柴油机排气微粒泡沫陶瓷过滤体微波再生过程的温度场研究

本文根据柴油机排气微粒过滤体微波加热的特点，在合理假 设的基础上建立了一个二维轴对称非稳态的泡沫陶瓷过滤体微波再生温度场数字模型，利用有限差 分法对该问题进行了数值计算，得出了与实际再生实验基本一致的计算结果，该研究为避免过滤体在微波再生时可能出现的局部烧熔和再生不均匀等现象提供了重要的理论指导。     

碳化硅泡沫陶瓷过滤器微波再生特性

利用所建立的柴油机排气微粒过滤器微波再生数学模型，对以新型过滤材料碳化硅为过滤体的微粒过滤系统进行了微波再生特性研究。并分析了几种主要因素对再生过程的影响。计算结果表明，碳化硅过滤材料具有良好的性能，基本满足微波再生要求。     

气流特征对柴油机微粒捕集器微波再生的影响研究

柴油机微粒捕集器过滤体再生时,流过过滤体的气流特征对再生过程有重要影响.根据泡沫陶瓷过滤体微波再生的特点,建立了一个适用于圆柱形过滤体的二维微波再生数学模型.模型中考虑了过滤体微波再生时气流与过滤体、碳烟微粒之间的对流换热、微波能量在过滤体空间的再分布和衰减变化、碳烟颗粒在过滤体空间的分布不均匀性等主要因素.使用该数学模型研究了尾气中含氧量、流速、温度等物性参数对过滤体再生时间和再生效率等再生特性的影响,计算结果与试验结果吻合良好,说明所建立的数学模型合理,能满足工程应用要求.研究结果揭示了泡沫陶瓷过滤体微波再生过程中的一些重要特征和规律,为微粒捕集器的设计和优化提供了依据.     

柴油机排气微粒过滤器微波再生试验研究（1）

本对目前国内广泛采用的几种柴油机微粒过滤材料的微波特性进行了测量计算，并利用建立的柴油机微粒过滤及再生系统对过滤体的微波加热及再生特性了研究，结果表明，微波再生技术是比较成功的，它简单可靠，具有较广泛的应用价值，试验结果同时也表明，不同过滤材料的微波特性具有很大差异，需根据过滤材料垢特性合理地设计再生系统及组织再生过程。     

泡沫陶瓷过滤体微波再生过程的理论分析

建立了一个用于柴油机排气微粒泡沫陶瓷过滤体微波再生过程模拟计算的数学模型。通过模拟计算，对过滤体微波再生特性进行了数值预测，并对影响过滤体再生的几种主要因素进行了分析。计算结果表明，过滤体微波再生技术是可行的，再生持续时间为（１０－１５）ｍｉｎ，再生效率一般可达到８５％左右，但再生效率和再生速率受再生时间，过滤体积碳量，气流中氧含量以及气流速度大小等因素的影响。计算结果可以为再生系统的进一步优化提     

微波能应用于柴油机排气微粒过滤体再生机理的研究

本文介绍了微波加热的基本原理及选择性加热的特性.实现了用微波对陶瓷过滤体进行再生的构想.通过对微粒及陶瓷过滤体的微波特性测量和计算,得出了过滤体上的微粒是微波选择性加热的主要对象的结论.文中描述了微波再生试验的结果,其再生效果也由过滤体的失重试验加以证实.此外还介绍了作者开发的一套微波再生试验系统,由此可以对过滤体的再生情况和规律进行分析研究.     

