畢業(yè)設計方案資料

1、I摘 要滾筒式采煤機是機械化采煤的主要設備，具有高產高效、適應性強的優(yōu)點，被廣泛應用于不同地質條件下的煤炭開采，其截割性能的優(yōu)劣對于整機的可靠性、運行穩(wěn)定性、采煤生產率以及企業(yè)的經濟效益具有重要意義。為此，本論文采用理論分析、仿真和實驗相結合的方法，對滾筒采煤機滾筒截割性能及截割系統(tǒng)動力學特性進行了研究。本論文以相似理論為基礎，以采煤機截煤理論為依據，通過建立煤巖性質、滾筒、截齒以及截割載荷的相似準則，研制了煤巖截割實驗臺、10 種截齒和10 種滾筒。同時，在考慮煤巖抗壓強度、密度的基礎上，將煤巖的節(jié)理、層理特性作為配置模擬煤壁的依據，研制了實驗用模擬煤壁，并通過實驗研究了其抗壓強度與粉煤和水

2、泥比值間的關系，研究表明，隨著粉煤與水泥的比值增大，煤壁抗壓強度成指數關系減小。以實驗為研究方法，以均質模擬煤層和含有煤巖界面模擬煤層為截割對象，研究了煤巖性質、截齒結構參數、滾筒結構參數以及截割運動參數對滾筒截割扭矩、截割比能耗、塊煤率的影響，并得到了相關參數間的關系表達式和變化規(guī)律。研究結果表明，滾筒截割扭矩、截割比能耗和塊煤率與大部分相關參數成指數形式變化；截割扭矩增量隨煤層中夾矸厚度、構成煤巖界面兩種煤巖抗壓強度的差值的增加成線性關系增大。以實驗數據為依據，以小波理論為指導，對截割載荷進行了小波分析和功率譜分析，得到了載荷變化的細節(jié)波形及其隨煤巖性質不同的變化趨勢；同時，也獲得了煤巖界

3、面形式對系統(tǒng)頻率的影響規(guī)律。但是，所有功率譜的變化趨勢基本相同，除了滾筒旋轉的基頻和倍頻之外，并無其它明顯主頻出現(xiàn)，發(fā)現(xiàn)頻譜分析不能對載荷譜進行有效識別，表明截割載荷是一種非周期信號。利用突變理論描述滾筒截煤過程的載荷變化，在建立滾筒截割煤巖本構模型和動力學模型的基礎上，建立了滾筒截割煤巖的尖點突變模型，并得到了采煤機有效截割煤巖的剛度條件和能量條件。研究表明，采煤機牽引系統(tǒng)的剛度必須小于煤巖的阻侵剛度，否則將引起采煤機截割部的強烈振動，導致滾筒、傳動部分的損壞；同時，滾筒的能量釋放率必須大于煤巖破碎所需能量，否則滾筒將出現(xiàn)堵轉，甚至損壞?；诜中卫碚?，建立了截割載荷的特征因子模型，并分析了截

4、割載荷中所蘊含的固有特性。通過研究發(fā)現(xiàn)，不同截割條件下的載荷具有明顯的不同截割特征因子，提供了一種對不同截割過程、不同煤巖性質的有效識別參數。并且，隨著煤層夾矸厚度和構成煤巖界面的兩種煤巖抗壓強度差值的增大，截割特征因子減小。同時，基于分形理論建立了煤截割塊度分布的分形模型，研究了塊度分布規(guī)律與截齒、滾筒、煤巖性質、切削厚度的關系，得出了煤的截割塊度分布具有分形特征的結論，找到了采煤機截割載荷具有分形特性的原因，并說明滾筒截割過程能量釋放是層次性。以混沌理論為依據，探索滾筒截割煤巖系統(tǒng)的動力學特性，將具有不確定性的載荷外在表現(xiàn)看作是某一確定性動力系統(tǒng)的混沌現(xiàn)象，揭示滾筒截割載荷的無規(guī)律性、不確

5、定性、非周期性等外在現(xiàn)象所蘊藏的內在本質規(guī)律。通過研究不同截割條件下載荷的 Lyapunov 指數譜和最大 Lyapunov 指數，證明采煤機滾筒的截割載荷不是隨機信號，而具有混沌特性，應以確定性模型對其進行描述。在此基礎上，建立了滾筒截割煤巖系統(tǒng)的混沌模型，并通過改變混沌因子的值，初步得到了可以模擬實驗載荷變化特征的曲線，為研究滾筒截割系統(tǒng)的動力學特性提供了一種新的方法。該論文有圖 190 幅，表 60 個，參考文獻 122 篇。關鍵詞：滾筒式采煤機；截割理論；采煤機滾筒；煤巖截割實驗臺；滾筒截割性能；1 / 6小波理論；突變理論；截割特征因子；分形理論；混沌理論；Lyapunov 指數；截

