本文選題：天然氣發(fā)動機 + 進氣道��； 參考：《中國艦船研究院》2015年碩士論文

【摘要】：天然氣發(fā)動機的開發(fā)、應用能有效促進我國能源結(jié)構(gòu)調(diào)整,實現(xiàn)節(jié)能減排。提高功率密度、提高熱效率、降低排放,是天然氣發(fā)動機開發(fā)過程中的研究熱點。合理的氣流組織對天然氣發(fā)動機實現(xiàn)清潔、高效燃燒有著重要的影響,而進氣道結(jié)構(gòu)是決定缸內(nèi)空氣量及渦流強度的關(guān)鍵因素,直接對氣流組織和燃燒過程產(chǎn)生影響。天然氣發(fā)動機在進氣道上布置有燃氣噴嘴和節(jié)氣門,其結(jié)構(gòu)同樣會對缸內(nèi)氣體流動產(chǎn)生影響。因此,以某中速大缸徑天然氣發(fā)動機串聯(lián)式切向氣道為研究對象,采用CFD模擬和氣道穩(wěn)流試驗相結(jié)合的方法,研究了進氣道結(jié)構(gòu),燃氣噴嘴及節(jié)氣門結(jié)構(gòu)對缸內(nèi)氣體流動的影響規(guī)律。具體研究內(nèi)容如下:首先,應用CFD仿真研究,提出了天然氣發(fā)動機進氣道結(jié)構(gòu)主特征參數(shù):氣道導向角Av,氣道喉口直徑dv,氣閥錐角An和彎曲半徑R,并研究了其對氣體流動的影響規(guī)律。模擬結(jié)果表明:當Av減小7%時,氣道平均流量系數(shù)降低約2%,平均渦流比提高約25%;當dv減小4%時,氣道平均流量系數(shù)降低約3%,平均渦流比提高約10%;當An減小17%時,氣道平均流量系數(shù)降低約2%,平均渦流比降低約15%;當R減小7%時,氣道平均流量系數(shù)降低0.2約%,平均渦流比降低約2%。同時可將各主特征參數(shù)對氣體流動的影響規(guī)律應用在相似機型進氣道的設(shè)計開發(fā),若考慮增大進氣道的流通性,可優(yōu)先增大喉口直徑dv;若考慮增大進氣道的渦流強度,可優(yōu)先減小氣道導向角Av。然后,應用CFD仿真研究,確定了燃氣噴嘴和節(jié)氣門結(jié)構(gòu)對氣體流動的的影響規(guī)律。模擬結(jié)果表明:加裝燃氣噴嘴和節(jié)氣門后氣道性能稍有變差,平均流量系數(shù)降低約4%,平均渦流比降低約2%,實際上這種影響主要來自于燃氣噴嘴結(jié)構(gòu)。最后,應用3D打印快速成型技術(shù)加工試驗件,該方法具有精度高,加工周期短的特點,大大減小了試驗件鑄造偏差對試驗結(jié)果的影響,并極大的縮短了加工周期。同時開展氣道穩(wěn)流試驗驗證了CFD仿真計算的準確性,分析表明:仿真計算與穩(wěn)流試驗結(jié)果有很高的一致性,可將兩者平均流量系數(shù)的偏差控制在3%以內(nèi),平均渦流比的偏差控制在10%以內(nèi)。本課題的研究實現(xiàn)了應用CFD仿真技術(shù)對氣道性能的定性判斷和定量分析,提高了試驗驗證的效率和水平。CFD仿真技術(shù)與氣道穩(wěn)流試驗的有機結(jié)合,可作為氣道設(shè)計開發(fā)的重要手段之一。
[Abstract]:The development and application of natural gas engine can effectively promote the adjustment of energy structure and realize energy saving and emission reduction. Increasing power density, increasing thermal efficiency and reducing emissions are the hot spots in the development of natural gas engine. Reasonable airflow distribution plays an important role in the clean and efficient combustion of natural gas engine. The structure of intake port is the key factor to determine the air volume and swirl intensity in the cylinder and has a direct impact on the airflow organization and combustion process. The gas nozzle and throttle are arranged on the intake port of the natural gas engine, and its structure will also affect the gas flow in the cylinder. Therefore, a series tangential port of a medium speed and large cylinder diameter natural gas engine is used as the research object. The structure of the inlet is studied by using the method of CFD simulation and steady flow test of the port. The influence of nozzle and throttle structure on gas flow in cylinder. The specific research contents are as follows: first, the application of CFD simulation research, The main characteristic parameters of intake port structure of natural gas engine are presented: Port guide angle Av, throat diameter DVD, air valve cone angle an and bending radius R, and its influence on gas flow is studied. The simulation results show that when AV decreases by 7, the mean flow coefficient of the airway decreases by about 2 and the mean eddy current ratio increases by about 25 percent; when DV decreases by 4, the average flow coefficient of the airway decreases by about 3 and the average eddy current ratio increases by about 10 percent; when an decreases by 17 percent, the flow coefficient increases by about 10 percent; and when an decreases by 17 percent, the flow coefficient increases by about 10 percent. The mean flow coefficient of the airway is reduced by about 2 and the mean eddy current ratio is reduced by about 15. When R is reduced by 7, the average flow coefficient of the airway is reduced by about 0.2 and the average eddy current ratio by about 2. At the same time, the influence of main characteristic parameters on gas flow can be applied to the design and development of the similar type of inlet. If the flow of the inlet is increased, the diameter of the throat can be increased first, and if the eddy current intensity of the inlet is increased, The airway guide angle Av can be reduced preferentially. Then, the influence of gas nozzle and throttle structure on gas flow is determined by CFD simulation. The simulation results show that the performance of the gas nozzle and throttle is slightly worse, the average flow coefficient is reduced by about 4 percent and the average eddy current ratio is reduced by about 2 percent. In fact, this effect is mainly due to the structure of the gas nozzle. Finally, the 3D printing rapid prototyping technology is used to process the test piece. The method has the characteristics of high precision and short processing cycle, which greatly reduces the influence of casting deviation on the test results and greatly shortens the processing period. At the same time, the accuracy of CFD simulation is verified by the steady flow test. The analysis shows that there is a high consistency between the simulation calculation and the steady flow test result, and the deviation of the average flow coefficient between the two can be controlled within 3%. The deviation of the average eddy current ratio is controlled within 10%. In this paper, the qualitative judgment and quantitative analysis of the airway performance are realized by using the CFD simulation technology, and the efficiency of the test verification is improved, and the level of the simulation technology is combined with the steady flow test. It can be used as one of the important means of airway design and development.
【學位授予單位】：中國艦船研究院
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TK403

