 权龙；

【作者基本信息】 太原理工大学 ， 机械工程， 2015， 博士

【摘要】 电梯作为在高层建筑中运送人及货物的垂直设备,在社会现代化进程中起到越来越不可替代的作用。电梯自被发明至今,产品历经多次更新换代和技术升级,一直为人们的出行提供便捷。诸多研究表明,电梯能耗占高层建筑总能耗的20%左右,随着全球能源日趋紧张,高能耗电梯的发展前景不容乐观,能耗问题严重制约其发展。国内电梯保有量随着社会经济快速发展及国民生活水平的提高而急剧上升,有关数据显示,2014年国内电梯总保有量已达360万台,并以每年大约20%的速度增长。在工业生产规模不断扩大的时代,我国发电能力较弱,能源供应疲软,能源供需矛盾日益突出,节能电梯的研究也越来越受到政府、生产厂商和客户的关注。因此实现电梯的节能降耗不仅具有十分重要的经济价值,能够推动电梯行业的快速发展,而且符合我国现阶段绿色和可持续发展的战略。为降低电梯能耗,达到电梯节能运行的目的,本文结合曳引电梯的结构特点、运行特性及能耗特性,提出一种新型液—电混合驱动曳引电梯节能新原理。该原理将液压泵/马达、蓄能器等元件与曳引机驱动系统相结合,组成可实现能量回收利用的液—电混合驱动曳引电梯节能系统。上述系统与曳引电梯自身驱动系统联接耦合,在电梯运行过程中,当曳引机处于发电状态时,大部分重力势能将以液压能的形式储存在蓄能器中;当曳引机处于电动状态时,蓄能器存储的液压能得以释放,从而辅助曳引机工作,最终达到降低能耗、节约电能的目的。仿真及实验结果表明新型节能电梯能够平稳启动,速度控制平稳,具有良好的速度控制性能;该新型节能电梯的节能效率约为15%,可显著降低电梯控制系统和机房温度;新型节能电梯采用现有曳引电梯的控制方法,简化了其控制策略。通过以上研究可知在蓄能器充液过程中随着蓄能器压力的增大,节能电梯曳引机将由发电状态转为电动状态造成二次能耗;在蓄能器放液过程中,由于初始压力较大,蓄能器提供的功率比电梯运行所需功率大而造成能量的二次浪费,因此本文进一步提出一种基于变量泵/马达的转矩补偿方法,仿真分析的结果表明该方法能够大幅降低曳引电梯的能耗,电梯运行基本不消耗电能。电梯能耗作为电梯发展的一个重要问题,是电梯研究的热点问题,但电梯安全事故时有发生,因此曳引电梯的安全性能问题不可小觑。电梯现有的保护装置安全钳—限速系统,可解决电梯由于控制失灵、制动器失灵及突然断电等原因造成轿厢的坠落或超速,但由于机械结构不能完全保证万无一失,因此电梯坠落事故还是不可避免。本课题中曳引电梯新型节能系统采用换向阀控制蓄能器的工作状态,当电梯突然断电时,对于不同类型的换向阀,其断电时的机能是不同的。换向阀处于工作位,当蓄能器充液或者放液状态时,此时泵/马达向电梯提供使电梯停止的反转矩,联合抱闸和安全钳使电梯停止运行;当换向阀处于停止位时,由于四个油口均关闭,此时液压泵/马达不能正反向转动,从而可以阻止电梯的坠落,使电梯处于安全驻停状态。液—电混驱曳引电梯节能原理在降低能耗的同时,还能够兼顾安全性,对于电梯运行来说安全性更加重要,新的原理可保证电梯在所有电气控制失灵的情况下,轿厢平稳运行至停止状态。论文的主要研究内容如下:第一章首先介绍了目前我国电梯市场的发展状况、发展趋势及现有电梯的能耗情况。进而对电梯的发展历史及分类进行综述,重点介绍了曳引电梯节能技术的发展概况和能量回收节能技术的发展及应用。最后基于上述综合分析,提出了本课题的研究意义和主要研究内容。第二章介绍了普通电梯的工作特性作,分析了曳引电梯的基本结构以及电梯处于典型四象限时的工作特性。对不同配重的电梯在不同运行工况时所受的力矩进行了详细分析,并建立了电梯的动力学模型;对电梯的动力学模型进行仿真分析,得到了当电梯配重不同时,电梯在不同载重、不同工况时所受到力矩。进而提出了一种新型的液—电混合驱动曳引电梯节能新原理及方法,分析了节能电梯的工作原理及工作特性。最后对系统中曳引机、各液压元件进行选型,并设计了高能效曳引电梯的控制系统。第三章对提出的高能效电梯节能系统进行了数学建模,主要针对同步曳引机、液压泵/马达、蓄能器等的特点及运行特征进行分析并建立其数学模型。分析计算电梯运行过程中的速度曲线,并对速度、加速度曲线进行仿真。本课题的目标是降低电梯系统的能耗,因此需要对普通曳引电梯能耗进行分析,了解电梯运行过程中电梯能耗的变化规律。本章通过simulationx仿真软件建立了普通曳引电梯模型,对电梯在不同工况运行时的能耗进行了仿真分析。第四章建立了课题所提出的高能效曳引电梯的仿真模型,并对采用不同配重下的电梯运行情况进行仿真分析。在配重为1000kg和1500kg这两种情况下,对普通电梯和节能电梯分别在轻载上行、轻载下行、重载上行、重载下行四种工况运行中的能耗变化情况进行了仿真分析,通过比较计算得到节能电梯的节能效率。进一步对采用变量泵/马达的节能系统,在使用转矩匹配控制后,电梯的节能效果进行了仿真分析。第五章基于上述理论研究及仿真分析,通过对节能电梯系统及结构的详细分析及参数优化,确定了节能电梯的试验元件及试验方案,搭建了高能效曳引电梯能耗试验台。首先对普通电梯在载重不同、运行距离不同工况下能耗进行了试验分析,并与仿真结果进行对比分析。然后将节能系统与曳引机驱动轴联接进行综合试验,通过地面空载试验与楼层空载试验的对比分析,得出节能系统的机械运行效率。进而对节能电梯在不同运行工况时的能耗进行了试验和分析,并与普通电梯的能耗进行对比,得到高能效电梯的节能效率。第六章主要对所作的研究工作进行分析总结,得出了主要的研究性结论,并针对本课题研究问题的不足提出今后的研究方向。课题所做的研究工作均表明,本文首次提出的液—电混合驱动曳引电梯节能新原理及方法是正确的、成功的,不仅具有较好节能效果,而且能够有效提高曳引电梯的安全、可靠性,基本达到预期目标。本论文的研究成果不但是曳引电梯节能方面的发展方向之一,而且在其它垂直提升机械中也具有较好的应用前景。更多还原

【Abstract】 Elevators are increasingly irreplaceable in the modernization of society, and since their invention,they have undergone several generations of replacement and technology upgrades, while providing convenience for people to move. Numerous studies show that the energy consumed by elevators accounts for about 20% of the total energy consumption of high-rise buildings. As the global energy shortage becomes increasingly relevant, the prospects for high-energy consumption elevators are not optimistic. The development of such technology is severely restricted by energy consumption issues.With rapid economic development and improving living standards, there has been a sharp rise in domestic elevator ownership: the data show that, in 2014, the total domestic elevator ownership has reached 3.6 million units with an annual growth rate of approximately 20%. In an era where the scale of industrial production continues to expand, China’s power generation capacity is relatively weak, as is the energy supply. The contradiction between supply and demand for energy has become increasingly prominent, and increasingly more focus has been placed on research on energy-saving elevators by the government, manufacturers, and customers. Therefore, the realization of energy consumption reduction is not only of important economic value, promoting the rapid development of the elevator industry, but also in accordance with the present stage of green and sustainable development strategies in our nation.To reduce the energy consumption of the elevator and