6、割系統(tǒng)動力學IIIAbstractThe shearer is the main equipment for mechanization coal mining, and it is widely usedfor coal mining under different geological conditions due to its high production, highefficiency and better suitability. And the cutting performance of the shearer has an importancesignificant for

7、the reliability, the running stability, the excavating productivity and theenterprise economic efficiency. With regard to this, the theoretical analysis, simulation and experiment are combined to investigate the cutting performance of shearer drum and dynamic characteristic of the cutting system in

8、this thesis.Based on the similarity theory and according to the shearer cutting theory, the similarity criterions for the coal characteristic, the drum, the pick and the cutting load are built. And the cutting test-bed of coal & rock, ten types of picks and drums are developed. Simultaneously, the a

9、nalogy coal wall for cutting test is developed by considering the compressive strength and density of the coal, and taking the joint and stratification of the coal as the foundation for making the coal wall. The relationship between the compressive strength of coal and the ratio of fine coal and cem

10、ent is researched by testing 。 the result indicates that along with the increasing of the ratio, the compressive strength decreases with a exponential form.Utilizing the experiment as research method and making the analogy coal wall of uniform property and with coal-rock interface as cutting object,

11、 the influence of the coal characteristic, pick structure parameters and drum structure parameters on the drum cutting torque, cutting specific consumption and lump coal percentage are investigated, and the relationship expression and variation laws are acquired. The results indicate that the drum c

12、utting torque, cutting specific consumption and lump coal percentage have a exponent relation with a majority of correlation parameters. The cutting torque increment has a linear relation with the gangue thickness and compressive strength difference value of coal, and it increases along with them.Ac

13、cording to the experiment data and taking the wavelet theory as guidance, the wavelet analysis and power spectrum analysis are conducted for the cutting load, the detail wave of the load change and the change trend of load along with the coal characteristic change are obtained. And the influence law

14、s of the coal-rock interface form on the cutting system frequency are acquired, too. But, the change trends of the power spectrums are all the same,there are not obvious main frequencies to appear, the frequency spectrum analysis can t availably recognize for the load spectrum, indicating that the c

15、utting process is a typicalIVaperiodic phenomenon.The load variation is described by utilizing catastrophe theory, and based on the built constitutive model of catastrophe and dynamic model, the cusp catastrophic model of the drum cutting coal is established, and the rigidity and energy conditions a

16、re acquired for the shearer cutting availably. The researches indicate that the rigidity of the shearer haulage system should be smaller than the resistance cutting rigidity of coal, otherwise the cutting part of shearer will vibrate strongly, and the drum and transmission part will be damaged. Simu

17、ltaneously, the energy release rate of the cutting drum should be bigger than the needed energy for coal broken, otherwise the drum stall will appear, even the drum damaged.Based on the fractal theory, the characteristic factor model of cutting load is established,2 / 6and the inherence properties i

18、ncluded in the cutting load are analyzed. And the phenomenon that the cutting loads have different cutting characteristic factor in different cutting conditions is discovered, providing an available parameter to distinguish different cutting process. And the cutting characteristic factor decreases a

19、long with the increase of gangue thickness and coal compressive strength. At the same time, the fractal model of cutting lump distribution is established, and the relationships between the lump distribution and the pick, the drum, the coal characteristic and the cutting depth are investigated. The c

20、onclusion that the cutting lump distribution of coal has fractal characteristic is acquired, and the reasons that there are fractal characteristics for the cutting load is found, and indicate that the energy release is stratified in the drum cutting process.On the bases of the chaos theory, the dyna

21、mic characteristic of cutting coal system is explored, and taking the phenomenon that cutting load has nondeterminacy which is its outward behave as a chaos phenomenon of a determinacy dynamic system, the inherence essence laws included in the external phenomenon which are disorder, nondeterminacy a

22、nd nonperiodicity are revealed. The conclusion that the cutting load is not random noise, moreover has chaos characteristic, which should be described with determinacy model, is obtained by investigating the Lyapunov exponent spectrum and the maximum Lyapunov exponent under different cutting conditi

23、ons. Based on this, the chaos model of the drum cutting coal system is established, and the curve for simulating the cutting load variation is acquired through changing the chaos factor value, which provides a new method for researching the dynamic characteristic of the drum cutting system.Keywords:

24、 shearer 。 cutting theory 。 shearer drum。 cutting test-bed 。 drum cutting performance。wavelet theory 。 catastrophe theory。 cutting characteristic factor 。 fractal theory 。chaos theory。 Ly1.1 課題來源 (Source of Subject本課題資助來源于：國家863 工程 (2008AA062202 “采煤機遠程控制技術及監(jiān)測系統(tǒng) ”；江蘇省普通高校研究生科研創(chuàng)新計劃資助工程 (CX08B_041Z “新型

