bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Application of Alternative Refrigerants R407C and R410A in Refrigeration-Type Compressed-Air Dryers
Authors: Liu Hui , Li Jin Hua , Xiao Hong
Published: October 2014

The coefficient of performance (COP), the volumetric refrigeration capacity and the pressure ratio of refrigeration cycle were studied in a refrigeration-type compressed-air dryer using environmentally friendly refrigerants R410A and R407C and compared with those using R22. Study indicates that under the working condition of a refrigeration-type compressed-air dryer, COP using R410A is 3% higher than that using R407C, the volumetric refrigeration capacity using R410A is 50 percentage points higher than that using R407C and the pressure ratio of R410A is 10% less than that of R407C. COP using R410A equals 96% of that using R22 and the volumetric refrigerating capacity equals 147% of that using R22. COP using R407C is equal to 93% of that using R22 and the volumetric refrigerating capacity is equal to 97% of that using R22. R410A is a more appropriate alternative to R22 than R407C in a refrigeration-type compressed-air dryer.
The Development of Device for On-Line Monitoring Circulating Cooling Water Stability
Authors: Zhang Li Qiang , Sun Mo Jie , Zhang Ting , Li Zhao , Wang Huan Wei
Published: October 2014

China is a country lacking of freshwater. With the water pollution from bad to worse, saving water become a serious matter which needs to be settled at once. In order to ensure the system working safely and the water quality, most power plants enable the circle cooling water to work in the low consistence, need more drainage and complement water which will make large waste of water. The good water quantity means that the water doesn’t make the furring and make cautery to the equipment. So we can improve the concentrated multiples of the cycle cooling water to save the water. Based on the specialty of the water used in the power plants, this subject study how to estimate the stability, doing the instrument and watching the stability degree, providing the scientific basis for disposing the circling water. After lots of experiments, we use the stability index as the estimation and use the pH determination as the alkalinity determination.The instrument uses the date collecting card to collect and use computer to dispose the date and control the instrument. The system inspects the stability of the cycle cooling water real time automatically.
Design and Simulation to Composite MPPT Controller on the Stratospheric Airship
Authors: Sun Kang Wen , Zhu Ming , Liang Gao Ming , Xu Dong Dong
Published: October 2014

In view of solar arrays applied in large-scale stratospheric airship, modular thinking was proposed by reasonable decomposition of solar array to design composite maximum power point tracking (MPPT) controller where the input and output are both in parallel, which ensures maximized solar energy output on a limited area. And each solar array sub-model was equipped with independent MPPT controller to control power tracking separately. Then, the solar array composed of three sub-models was used for simulation and its result indicates that MPPT controller of each sub-model can track the power quickly, and the output power can reach 93% of maximum input power when the efficiency loss of converter in reality is not considered . So, the model constructed in this paper can be used to optimize the design and analyze output characteristics quantitatively for the large-scale stratospheric airship's solar array.
Experiment Research on the Purification Technology of Biogas as Engine Fuel
Authors: Wang Kang , Fang Zu Hua , Sun Ying , Xu Hong Bing , Wu Jian Min
Published: October 2014

This paper presents an overview of biogas purification technology and industry status, studies the purified rules in biogas purification processing and a lot of experiments are made to verify the influence of purification efficiency by various influencing factors. Carbon dioxide in biogas, which occupies at least 30%, can be absorbed by the lye based on the acid-base neutralization reaction and the absorption efficiency can be improved by controlling the inlet pressure and other factors in the biogas purification processing. The experimental results show the purification rules that purification efficiency of biogas is proportional to concentration ratio of methane and carbon dioxide before reaction, inlet pressure, fluid volume of lye, lye concentration and volume of filler, but inversely proportional to the total inlet flow, which builds theoretic foundation for the later design of the biogas purification device.
Impedance Control Based Sliding Mode for Lower Limb Rehabilitation Robot
Authors: Cao Fu Cheng , Du Li Min
Published: October 2014

