Kunming Yunnei Power CO.

Kunming, China

Kunming Yunnei Power CO.

Kunming, China
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Yang T.,Kunming University of Science and Technology | Yang T.,Kunming Yunnei Power Co. | Guo Y.,Kunming University of Science and Technology | Wu X.,Kunming University of Science and Technology | And 2 more authors.
Mechanical Systems and Signal Processing | Year: 2016

Vibration from incipient faults of rolling element bearings (REBs) is usually too weak to be observed in a conventional spectrum analysis. The envelope analysis or high-frequency resonance technique is an effective tool for the incipient fault detection of REBs. The newly developed envelope order tracking, an improved version of the envelope analysis, can be well performed even in a varying-speed condition. However, the envelope order tracking can be invalid for multi-impulsive sources. To address this issue, a scheme for the weak feature extraction of faulty REBs has been proposed in this paper by combining the envelope order tracking and the constrained independent component analysis (cICA). In the proposed scheme, the envelope order tracking approach is utilized to obtain the envelopes of sensor observed mixtures at different positions. Then, the envelopes are turned from the time domain into the angle domain by the constant-angle increments resampling scheme in the computed order tracking (COT). Subsequently, the cICA method is employed to extract the interesting envelope independent components (ICs) by a reference signal, which is constructed according to the prior-known feature frequency of the bearing. As a result, the faults related features can be clearly exposed in the spectra of the obtained interesting envelope ICs. Simulations and experimental results support the proposed method positively. © 2017.

Wang Z.,Kunming University of Science and Technology | Guo Y.,Kunming University of Science and Technology | Cao Y.,Kunming Yunnei Power Co. | Wu X.,Kunming University of Science and Technology
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2017

Planetary gearboxes are widely used in wind turbines and other large type machineries. Their vibration feature extraction is particularly important in fault diagnosis field. Due to non-stationary, modulation, and complex transmission path and its time-varying characteristics, the synchronous averaging (SA) technique for conventional fixed-shaft gearbox fault detection is not directly applicable for planetary gearboxes. Here, based on the original windowed synchronous averaging method in time domain, the windowed synchronous averaging method in angle domain was proposed for planetary gearboxes with time-varying transmission paths and varying-speed working conditions. It was employed to extract the desired signals and reduce effects of transmission paths. Using this method, according to computed order tracking (COT), windowed signals in time domain were sampled with constant angle increments, the non-stationary signals in time-domain were converted into the quasi-stationary ones in angle domain. Then, those signals in angle-domain were processed with the synchronous average (SA) method. Test results showed that the proposed method can effectively extract the feature information of a sun gear's faults of a planetary gearbox. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.

Wang J.,Kunming University of Science and Technology | Shen L.,Kunming University of Science and Technology | Yang Y.,Kunming Yunnei Power Co. | Bi Y.,Kunming University of Science and Technology | Wan M.,Kunming University of Science and Technology
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2017