achieve its energy-saving operational purpose, this study proposed and designed a new type of high-efficiency hybrid hydraulic-electric drive energy-saving traction elevator system based on the structural, operating, and energy-consumption characteristics of traction elevators. The system combines pump/motors, accumulators, and other elements of the traction motor drive system to form an energy-recycling hybrid hydraulic- Electric energy-saving drive system. This system and the traction drive system are coupled. For an elevator in operation, when the hoisting machine is in the power-generating state, the majority of the gravitational potential energy is stored in the accumulator in the form of hydraulic energy; when the hoisting machine is in the power-driven state, the energy stored in the hydraulic accumulator is released, thus assisting the hoisting machine and, ultimately, reducing energy consumption and thus saving energy. The simulation and experimental results showed that the new energy-saving elevator could start up steadily and smoothly with good speed control performance. The energy-saving efficiency of the new elevator is approximately 15%, significantly reducing the temperatures of the elevator control system and engine room. The new elevator uses the existing traction elevator control method, simplifying the control strategy. It’s known from the research that the traction motor of the energy saving elevator will change from generating state to electric state as the pressure of accumulator becoming large in the process of accumulator filling which will cause the energy consumption again.When the accumulator is in the process of releasing oil, for the large initial pressure, the output power of the accumulator is larger than the operation required power of elevator which will cause the energy dissipation again. So in this study, a torque-compensation method based on a variable- displacement pump/motor is put forward, and the simulation results show that this method could effectively reduce the energy consumption of the traction elevator.In recent years, elevator accidents have occurred; thus, the safety issue of traction elevators cannot be overlooked. The existing protection system of the safety gear-overspeed governor system of elevators can resolve the falling and over-speeding of elevators caused by control failure, brake failure, and sudden power outages. However, because mechanical structures are not guaranteed to be infallible, accidents involving falling elevators cannot be totally avoided. In this research, the new energy-saving traction elevator system uses a directional valve to control the working state of the accumulator. In a sudden power outage, each type of valve has a different power-off mechanism. That is to say, when the directional valve is in the state of filling the accumulator, the pump/motor provides a reverse torque that stops the elevator, and works together with the safety gear to halt the operation of the elevator. When the valve is at the stop position, because the four oil ports are all closed, the hydraulic pump/motor cannot rotate forward or backward, which could prevent the elevator from falling and instead park it safely.The energy-saving principle of Hydraulic-Electric hybrid traction elevator can not only reduce energy consumption, but ensure security and safety that is more important for its running. Especially in the case of all electrical control failure, the elevator can also keep in stop state moothly.The main contents of the thesis are as follows:Chapter I describes the current development status and trends in China’s elevator market and the energy consumption of existing elevators. Furthermore, elevator history and classifications are reviewed, focusing on an overview of energy-saving technologies used in traction elevators and the development and application of energy-saving and energy-recycling technologies. Finally, based on the comprehensive analysis mentioned above, the significance of this research and the main research