DEStech Transactions on Environment, Energy and Earth Science最新文献

{"title":"Analysis of the Coupling Laws of Disaster Inducing Factors of Frozen Rain and Snow Disasters in Southern China—Taking Changsha City as an Example","authors":"Guanning Wang, Tao Chen, Zhenxing Chang, Wanjie Hu, Junjie Yuan, Qiyao Sun","doi":"10.12783/DTEEES/PEEES2020/35494","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35494","url":null,"abstract":"In order to study the causes and laws of freezing rain and snow disasters in southern China caused by coupling of multiple disaster inducing factors, the meteorological observation data of the severe rain and snow freezing disasters in Changsha in January 2008 was analyzed in this paper. The fluctuation characteristics of typical disaster inducing factors and disaster factors coupling law were studied, and the following conclusions were drawn: (1) Temperature-humidity coupling system will promote the occurrence of freezing disasters such as glaze, freezing fog, freezing rain and sleet; (2) Wind and precipitation are important causes for the occurrence of freezing disasters, and their coupling effect will lead to typical disasters such as snow drift and rain-wind phenomenon, which will aggravate freezing disasters; (3) Daily maximum temperature, daily minimum temperature and the average temperature are significantly negatively correlated with the degree of freezing disasters, and the effects of humidity and precipitation on freezing disasters are significantly positively correlated. The results showed that the coupling analysis of disaster inducing factors could provide a powerful tool for the freezing disasters prevention and emergency management.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73386714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Day-ahead Scheduling of Islanding Microgrids Based on Wind Power Forecast","authors":"Yusang Chen, Min-fang Peng","doi":"10.12783/DTEEES/PEEES2020/35474","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35474","url":null,"abstract":"Wind power, as the main energy source of the island microgrid, has uncertain output. Reasonable setting of TOU price can improve adaptability to changes in wind power output. Based on the time series characteristics of wind speed, the EWMA is used to predict the wind speed day-ahead. Then through the method of distribution superposition fitting and roulette, the day-ahead forecast data of wind power considering power fitting error is obtained. As a reference, a new TOU price division method based on wind power output is proposed. At the same time, P2G and energy storage devices were introduced into the cogeneration system to achieve Gas-electric transformation functions. Combined with the heating and electric demand response of the user side, comprehensively considering the mutual conversion relationship between multiple energies. On the premise of considering economy and environmental protection, the Gurobi solver is called by Yalmip to get the start-stop status of the powerside unit and the user-side unit.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78680173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on Lean Operation and Maintenance Technology of Intelligent Electric Energy Meter Based on Artificial Intelligence","authors":"Lifang Zhang, Yongle Dong, Liu Yupeng, Fan Zhang, Tong Wang","doi":"10.12783/DTEEES/PEEES2020/35501","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35501","url":null,"abstract":"The existing power metering device does not realize on-line monitoring, operation health evaluation and dynamic inspection of equipment in the process of operation and inspection. The purpose of this paper is to solve the technical problems of online monitoring and evaluation of the operation status of the electric energy metering device, analyze the technical difficulties encountered in the process of realizing the lean operation and maintenance of the electric energy metering device and the supporting technologies available at this stage in detail, and propose a lean operation and inspection technology of the electric energy metering device to improve the working efficiency and level of intelligence management.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"112 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90676760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation Analysis of Emulsion Droplet Excited by Chaotic Frequency Pulse Electric Field","authors":"Liao Zhixiang, Haifeng Gong, Ye Peng","doi":"10.12783/DTEEES/PEEES2020/35508","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35508","url":null,"abstract":"The frequency of the chaotic pulse electric field is random in a limited range, which can be adjusted and controlled, thus can effectively cover the harmonic resonance frequency of the droplets in the oil, and realize the efficient coalescence and demulsification of the droplets. In this study, the chaotic frequency pulse electric field is constructed by embedding the chaotic sequence into the pulse interval with the Chaotic-Pulse-Position Modulation method, and the vibration dynamics simulation model of the emulsion droplet in the chaotic frequency electric field is established. The vibration dynamics response of the emulsion droplet under the action of the chaotic frequency pulse electric field is obtained by numerical calculation, and the dynamic analysis, phase diagram analysis and maximum Lyapunov exponent calculation of the response output are carried out. It is found that under the action of chaotic frequency pulse electric field, the emulsion droplet can obtain large tensile deformation at high frequency, but relatively small at low frequency, and the fluctuation is stable, which can qualitatively and quantitatively identify the chaotic vibration characteristics of the droplet.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91319111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the Treatment of Coal Washing Wastewater by Pressureless Filtration Technology in Yidong Preparation Plant","authors":"Zhiming Ma, Jiaxing Fu","doi":"10.12783/DTEEES/PEEES2020/35457","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35457","url":null,"abstract":"This article takes the coal washing wastewater of the Yidong Coal Preparation Plant as the research object. With the change of the raw materials to be washed, the effect of its existing treatment process is not ideal. The multi-factor response surface analysis of the four factors of PAC dosage, PAM dosage, stirring speed and stirring time was carried out, and the optimal dosage and operating parameters were obtained as PAC dosage 30.52 mg/L, PAM dosage The dose is 20.75 mg/L, the stirring speed is 407 r/min, and the stirring time is 82.5 s. Through the field industrial test, the application effect and rationality of the pressureless filtration technology are verified.