生物質(zhì)論文基于生物質(zhì)碾壓成型機(jī)理的成型能耗影響因素研究

1、 生物質(zhì)論文：基于生物質(zhì)碾壓成型機(jī)理的成型能耗影響因素研究【中文摘要】生物質(zhì)固體成型技術(shù)可使松散的生物質(zhì)致密化,變低品位能源為中上等品味能源,已成為規(guī)模化利用生物質(zhì)能源的一種有效途徑。但是目前該技術(shù)發(fā)展存在一些瓶頸,如微觀機(jī)理研究的欠缺、產(chǎn)品設(shè)備能耗過(guò)高、設(shè)備壽命短等問(wèn)題,因此,開(kāi)展相關(guān)生物質(zhì)固體成型技術(shù)的研究對(duì)于生物質(zhì)能源的廣泛利用具有重要意義。本文以生物質(zhì)壓塊成型機(jī)為研究對(duì)象,以降低生物質(zhì)壓塊機(jī)能耗為總線,從生物質(zhì)物料的成型微觀機(jī)理、環(huán)模的靜態(tài)力學(xué)特性及結(jié)構(gòu)參數(shù)著手,探求了物料的生物構(gòu)造、理化性質(zhì)以及微觀力學(xué)特性對(duì)成型過(guò)程的影響規(guī)律,提出了碾壓成型機(jī)理,從微觀機(jī)理方面降低了生物質(zhì)成型機(jī)能耗

2、；通過(guò)成型區(qū)受力分析,以求獲得最佳環(huán)模結(jié)構(gòu)參數(shù)；之后基于大變形彈塑性理論,分析生物質(zhì)成型過(guò)程的彈塑性特性,借助于ANSYS有限元分析軟件對(duì)成型過(guò)程進(jìn)行非線性接觸靜力學(xué)模擬,揭示了物料在成型過(guò)程的流變特性及環(huán)模與物料的應(yīng)力應(yīng)變規(guī)律,不僅驗(yàn)證了之前微觀機(jī)理的正確性,同時(shí)為設(shè)備結(jié)構(gòu)的優(yōu)化提供理論依據(jù)；最后搭建物料壓縮成型試驗(yàn)臺(tái),獲得了物料成型時(shí)最佳的成型條件與工藝參數(shù)并驗(yàn)證了有限元模擬結(jié)果的正確性。課題以生物質(zhì)成型的微觀機(jī)理與大變形彈塑性理論為基礎(chǔ),采用靜力學(xué)分析、有限元模擬以及現(xiàn)場(chǎng)實(shí)驗(yàn)多種研究手段,從物料特性、環(huán)模設(shè)備結(jié)構(gòu)參數(shù)、成型工藝條件多角度探討如何降低生物質(zhì)成型能耗。最終,基于應(yīng)力偏張量理論

3、,提出了碾壓成型機(jī)理,即增大物料所受的偏張量,促使物料更好地滑移、摩擦、交織,從而減少成型能耗；采用靜力學(xué)分析方法,獲得成型區(qū)可實(shí)現(xiàn)制塊的最佳攫入角與物料高度,得到環(huán)模與壓輥的直徑比及間隙調(diào)整準(zhǔn)則,并且詳盡分析了基于碾壓成型機(jī)理的物料受力情況,通過(guò)對(duì)比分析碾壓成型與傳統(tǒng)方法下物料變形后的微觀結(jié)構(gòu),驗(yàn)證碾壓成型機(jī)理的正確性；通過(guò)有限元模擬計(jì)算,揭示了環(huán)模成型過(guò)程中物料的流變規(guī)律,得到物料軸向應(yīng)力分布規(guī)律以及物料所受摩擦力隨時(shí)間變化圖,為生物質(zhì)成型設(shè)備的優(yōu)化奠定了理論基礎(chǔ)；最后采用電子萬(wàn)能實(shí)驗(yàn)機(jī),對(duì)影響成型的環(huán)模轉(zhuǎn)速、環(huán)模長(zhǎng)徑比與環(huán)模開(kāi)口角度以及物料含水率等成型條件與工藝參數(shù)進(jìn)行試驗(yàn)分析,獲得了降

4、低生物質(zhì)成型機(jī)能耗的最佳參數(shù)?！居⑽恼緽iomass briquetting technology can densify loose biomass, significantly improve the energy grade of the source, making it an effective approach to widely utilize biomass resources. However, there are still some development bottlenecks, such as the lack of microscopic mechanism r

5、esearch, high energy consumption, short lifetime of key equipment components, etc. Thus, further research to solve the bottlenecks on the Biomass briquetting technology is imperative.This paper presents a thorough study of briquetting microscopic mechanism and factors of energy consumption, with the

6、 primary purpose to reduce the production energy consumption. Firstly, taking the two aspects of briquetting microscopic mechanism and circular mould Static mechanical as the instruction, biological structures, physical and chemical properties and micro-mechanical properties of biomass raw are resea

7、rched to present the biomass briquetting law and reduce the energy consumption at the source. Also stress on briquetting zone is analyzed to get the optimal structure parameters of circular mould. Then, basic on theory of elastic-plastic large deformation, contact mechanics and viscoelasticity, The

