基于PLC的矿井通风机控制系统设计（全套含CAD图纸）
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下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 11970985I摘 要煤矿的安全生产中，矿井通风系统起着极其重要的作用，它是煤矿安全生产的关键环节。而矿井通风机又是矿井通风系统的主要设备之一，因此对其进行 PLC 控制的变频调速系统的设计和研究，不仅可以大大提高煤矿生产的机械化、自动化水平，还能节省大量的电能，具有较高的经济效益。本系统将PLC与变频器有机地结合起来，采用以矿井气压压力和瓦斯浓度为主控参数，实现对电动机工作过程和运转速度的有效控制，使矿井通风机通风高效、安全，达到了明显的节能效果。且PLC控制系统具有对驱动风机的电机有过热保护、故障报警、机械故障报警和瓦斯浓度断电等功能特点，为煤矿矿井通风系统的节能技术改造提供一条新途径。与常规继电器实施的通风系统相比，PLC系统具有故障率低、可靠性高、接线简单、维护方便等诸多优点，PLC的控制功能使通风系统的自动化程度大大提高，减轻了岗位人员的劳动强度。关键词：PLC，变频器，传感器，通风机，压力检测下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 11970985AbstractIn the safe production of coal mine, the mine ventilation system plays a very important role, it is the key link of coal mine safety production. The mine ventilation machine is one of the main equipment in the mine ventilation system, so the for the design and research of PLC control system of frequency control of motor speed, not only can greatly improve the mechanization and automation level of the coal mine production, but also save large amounts of electricity, has high economic benefit.The system PLC and inverter organically are combined with the pressure and the gas pressure in order to mine the concentration of controlling the parameters of the working process and operation of the motor speed control, so mine ventilation fan efficiency, safety, achieved significant energy savings. And the PLC control system on the drive fan motor with overheating protection, fault alarm, mechanical failure alarm and the concentration of power and other features of gas for coal mine ventilation system to provide a new way to energy transformation. Here to enter the need to translate words and general relay in the implementation of the ventilation system, the system has the plc failure rate low and high reliability, the simple, easy and with the advantage of the plc, the control function of the ventilation system of automation is greatly increased, the posts of staff labour intensity.Keywords: PLC, Inverter, Sensors, Ventilation units, Pressure testing下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709851目录摘要.Abstract.第 1 章绪论. .1 1.1 矿井通风系统的简介.11.2 本课程设计研究的意义.21.3 国内外发展状况.2第 2 章系统的结构与工理.42.1 系统设计功能.42.2 系统结构.5第 3 章系统硬件择.63.1 电路设计.63.1.1 主电路.63.1.2 控制电路.73.2 plc 的类型. .83.2.1 plc 的概述.83.2.2plc 的基本成.93.2.3 plc 的工作原理.93.2.4.4PLC 类型的选用.103.2.5 PLC 内部分配.113.2.6 CPU 模块的外部连接.123.2.7 扩展模块的外部连接.123.3 传感器概述.133.3.1 瓦斯浓度传感器.143.3.2 温度传感器.143.3.3 空气压力传感器.153.4 变频器部分. .16第 4 章通风机总体结构设计.17下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709854.1 结构方案简图设计.184.1.1 扩散器.184.1.2 集流器与流线罩.194.1.3 叶轮.214.1.4 外壳.224.2 第一级叶轮的设计.234.2.1 确定叶轮毂比 及轮毂直径 .23_dd4.2.2 确定计算截面.244.2.3 叶片几何尺寸的计算.254.2.4 键的校核.274.3 第二级叶轮的设计.294.3.1 确定叶轮毂比 及轮毂直径 .29_dd4.3.2 确定计算截面.304.3.3 叶片几何尺寸的计算.324.3.4 叶片的绘制.334.4 电机的选择.35第 5 章主通风机系统的软件设计.375.1 温度控制部分.375.2 瓦斯浓度控制部分. . .405.3 压力控制部分. .425.4 机械故障处理部分. .46致谢.47参考文献.48下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709851第 1 章 绪论1.1 矿井通风系统的简介 其通风系统的基本主要任务是： 供给井下足够的新鲜空气，满足人员对氧气呼吸的需要，冲淡井下有毒有害粉灰及空气，保证人员安全生存，调节矿井下的空气环境创造保证安全的工作环境。矿井的通风系统是影响矿井安全生产的重要因素。矿井通风系统可以分为不同的类型，其划分标准是不同的因素。如根据瓦斯的浓度、煤层的自燃还有高温的因素等。一般矿井通风系统的分类：通俗一般型、相对降温型、防火型、排放瓦斯型、防火及降温型、排放瓦斯及降温型、排放瓦斯及防火型、排放瓦斯与防火及降温型几种。