content are proposed.Chapter II introduces the operating characteristics of conventional elevators and analyzes the basic structure of the traction elevator and its typical operating quadrants. Torques exerted on elevators with different counterweights at different operating conditions are analyzed in detail, and the dynamic model of the elevator is constructed. Through the analytical simulation of the dynamic model, the torques exerted on elevators with different counterweights are obtained under different loading and working states. A new hybrid hydraulicElectric drive traction elevator energy-conserving principle is proposed by analyzing the working principle and operating characteristics of the energy-saving elevator. Finally, hoisting machines and hydraulic components are selected for the system, and an energy-efficient traction elevator control system is designed.Chapter III constructs a mathematical model for the high-efficiency energy-saving elevator system, mainly based on the analysis and mathematical modeling of the features and operating characteristics of synchronous traction machines, hydraulic pump/motors, and accumulators. The two-speed curves of an operating elevator are analyzed and compared, and curves of velocity and acceleration are simulated. The goal of this project is to reduce the energy consumption of the elevator system, so an energy-consumption analysis of conventional elevators is necessary to understand variations in the process. This chapter establishes conventional elevator models using the simulation software SimulationX, and analyzes the simulation of elevator energy consumption under different operating conditions.Chapter IV establishes the proposed simulation model for the energyefficient traction elevator and analyzes the simulation of elevators with different counterweights. In cases with counterweights of 1000 and 1500 kg, the change in energy consumption is analyzed in the simulation under four different working conditions: light-load upward, light-load downward, heavy-load upward, and heavy-load upward, and the energy efficiency of the energy-saving elevator is calculated. Furthermore, the energy-saving results of the elevator with the variable-displacement pump/motor energy-saving system is simulated and analyzed after the adoption of torque-matching control.Based on the above theoretical research and simulation analyses, Chapter V determines the test components and test plan of the energy-saving elevator through the detailed analysis and parameter optimization of the energy-saving elevator system and structure. The energy-efficient traction elevator energy-testing rig is built. First, tests and analyses are conducted for the energy consumption of conventional elevators with different loads and different operating distances, and the results are compared with simulation outcomes. Then the energy-saving system and traction drive shaft are coupled for the integrated test. Through the comparison and analysis of no-load tests on the ground and on the floors, the operating efficiency of the mechanical energy-saving system is obtained. Furthermore, the energy consumption of the energy-saving elevator at different operating conditions is tested and analyzed, and the energy consumption of traditional elevators is compared to obtain the energy efficiency of the proposed high-efficiency elevators.The sixth chapter summarizes the research work, arrives at the main research conclusions, and proposes future research directions for material not addressed by this work.The research work showed that the proposed hybrid hydraulic-electric drive energy-saving traction elevator system had the correct design principles and good energy saving results, and could effectively improve the safety and reliability of traction elevators and achieve the desired objectives. The research achievement of the paper not only is one development direction of the energy saving elevator, but also has good application prospect in other vertical elevatoring mechanical devices.更多还原