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Optimal Configuration of Wind Turbine and Photovoltaic Based on Day-ahead Economic Dispatch
Bing Sun,
Yunfei Li,
Yuan Zeng
Issue:
Volume 9, Issue 3, June 2021
Pages:
91-96
Received:
8 March 2021
Accepted:
Published:
8 May 2021
Abstract: With the gradual increase of the penetration rate of wind and photovoltaic (PV) electricity, the power system is facing great challenges in integration and peak-shaving capacity. As flexibility resources of the system is limited, wind and PV power generation will not be consumed completely. Allowing the curtailment of the peak output of wind turbine and PV can reduce the cost of auxiliary services such as peak-shaving, relieve the huge pressure in the operation and planning of the system, and improve the overall power supply economy of the system. Firstly, the reason and optimization principle of the curtailment of the peak output of wind turbine and PV are explained. Then, a capacity optimal configuration method of power supply based on day-ahead economic dispatch is proposed. On the premise of allowing the curtailment of the peak output of wind turbine and PV, the corresponding annual power supply cost of wind turbine and PV capacity combination is calculated based on day-ahead unit commitment. The function fitting between power supply cost and wind turbine capacity is carried out. The best wind turbine and PV capacity combination is the value of the extreme point. Finally, the sensitivity analysis of example system is carried out. It is found that with the decrease of unit investment cost of wind turbine and PV equipment, developing wind and PV power generation will be a more economical choice in the future.
Abstract: With the gradual increase of the penetration rate of wind and photovoltaic (PV) electricity, the power system is facing great challenges in integration and peak-shaving capacity. As flexibility resources of the system is limited, wind and PV power generation will not be consumed completely. Allowing the curtailment of the peak output of wind turbin...
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Analysis on Activities of Daily Living Ability and Its Influencing Factors of the Elderly in Community
Yifan Cao,
Lingshan Wan,
Hansheng Ding
Issue:
Volume 9, Issue 3, June 2021
Pages:
97-100
Received:
12 March 2021
Accepted:
Published:
24 May 2021
Abstract: Objective: To understand the activities of daily living (ADL) status of the elderly in Shanghai community and its influencing factors. Methods: Cluster sampling method was used to sample 8143 elderly aged 60 or above, living in a community of Jing’an District, analyze their ADL status and its influencing factors. Results: Among the individuals, about 34% of the elderly were suffered from ADL impaired, including 12% were moderately or severely dependent. Age, education level, spouse, support from family and children, indoor facilities and self-rated health were the factors that affected ADL. Conclusion: Nearly 1/3 of the elderly in the community have certain degree of ADL disability, and the risk of disability is significantly increased in the elderly aged 80 and over. Elderly with emotional support from family or children, good self-rated health or living with their spouse are tend to have a better activities of daily living. It is suggested that the community and family should pay more attention to the elderly people with risk factors, and provide them with more psychological and spiritual support and help. It can provide reference for improving the quality of life of the elderly and making relevant pension service policies
Abstract: Objective: To understand the activities of daily living (ADL) status of the elderly in Shanghai community and its influencing factors. Methods: Cluster sampling method was used to sample 8143 elderly aged 60 or above, living in a community of Jing’an District, analyze their ADL status and its influencing factors. Results: Among the individuals, abo...