Aimed at improving the dynamic response of the lower limb for patients, an impedance control method based on sliding mode was presented to implement an active rehabilitation. Impedance control can achieve a target-reaching training without the help of a therapist and sliding mode control has a robustness to system uncertainty and vary limb strength. Simulations demonstrate the efficacy of the proposed method for lower limb rehabilitation.
Optical Microscope Automatic Focusing Methods Research
Authors: Zhu Lan Xiang , Yang Wei Wei , Wang Zhen , Liu Qi Fan
Published: October 2014

This paper proposes an auto-focus method that is based on Ostu segment. The method uses the variance of the two classes of the segment results as the guidance of the auto-focus system. This guidance function responses to wide range of object distance range, it has a strong anti jamming ability and it provides a wide range of the guidance value. The result shows that this method can work well and the time it takes to focus is unconcerned to the position when the focus process starts and it responses to a wide range of object distance.
The Design of Depth Drill Machine Based on Automatic Control AC Servo System
Authors: Wang Xian Wei , Qin Hong Wu
Published: October 2014

Based on AC servo system of deep hole processing,a new kind of open CNC system is proposed by calling the dynamic link library under Windows operating system, which is made up of googol motion controller GE-400-PV,Panasonic MINAS driver and AC servo motor, has good man-machine interface, solved that the traditional methods is difficult to satisfy the practical requirements in the precision and efficiency of the deep hole processing, experiments show that, the control system can achieve the effect of precision processing, fully meet the requirements of mechanical technology in practical application.
Combined Support Technology with Bolt, Steel Mesh and Anchor Applied in Baoxin Coal Mine
Authors: Song Bao Sheng , Jing Dan Yang , Zhu Shi Ting , Chen Lin Lin
Published: October 2014

For the caving danger of the haulage roadway with thin and broken coal roof in Baoxin coal mine, the combined support technology with bolt, steel mesh and anchor was proposed. According to the geological conditions of the mine, the appropriate support program was determined. The simulation analysis by FLAC3D software showed that the program could effectively increase the roadway confining pressure, reduce roadway displacement and deformation, and thus keep the stability of the surrounding rock. Site practice showed that the support program was feasible and the control effect was good.
Review of Crumb Rubber Concrete
Authors: Li Wei , Huang Zhen , Wang Xiao Chu , Wang Jun Wei
Published: October 2014

Rubber concrete acted as one kinds of building materials came from the traditional modification concrete, and it had the excellent thermal insulation properties, such as light, good toughness, good thermal insulation, so it had been initially used in civil engineering, such as railways, highways and so it’s like. It improved the large rigidity and insufficient toughness for the ordinary high strength concrete, and also offered a better choice for the treatment of waste rubber. This paper combined the rubber research institute of concrete for at home and abroad about 30 years, and summed up the way of modification, the mechanical properties, application status, and indicated the existing problems about the studies concrete to the rubber concrete.
Crack Resistance Design for the Circular Hydraulic Tunnel Lining Structures
Authors: Shen Wei
Published: October 2014

In this paper, an indoor large scale model test on the crack resistance of hydraulic tunnel structure which has first adopted the real water load in China was conducted in Dalian University of Technology. The model test can reveal the load carrying capacity and the deformation of the lining structure effectively. Based on the test results, models respectively for the mean crack width and the mean stress of reinforcing bars were developed and then compared with existing monitoring data provided by a hydroelectric station. The results shows that the model for predicting the crack width of lining structure has a good accuracy and thus is of great value in the engineering application.
Heating and Cooling Load Characteristics Comparison between Normal Building and Low Energy Consumption Building
Authors: Su Yuan , Wang Fu Lin , Fan Yue
Published: October 2014

In this research, a normal building and low energy consumption building were chosen to compare and analyze heating and cooling load characteristics. Firstly, the abstract of two buildings were carried out. Secondly, methodology of measurement and calculation was researched. At last the heating and cooling load of two buildings was examined using this methodology.
Relaxation Laws of Anchor on Pressure Dispersive Retaining Wall
Authors: Wu Jian Qing , Li Ying Yong , Zhang Hong Bo , Song Xiu Guang , Meng Qing Yu , Zhang Si Feng
Published: October 2014