矿井内部通风的方式根据得到的风力的动力来源的不同，分为两种：自然风、机械辅助通风。自然通风：这是则是一种利用大自然气压的不同而产生的通风动力，使得空气在井下巷道流动的流通方式叫做自然通风。自然通风的风压一般都比较小，而且不稳定因素很多，所以在煤矿安全规程有规定：每一处矿井都必须要采用机械通风。机械通风：这是一种利用安装主风扇用电机运转带动而产生的鼓风动力，从而致使空气在井下各个巷道之间互相流动的流通方式叫做机械通风。矿井的通风系统一般要求是： 1每一个矿井，至少要有两个安全出口，并且通到地面。2进风井口要有利于防洪，不受粉尘，有害气体污染。 3北方矿井、井口需装供暖装备。 4总回风巷不得作为主要人行道。 5工业广场不得受扇风机噪音干扰。 6装有皮带机的井筒不得兼作回风井。7装有箕斗的井筒不应作为主要进风井。 8.如果一个矿井可以独立痛风病，必须独立通风，坚决不能合并通风系统。保证系统能够独立地进行工作，这样当一个矿井出现故障时，另一个矿井的通风工作不受影响,使生产不受大面积的受阻。下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 1197098521.2本课程设计的研究意义煤矿的矿井地下通风系统是否正常工作和矿井内的工作环境条件，生产效率，安全生产息息相关。随着国家对各行业的安全生产监管不断扩大，特别是对煤矿的生产安全越来越严，煤矿的矿井通风系统的技术改造，提高该系统运行稳定性，可靠性和节能性势在必行。 国内煤矿重大瓦斯事故造成的井下人员出现大量的伤亡大多数都是通风系统抵抗灾难能力不强，使正常生产时，分区通风在瓦斯爆炸条件下受到破坏，爆炸气体进入了爆源以外的地方从而导致其他通风分区或者全矿井下的人员中毒身亡。 因此以各采掘工作面为核心的分区通风成为了煤矿通风的基本规定和实践。在矿井灾变条件下维持正常分区通风的能力是评价矿井通风系统抗灾能力的基本考虑因素。除巷道布置这一重要但难以调整的因素之外分区通风及风量分配调节主要依靠于风门、风窗等通风设施的应用其类型、数量、分布上的合理性是影响通风系统合理性的基本因素扇风机及通风构筑物受矿井生产活动及灾变影响而失去原定功能时矿井通风维持在合理水平上的能力则是通风系统可靠性的重要标志。 现在来说煤矿的矿井通风的控制系统，大部分采用继电接触器控制系统，但是这种控制系统体积大、机械的触点很多、接线特别复杂、可靠性低、排除各种故障困难等很多缺点；如果通风机不应用变频控制，则矿井通风量的调节方法，只能靠两个垂直风门提起的高度、调节风机扇叶的数量和角度等。那么主通风机一直高速运行，备用通风机就会停止，不能轮流工作，很容易使通风机产生故障，降低其使用寿命。 随着电子技术和微电子技术的快速发展，PLC和变频器逐渐成为通用、廉价和性能非常可靠的控制驱动设备，并且得到广泛的应用。该系统将 PLC和变频器有机结合，通过以矿井气压为主控参数，然后对电动机的工作过程和运转速度进行控制，使矿井中的通风机通风效率高、安全，非常明显的达到节能效果。PLC控制的风机的通风系统，具有很高的可靠性和很好的节能效果，容易组建成整体自控系统，方便地实现各种控制和切换。PLC的控制系统还有对风机的电机有着过热保护、机械故障报警、故障报警和瓦斯浓度断电等功能特点。1.3国内外发展情况 国内外矿井通风机发展历史悠久，早在1902年爱尔兰就研制成功了世界上第一台多叶片矿井通风机，且将当时最初一台多叶片矿用通风机用在英国Pelton煤矿，这台通风机的安装使井下通风发生了巨大的变化。从此多叶片风机对于发展整个通风技术做出了重大贡献。1949年至1950年间，丹麦诺迪斯克公司研制生产了首台运行中叶片能自动调整的轴流式风机，其后德国的TLT.K.K.等公司也相继生产了这类风机。由于该风机的下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709853优越性，到50年代中期首先在欧洲一些国家得到应用。美国，前苏联，日本等国也相继在1970年前后开始推广使用这种风机。20世界50年代初至70年代末我国矿山使用的矿井轴流主扇几乎是仿制苏联的BY型和K70型等风机，风量范围7-160m3/S,静压范围400-5900Pa，全国各类矿井共使用约5000台左右。不过这类风机在20世纪的80年代被国家列为淘汰产品，早已不再生产。 20世界的70年代开始沈阳鼓风机厂经技术研发与实验，研制成功了62A型单级主扇。其全压，风量以及各种参数标准非常基本适合我国国情的矿井通风网络，在中条山有色金属公司和邯郸矿务局的一些风井上使用。因其本机效率未达到设计要求，相差甚远，没有进一步改进和完善就停止了生产，在此基础上在20世界80年代该厂参考原苏联中央流体动力研究所提供的通风机启动略图和特性曲线又研制了2K60式轴流式通风机。在此期间沈阳风机厂研制了1K58和2K58型矿井轴流风机。下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709854第 2 章 系统的结构和控制方案 2.1 系统的设计功能 本控制系统采用通风机组的启动、互锁和过热保护等功能。与常规继电器实施的通风系统相比，PLC系统具有故障率低、可靠性高、接线简单、维护方便等诸多优点，PLC的控制功能使通风系统的自动化程度大大提高，减轻了岗位人员的劳动强度。PLC和变频器与空气压力变送器配合使用，使系统控制的安全性、可靠性大大提高，也使通风机运行的故障率大大降低，不仅节约了电能，而且还提高了设备的运转率。为满足矿井通风系统自动控制的要求，系统的具体设计要求如下：（1）本系统采用手动自动两种工作模式，具有状态显示以及故障报警等功能。（2）模拟量压力输入经PID运算，输出模拟量控制变频器。（3）在自动方式下，当井下压力低于设定压力下限时，两组风机将同时投入工作运行，同时并发出指示和报警信号。（4）模拟量瓦斯输入，当矿井瓦斯浓度大于设定报警上限时，发出指示和报警。当瓦斯浓度大于设定断电上限时，PLC将切断工作面和风机组电源，防止瓦斯爆炸。（5）运用温度传感器测定风机组定子温度或轴承温度，当定子温度或轴承温度超过设定报警上线时，发出指示和报警信号。当定子温度或轴承温度超过设定风机组转换温度界线时，PLC将切断指示和报警信号并自动切断当前运行风机组，在自动方式下并能自动接入另一台风机组运行，若在手动方式下，工作人员手动切换。（6）手动方式下，有防止风机组频繁启动功能。由于定子温度或轴承温度过高，若当前风机组停止运行后，当其温度下降到设定下限时该风机组不能连续二次启动，只有接入另一台风机组进行工作，即防止温度在临界线状态而频繁启动。下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709855手动控制温度状态采集瓦斯浓度采集PLC 主程序通电初始化数据转换数据转换自动控制压力中断数据转换PID 转换压力浓度采集结束图2.1 系统设计流程图2.2 系统结构系统的结构框架如图所示，整个控制系统主要由 PLC、变频器、瓦斯传感器、压力传感器、电机组、通风机组等组成，该系统主控单元采用 PLC，被控元件为变频运行的通风电机，主控参数为瓦斯浓度。瓦斯传感器、温度传感器、实现对电机和 PLC 的有效保护。