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Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Since the measurement of oil quantity in aviation engine lubrication systems is susceptible to multiple parameters, it is difficult to calculate and predict oil consumption rates. We propose an improved method for extracting oil quantity data and predicting oil consumption rates. Engine data are cleansed using density-based clustering algorithms, including density based spatial clustering of applications with noise (DBSCAN), to obtain stable oil quantity data during steady flight conditions. By the least squares method, oil consumption rates are derived with an average fitting goodness of 0.86. Subsequently, a multi-layer perception (MLP) is employed to establish the relationship between oil consumption rates and flight status parameters, resulting in a predicted average absolute percentage error of 1.15%, compared to actual values. The proposed method meets practical engineering requirements, providing a reliable reference for assessing the health status of aviation engine lubrication systems. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The threshing cylinder of the combine was used for soybean threshing and auxiliary soybean separation. However, soybean in Southern China has a high ratio of grass to grain and immature pods during harvest. The existing nondifferential speed threshing cylinder has poor adaptability to this feature, resulting in low threshing quality, low operating efficiency and high fuel consumption in the harvesting process. Therefore, this study aims to improve the adaptability and comprehensive performance of the threshing cylinder of soybean combine harvester in Southern China. Aims at the high ratio of grass to grain and the proportion of immature pods in soybean harvest in Southern China, a longitudinal axial flow differential threshing cylinder with adjustable cylinder speed difference was designed, it's front cylinder threshes the pods that are easy to thresh at a lower rotating speed, while the rear cylinder threshes the pods that are difficult to thresh at a higher rotating speed. And two types of threshing teeth were made, the full rod tooth threshing teeth was the front and rear cylinders were adopt rod teeth, and the rasp-rod combined threshing teeth was the front cylinder adopts the rasp bar, and the rear cylinder adopts the rod teeth. At the same time, in order to study the impact of the structure and parameters of the threshing cylinder on the threshing quality, the type of the threshing teeth, front cylinder speed and cylinder speed difference related to the threshing cylinder are selected as factors, and the Epicit Dnamics module of ANSYS software was used to analyze the impact of different factors on material changes from the perspective of energy and shape variables. It can be speculated that the cylinder with the rasp-rod combined threshing teeth has lower the percentage of broken, the percentage of unthreshed and the percentage of separation loss grains. In the end, the optimal parameter combination of the differential threshing cylinder and the traditional nondifferential threshing cylinder was obtained through experimental analysis, and the threshing quality, operating oil consumption and maximum operating efficiency of the two threshing cylinders are compared under the optimal parameter combination, evaluated the comprehensive working quality of the threshing cylinder, which provides a reference for the research of soybean harvester threshing device in many aspects. In the field test, due to the limitation of test cycle and safety, it is impossible to measure the fuel consumption and maximum operating efficiency in each group of tests. Therefore, the percentage of broken, the percentage of unthreshed and the percentage of separation loss that reflect threshing quality are taken as evaluation indicators, and a single factor comparative test was conducted, and the fuzzy comprehensive evaluation method was adopted, It was determined that the threshing cylinder most suitable for soybean characteristics in the Southern China was the differential speed threshing cylinder, and the threshing teeth type was the rasp-rod combined threshing teeth. The optimal parameter combination was: the speed of the front cylinder was 450 r/min, the speed difference of the cylinder was 150 r/min, and the optimal rotational speed of the traditional nondifferential speed threshing cylinder with rod tooth was 500 r/min. Under the optimal parameter combination, the comprehensive performance comparison test of two threshing cylinders was carried out. The results showed that the threshing quality of the differential threshing cylinder was higher, its fuzzy comprehensive evaluation value was 0.4 higher than that of the traditional rod tooth threshing cylinder, the fuel consumption was 2.7 L/hm2 lower, and the working efficiency was 10.35% higher, It was proved that the differential speed threshing cylinder with the rasp-rod combined threshing teeth can improve the adaptability and comprehensive working performance of the harvester to soybeans. This discovery provides a favorable technical support for mechanized soybean harvesting in Southern China. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A tractor is a typical representative of power machinery in agricultural production. Two working conditions of tractors include road transportation and field operation. These working conditions can also be subdivided into plowing, rotary tillage, and fertilization, according to the carried agricultural implements. However, there are high oil consumption and low energy-saving in tractors, where the external load fluctuates frequently, as the working environment changes. Furthermore, a large number of gears have been equipped and frequently shifted to fully meet the needs of different working conditions in the traditional tractors, leading to the difficulty of tractor operation. In this study, a hybrid-mechanical-hydraulic power system was designed for a tractor using continuously variable transmission and hybrid power technology. The driving and transmission modes of the system were realized to obtain the speed regulation curve of the continuously variable transmission. The mounted hydro-mechanical continuously variable transmission (HMCVT) was also optimized for the best performance of the power system. Taking the engine economy curve as the target, the economic speed ratio map of HMCVT was drawn by the MATLAB