In order to study anchor relaxation of pressure dispersive retaining wall, the numerical simulation model was designed to simulate the retaining wall with single anchor plate. The results showed that the pressure dispersive retaining wall had good overall stability. Anchor Relaxtion had two sudden changes. As a result, the lateral soil pressure near the anchor had been released and the displacement Significantly increased.
Research on the Pass Optimization Design of Sintered Shale Porous Brick
Authors: Liu Jian Long , Xie Jie Nan , Liu Peng , Huang Mu Ye
Published: October 2014

The equivalent thermal conductivity coefficient of 10 kinds of sintered shale porous brick with different void number, void ratio, and arrangement (size: 240mm x 190mm x 90mm) are studied through 3D numerical simulation. An optimal structure design of the shale perforated brick design has been obtained. At the same time, factors such as void ratio, void number and arrangement of porous brick affected thermal insulation performance are systematically analyzed, which provides a reference to further improving the thermal insulation performance of insulation sintered shale porous brick model.
An Efficient Coverage Hole Patching Algorithm Based on Intersection Knowledge
Authors: Wu Hong Jie , Yu Ying Hua , Guo Li Xia , Meng Xian Chen , Qin Ning Ning
Published: October 2014

Aiming at the phenomenon of coverage holes because of energy depletion and random nodes deployment in wireless sensor networks (WSN), a principle for hole coverage was proposed. Based on the triangular geometry knowledge, firstly, determined the optimal patching station in basis of the benchmark-intersection, and then active inactive nodes to patch the hole. The simulation experiments demonstrate that this algorithm makes full of energy resources in the premise of complete coverage to patch coverage hole, and has a better performance in the number of the mobile nodes、resource utilization rate and algorithm running time efficiency compared with the existing DACHP and PATT algorithm.
Abstracting Clinical Pathway Sequence with Genetic Algorithm
Authors: Wu Yan Ping , Du Shu Feng
Published: October 2014

In this paper, execution sequence of clinical pathway (CP) is abstracted with genetic algorithm (GA). For the purpose, implemental sequence from historical clinical event logs for necessary clinical activities in published CP is used as the gene values of each chromosome. Through probability computation in fitness function, the optimal sequence of CP for a certain hospital is abstracted which reflecting the actual execution of CP. The application in Primary lung cancer surgery has demonstrated the feasibility of the method.
Application of Wavelet Analysis in Random Drift Signal Filtering of Fiber Optic Gyroscope
Authors: Liu Hong Liang , Chen Wei Yi , Xu Zhong Sheng
Published: October 2014

Wavelet analysis technique is proposed in the filter processing to remove the noise from random drift signal of fiber optic gyroscope (FOG). Based on the component elements of random drift signal of FOG, mathematical model of random drift signal of FOG is built. According to the shortcomings of hard threshold and soft threshold, threshold function of forced denoising is used in signal filtering. It is shown from simulation and statistic analysis that the wavelet analysis technique is an effective method to eliminate noise from random drift signal of FOG, and that selection of wavelet base and decomposition scale also has an impact on filtering effect of wavelet analysis.
MCL and ACO Based QoS Routing Algorithm for WSN Used in Power Line Monitoring
Authors: Li Li Fen
Published: October 2014

This paper presents a new cross-layer QoS routing algorithm for wireless sensor networks. Basing on the principle of cross-layer design, the algorithm adopts delay, nodes’ load and link quality as QoS metrics. The QoS routing metrics are regarded as heuristics correction factors in ant colony algorithm (ACA). The ants are divided into a number of different populations. Through the interaction of pheromone between multi populations, the routing algorithm searches for the feasible paths in parallel and updates the pheromone in time. To overcome the slow convergence of ant colony algorithm, membership cloud model (MCL) is used to control the randomness of the ants. The simulation results demonstrate that the routing algorithm can guarantee the real time, reliability and robustness of wireless sensor networks. It can also achieve the network load balancing.
Application and Research of Systematic Cluster in IED Switch Online Condition Monitoring
Authors: Ma Kai , Hu Chun Chao , Feng Shan Qiang , Tan Shu Feng , Jiang Xu , Chen Hu
Published: October 2014