图2.2 系统功能块框架图1#定子温度传感器2#轴承温度传感器2#定子温度传感器1#轴承温度传感器空气压力传感器瓦斯浓度传感器2#通风机组1#通风机组 声光报警控制回路S7-200可编程控制器EM231扩展模块开关信号EM235扩展模块变频器下载后文件包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709856第 3 章 系统硬件选择3.1.1 主电路主电路中 MA1，MA2 为对旋式轴流风机的两台电机，交流接触器 QA4、QA6 分别控制 MA1、MA2 的工频运行；交流接触器 QA3、QA5 分别控制 MA1、MA2 的变频运行；QA1为主电路电源的隔离开关；FA 为主电路的熔断器；BB1、BB2 为电机 MA1、MA2 的热继电器。图 3.1 系统工作主电路图 Stress-strain State and Vibration Frequencies of Blades of the Main Mine Fan Impeller N. V. Panova, E. A. Spiridonov N.A. Chinakal Institute of Mining, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia Novosibirsk state technical University Received 2013 ABSTRACT The paper discusses geometrical characteristics and strength parameters of fan blades equipped with replaceable active part it end ended to improve the fan adjustability owing to replacement or removal of the active part, which allows the fan to maintain a wide range of ventilation modes. Keywords: Stress-strain State; Vibration Frequencies; Mine Fan Impeller 1. Introduction The main ways to control air purity in a mine are dilution and carryover of mining-induced toxic contaminants us- ing main mine fans. Main mine fans in existence are uneconomic and ac- cident-sensitive; they take too much space to be located on land surface and, among other shortcomings, are poor-adaptable to mine ventilation mode changes when- ever required. Deficient adjustability results in low technical and economic performance of a ventilation network unit or a main mine fan for most of its running time; or else a main mine fan, after several year of operation, becomes incapable to service this particular ventilation network and, consequently, modification of the ventilation net- work or construction of new mine fans is required. To study behavior of ventilation network parameters in terms of actual mines in Russia, Ukraine and Kazakhstan (e.g., Kuznetsk and Donetsk Coal Basins, and others), the representative statistics over a period of 9 to 10 years have been collected and processed. The basic index was chosen the rate of change of the studied parameters, de- termined as the ratio of the later time-interval value of a parameter to its former time-interval value, the time lengths being varied. It was found that the rates of change of ventilation pa- rameters in mines are not constant in time, are different in different basins and vary in a wide range; at that, the average capacities are VQ = 4.5 - 15.4% per year for a fan and VA= -4.0 - 5.5% for an effective opening of a venti-lation network. Accordingly, if the required fan capacity has been increased by 0.9% per three months (QV= 1.009), or by 3.8% per year, then the fan reserve (10%) would be worked out less than in three years, and insuf-ficient performance of the fan would retard development of mining operations. The analysis of different approaches to enhancement of adaptability of main mine fans 1 showed the possi- bility to provide the desired ranges for the fan capacity (ten times and higher) and pressure (five times and higher) by using modified axial fans with possible re- placement or removal of a number of blades from the fan impeller. The research into aerodynamics of axial fans, con- ducted at N.A. Chinakal Institute of Mining, Siberian Branch of the Russian Academy of Sciences 2, showed that it is only