platform. The target speed ratio was then obtained, according to the vehicle speed and throttle opening. As such, a speed ratio control strategy was formulated using the engine economy curve. Moreover, an energy management strategy was constructed using the minimum equivalent fuel consumption. The equivalent factor was integrated into the working division using the logic threshold. The penalty function was then introduced to maintain the battery State of Charge (SOC) stability. A strategy was designed for the rule-based mode division and the minimum fuel consumption power allocation using the adaptive equivalent factor. Specifically, the vehicle speed, demand torque, battery SOC, and speed ratio were firstly used as the logic threshold for the mode division, and then the minimum instantaneous equivalent fuel consumption was used as the objective function. Finally, the corresponding constraint conditions were introduced to calculate the minimum fuel for the engine and motor at any moment. The dynamic model of the tractor system was established in the SimulationX software. A test bench was also built using a dynamometer. The simulation and experimental analysis of the tractor were performed on the three typical working conditions of plowing, harvesting, and transportation. The results showed that the error between the simulation and test value was less than 5%, indicating a reliable model. The HMCVT efficiency was above 0.80 under the three working conditions, whereas, the efficiency of the whole power system was around 0.4. The SOC values were achieved at +1.96, -0.37, and -0.19 at the end of the plowing, harvesting, and transportation, respectively, indicating near the target value. The fuel consumption values were 2.72, 6.80, and 1.77 L in the plowing, harvesting, and transportation, respectively. Therefore, the 18% and 15% oil consumption was saved under the power output condition, compared with the power shift tractor, and the continuously variable transmission tract published by the German Agricultural Association, respectively. By contrast, 15% and 19% of the oil were saved under the transportation condition, compared with the power shift tractor, and the continuously variable transmission tractor, respectively. The 9%-20% fuel was also saved under three working conditions, indicating the feasible power system and the control strategy. The finding can provide a better solution to reduce the tractor energy consumption under multi-working conditions. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the mechanism of lubricating oil consumption,taking a 12v diesel engine as the research object, the dynamic simulation model of piston assembly was established, and the influence of piston pin offset mode and amount on lubricating oil consumption was analyzed. The results show that the offset mode of piston pin generally leads to the decrease of lubricating oil consumption, improves the oil channeling and oil throwing obviously, and the piston pin offset to anti-thrust side (ATS) has the best effect on reducing the consumption of lubricating oil. The offset of piston pin has a great influence on the consumption of lubricating oil. When the offset increases,the oil channeling first decreases and then increases, and the oil throwing decreases continuously. When the piston pin deviates 3 mm to ATS, the best comprehensive effect on reducing lubricating oil consumption is obtained. With the increase of diesel engine speed, the consumption of lubricating oil shows a growing trend, resulting in the reduction of engine efficiency. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Accelerating the development and utilization of natural gas and optimizing the energy structure are important tasks for China to promote energy production and consumption revolution and to build a clean, low-carbon, safe and efficient energy system. However, the energy structure transition will lead to energy assets stranding, supply security and system risks. To solve these issues, this study proposed a system dynamic model for energy substitution system in light of the putty-clay of energy equipment capital, getting a deep insight into the mechanism of natural gas substitution effects of energy supply security shock and assets stranding risk of traditional fossil fuels. Moreover, energy transition security was evaluated comprehensively from three dimensions of energy structure optimization, supply security and asset stranding, and several schemes for improving energy structure driven by natural gas substitution on transitional fossil fuels were put forward for future policymakers. The results showed that: (1) The huge coal and oil equipment capacity capital stock has led to the path dependence on the traditional fossil energy consumption, which is the capital resistance of natural gas substitution and clean energy transition. This means that there will be a long-term and gradual process for natural gas to substitute traditional fossil energies to realize energy structure transition. (2) If the existing carbon price (50 yuanton) and natural gas premium (-11 472 yuan/toe) remain unchanged, China's natural gas consumption will account for about 12% by 2050, and the energy structure dominated by coal and oil consumption will not have been fundamentally changed. (3) Increasing carbon price and reducing natural gas premium can increase the substitution of natural gas for coal and oil, and strengthen the market orientation of clean energy consumption, such as electricity. However, this is at the cost of energy supply security and assets stranding of traditional fossil fuels. (4) It is necessary for policymakers of natural gas substitution to follow the cost constraint of capacity capital putty-clay on energy structure optimization. Three optimal schemes should be adopted by 2050: reducing natural gas premium by 60%; decreasing the premium gradually from 20% to 60%; increasing carbon price gradually from 100 to 600 yuan/ton while decreasing the premium gradually form 20% to 60%. These three schemes can increase the proportion of natural gas consumption to about 20%, and reduce the proportion of coal and oil consumption to below 60%. (5) To ensure energy transition security, it is necessary to intensify the reform and construction of carbon market and natural gas market, and give full play to the market guiding effect of price mechanism on energy consumption and investment in equipment capital. At the same time, it is also necessary to strengthen the macro-control role of government investment in energy market to gradually reduce investment in coal and oil production capacity, to increase investment in equipment capacity capital of clean energies such as natural gas and electricity, to reduce asset stranding in the process of energy transition and to prevent systematic risks of energy supply. [ABSTRACT FROM AUTHOR]