8、finite element model of the biomass briquetting process, a strongly nonlinear problem, is analyzed by the finite element package ANSYS The rheologic and Stress-strain laws are revealed during the process by the simulating. The simulating results are also examined and certified by the self-designed b

9、riquetting experiment platform, which not only illustrate the validity of the microscopic mechanism but also provide the theory basis on structural optimization. The optimal briquetting conditions of the raw are also obtained by the simulating and experimental results.On the basis of biomass briquet

10、ting microscopic mechanism and Elastic-plastic large deformation theory, Factors such as Material Properties, equipment structure parameters and briquetting technological conditions are compositely researched to reduce energy consumption, by using several research methods, including statics analysis

11、, the Finite Element Numerical Simulation and experiment.Finally, rolling forming mechanism is proposed originally based on the stress tensor theory, namely enhancing the global tensor of the materials which makes materials slip, rub and interleave easier, thus the energy consumption is decreased; b

12、ased on the static analysis, the briquetting zone, the swoop angle and the height of the materials and the diameter ratio between the circular mould and press roll are obtained. And the force condition of the materials was analyzed exhaustively. Through the comparative analysis of the microstructure

13、 of the materials formed under the traditional method and rolling forming method, the rolling forming mechanism is validated; based on the FEM simulation, the rheologic law of the materials in the rolling forming processes, the stress distribution law along Y axis and the changing tendency between t

14、he frictional force and the time is revealed, which provide the important theoretical support in the optimization of the structure design; Then the universal stuff experimental equipment is used to conduct the experimental analysis about the briquetting conditions, such as rotational speed, length d

15、iameter ratio of the mould, split taper and moisture ratio and so on, and the technological parameter, and the optimal parameters for reducing the energy consumption are obtained.【關(guān)鍵詞】生物質(zhì) 成型 環(huán)模 碾壓 有限元【英文關(guān)鍵詞】biomass briquetting ring rolling forming ANSYS【目錄】基于生物質(zhì)碾壓成型機(jī)理的成型能耗影響因素研究目錄5-7Contents7-9摘要9-1

16、1Abstract11-12第一章 緒論13-231.1 課題研究背景13-141.2 課題研究意義14-151.3 成型技術(shù)國(guó)內(nèi)外研究現(xiàn)狀15-201.3.1 壓縮成型壓力與壓縮密度關(guān)系研究15-171.3.2 壓縮成型過(guò)程中的流變學(xué)研究17-181.3.3 影響壓縮成型的主要因素及成型模具研究18-191.3.4 比能耗的研究19-201.4 存在問(wèn)題20-211.5 課題研究?jī)?nèi)容21-23第二章 生物質(zhì)固體成型微觀機(jī)理23-372.1 生物質(zhì)固體成型微觀機(jī)理23-332.1.1 生物質(zhì)的基本構(gòu)造23-262.1.2 生物質(zhì)的化學(xué)性質(zhì)26-282.1.3 成型過(guò)程中生物質(zhì)內(nèi)部粒子形變規(guī)律2

17、8-302.1.4 成型過(guò)程中力學(xué)性質(zhì)30-322.1.5 成型過(guò)程的粘接機(jī)制32-332.2 玉米秸稈原料特性33-352.3 本章小結(jié)35-37第三章 環(huán)模的力學(xué)特性及對(duì)結(jié)構(gòu)的影響37-573.1 低能耗秸稈壓塊成型設(shè)備工作過(guò)程簡(jiǎn)介37-383.2 環(huán)模壓塊成型機(jī)工作原理38-403.3 環(huán)模壓塊機(jī)能量消耗形式403.4 環(huán)模壓塊機(jī)制塊的力學(xué)條件分析40-443.4.1 攫入角的確定40-423.4.2 物料層高度確定42-443.5 成型區(qū)受力狀況44-473.5.1 環(huán)模受力44-453.5.2 壓輥受力45-463.5.3 物料受力46-473.6 環(huán)模與壓輥尺寸分析47-483.6

18、.1 環(huán)模壓輥直徑比47-483.6.2 環(huán)模與壓輥工作間隙483.7 成型過(guò)程力學(xué)分析48-523.7.1 軸向壓應(yīng)力F_L與徑向壓應(yīng)力F_R的關(guān)系50-513.7.2 軸向壓應(yīng)力F_L與徑向壓應(yīng)力F_R沿原料運(yùn)動(dòng)方向上的分布規(guī)律51-523.8 碾壓成型受力規(guī)律52-553.9 本章小結(jié)55-57第四章 生物質(zhì)壓縮成型過(guò)程有限元模擬57-814.1 有限元法簡(jiǎn)介57-594.2 彈塑性有限元法59-684.2.1 彈塑性變形理論594.2.2 生物質(zhì)形變流變準(zhǔn)則59-644.2.3 彈塑性本構(gòu)關(guān)系64-664.2.4 成型過(guò)程非線性接觸66-684.3 環(huán)模幾何模型的建立68-694.4 選取單元類型及定義材料參數(shù)69-704.5 建立接觸副70-714.6 施加載荷并求解71-724.7 模擬結(jié)果分析72-784.7.1 物料的流動(dòng)變形72-734.7.2 物料的應(yīng)力和應(yīng)變73-764.7.3 接觸部分摩擦力分布情況76-774.7.4 環(huán)模開(kāi)口角度對(duì)壓縮成型