25、采煤機滾筒的?；芯?”。1.2 滾筒式采煤機概述(Summarization of Shearer滾筒式采煤機是機械化采煤的關鍵設備，是典型的大型復雜機電液系統(tǒng)產品，直接決定著采煤效率和成本，具有大功率(300 2400kW 、大質量 (20 120T 、高產量(1001000 萬噸 /年 等特點，在所有機械化采煤設備中的使用量占到90% 以上。滾筒采煤機分為單滾筒采煤機和雙滾筒采煤機，單滾筒采煤機只有在薄煤層中使用，并且現(xiàn)在使用量很少，為此本文所闡述的滾筒采煤機主要指雙滾筒采煤機。雙滾筒采煤機可免開缺口，能適應較復雜的頂、底板條件，適用于各種硬度煤層，能截割硬煤；且采高范圍大，調高方便，在

26、緩斜煤層中采高為 0.656.0m ，采用無鏈牽引可在 35 54 的大傾角條件下工作1-2。由于具有上述優(yōu)點，滾筒采煤機很快得到了廣泛使用，并且在結構和性能方面不斷改進和完善。apunov exponent。 cuttingsystem3 / 6dynamic1博士學位論文2固定箱下邊的滑靴與布置在工作面的刮板輸送機滑軌接觸，并被支撐。行走部利用牽引電機或液壓馬達輸出的動力經減速后，傳到行走箱的行走輪，與刮板輸送機上銷軌相嚙合，使采煤機行走，可以實現(xiàn)無極調速，即在截割過程中隨著截割煤層的硬度不同而改變牽引速度。截割部包括搖臂和滾筒兩部分，搖臂主要起減速、傳動、改變采高的作用，滾筒旋轉直接作用

27、于煤壁，靠安裝其上的截齒破煤，并利用螺旋葉片將破落下來的煤輸送到與采煤機配套的刮板輸送機上。在上述采煤機的四大部分中，截割部的滾筒是采煤機的工作機構，直接作用于煤巖，工作條件極其惡劣，因此，其截割性能的好壞直接影響著整臺采煤機的截割性能和使用壽命，并對煤炭生產企業(yè)的經濟效益產生直接影響。采煤機滾筒主要包括截齒、齒座、螺旋葉片、端盤、筒轂和噴霧系統(tǒng)六個部分，如圖1-2 所示。圖 1-2 滾筒結構圖Figure 1-2 Drum structure1.3 選題背景及意義(Background and Significance根據我國能源資源狀況，煤炭作為主體能源在很長一段時間內不4 / 61 緒論

28、3整個采煤機裝機功率的80-90% ，并且采煤機的生產能力、比能耗、工作時的負載狀況、截齒的受力情況、塊煤率、粉塵量、工作平穩(wěn)性、可靠性、裝煤效果等各項性能指標都與滾筒有著密切的關系。因此，滾筒截割性能的優(yōu)劣直接影響著整臺采煤機的生產效率和可靠性。一旦根據煤層條件，滾筒的截割功率、結構參數確定后，采煤機其它部件參數的設計均可以此為基礎進行。雖然國內外學者對采煤機滾筒進行了大量研究，但大多是零散的，只研究了一個或幾個參數對其截割性能的影響。并且，目前我國采煤機設計使用的截割力計算公式依然應用前蘇聯(lián)學者上世紀50 年代建立的模型，此模型是利用直線截割原理得到的；并且，此公式只涉及了截齒的相關參數，

29、導致在計算滾筒截割力時存在較大誤差。因此，作為發(fā)展采煤機械化的技術基礎之一，對采煤機滾筒截割性能以及截割載荷與相關參數關系的研究應當受到高度重視。隨著煤炭的逐年開采，一些礦井中的厚、中厚煤層已基本采完，為了延長礦井服務年限以及提高資源回收率，對難開采煤層(薄、極薄煤層，夾矸煤層，小斷層煤層開采日顯重要。并且，一些礦井中這些煤層的賦存量占總煤炭儲量的20%左右，開采這部分煤炭，對節(jié)約資源、提高煤炭回收率具有重要意義。采煤機開采這些煤層時，截割對象已不是單純的煤，而是煤與巖石的混合體。在此過程中，影響采煤機截割性能的主要因素除其本身的截割參數和運動參數外，煤與巖石的相對界面形式起著關鍵作用，由于煤層地質結構和賦存條件不同所形成的煤與巖石的界面特征也各不相同。但是，目前對截割特殊煤層載荷的變化特征缺乏研究，按常規(guī)煤層設計的采煤機在此煤層應用時，由于截割沖擊載荷較大，使得截齒、滾筒受損嚴重，甚至引起整個搖臂損壞，導致停產，造成較大經濟損失。為此，所設計的采煤機要在這些煤層有效使用，必須對采煤機滾筒截