廢氣再循環(huán)對壓力波增壓器平均價值建模的影響外文翻譯-資料下載頁
2025-05-12 02:59本頁面
【導(dǎo)讀】點火發(fā)動機的泵氣損失。試圖改善這個缺點的方法是縮小發(fā)動機并回收增壓發(fā)動機。相比自然吸氣式汽油機，小型增壓汽油機工作在中等負荷和低負荷范圍間。的泵氣損失更小，更為有效。面直接接觸，不良廢氣再循環(huán)可能通過增壓器。突然的高壓廢氣再循環(huán)，將會導(dǎo)致。發(fā)動機扭矩崩潰。為了保證良好的操控性，廢氣再循環(huán)必須避免。工作目標(biāo)是建立模型，并排除排氣壓力波增壓器內(nèi)氣體循環(huán)的影響。該系統(tǒng)模型能夠預(yù)測如壓力、溫度、質(zhì)量流量、發(fā)動機扭矩精度狀態(tài)，并在。排氣穩(wěn)態(tài)和瞬態(tài)工況時通過增壓器進行廢氣再循環(huán)。在凈化時負荷會惡化。因此，壓力波增壓器的泄漏損失和混合區(qū)的長度不可測量，廢氣和新鮮空氣。統(tǒng)分析和系統(tǒng)優(yōu)化，并應(yīng)用于模型控制器設(shè)計。該發(fā)動機的扭矩只能通過改變進氣歧管。壓力，即控制油門降低環(huán)境壓力強度，耗損進氣歧管壓力強度。進氣管和排氣管之間的負面壓力差造成發(fā)動機的吸氣損失。正在研究的課題，因此沒有進一步討論。發(fā)動機在接近最經(jīng)
【正文】 Approach In order to model the entire systemPWS SI engine, the system is substructured into devices which can store mass and energy (receivers) and devices which produce the flows between these receivers (generalized throttles). The relevant dynamics of the model are represented by the energy and mass storage of thereceivers, whereas the throttles are described by static algebraic relations. The main part of the simulation tool PWS Engine Model is the static submodel PWS Model. The PWS is modeled as a generalized throttle, ., the outputs of the PWS Model are mass and enthalpy flows. The model neglects the fast dynamics of building a new stationary pressure wave diagram since the dynamics of the system caused by the fillingemptying process of the tubes are predominate. The PWS Model calculates a simplified pressure wave process and the corresponding pressure wave diagram, based on the theory of the onedimensional,linear gas dynamics. The PWS Model is validated by steadystate measurements. 5 Main Contributions The main contributions of this research are: Description of the pressure wave process of a pressure wave supercharger including steadystate exhaust gas recirculation by a physically based mean value model approach. The model calculates the outputs as a function of the measured states as pressures and temperatures in the channels of the PWS and of the actual PWS rotational speed. The calculation is based on the algebraic relations of the onedimensional linear gas dynamics. The resulting model is the static model PWS Model whose outputs show an error which is smaller than 5%. Derivation of the nonmeasurable, PWS typical leakage losses out of the cell wheel, the nonmeasurable mixing zone length, and its exhaust gas fraction profile by model parameter identification. Presentation and explanation of one possibility of how transient exhaust gas recirculation during a load step can be avoided. Moreover, this study points out clearly the working principle of the gas pocket valve and explains its influence on the pressure wave process. Development of a simulation tool which can be used for system analysis, system optimization, and model based controller design. 6 Conclusions The model of the pressure wave supercharger is validated by the identification of the following physically motivated model parameters: pression efficiency reflection efficiency scavenging pressure length of mixing zone The absolute value of the gas pocket pressure drop depends on the closing velocity of the gas pocket valve. The faster the gas pocket valve is closed,the more the gas pocket pressure drops: increasing gas pocket valve closing velocity ↓ gas pocket pressure drops lower ↓ scavenging is worse Furthermore, the model extrapolation demonstrates that the gas pocket pressure drop only slightly depends on the volume of the gas pocket receiver when the gas pocket valve is closed within a realistic closing time. Only for an unrealistically short closing time, the receiver volume of the gas pocket significantly influences the dynamics of the gas pocket pressure. An increased gas pocket volume would thus result in a smaller gas pocket pressure drop and therefore help the scavenging to be plete. In a future step, the developed simulation tool may be used for further investigations and optimizations such as changing the volumes of the tubes, connecting the tubes in a different way, etc. Besides these system parameter analysis, the tool mainly may be used for model based controller design.
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