本文關(guān)鍵詞： 導(dǎo)流器 一次風(fēng)管道 數(shù)值模擬 靜力學(xué)分析 諧響應(yīng)分析　出處：《內(nèi)蒙古工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：鍋爐機(jī)組在設(shè)計(jì)、建造過(guò)程中,考慮空間的有效利用,煙風(fēng)系統(tǒng)存在很多彎管。由于彎管的結(jié)構(gòu)特點(diǎn),管內(nèi)流體呈現(xiàn)復(fù)雜的流動(dòng)特性,如速度分布不均、氣固兩相流在彎管附近形成分離區(qū)等。這些流動(dòng)特性會(huì)造成流體總壓和能量損失,會(huì)造成風(fēng)量測(cè)量不準(zhǔn)、管道振動(dòng)等。首先,本文針對(duì)循環(huán)流化床鍋爐熱一次風(fēng)管道的彎頭多、直管段較短的特殊結(jié)構(gòu),提出在直管段入口位置加裝柵格導(dǎo)流器。利用商業(yè)軟件ANSYS workbench對(duì)柵格導(dǎo)流器結(jié)構(gòu)進(jìn)行了優(yōu)化,包括確定導(dǎo)流器的柵格數(shù)量、柵格高度、柵格與管道軸線夾角和柵格板厚度等。優(yōu)化結(jié)果為在導(dǎo)流器柵格數(shù)量為4×4、并分別與管道軸線成10°夾角、導(dǎo)流板高度為240mm、厚度為4mm時(shí),均流效果較好、阻力損失較小。其次,將理論分析的優(yōu)化結(jié)果在循環(huán)流化床鍋爐上進(jìn)行了實(shí)驗(yàn)驗(yàn)證。實(shí)驗(yàn)在三個(gè)工況下測(cè)試了安裝導(dǎo)流器后熱一次風(fēng)管道內(nèi)風(fēng)量測(cè)量裝置位置的風(fēng)速分布。實(shí)驗(yàn)結(jié)果顯示,加裝導(dǎo)流器后,一次風(fēng)管道內(nèi)的風(fēng)速分布較均勻,說(shuō)明導(dǎo)流器起到了均流效果。同時(shí),模擬結(jié)果與實(shí)驗(yàn)結(jié)果的吻合較好,說(shuō)明模擬結(jié)果的準(zhǔn)確性較高。最后,采用單向流固耦合的方法,利用ANSYS workbench軟件,對(duì)加裝導(dǎo)流器前后的熱一次風(fēng)管道進(jìn)行了靜力學(xué)、模態(tài)、諧響應(yīng)、疲勞分析。靜力學(xué)計(jì)算發(fā)現(xiàn),加裝導(dǎo)流器后,各工況下一次風(fēng)管最大變形及最大應(yīng)力比添加導(dǎo)流器前有小幅增加,說(shuō)明導(dǎo)流器的添加對(duì)一次風(fēng)管結(jié)構(gòu)有影響,不過(guò)影響很小;模態(tài)分析發(fā)現(xiàn),添加導(dǎo)流器后的一次風(fēng)管道比添加導(dǎo)流器前的各級(jí)固有頻率要小;諧響應(yīng)分析發(fā)現(xiàn),添加導(dǎo)流器后的一次風(fēng)管道的共振頻率比添加前小;疲勞分析發(fā)現(xiàn),添加導(dǎo)流器前后疲勞分析結(jié)果基本相同,說(shuō)明導(dǎo)流器添加不會(huì)對(duì)一次風(fēng)管增加額外的疲勞損傷。通過(guò)本文的研究發(fā)現(xiàn),在循環(huán)流化床鍋爐一次風(fēng)管道上加裝柵格導(dǎo)流器對(duì)管道流場(chǎng)有明顯的改善,對(duì)管道的振動(dòng)有一定的影響,對(duì)管道壽命幾乎沒有影響。因此,在一次風(fēng)彎管添加?xùn)鸥駥?dǎo)流器改善流場(chǎng)的方法是可行的。
[Abstract]:In the design and construction of boiler units, considering the effective use of space, there are many bends in the smoke and air system. Because of the structural characteristics of the bends, the fluid in the pipe presents complex flow characteristics, such as uneven velocity distribution. The gas-solid two-phase flow forms a separation zone near the bend tube. These flow characteristics will result in the loss of the total pressure and energy of the fluid, the inaccurate measurement of the air volume, the vibration of the pipeline, etc. Firstly, this paper aims at the number of bends in the circulating fluidized bed boiler heat primary air pipe. In this paper, a special structure with short straight pipe section is proposed, and a grid flow guide is installed at the entrance position of the straight pipe section. The structure of the grid diversion device is optimized by the commercial software ANSYS workbench, including determining the grid number and the grid height of the diversion device. The optimum results are as follows: when the number of grids is 4 脳 4, the angle is 10 擄with the pipe axis, the height of the guide plate is 240 mm, and the thickness is 4 mm, the effect of flow equalization is better and the loss of resistance is small. The optimized results of the theoretical analysis are experimentally verified on a circulating fluidized bed boiler. The wind velocity distribution of the air volume measuring device in the heat primary air pipe after the installation of the diffuser is tested under three operating conditions. The experimental results show that, The distribution of the wind velocity in the primary air duct is more uniform after the installation of the diversion device, which shows that the flow guide has the effect of flow equalization. At the same time, the simulation results are in good agreement with the experimental results, which shows that the accuracy of the simulation results is high. Finally, Using the method of unidirectional fluid-solid coupling and using ANSYS workbench software, the static, modal, harmonic response and fatigue analysis of the hot primary air pipe before and after the installation of the flow guide are carried out. The maximum deformation and maximum stress of primary air duct are slightly increased compared with those before adding diversion, which indicates that the addition of diversion has an effect on the structure of primary air duct, but the influence is very small. The modal analysis shows that the maximum deformation and maximum stress of primary air duct have little effect on the structure of primary air duct, and the modal analysis shows that, The resonance frequency of the primary air duct after adding the diversion is smaller than that before adding the diversion, and the harmonic response analysis shows that the resonance frequency of the primary air duct after adding the diversion is smaller than that before adding it, and the fatigue analysis shows that the resonance frequency of the primary air duct after adding the diversion is lower than that before adding it. The results of fatigue analysis before and after adding diversion device are basically the same, which indicates that the addition of diversion device does not increase the additional fatigue damage to primary air duct. The installation of grid guide on the primary air pipe of circulating fluidized bed boiler has obvious improvement on the flow field of the pipe, has certain influence on the vibration of the pipe, and has almost no effect on the life of the pipe. It is feasible to improve the flow field by adding a grid guide to the primary wind bend.
【學(xué)位授予單位】：內(nèi)蒙古工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TK229.66

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本文編號(hào)：1510346