【參考文獻】

相關(guān)期刊論文 前3條

1 張國勇;陳志忠;;船用柴油機進氣道類型及結(jié)構(gòu)參數(shù)對流通性能的影響[J];艦船科學技術(shù);2010年08期

2 周冬;柴油機改裝天然氣發(fā)動機的意義及技術(shù)措施[J];山東內(nèi)燃機;2005年01期

3 陳日軍,徐宏;發(fā)動機缸蓋氣道及水腔模具快速成型技術(shù)研究[J];新技術(shù)新工藝;2005年03期

相關(guān)碩士學位論文 前6條

1 侯元靜;增壓柴油機雙進氣道流動特性的三維數(shù)值模擬研究[D];北京交通大學;2011年

2 胡云萍;船用柴油機氣體流動的數(shù)值模擬[D];山東大學;2006年

3 崔東曉;4V105柴油機四氣門缸蓋進氣道的設(shè)計研究[D];湖南大學;2006年

4 吳浩;柴油機螺旋進氣道結(jié)構(gòu)參數(shù)對氣道性能的影響及其優(yōu)化設(shè)計[D];華中科技大學;2006年

5 王麗平;基于CAD/CFD的135型柴油機螺旋進氣道的研究[D];大連理工大學;2007年

6 李全武;H12V190ZLT型高增壓、稀燃天然氣發(fā)動機的設(shè)計開發(fā)[D];山東大學;2008年

，

本文編號：1935561