China Stage III emission standard for diesel engine of non-road mobile machinery has been executed since April 1, 2016. Some manufactures have begun to adopt a high pressure common rail system to cope with this emission regulation. Fuel injection parameters can be adjusted flexibly by using the high pressure common rail system. Therefore, combustion process can be improved. However, it brings the problem of increasing the workload of the calibration and optimization significantly. With the increasing of calibration variables, the calibration combinations will increase exponentially. The traditional calibration method, such as the single variable search method or the single variable sweep method, their calibration results may not be able to make the engine to achieve best performance, especially when the number of calibration parameters is more than two. Nowadays, a majority of optimization calibration methods are using a non-parametric modeling method to fit the calibration model and optimizing the calibration model by using an intelligent optimization algorithm. However, the non-parametric modeling method cannot give the descriptions of the model structure or the model coefficients. Meanwhile, it needs a large number of test data to fit an accurate calibration model. Moreover, the non-parametric modeling method and the intelligent optimization algorithm are both very complex. A polynomial modeling method has a good compromise between complexity and computational efficiency of the model. Therefore, in allusion to the calibration stage of a non-road high pressure common rail diesel engine, 4 calibration variables, i.e., main injection quantity, pilot injection quantity, main injection timing and injection pressure, were chosen as the factors. The non-road diesel engine design index and related constraint parameters were chosen as the responses at the peak torque speed of 1 600 r/min and the rated power speed of 2 600 r/min, respectively. The reasonable factor levels of the design of experiments (DoE) were selected. By using the response surface methodology (RSM) of Box-Behnken design, the DoE matrices were obtained at the engine speed of 1 600 r/min and 2 600 r/min, respectively. Meanwhile, the corresponding test was conducted according to the experiment design. The second order regression models of all the responses were got and evaluated. The interaction effects of the 4 calibration parameters on engine performance were investigated by using the RSM. The corresponding optimization was conducted respectively at the engine speed of 1 600 and 2 600 r/min taking the target torque and target power as the setting target under the principle of the minimum brake specific fuel consumption, the maximum air-to-fuel ratio, the minimum peak cylinder pressure and gas temperature of exhaust manifold. The combination of calibration variables was obtained at 2 engine speeds, and the proposed method was verified by experiments. The results showed that all the quadratic response surface regression models had a good accuracy and a good predictive ability. The determination coefficient R2, the adjusted determination coefficient R2 adj, and the prediction determination coefficient R2 pred were all above 0.92. The maximum error between test value and predicted value was less than 3.07 %. With the optimized calibration parameters, the peak torque and the rated power of the non-road high pressure common rail diesel engine reached 200.7 N·m and 40.1 kW, respectively. The engine achieved the design index, and moreover, the brake specific fuel consumption, air-to-fuel ratio, peak cylinder pressure, and gas temperature of exhaust manifold were all under the range of acceptance. It is feasible to optimize the diesel engine design point by using the RSM. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.

He C.,Southwest forestry University | Li J.,Southwest forestry University | Li J.,Beijing Institute of Technology | Wang Y.,Southwest forestry University | And 4 more authors.
Applied Thermal Engineering | Year: 2017

In order to investigate the size-resolved characteristics of diesel exhaust particles, four size bins particles were collected by electrical low pressure impactor from a diesel engine fueled with diesel and four oxygenated fuels and then studied by the thermogravimetric analysis. The results indicate that the higher oxygen content of fuel leads to the lower total particle and element carbon mass emission of the diesel engine. The element carbon mass fraction of the particles with the diameter of 0.03 ∼ 0.10 µm is lower than that of total particles for all five fuels, especially for high oxygen content fuels. The composition pattern of the particles with the diameter of 0.10 ∼ 0.25 µm and 0.25 ∼ 0.99 µm is similar with that of total particles, whose element carbon fraction decreases and high volatility fraction increases with the increasing fuel oxygen content. For the particles with the diameter of 0.99 ∼ 2.46 µm, the high volatility fraction is higher than that of other size bin particles. The derivative mass loss fraction curves of 4 size bins particles have 3 peaks, which is different from that of total particles having 2 peaks. The soot emitted from oxygenated fuels is easier to be oxidized than that from diesel for different size bin particles and total particles. The research is helpful to understand the interaction of diesel particles with the engine and particle trap. © 2017 Elsevier Ltd

Yan W.-S.,Kunming University of Science and Technology | Chen H.,Kunming University of Science and Technology | Shen L.-Z.,Kunming University of Science and Technology | Yang Y.-Z.,Kunming Yunnei Power Co. | Lei J.-L.,Kunming University of Science and Technology
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2012