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"120 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87714993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Study on the Unsteady Film Cooling Characteristics of Turbine","authors":"Huang Kang, Shi Peijie, Junqiang Wu, Husheng Ma","doi":"10.12783/DTEEES/PEEES2020/35497","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35497","url":null,"abstract":"In view of the main flow pulsation phenomenon and the new pulsating film cooling mode in the aeroturbine engine, the numerical calculation method is used to study the film cooling characteristics under the condition of the main flow velocity pulsation and cooling gas velocity pulsation with the classical circular film hole as the research object. In order to eliminate the influence of other factors on the film cooling characteristics of turbine blades as much as possible, a circular film hole of flat plate model similar to the small curvature section of turbine blades was established, and the influence of different cooling air pulse frequency, blowing ratio and mainstream pulse frequency on the film cooling characteristics was analyzed in depth. The results show that: with the increase of cooling air pulse frequency, the film cooling efficiency of cooling gas pulsation scheme can be achieved approximately the steadystate condition with blowing ratio of 1.0 while only half of the cooling air flow is consumed; at high blowing ratio, the cooling effect will be better when using the cooling air pulsating film cooling scheme compared with the steady-state scheme; in the main pulsating frequency range of the study, the frequency of main flow pulsation has little effect on film cooling efficiency.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"216 0 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79558481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Practice and Thinking of Online Courses Based on \"Dingtalk + Chaoxing\" in COVID-19 Epidemic Situation","authors":"Yan Ma, Qiu Yan","doi":"10.12783/DTEEES/PEEES2020/35481","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35481","url":null,"abstract":"Since the outbreak of Novel coronavirus pneumonia (COVID19) at the beginning of this year, colleges and universities have actively responded to the call of \"Suspension of classes and non-stop learning\" by the Ministry of education, and have adopted online teaching methods to organize teachers and students to teach and learn. Under this background, the method of \"DingTalk live broadcast + online interactive Chaoxing network teaching platform\" is used for the online courses of \"Single-chip microcomputer principle and interface technology\" and “Database principle and Application”. Multiple ways combined the interaction are used to mobilize the classroom atmosphere in class, and homework and test are arranged to consolidate the learning points after class. Therefore, using this teaching mode can achieve good teaching and learning effect. Since January 2020, coupled with the shutdown of many enterprises during the Spring Festival, novel coronavirus pneumonia (COVID-19) broke out nationwide, which greatly affected the industry, agriculture and service industry. Not only that, the teaching of students at all levels was affected. In order to stabilize the epidemic, the Ministry of Education issued a notice of “Suspension of classes and non-stop learning\" on January 27, calling on schools to conduct online teaching. In some provinces, online classes have started before the end of winter vacation. This is the first large-scale online teaching in our country, so most teachers and students lack teaching and learning experience in online classes. At the beginning of a period of time, various problems have appeared: the network is unstable and often disconnected. The teacher is not familiar with the live broadcast software in class, and some of them forget to turn on the microphone or forget to turn off the live broadcast after class. Students are also tired of listening to the class, because they are still on vacation and sometimes forget the class time, etc. Different courses are taught on different platforms. So students need to download various Apps and find out the operating routines and various clock-in (including attendance, homework, exercises and tests). Staring at the computer or mobile phone for a long time to learn , their eyes are tired, and learning efficiency is very low [1,2] . Under the call of the Ministry of Education, we are asked by the college to start online classes on February 17. This paper mainly introduces the specific implementation, experience and thinking of the online lectures of the course \"Single-chip Microcomputer Principle and Interface Technology\" and “Database principle and Application” taught by the author.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82705052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of BP Neural Network in Cross- Sensitivity Solution of Temperature and Strain of FBG Sensor","authors":"Yingshan Ma","doi":"10.12783/DTEEES/PEEES2020/35509","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35509","url":null,"abstract":"Fiber Bragg grating (FBG) sensor has the advantages of long transmission distance and less channel occupied by data acquisition instrument, so it can be used for strain measurement of power engineering and electronic engineering and so on. FBG is sensitive to both strain and temperature, that is, both changes can change the central wavelength of the grating. In structural health monitoring, the load on the tested part is complicated, and the temperature also changes greatly in the long-term monitoring process. If the FBG sensor is fixed on the tested component, it will inevitably be affected by the combined action of temperature and strain at the same time, making the test result produce error or deviation. In this paper, the temperature compensation of FBG strain sensor is analyzed and studied. Based on the calibration data, the FBG strain sensor temperature compensation is realized by BP Neural Network Algorithm. The research results of this paper can be used as a reference for health monitoring of large-scale structures using FBG sensors.