This paper investigates the application of systematic cluster, one of the cluster analysis methods, in the IED switch online condition monitoring. So far, problems still exsit in the IED switch online condition monitoring based on the control system of smart substation. In order to figure out a relatively stable online model and make classification from the online information of IED switch, this paper firstly fliters and preprocesses the online condition information of IED switch, and uses data matrix to describe the online condition of IED switch. Based on this, the paper inroduces a special dissimilarity degree formula to transfer the data matrix into dissimilarity degree matrix, and conducts analysis with clustering pedigree chart out of systematic cluster algorithm. Finally, the paper verifies the feasibility of systematic cluster in the IED switch online condition monitoring.
Star Simulator Base on Multiple LEDs, Optical Fiber and Integral Sphere
Authors: Gan Xin Ji , Chen Yan
Published: October 2014

In order to design a compact star simulator based on multiple LEDs, optical fibers, an integral sphere and tiny collimated optical systems are employed in the system. Firstly the system configuration block diagram of the star simulator is given in this paper. Then the luminous flux calculation of LED is calculated based on the optical system. Finally the principle of PWM control of LED is illustrated. The analysis shows that the simulated precision of star magnitude can achieve ±0.1m.
A Theoretical Framework on the Resource Industry: From the Value of Resource in Economy
Authors: Zeng Meng Xia , Gao Min Xue
Published: October 2014

For researches on the relation between natural resource and economy, the concept of (natural) resource industry is a crucial element. However there is scarcely any theoretical study on the connotation and denotation of resource industry. We hold that the characteristics of resource industry stem from its attributive adjective – (natural) resource, which should be deeply analyzed in order to learn the appropriate meaning of resource industry. On this account, we focus on the theoretical framework of resource industry, by taking the concept of natural resource value as a starting point, and then presenting two definitions of resource industry to meet the different requirements of relative researches. This paper would lay the foundations for the analysis and evaluation of resource industry economy, and establish a more explicit perspective for the empirical studies of the relationship between resource and economy, such as the validation of Natural Resource Curse Hypothesis.
Comprehensive Evaluation Index on Voltage Fluctuation and Stability Considering Wind Power Generators
Authors: Li Dong Dong , Liang Zi Chao
Published: October 2014

In this paper, voltage fluctuation and stability analysis of critical buses was performed using multiple indexes to power system with wind farm connected. Considering the intermittency and randomness of wind speed, this paper constructed three voltage fluctuation indexes according to the characteristic of voltage random distribution. Bus voltage stability index was also calculated with the help of PV and QV curves in the paper. The simulation analysis performed in the DIgSILENT/PowerFactory basing on three machines nine nodes system with double-fed wind farm was carried out to reveal the impacts of wind generation uncertainty on voltage fluctuation and stability.
Adjust Energy Structure, Promoting Chinese Environmental Protection
Authors: Li Ji Gang
Published: October 2014

With the sustained and rapid development of Chinese economy, the energy issue has become a constraining "bottleneck" in economic and social development. Therefore, optimization of energy structure is an inevitable trend. In this paper, through the contrast of China and the other countries energy structure and environmental conditions, we think Chinese adjustment of energy structure is still have large space and environment protection efforts need to be strengthened. At last we puts forward some suggestions about promoting environmental protection and reducing carbon emissions.
On the Influencing Factors and the Continuous-Improving Mechanism of China’s Energy Efficiency
Authors: Jing Yong Ping , Wen Dan Dan
Published: October 2014