possible to enlarge the area of reasonably possible modes of fans in the coordinates QP by de- signing of axial fans with replaceable, double, sheet blades. To reach the objectives, fans, series VO, were furnished with replaceable (to be adaptable to different ventilations network standards) and rotable-in-run blades, which al- lowed continous control over their operation (see Figure 1: within b to b; from to ; from to ). In this case, the fan adjustment to changes in airing parameters is ac- complished by replacement or removal of a number of blades within the modes aa, bb or cc, upon variation in air resistance of the ventilation network, within R1, R2 and R3, respectively (refer to Figure 1). The double, sheet blades designed for axial fans in- clude a rotary base with a root fixing, two special-ge- ometry blades and a connecting strap to maintain the required stiffness of the blades. The double, sheet blades as against profiled blades are advantageous for (1) total elimination of bending and twisting moments of cen- trifugal forces relative to the fan rotation axis; and (2) greatly simplified manufacturing technology. Figures 2 and 3 show the calculation schemes for cen- trifugal forces and moments that influence the double, sheet blades of axial fans. The double, sheet blades are designed 1 for pre-set parameters of a fan (pressure, capacity, etc.), additionally considering the requirement of zero moment of centrifu- gal forces on the blades 2, which is achieved by locat- ing center of masses 1 and 2 of the blades so that the center of masses of the entire blade couple is on the axis Z: moment Mz is zero (see Figure 2). Figure 1. Aerodynamic characteristics of fan, model VO- 21K, at rotation frequency 1000 (1500) rpm, with blades in amount of Zimp= 8 and Zimp = 4, mounted on the fan impel-ler according to aerodynamic schemes AM-17A (1 and 1, high-pressure) and AM-19A (2 and 2, high-capacity), at pitch = 1550 and air resistances R1, R2 and R3. Figure 2. Calculation scheme for moments on fan blades: x, My, Mzmoments of forces affecting the blades relative to the axes X, OY, OZ, respectively; impeller rotation frequency; 1 and 2centers of masses of the blades; pitch of the blades. Figure 3. Calculation scheme of forces affecting fan blades. An illustration of the forces affecting a blade is given in Figure 3, in the coordinates , , Z, where it is assumed that the resultant of the forces is at the point 2. It is taken that mine fans rotate counterclockwise if watched from the direction of indraft, and the OX-way projection dR is composed of the blade draft force dR and the blade rotational resistance dRu. The components dR and dRu of the force dR are mainly of aerodynamic nature. The OM-way projection dP of the force dR is conditioned by inertia (centrifugal) forces influencing the blades. The aerodynamic forces dRu and dR generate the twisting and bending moments, respectively, while the centrifugal force dP creates tensile effect and twisting moment on the blades. Out of the forces dRu, dR and dP, the centrifugal force dP produces the highest load on the holder group of blades, power of impeller and rotation mechanism of blades. The centrifugal component