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82813894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Boiler Bypass Flue to Adjust Denitration Inlet Flue Temperature Automatic Control System Design and Analysis","authors":"P. Ge","doi":"10.12783/DTEEES/PEEES2020/35487","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35487","url":null,"abstract":"Under low-load boiler operating conditions, the flue gas temperature at the inlet of the denitration system is lower than the normal working temperature of the catalyst. In order to ensure the reliable input of the denitration system, a bypass flue and an adjustment damper are added to the boiler economizer. Configure control logic and actual debugging to realize automatic control of the inlet temperature of the denitration system, and ensure that the denitration system can be continuously operating when the boiler is running in the 30% -100% load range. At present, environmental protection requirements are getting stricter, almost all the boiler equipment of thermal power plant units have completed the desulfurization, denitration and electrostatic precipitator transformation to meet the pollutant emission standards. The desulfurization and electrostatic precipitator can be used during all load range, however, due to the chemical reaction principle, the denitration system cannot running in low load conditions. In recent years, the flue gas denitration technology widely used in coal-fired power plant boilers is selective catalytic reduction (SCR). Economizer is the last heated surface of the boiler before the air heater, and the purpose is to reduce inlet flue gas temperature of the air preheater and save fuel. The denitration system is arranged between the economizer and the air heater. Generally, the operating temperature of the catalyst used in the selective catalytic reduction reaction is between 300-400°C. The catalyst will not play its due role beyond the temperature range. In the design of conventional boilers, there will be the following problems: when the boiler is operating under high load conditions, the flue gas temperature at the inlet of the denitration system is just within the normal operating range of the catalyst; however, the normal operating temperature of the catalyst cannot be met when the boiler load is low. If the design is changed to increase the flue gas temperature at the inlet of the denitration system to meet the catalyst requirements under low load conditions, the overall flue gas temperature of the boiler will be further increased during high-load operation, resulting in high flue gas temperature, low boiler efficiency and large coal consumption. Therefore, according to the traditional design, the denitration system cannot be put into operation when the boiler is running under low load condition, but this has not been able to meet the requirements of the latest nitrogen oxide emission index. In order to solve the contradiction that the flue gas temperature at the inlet of the denitration system at low load does not meet the working conditions of the catalyst, the","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"248 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81853585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calculation and Optimization of Volumetric Efficiency of Aviation External Gear Pump","authors":"Jing Ma, Yuan Xu","doi":"10.12783/DTEEES/PEEES2020/35496","DOIUrl":"https://doi.org/10.12783/DTEEES/PEEES2020/35496","url":null,"abstract":"The power consumption of aviation gear pump has a direct impact on the performance of aero-engine. To improve the efficiency of aviation external gear pump, this paper analyses the leakage of gear pump, and calculates the leakage of axial, radial clearance, gear face meshing clearance, and the elastic loss of liquid compression. Mathematical models of volumetric efficiency are established including the effect of temperature and pressure. Comparing the theoretical value with experimental results, the effectiveness of the models is verified with the error less than 5%. On this basis, the design variables of gear pump are optimized with the maximum theoretical displacement as the optimization objective function. The simulation results show significant volumetric efficiency improvement of the external gear pump. And some suggestions on actual products design and analysis in the aviation fuel device are proposed accordingly. External gear pump is widely used in aviation as the main fuel pump, and oil transfer pump, booster pump and return pump of lubricating oil system in aviation power plant, and as the main hydraulic pump in aircraft hydraulic system. With the development of aviation power plant, high-pressure, low pulsation, low noise and large displacement have become the development trend of gear pump [1]. In order to reduce the power consumption of aeroengine, the total efficiency of aero fuel pump is required to be optimized, and the volumetric efficiency of gear pump must be improved accordingly. Various researches in this field mainly studied the improvement of volumetric efficiency and the solution to leakage problem respectively. The method of improving gear pump volumetric efficiency in engineering is studied in [2]. The leakage problem of axial clearance of gear pump is analysed and a new processing technology is proposed in [3]. The mathematical model of leakage in external gear pump is established in [4][5]. And the model of volumetric efficiency of gear pump by experiment is studied in [6][7]. Few studies are taking a holistic view of the problem. Therefore, by establishing and verifying the mathematical model of volume efficiency, the paper proposes a possible integrated method to optimize the volumetric efficiency with theoretical solution to the leakage problem and achieve energy saving consequently.","PeriodicalId":11369,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Science","volume":"94 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74210249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}