工作面刮板輸送機選型與設(shè)計畢業(yè)論文-資料下載頁

　　

【正文】 environment, the extremely bad conditions, equipment failure rate correspondingly increased, the greater difficulty of maintaining the higher operating costs and narrow work space constraints of the CST in China mine AFC Machine applications. 　　(三) Frequency softstart mode. Scraper conveyor used, its performance advantages not play。 expensive, the general mine unbearable。 ponents used its power IGBT modules, highvoltage IGBT module of the international embargo on China, so its difficult to voltage levels To 1140 V, to its coal mine conveyor on the application has brought great difficulties. 　 (四) SRMdriven approach. SRM is a new driver, in other sectors (such as the textile industry, machinery manufacturing, washing machines, etc.) have a very wide range of applications. The main feature is activated when the current low torque, speed performance, and easy to use pure electric control to achieve stepless speed regulation, and long run. Motor exclusive use of SRM, but flow, not burning motor, with good prospects for development. Components used for power IGBT module, it is very difficult to achieve voltage 1140 V. The current highpower explosion SRM is still in the development stage, the bulk smaller, higher cost, not suitable for the underground mine scraper conveyor application. 　　(五) softstart mode. Taiyuan, the pany developed the Whitby soft startFMspeed technology, speed regulator technology, vacuum technology for magnetic start one, start with the characteristics of analog FM. The surge started with the way the soft startvoltage slope start, current feedback sudden jump start and start pared to the initial start more torque, can achieve the lowspeed torque activated to ensure that equipment from the takeup, by Static to dynamic start running, you can solve the problem of overloading difficult start. 三、application 　　Pingdingshan Coal Mining Group after analysis and parison, in October 2004 quoted a 2QJT250/1140 (660) soft start, and Zhangjiakou Coal Factory production SGZ764/400scraper conveyor support, instead of the original The restrictions start filling hydraulic coupler, in a small mining 631080 fully mechanized coal face applications, is now running for six months, and its softstart control of the scraper conveyor incident does not appear, betterperforming. The starter the following key features: ① and hydraulic coupler, pared with twospeed motor, scraper conveyor drive system and power supply system to maximize the simplified, the reliability of the system significantly increased. ② start the process of, 5 s power to block protection. ③ start the process of automatic measurement load, automatically determine sudden jump start, the mencement of the biggest obstacles, the largest motor torque, the buck started to overe the shortings. ④ the starter alldigital control circuit, is set up to facilitate the actual starting current can be accurately controlled in the following 4 Ie, the current small motor launch, reduce the impact of the power grid. ⑤ scraper conveyor loaded with empty and a smooth start to maximize the Elimination of Transmission of