柴油机排气微粒捕捉器燃气再生技术的研究

提出了一种新的柴油机排气微粒捕捉器的加热再生技术 ,即利用燃气与排气中的氧气燃烧清除微粒捕捉器中沉积的微粒 ;根据液化石油气的物化特性和排气中的含氧量 ,对这种方法的可行性进行了理论分析和试验验证 ;研制了一种以液化石油气为再生燃料的柴油机排气微粒捕捉器 ,并对燃气流量、过滤体内的微粒沉积量以及再生时间等影响因素进行了台架试验研究。     

柴油机排气微粒过滤器微波再生试验研究（2）

对开发研制的柴油机排气微粒后处理系统的微波再生特性进行了试验研究，试验结果表明，系统中采用的微波再生可靠有效。过滤体的再生效率为８０％左右；积碳量的多少对过滤体的再生效果没有显的影响，有效再生范围宽；再生时间为１０ｍｉｎ－１５ｍｉｎ左右，再生持续时间适当；再生空气的供给对再生结果有一定的影响，合适的再生空气供给可以加速再生和提高再生效率。     

柴油机微粒过滤器滤芯结构设计

本文设计了两种内部有曲折气流通道的柴油机排气微粒过滤器滤芯结构,并进行了柴油机台架实验。结果表明:改进过滤器滤芯的几何结构可以大大降低过滤器的排气背压,减小过滤器对发动机输出功率的影响,改善微粒在滤芯内部分布的均匀性,提高滤芯的有效过滤体积。     

汽车柴油机排气微粒后处理系统的开发及研究

介绍所开发研制的以过滤体微波再生技术为基础的汽车柴油机排气微粒后处理系统的总体组成、工作原理及其特点。对装有６１１０Ａ型柴油机和排气微粒后处理系统的ＣＡ１４１型柴油车进行了整车台架及道路试验,考核了微粒后处理系统在柴油车实际使用条件下的净化效率、系统的工作可靠性和耐久性。研究了后处理系统对汽车动力性的影响以及降噪能力。研究结果表明,后处理系统基本满足设计要求。     

A new procedure for power efficiency optimization in microwave ovens based on thermographic measurements and load location search

In this work, a novel procedure for increasing the power efficiency of microwave ovens is presented. The procedure consists of iteratively moving the sample within the microwave oven until a maximum average temperature increment is detected across the sample. A new experimental set-up consisting of a multimode microwave cavity, a dielectric tracking system, a microwave power source and a thermographic camera has been built and tested. Results show that it is possible to find optimal positions for the sample within the oven for which microwave power transfer to the sample is maximized.     

Soot deposition effects and microwave regeneration modelling of diesel particulate filtration system

Regeneration of accumulated soot particles in the substrate walls of the diesel particulate filtration system is one of the major challenges faced by the automotive industry. This study investigated the conversion efficiency and filtration behaviour of the after treatment system comprising of diesel oxidation catalysis (DOC) and diesel particulate filtration (DPF) system. The average conversion efficiency of hydrocarbons was close to 54% and filtration efficiency of the particle number emissions was around 92%. Characterization of the DOC and DPF substrate were conducted using microscopic imaging, Fourier transform infrared spectroscopy (FTIR) and particle size analysis (PSA). The results of FTIR study indicated the presence of carcinogenic agents trapped in the porous walls of the filter substrate. A model for microwave based regeneration system is proposed in this article and CFD analysis were conducted to determine the temperature and electric field distribution in the DPF substrate for a regeneration time of 180 s. Results of simulation showed that the microwave radiations raise the temperature close to soot oxidation temperature (873 K), ensuring effective regeneration.     

Experimental and computational study on the microwave energy based regeneration in diesel particulate filter for exhaust emission control

The uncontrolled combustion and early-life failure of the Diesel Particulate Filter substrate during fuel-based regeneration has raised the requirement for an alternate regeneration technique. The Latest emission norms have made it a mandatory requirement to retrofit the Diesel Particulate Filtration system in the exhaust line of CI engines to bring down the Particulate emissions. In this work, a novel technique through application of microwave energy has been developed for active regeneration of soot particles accumulated in the filter channel. Modelling of soot layer formation and microwave regeneration were carried out using CFD software (COMSOL MULTIPHYSICS). Performance and emission characteristics of multi-cylinder CI engine were evaluated after retrofitting the developed after-treatment system comprising of Diesel Oxidation Catalysis (DOC) and microwave regeneration based Diesel Particulate Filtration (DPF) systems. Soot accumulation rate and regeneration rate were experimentally investigated at different engine loads and magnetron (microwave radiation source) power levels. The experimental results showed that the developed after-treatment system has an average filtration efficiency of 90% for brake specific particle number emissions and 55% for hydrocarbon emissions. The regeneration rate was observed to be a maximum of 0.21 g/min at 50% power levels owing to the non-linear behaviour of magnetron. Energy consumption pattern of other regeneration techniques has been compared with the developed microwave regeneration system. The effect of soot accumulation and regeneration on the morphology, microstructure, chemical composition and particle size of DPF substrate were examined using characterization studies like Scanning Electron Microscopy – Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infra-Red spectroscopy (FTIR), Particle Size Analysis (PSA) and microscopic imaging.     