With the continuous development of economic globalization and the overall deepening of China's reform and opening up, energy efficiency has increasingly become a major strategic issue related to national social-economic development, energy security and environmental protection. At present, the general trend of energy efficiency in China is continuously improving, but the development among regions is seriously uneven. There is still a big difference compared with the current and the international advanced level. Therefore, establishing the policy support system and the long-term development mechanism helping to continuously improve energy efficiency will undoubtedly be a strategic topic both for present and future.
Define China's Wind Power Industry Life Cycle Based on the Compartz Curve Model
Authors: Li Han , Wu Lin
Published: October 2014

Compartz curve model is used to define China's wind power industry according to the statistics of the decade's new wind power capacity worldwide and China’ new wind power capacity. Studies shown that China’ new wind power industry is in the growth stage of the industry life cycle. With the industry's characteristics of this phase, given the policies of soft environment improvement, leading enterprises development, market mechanisms introduction, technology innovation system building,industry service system improvement and intellectual property protection system establishment to our goverment.
The Strategic Choice of Hexi New Energy Base under the Framework of the Silk Road Economic Belt: Based on the SWOT Analysis
Authors: Yan Lei
Published: October 2014

The author uses a SWOT method to analyze the advantage, weaknesses, opportunities and threats of Hexi new energy industry base.And on this basis,the author put forward a suggestion and countermeasures of new energy industry base, such as SO Strategies, ST Strategies, WO Strategies, and WT Strategies. Then,the article comes up with some suggestions to promote the development of the new energy base .
Research on the Evolution of the Complex Network Theory Based on the International Coal Trade
Authors: He Yang Yang , Wang Ling
Published: October 2014

According to the international coal trade data of the years from 1996 to 2011 published by UN COMTRADE (UNSD), it can be inferred that the data is mainly about international trade of raw coal and related coal products. By adopting the theory of complex network analysis, this paper calculates the complex network of international coal trade in the aspect of its density, node degree, centrality, point strength, clustering coefficient. Based on these properties, this paper further analyzes the evolution rule for international coal trade network of raw coal, coal briquettes and ovate coal over the last 16 years, as well as the difference between the pre-and after financial crisis.
Renewable Energy Promotion Policy for Elementary, Middle, and High Schools in Seoul
Authors: Ju Jae Won
Published: October 2014

Sunlight generation in the schoolyard and geothermal generation are typical examples. However, from someday, sunlight generation is not doing its function enough. Many schools are trying to utilize renewable energy. But, in most of the cases, unlike preliminary plans, schools are not substantially utilizing renewable energy efficiently. In order to maximize the energy efficiency of school’s renewable energy, multiple renewable energy needs to be comprehensively combined and applied. The current method of solar energy is used in the rooftops of schools. Geothermal energy is installed using the large area of the schoolyard. Acupressure energy device using piezoelectric element is installed in the school gate, the 1st floor stairway, and the school building’s main entrance. Also, in the school’s streetlamps, noiseless, small wind energy generator is installed to generate wind energy. In conclusion, efficiently applying solar energy, geothermal energy, acupressure energy, wind energy will increase the school’s renewable energy effect.
New Fuzzy Classified Model for Disaster Loss
Authors: Shao Lei , Yu Ting , Xu Qiang
Published: October 2014

The quantitative assessment and classification of the disaster loss is a complex and difficult work. It often encounters the problem that different people will arbitrarily create different membership functions for the same issue, so the results of different model can not be compared. The other problem for the current classified models of the loss of disaster is that the evaluation factors may have mutual relationships between each other, which will affect the results. In the aim of solving these problems, a new model for fuzzy classification for the loss of disaster is proposed. Firstly, the related indexes are decomposed based on orthogonalization theory in order to solve mutual relations between the factors of loss. And then, in term of fuzzy and probabilistic reasoning theory, the fuzzy membership interval function of loss of disaster is obtained through establishing optimization model. Through solving the optimization model by Genetic algorithms, the fuzzy classified model is established. Finally, the model proposed is utilized to evaluate the loss of mud-rock flow in Bijie area Guizhou province. The conclusion shows that model proposed has highly precision to evaluate the loss of disaster.
Dynamic Torsional Load Control of Double-Fed Wind Turbine Drive-Train Based on Three-Mass Shaft Model
Authors: Wang Xiao Dong , Li Huai Qing , Liu Ying Ming , Zhu Jiang Sheng , Xu Zhong Min , Ma Xiao Xu
Published: October 2014