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Overview on Equipment of Distributed Proton Exchange Membrane Fuel Cell
Junxiang Zhai,
Guangli He,
Congmin Liu,
Zhuang Xu,
Zhonghui Tian
Issue:
Volume 9, Issue 3, June 2021
Pages:
101-107
Received:
16 March 2021
Accepted:
Published:
24 May 2021
Abstract: Distributed proton exchange membrane fuel cell (PEMFC) is one of choices for distributed power equipment, which is efficient, eco-friendly, reliable and responsive. They can be used in different occasions such as house, communication stations and chemical industry. This paper introduces combined heat and power (CHP), backup power and stationary power station, and details their system structure, technical specification and sales distribution. CHP are mainly applied in Japan and Europe, especially in Japan. PEMFC backup power is mainly carried out by large network and communication companies, which are about total 900 units in global, and the actual examples of PEMFC power station are lesser. Through the analysis of representative cases, this paper sums the actual operation and fault cause of distributed PEMFC equipment. Research will be better developed based on this analysis. Meanwhile, this paper sums these distributed power equipment from view of economy. Finally, application of domestic distributed PEMFC is pointed out. Generally speaking, distributed PEMFC receives less attention in our country. However, there are multitudinous chemical industries and so hydrogen in by-product is abundant. As PEMFC technology matures and cost falls, PEMFC power station is a suitable mode for our country based on comprehensive utilization of resources.
Abstract: Distributed proton exchange membrane fuel cell (PEMFC) is one of choices for distributed power equipment, which is efficient, eco-friendly, reliable and responsive. They can be used in different occasions such as house, communication stations and chemical industry. This paper introduces combined heat and power (CHP), backup power and stationary pow...
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Inspection and Analysis of Air Quality Forecast Effect by Using 4 Years Data in Ningxia Base on the Newest National Standard
Shao Jian,
Yang Yuanyuan,
Chen Min,
Du QingYang
Issue:
Volume 9, Issue 3, June 2021
Pages:
108-113
Received:
26 March 2021
Accepted:
Published:
24 May 2021
Abstract: In this paper, the characteristics of air quality index, air quality grade, pollutant concentration and the type of primary pollutant were tested, and the forecast result was analyzed by the daily observe and forecast data of air quality index, concentration of pollutants, primary pollutant types in Yinchuan from January 1st 2015 to December 31th 2018. The results showed that the forecast result was not satisfactory for the air quality grades. The annual TS of air quality grade forecast in Yinchuan were increased year by year, which between 20% and 40%，but the point out rates (PO) and the not hit rates (NH) were high, which showed a decreasing trend. For the weather with a good air quality grade, the TS were significantly higher than that of other grades. The average absolute error of the air quality index (AQI) forecast decreased over the year, and presented seasonal fluctuation characteristics, but increased with the pollution grades. The model was good at predictive capacity of primary pollutant types, which TS generally reached 40%-60%. There was little difference in the forecast results of each predictable scale by the simple and objective revise, that was to say, the forecast capability of the product had not been improved obviously with the variation of forecast timeliness, so that the forecast product should strive for more room for its improvement, which still has a long way to go.
Abstract: In this paper, the characteristics of air quality index, air quality grade, pollutant concentration and the type of primary pollutant were tested, and the forecast result was analyzed by the daily observe and forecast data of air quality index, concentration of pollutants, primary pollutant types in Yinchuan from January 1st 2015 to December 31th 2...
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Simulation Study on Blast Resistance Test of Blast Wall Based on LS-DYNA Coupling Method
Issue:
Volume 9, Issue 3, June 2021
Pages:
114-120
Received:
14 April 2021
Accepted:
Published:
24 May 2021
Abstract: In order to study the pressure change with time at the blast face of the blast resistant wall when the shock wave acts on the blast resistant wall after the explosion of TNT explosive, the equivalent model of the blast resistant wall is designed based on the similarity theory, and the TNT near ground explosion test is carried out. During the test, the pressure change data of the design measuring point on the blast resistant wall with time are collected by high-speed data acquisition instrument and pressure sensor, The time history curve of shock wave overpressure was obtained by processing the data. Then, LS-DYNA finite element analysis software is used to establish a separate finite element model of the blast wall. At the same time, the relevant parameters of air, explosive, concrete and ground in the explosion field are set. The numerical simulation of the explosion field is carried out, and the overpressure time history curve at the measuring point is extracted by the finite element analysis post-processing software. Compared with the numerical simulation results, it is found that the numerical simulation results are in good agreement with the experimental data, which indicates that the selection and setting of parameters in the simulation calculation are reasonable. The model and algorithm provide an effective means for the numerical simulation of blast wall in the explosion field.