柴油机微粒捕集器过滤材料与再生方法分析与研究

柴油机微粒捕集器的关键技术是过滤材料和再生方法的研究，在介绍其过滤材料和再生方法的基础上，对比分析和研究了它们的特点和主要问题，建议将壁流式蜂窝陶瓷作为柴油机微粒捕集器的过滤材料并采用微波再生系统。     

Regeneration characteristics of desiccant rotor with microwave and hot-air heating

Microwave heating, because of its advantages of direct and rapid heating of materials, has the potential to be employed as a novel regeneration method of desiccant rotors in humidity conditioners. We proposed a combined regeneration process, which combines microwave heating and conventional hot-air heating. The system is expected to achieve high heating rate during an initial regeneration period by assisting water desorption using the additional energy of the microwave. In this study, the regeneration characteristics of a desiccant rotor were experimentally investigated under conditions of microwave heating, hot-air heating, and combined heating at various microwave powers and hot-air temperatures. The effectiveness of the combined regeneration was evaluated in terms of the regeneration ratio, the initial regeneration rate, the temperature distribution in the rotor, and finally in terms of the energy consumption. It was demonstrated that combined heating was effective at leveling non-uniform temperature distribution in the rotor. Combined heating achieved higher ratios and initial rates in regeneration compared to just microwave and hot-air heating. This result was obviously attributed to the additional input of microwave energy, resulting that average rotor temperature increased by microwave absorption of rotor. Moreover, it was also effective for enhancement of regeneration to level the temperature distribution in the rotor by combination of two heating methods with different heating mechanisms. Both the initial regeneration rate and the equilibrium regeneration ratio for combined heating were found to increase as the microwave power increased. A linear relationship was observed with respect to microwave power. From the viewpoint of energy consumption, it may be possible to apply combined and microwave heating to humidity control systems that switch between adsorption and regeneration in short cycle times, if the conversion and absorption efficiencies of the microwave are significantly improved.     

过滤器微波再生系统的射频测控技术

根据微粒过滤器微波再生的需要,提出了过滤体微粒沉积及再生的射频测控方法。叙述了射频测控技术的基本原理。通过理论推导给出了检测天线的设计方法,并从功率容量的要求出发对检测天线进行了设计。利用设计的测试系统在柴油机上进行了大量的试验测定,对实际测量结果进行了分析,并对各种影响因素进行了研究。试验结果验证了过滤体微粒沉积量射频测试方法的可行性。文中提出的射频测控技术为柴油机微粒后处理系统的实际应用奠定了基础     

Microwave processing of porcelain tableware using a multiple generator configuration

In this work we developed a microwave oven capable of processing porcelain tableware, with different sizes and shapes. We used a multimode cavity fed by 6 magnetrons with 1 kW each one, operating at 2.45 GHz, as the only heating source. Controlling the radiation power, in each stage of the process, we can create a more homogeneous electromagnetic field, avoiding the natural inhomogeneity which is a critical problem in the sintering process with microwave radiation.To characterize the quality of the sintered porcelain we measured the rupture energy, impact resistance, porosity, water absorption and concentration of undesired elements. These measurements have been compared with the obtained in similar porcelain pieces prepared by conventional methods, showing equivalent features and with parameters in the acceptable limits. It was observed that the sintering process is faster, with consequent lower costs and lower local emissions of harmful gases into the atmosphere.