With the rapid development of wind power technology and industry, the structural loads become a limiting factor for safe wind turbine operation and wind turbine operation life. In this paper we present a design of dynamic torsional load control and the design are based on fuzzy control. Simulations are presented to demonstrate the efficiency of our design.
Accounting “Pure” Risks in Early Stage of Investment in Construction Projects with Energy Efficient Technologies in Use
Authors: Ginzburg Alexander , Ryzhkova Anastacia
Published: October 2014

Construction projects with energy-efficient technologies in use are systems that require more detailed analysis of potential risks than it could be in the evaluation of other construction projects. For that matter it is necessary to take into account non-economic "pure" project risks that are possible in the spheres, which traditional risk management does not consider in-depth. The traditional management of such "pure" risks comes down to estimating the extent of insurance coverage and redundancy in their implementation. Creation of user-friendly program could help investors to assess pure risks quickly and qualitatively and significantly reduce their time and cost spends.
Application of IOT in Physical Teaching of Ethnic Colleges
Authors: Dang Cun Cai , Li Yue Guang
Published: October 2014

This paper firstly introduces the basic content of Internet of things and the application in all walks of life. In view of physical teaching problems in ethnic colleges, combined with the advantages of the Internet of things, taking Gansu Normal University for Nationalities as an example, its prospect is discussed. The application of The Internet of things in physical teaching of ethnic colleges, Facts prove that it is useful to improve the physical teaching effect of ethnic colleges.
Good Teaching Spirit Connotation and Countermeasure Analysis
Authors: Sun Cheng , Zhou Zi Ming , Liu Hai Yan
Published: October 2014

This article from the construction of excellent teaching style of meaning, purpose, several aspects of the connotation of good teaching style building were discussed, to find solutions to issues related to countermeasures by analyzing the content, thus providing some practical advice for building an excellent teaching style.
Effect of Large-Scale Wind Power Integration on Inter-Area Oscillation of Power System
Authors: Luo Xu Zhi , Li Hai Feng , Sun Hua Dong , Wang An Si , Chen De Zhi
Published: October 2014

With the fast development of the wind power, security constraints of power systems have become the bottleneck of the acceptable capacity for wind power. The underdamping oscillation modes of the inter-area is an important aspect of the constraints. In this paper, an equivalent model of a power system with wind plants has been established, and the impact of the integration of the large-scale wind power on the inter-area oscillation modes has been studied based on the frequency-domain and time-domain simulations. The results indicate that the damping of inter-area oscillation mode can be enhanced by the replacement of synchronous generators (SGs) with the wind generators. The enhancing degree is up to the participation value of the SGs replaced. The conclusion has been verified by the actual system example of Xinjiang-Northwest grid. It can provide a reference for system programming and operation.
Technology of Wind Power Forecasting Accuracy Assessment and Curtail Quantity Estimation with Power Capacity Limited
Authors: Cao Xiao , Peng Pei Pei , Zhou Hai , Cheng Xu
Published: October 2014

Eastern Inner Mongolia is by now one of the areas with the most rapid development of wind power in China. There exists mismatching between wind power supply ability and level of local economy. Thus, wind farms will be inevitability partly involved in peak shaving. The researches on accuracy assessment on wind power forecasting and estimation of power rationing quantity on condition of wind power curtail contribute to provide effective data evidence for scheduling and dispatching operations. In this paper, a new method for accuracy assessment on wind power forecasting and estimation of power rationing quantity through calculating theoretical power were presented first. Then, the algorithm of theoretical power calculation was presented. Case study proved the feasibility and effectiveness of the method. The conclusion indicated that the method has feasible and objective mean for accuracy assessment on wind power forecasting on condition of wind power curtail, which can provide objective and accurate theoretical and data support for dispatching and scheduling operations on condition of wind power curtail.
Three-Column Floating Wind-Current Generator and the Analysis of Performance
Authors: Ma Yong , Zhou Heng , Zhang Liang , Chen Shuo , Zhi Yu Chang
Published: October 2014