Abstract: In order to study the pressure change with time at the blast face of the blast resistant wall when the shock wave acts on the blast resistant wall after the explosion of TNT explosive, the equivalent model of the blast resistant wall is designed based on the similarity theory, and the TNT near ground explosion test is carried out. During the test, ...
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Numerical Analysis of Ultimate Mechanical Characteristics of Suspension Bridges’s Cable in High Temperature Fire
Jiarun Song,
Xuehong Li,
Weiqing Liu
Issue:
Volume 9, Issue 3, June 2021
Pages:
121-127
Received:
19 April 2021
Accepted:
Published:
24 May 2021
Abstract: Relying on the joint research project, research is carried out on the ultimate mechanical characteristics of suspension bridge slings under high temperature fire. The establishment of a local transient temperature field heat transfer model based on the FDS software, and the analysis of the temperature distribution law of the fire source at different wind speeds. The most unfavorable fire condition is the combination of the fire source heat release rate of 300MW and the wind speed of 14m/s; the overall structure model of the bridge is modeled by ANSYS software. Firstly, the modal analysis of the whole bridge model is carried out to verify the accuracy of the modeling, and then the thermal structural coupling analysis is carried out under the most unfavorable fire conditions to obtain the structural response of the whole bridge structure under the sling fire. According to the change trend of the structure response of the cable under fire, the fire resistance limit of the bridge structure is obtained as 460°C; Under the most unfavorable fire burning situation, when the limit number of broken cable in the span is 3, the cable will be caused into collapsing continuously; the composite protective layer has a significant effect on the fire resistance of the cable.
Abstract: Relying on the joint research project, research is carried out on the ultimate mechanical characteristics of suspension bridge slings under high temperature fire. The establishment of a local transient temperature field heat transfer model based on the FDS software, and the analysis of the temperature distribution law of the fire source at differen...
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Synthesis and Characterization of a Carborane-containing Precursor for B4C Ceramics
Dexuan Yan,
Jiahui Chen,
Yu Zhang,
Yanzi Gou
Issue:
Volume 9, Issue 3, June 2021
Pages:
128-132
Received:
15 April 2021
Accepted:
Published:
24 May 2021
Abstract: B4C ceramic is one of widely used ceramics with properties of low density, high hardness, high thermal-stability and high neutron absorption cross-section. However, the high melting point and high hardness of B4C make it difficult to be prepared as materials with complex shape. Precursor derived method is an effective approach to prepare special-shaped ceramics. In the early research of B4C ceramic precursors, highly toxic and unstable decaborane was generally used as the boron source material, and precursors were also unstable and difficult to synthesize. In this work, a new B4C precursor is designed and synthesized, and m-carborane, which has stable chemical properties and high thermal stability, is used as the boron source. Firstly, m-carborane is converted into lithium salt after removing active hydrogen by n-butyllithium. Then, catalyzed by Cu(I), the lithium salt reacts with m-chloroiodobenzene so that monomer, bis(3-chlorophenyl)-m-carborane, is prepared. The monomer is polymerized through Ullmann Coupling reaction at the present of Ni(0) catalyst and Zinc powder, and precursor poly[bis(3-chlorophenyl)-m-carborane] is finally synthesized. The precursor is stable at room temperature in air and soluble in Tetrahydrofuran, with Mw of 1013g/mol, and ceramic yield of 62.20% at 900°C in N2. The precursor pyrolytic product is composed of B4C and graphite after heat treated at 1600°C in inert atmosphere.
Abstract: B4C ceramic is one of widely used ceramics with properties of low density, high hardness, high thermal-stability and high neutron absorption cross-section. However, the high melting point and high hardness of B4C make it difficult to be prepared as materials with complex shape. Precursor derived method is an effective approach to prepare special-sh...
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