of mass of blades relative to rotation axis of rotor shaft is calculated from the for-mula To make the replacement of impeller blades simpler, for instance, when the blades with other aerodynamic characteristics are required to increase the main mine fan pressure or capacity, the design of the unit of blades has been modified: the base and replaceable part of the unit of blades are fixed using a bolted-type connection (Fig-ure 4). where: q(t)time-variant load per unit length of blade; qconsconstant load on blade; qkzamplitude of the time-variant load per unit length of blade at frequency f = knz; 2ntangular coordinate of blade rotation; zphase angle. Reliability of blades is assured through (1) their suffi-cient structural strength and (2) absence of resonance phenomena as a response to the nonstationary exposure, e.g., rotor speed, ventilation network vibrations, etc. In the first case it is required to sustain permissible stress in a blade, considering strength limits and load factors of the materials used; the second target is achieved owing to safe tuning-out of the blade vibration frequencies under the excitation forces and, thus, elimination of hazardous dynamic stress under probable resonance effect. The main way to solving the engineering tasks above is the optimized selection of design variables of blades so that to ensure required strength and frequency. Along with classical approaches, such as material selection and change of cross-sections in strained members of blades, in case of the double, sheet blades, there is an additional option of stress and frequency control by means of nu-merical modeling of the parameters of connecting straps, stiffening plates, etc. Figure 4. Adaptable unit of blades for fans VO: are- placeable part; brotary base with root fixing; 1blades; 2connecting strap; 3stiffening plates; 4opening for the bolted-type connection; 5the strap and blade fixture point; 6keyseat in the root fixing. The mentioned above design of a blade unit, but with-out the replaceable part, was analyzed earlier, though the influence the bolted-type connection has on the strength and resonance of the blade unit was left beyond the analysis. The authors of the present paper have assessed the stress-strain state and frequencies of the adaptable blades, and the stress-strain state of the bolted-type con-nection between the replaceable part and the base; the principal condition here was the equal strengths of all members of a blade unit and the tuning-out of excitation force at the known frequency. The strength calculations of different structures com-monly use the finite element method that can be suc-cessfully accustomed to the developed electronic and computer technologies as well as allows computation of complex objects, including their geometry, load distribu-tion, boundary conditions and physical properties of the materials the analyzed devices are made of. The analysis of stress-strain state, frequencies and vi-brations in the case in question used the ANSYS program, three-dimensional modeling and finite-element modeling. The blades were divided into 3D four-unit finite elements. The bolting modeling involved imposition of zero dis-placements