China is facing two major problems from energy shortage and environmental pollution due to the rapid development of economy. The exploitation of clean and renewable energy brings hope to China. Owning wide seas, China is rich in offshore wind energy and current tidal energy. This paper considers installing turbines on the platform of the generator of floating wind turbines, designing a floating co-generator of wind and tidal current to achieve co-generation of wind turbines and turbines. Firstly, this paper conducts a preliminary design of three-column floating wind-current generator. Then this paper uses the GeniE and HydroD modules of SESAM to model the co-generator and perform stability analysis. Finally, based on the Catenary Theory, this paper designs mooring system for the co-generator and uses AQWA to perform time-domain analysis, ensuring the steady operation of the co-generator at working seas.
Application of Improved Invariant Moments and SVM in the Recognition of Solar Cell Defects
Authors: Wang Yong Qing , Tian Dan , Song Deng Yuan , Zhang Lei
Published: October 2014

The infrared image of solar cell's electroluminescence (EL) is one of the important means of hidden defects detection. In order to improve the automatic recognition rate of defect images, this paper adopts improved invariant moments for feature extraction. The scale factor of the improved invariant moments is eliminated by transformation. Therefore they have the properties of translation, rotation and scale invariance simultaneously in discrete state. At the same time, Support Vector Machine (SVM) is used to distinguish the defect image. The system which combined invariant moments with SVM is applied to classify the debris, crack, off-grid, open weld and black pieces. The recognition rate of 5 kinds of defects has reached more than 90%.
Economic Comparison of VSC-HVDC and HVAC Systems for Connections of Offshore Wind Farms
Authors: Zhang Jian , Zheng Xin Long , Chen Guo Zhi , Zhang Zhi Gang , Xu Bei Bei
Published: October 2014

Large-scale offshore wind power has been developed in recent years, and two possibilities are considered for the transmission system between the offshore wind farms and the onshore grid: VSC-HVDC and HVAC. The paper aims to compare both systems for 300MW offshore wind farms, 25 km, 50km and 75km from the Point of Common Coupling on an economic basis using a DCF(discounted cash flow) analysis. A linear fit to the net present values has been made, obtaining the break-even distance of 47km. When the transmission distance is shorter than 47km, the HVAC system is more economic, otherwise the VSC-HVDC system is a more cost-efficient option.
Quantifying the Risk of Wind Power Forecasting Error on Power System Optimal Dispatching
Authors: Ren Hui , Fan Jia Qi , Watts David , Wei Dan
Published: October 2014

With large-scale wind power integrates into power system, the risk brought by the uncertainty of wind power output can no longer be neglected. Under this circumstance, the operation risk due to the uncertainty of wind generation and the contribution of wind power to energy conservation and emission reduction are quantified, and the corresponding quantified operational cost, environmental cost and operation risk are being integrated into the economic dispatching model to establish a multi-objective optimization dispatch model. Non-dual interior point method is used to solve the optimization problem. The method is applied to Hebei Southern power grid, simulated with actual wind power output data of one typical day. Simulation results show the rationality and effectiveness of the proposed method.
Experimental Study of the Temperature Field in Fire Caused by Sodium Leakage in Sodium-Cooled Fast Reactor Loop
Authors: Wu Hong Mei , Huo Yan , Liu Chong Lin , Zhang Zhi Gang , Zhou Rong , Wang Xin
Published: October 2014