In order to clear effect of atmospheric pressure on performance and emissions of the diesel engine fueled with diesel oil mixed by 15% hydrous ethanol, comparative tests on bench were conducted in a turbocharged diesel engine fueled separately with pure diesel oil and E15 hydrous diesel/ethanol blend under different atmospheric pressures. Results indicate that with the atm. pressure rising, engine power is slightly increased; the brake specific fuel consumption b e gets great improvement with the atm. pressure rising from 81 kPa to 90 kPa, while with it rising from 90 kPa to 100 kPa, the improvement lowers; and the atm. pressure rising has little influence on b e in low load condition but has remarkable influence in middle and high load conditions. At 81 kPa atm. pressure, HC and CO emissions go up significantly in low and middle load conditions, but with atm. pressure rising it gets remarkable improvement, meanwhile in high load conditions the HC and CO emissions trend to diesel engine level or worse. The atm. pressure has little influence on NO x emissions, but NO x emissions have a slight drop at all load conditions. When the atm. pressure declines below 90 kPa, the smoke has a remarkable drop compared to that of diesel engine. When the atm. pressure is over 90 kPa, the improving effect weakens.

Li L.,Kunming University of Science and Technology | Yu K.,Kunming University of Science and Technology | Li Y.,Kunming Yunnei Power Co.
Advances in Intelligent and Soft Computing | Year: 2012

In the manufacturing industry, negative inventory balances is an especially sticky subject for each enterprise. If enterprise does not allow negative inventory balances, that will affect transfer speed of logistics and information, but allowing negative inventory balances will exist inventory inaccurate risk. This paper mainly analyzed in the inaccurate problems caused by calculating inventory costs based on allowing negative inventory balances exists, and how to improved algorithm to solve them. © 2012 Springer-Verlag GmbH.

Li J.Q.,Southwest forestry University | Wang Y.Y.,Southwest forestry University | He S.C.,Kunming Yunnei Power Co. | Yan H.B.,Kunming Yunnei Power Co. | He C.,Southwest forestry University
MATEC Web of Conferences | Year: 2016

Due to their adverse health effects and their abundance in urban areas, diesel exhaust ultrafine particles caused by the aftertreatment devices have been of great concern in the past years. An experiment of particles number emissions was carried out on a high-pressure, common rail diesel engine with catalytic diesel particle filter (CDPF) to investigate the impact of CDPF on the number emission characteristics of particles. The results indicated that the conversion rates of CDPF is over 97%. The size distributions of particles are bimodal lognormal distributions downstream CDPF at 1400 r/min and 2300 r/min. CDPF has a lower conversion rates on the nucleation mode particles. The geometric number mean diameters of particles downstream CDPF is smaller than that upstream CDPF. © 2016 The Authors, published by EDP Sciences.

He C.,Southwest forestry University | Li J.Q.,Southwest forestry University | Wang Y.Y.,Kunming Yunnei Power Co.
Applied Mechanics and Materials | Year: 2013

Vehicle emissions and their control (VEC) is an important course for majors about automobiles, such as vehicle engineering, Automobile Service Engineering and thermal energy and power engineering. In order to meet the development of automobile technology and culture the corresponding talents, the teaching method should be reformed and innovated. In this paper, the difficulties in VEC course teaching were summarized and analyzed, and the countermeasures and suggestions were put forward. The course content was redesigned and the laboratory experiment was re-arranged. The innovation training program of students was put forward. Some pedagogical techniques and evaluation methods for VEC course were proposed. © (2013) Trans Tech Publications, Switzerland.

Zhou J.,South China University of Technology | Li L.,South China University of Technology | Hu Y.,Guangxi University of Technology | Wang M.,Kunming Yunnei Power CO.
Materials Science Forum | Year: 2011

The article points out the television plastic part size, giving the general design route, then describing the general design process of television back shell by Pro/E. The mold design also is introduced, including mold cavity distrubition, size determining of cavity mold and punch mold, selection of mold frame, set of pushing rod and stripping, sizes of part and mold, side core-drawing mechanism, cooling system design, mold's assembly, through simulation, the mold's design can be determined whether good or bad.

Li G.-J.,Kunming Yunnei Power Co.
Zhuzao/Foundry | Year: 2015

The effect of graphitization and high sulfur nitrogen recarburizer on mechnical properties of engine cylinder head was studied. The production test show that tensile strength of separately cast bar was increased 50 MPa, hardness was increased HBS10, the processing performance of cylinder head was improved, the production cost was decreased. © 2015, Chinese Mechanical Engineering Society. All right reserved.

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