and rotations; centrifugal forces were calcu-lated automatically, via setting of a special option. As a result, stress-strain state diagrams were obtained for the given design blade unit and a fan with impeller diameters of 2100 mm, 2400 mm, 3000 mm, 3600 mm, 4300 mm and 5000 mm and rotation frequency range from 375 rpm to 1500 rpm. For every dimension-type of the fans, the authors have determined the following characteristics: 1) Efficient geometrical characteristics and amount of stiffening plates of the rotary base; 2) Permissible thickness of the material sheet to manufacture the blades and connecting straps; 3)O Permissible width of the connecting straps; 4) Stress-strain state and frequencies of the blade unit: individually for the replaceable part and the base; 5) The stress-strain state and frequencies of the blade unit as an assembly. Table 1 below presents the data of the analysis into the influence of the connecting strap width, given the equal width of the blade sheets, on the stress-strain state and frequency of the blade unit mounted on the fan model VO-43K with impeller diameter of 4300 mm and speed = 600 rpm. The width of the connecting strap was varied as a percentage of the blade chord length in the calculation cross-section; the following strap width- to-chord length percentage ratios were analyzed: 52%, 68%, 73%, 84%, 94%. It has been found that the maxi-mal stresses arise either at the keyseat of the root fixing (6 in Figure 4), or at the fixture point of the strap2/3 of the blade length from the base (5 in Figure 4), de-pending on the percentage. Table 1. Influence of width of the connecting strap on the stress-strain state in the elements of the blade. It follows from Table 1 that when the connecting strap is reduced in width, the weight of the blade unit gets lower, from 5 kg to 9 kg, and the centrifugal forces and stresses at the keyseat of the root fixing decrease. After the certain value of the percentage ratio between the strap width and the blade chord length in the calculation cross-section (namely, 68%), the maximum stresses are observed at the strap fixture point; under further diminu- tion of the connecting strap, the maximum stresses grow and so do the maximum displacements at the tips of the blades. The analysis of the free vibration frequencies of the blade unit has shown that at the percentage ratio be- tween the strap width and the blade chord length of 94%, the first, second and third free frequencies were 26.6 Hz, 89.5 Hz and 115 Hz; the same for the percentage ratio of 52% made up 26.3 Hz, 91.8 Hz and 111.7 Hz, respec-tively. It is seen that the frequencies differ insignificantly, and the required tuning-out of resonance is achieved. The strength assessment included calculation of the factor of safety: n = abs/appl. For the analyzed blade units of the fans VO, the factor of safety ranges from 1.4 to 4.5. According to Russian Federation standards for the mine fan designing, the deviation of the blade profile (by tips), vane ring and directing vanes off the nominal pro- file should be no more than 0.002 of the nominal diame- ter of fan impeller. Accordingly,
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