the fixedload, effectively preventing the Duanlian, breakpoints, roller key transmission ponents, such as damage to the accident. ⑥ VVVF soft start with a fuzzy control technology, based on load automatically determine the size of startup time. Load large, extended startup time, reduce the equipment dynamic impact load hours, because of the dynamic impact of the equipment smaller, the system automatically reduce the startup time, can reduce the impact of the motor life. Mine transportation equipment, long working hours (16 ~ 18 h / d), a large number plex system, supporting equipment, supporting links, delivery of materials by block, the impact of waste, launched frequent launch accidents. Fullyface failure in the electrical and mechanical equipment, scraper conveyor failures accounted for about 40 percent. In light of the above reasons, and because of softstart the development of fully mechanized coal face scraper conveyor launch control for technical improvements is not only necessary but also feasible. SCR Mine scraper conveyor softstart is the high yield and high efficiency fully mechanized coal face of the important technology and equipment, with great application value. The project39。s successful application to reduce the fully mechanized coal face mechanical and electrical accidents, improve yield and reduce consumption is of great significance.翻譯部分礦用刮板輸送機軟啟動方式的選擇與應(yīng)用在煤礦高產(chǎn)高效綜采工作面的建設(shè)中,以工作面大采長、大走向的要求配套了大功率的采煤機和刮板輸送機。普通綜采工作面的采長一般在150m左右,刮板輸送機的運輸能力500t/h左右。而高產(chǎn)高效綜采工作面的采長一般達到180～300m,刮板輸送機的運輸能力達800t/h以上,因此,輸送機功率增長較大。以平煤集團公司為例,刮板輸送機的功率大都在400(2200)kW 以上,最大的為750(2375)kW。刮板輸送機的啟動以雙速啟動為主,少數(shù)采用限矩型液力耦合器,這2種啟動方式,不僅運行費用高,而且停機率高。因此,需尋求新的技術(shù)和裝備來滿足高產(chǎn)高效的要求。一、目前現(xiàn)狀及存在的問題(一)限矩型液力耦合器在大功率、大負荷時,本身體積龐大,當它與電動機和減速機聯(lián)接后,所占空間更大。在工作空間受到限制的場合,過大的體積會使刮板輸送機的布置變得困難。液力耦合器增大了傳動距離,并且在高速狀態(tài)旋轉(zhuǎn),易產(chǎn)生較大的徑向動負荷沖擊,而造成電動機和減速裝置的損壞。耦合器的輸出轉(zhuǎn)速與輸入轉(zhuǎn)速之比通常不高于97%,即無法實現(xiàn)輸入軸和輸出軸的同步,因而必然存在較大的功率損失,降低了傳動系統(tǒng)的效率。(二)雙速電動機驅(qū)動系統(tǒng)目前在我國礦用刮板輸送機中普遍采用。通常情況下,電動機以額定轉(zhuǎn)速的一半啟動,相應(yīng)地啟動功率也是電動機額定功率的一半。電動機以低速啟動,當完成啟動過程后再切換到高速運轉(zhuǎn),從啟動到正常運轉(zhuǎn)分兩級進行,部分地減小了啟動沖擊。這種方式要使用專門的雙繞組電動機、雙根電纜和雙速開關(guān)。雙速電動機結(jié)構(gòu)復(fù)雜,造價高,供電系統(tǒng)相當于2臺電動機,低速切換不易有效控制,故障點多,經(jīng)常出現(xiàn)啟動失敗。隨著綜采工作面的推進,要不斷地移動設(shè)備和電纜,增大了設(shè)備電纜移動的難度,同時,電纜的故障也會成倍的增加。二、幾種先進軟啟動方式的對比(一)晶閘管調(diào)壓軟啟動方式。啟動過程分斜坡啟動、脈沖突跳啟動、加速斜坡、快速斜坡。脈沖突跳啟動方式可以短時輸出最大達95%的額定電壓,施加一個短時的大啟動力矩(相當于90%直接啟動轉(zhuǎn)矩),以克服大的靜摩擦力和大的傳動系統(tǒng)慣性。這種軟啟動方式應(yīng)用前景廣闊。(二)液體粘性傳動軟啟動方式。典型的是美國Dodge公司CST(連續(xù)啟動傳動)軟啟動裝置。CST軟啟動裝置目前主要依賴進口,其價格昂貴,一般礦井難以承受。CST集機械、液壓、電子控制、冷卻、材料為一體,制造、控制精度高,備件供應(yīng)特別不便。刮板輸送機是移動設(shè)備,工作環(huán)境不斷變化,條件極為惡劣,設(shè)備故障率相應(yīng)增大,較大的維護難度、較高的運行成本和狹窄的工作空間限制了CST在我國礦用刮板輸送機上的應(yīng)用。(三)變頻軟啟動方式。應(yīng)用于刮板輸送機上,其性能優(yōu)勢得不到發(fā)揮。價格昂貴,一般礦井難以承受。其功率元件采用IGBT模塊,高電壓等級的IGBT模塊在國際上對我國禁運,所以其電壓等級很難達到1140V,給其在煤礦井下輸送機上的應(yīng)用帶來了很大的困難。(四)開關(guān)磁阻電動機驅(qū)動方式。開關(guān)磁阻電動機是一種新的驅(qū)動方式,目前在其他行業(yè)(如紡織工業(yè)、機械制造業(yè)、洗衣機等)有著十分廣泛的應(yīng)用。主要特點是啟動時低電流大轉(zhuǎn)矩,調(diào)速性能好,容易用純電氣控制實現(xiàn)無級調(diào)速,并可長時間運行。電動機采用專用開關(guān)磁阻電動機,不過流,不易燒毀電動機,具有良好的發(fā)展前景。因功率元件采用IGBT模塊,電壓等級很難達到1140V。目前大功率防爆開關(guān)磁阻電動機尚處于研制階段,批量較小,成本較高,不適合在煤