In order to promote the transformation of China's energy consumption and reduce CO2 emissions, this paper first uses the club convergence test method to conduct a detailed empirical study of the differences in the inter-provincial evolution of different types of fossil energy consumption. Then, based on the results of convergence clustering, a hierarchical (group) forecasting method is used to predict short-term CO2 emissions at different levels. The results show that due to the different dependence of economic development on coal consumption, coal consumption of various provinces converges to three levels. Driven by the energy intensity and structural effects, the province's oil and natural gas consumption have generally converged upward. The forecasts indicate that CO2 emissions from fossil fuels will be dominated by coal, which is dominated by the 13 provinces in clubs2. Meanwhile, oil consumption will increase CO2 emissions, natural gas will reduce total emissions, and provincial CO2 emissions and its growth rates will still have large differences. These findings have important implications for the establishment of specific regional energy consumption and emission policies:clubs2's provinces are key areas for controlling coal consumption and reducing CO2 emissions; strictly controlling oil consumption in high-income and heavy-industry provinces will further reduce total CO2 emissions. [ABSTRACT FROM AUTHOR]

Volume rate of blow-by and oil consumption are both critical indexes of assessing piston ring assembly development activities. Gas blow-by along with oil consumption exerts a bad influence on engine performance, worsening emissions and polluting the environment. It is indicated in the literature that the in-cylinder oil consumption through piston-ring-cylinder liner friction pair is an important source of particulate matter （PM）emissions of diesel engines. Controlling in-cylinder oil consumption proves to be an effective way of meeting stricter emission control limits. Blow-by could contribute to oil aging, thus deteriorating engine components lubrication, which can also lead to fuel corrosion and PM emissions. Factors affecting in-cylinder oil consumption and blow-by primarily includes piston ring radial thickness, piston ring end gap, tangential elastic force, cylinder bore match clearance, cylinder clearance and other structure parameters, as well as oil quality/pressure and working condition. The piston assembly of a four-cylinder common rail diesel engine was chosen as the research object in this study. Piston temperature distribution was measured by using a hardness plug method. The hardness plug was mounted in piston top surface, combustion chamber bottom and throat along with the top, second, and third ring groove. Temperature of key points on cylinder liner outer surface was obtained using thermocouples mounted axially every 90° around the circumference. The test data showed that there was an apparent temperature distribution difference on piston top where a max temperature of 356 ℃ was obtained on combustion chamber throat near the exhaust. The average temperature of ω-shaped combustion bottom was 307 ℃, whereas the temperature of combustion chamber center hump reached up to 328 ℃. The average temperature decreased from top to the third ring groove. The lowest temperature on cylinder liner outer surface was 96.8 ℃ obtained by the thermocouples. Top temperature gradients changed dramatically in the range of 30 mm down from the top of the cylinder liner and the highest temp in this region was 178.3 ℃. The cylinder pressure data, and the temperature field of the piston and cylinder obtained by the experiment were used for setting the boundary conditions for the dynamic simulation model. The weighed oil consumption verified the accuracy of the model. The influence rules of different clearance of piston ring land, piston ring groove and piston ring gap along with radial elastic force of top piston ring on in-cylinder oil consumption as well as blow-by was investigated. Results obtained using response surface methodology of Box-Behnken design showed that blow-by and oil consumption went up with the increase of piston ring land clearance and piston ring gap. The blow-by and oil consumption can be reduced if piston ring land gap and ring gap decreased when the performance of piston ring component was guaranteed. Variation of ring groove depth and top piston ring upper clearance had a slight influence on blow-by. Radial elastic force of the top ring is found obviously linear with blow-by, the sealing ability to the air of the top ring was better than that of the second ring. [ABSTRACT FROM AUTHOR]

For the purpose of researching on diesel bus emission, finding out the relationship between oil consumption and emission, and establishing a diesel bus emission model, this paper first studies the diesel truck emission model using CMEM (comprehensive modal emissions model) in foreign countries, then compares the difference between diesel buses in China and standard diesel trucks in CMEM. Some parameters of the model, like speed, acceleration, quality, transmission efficiency and so on are revised, and then the calculating formula which is suitable for diesel buses emissions in China is obtained. It shows that the data calculated by the modified model fits the test data in Harbin city well. [ABSTRACT FROM AUTHOR]

With the rapid development of China's economy,the oil consumption is increasing by leaps and bounds. Analyzing the great change in oil consumption, an in-depth investigation was done for the relation between oil consumption and economic growth in the period 1953-2004. Then, the cointegration theory and Granger causality test were introduced into the investigation to make an empirical analysis in time series to verify the oil consumption in relation to GDP. It was therefore found that there was a cointegration relation between China's oil consumption and GDP from 1953 to 2004 and that the former was the cause of the latter but, from 1978 to 2004, GDP showed obviously an one-way causality in the cointegration relation between it and oil consumption. [ABSTRACT FROM AUTHOR]