In order to explore the characteristics of fire caused by sodium leakage in sodium-cooled fast reactor loop, an experiment on the sodium fire in form of columnar flow has been conducted. Temperature field characteristics were analyzed by measured results. Near the axis of the combustion container, the high-temperature region of the sodium fire in form of the columnar flow is located in the bottom and the temperatures are all less than 100°C at height from 0.5m to 2.0m under natural ventilation. The temperatures of the space reach the maximum values after forced ventilation and the highest temperature is up to 950°C at height 0.8m above the ground. Once the lateral distance to the sodium flow is more than 0.4m, the temperature field is affected less by the sodium fire in form of columnar flow.
Novel Trapezoidal-Loop Piezoelectric Energy Harvester
Authors: Jiang Bing , Yuan Shuai , Xu Xiao Hui , Ding Mao Sheng , Yuan Ye , Zhang Hua Qing
Published: October 2014

In recent years, piezoelectric energy harvester which can replace the traditional battery supply has become a hot topic in global research field of microelectronic devices. Characteristics of a trapezoidal-loop piezoelectric energy harvester (TLPEH) were analyzed through finite-element analysis. The output voltage density is 4.251V/cm2 when 0.1N force is applied to the free end of ten-arm energy harvester. Comparisons of the resonant frequencies and output voltages were made. The first order resonant frequency could reach 15Hz by increasing the number of arms. Meanwhile, the output voltage is improved greatly when excited at first-order resonant frequencies. The trapezoidal-loop structure of TLPEH could enhance frequency response, which means scavenging energy more efficiently in vibration environment. The TLPEH mentioned here might be useful for the future structure design of piezoelectric energy harvester with low resonance frequency.
Optimal Design of the Mooring System for a Floating Hybrid Ocean Renewable Power Generation System
Authors: Lin Mou , Ma Yong , Zhang Liang
Published: October 2014

This paper presents an optimal design model for the floating platform catenary mooring system and applies it to a floating hybrid ocean renewable power generation system. The mathematic description on the model is established based on catenary theory and static analysis method and a MATLAB toolbox is developed to get the optimized mooring system design. A numerical verification to the mooring system’s performance in AQWA is then carried out and proves the effectiveness of the presented optimization model.
Research on Geothermal Power Generation Technology and its Development Trend
Authors: Zhang Yu Peng , Wang Shu Zhong , Jing Ze Feng , Lv Ming Ming , Zhai Zhen De
Published: October 2014

More and more attention is paid to geothermal energy because of its cleanability and renewability. Geothermal power generation technology has quantities of advantages and the research is booming. There are three main types of geothermal power generation technologies namely dry stream, flashed stream and binary power generation. It is discussed that working principles, cycle efficiency, advantages and disadvantages, and application. Technology development trend is introduced. The technologies in the future are hot dry rock, magma, combined cycle and low temperature geothermal energy power generations. And they are all of great potential and application prospect.
Environmental Assessments for Wetlands and Estuaries Management near Tidal Power Plant Using of Mass Balance Simulation
Authors: Shin Bum Shick , Kim Kyu Han
Published: October 2014

The closed bay formed by a tidal power plant on the west coast of Korea has caused water quality to change due to nutrient increase and salinity alternation. The nutrients of the inner bay are often kept a balance with the aid of the outflow at the mouth of the bay. Hence it is necessary to minimize the environmental effects by forecasting the potential environmental changes caused by a tidal power construction. Seasonal observations of mass balance in the inner and outer Garolim Bay were performed. The low quality nutrients released from sediments, land and river were more dominant than the nutrients released from the outer bay in the study area. It was observed that the tidal power plant construction made water exchange ratio 57%.Various mitigation strategies such as water gates were studied so that the water exchange rate can be reduced. The change in the water exchange ratio is significantly reduced as the cross-section and the number of water gates is increased. The water exchange ratio was decreased by 8%, which increased nutrients in the inner bay. Results of numerical the nutrients decreased with the 7% increase in the inflow while the decrease in outflow discharges. However, it is considered only 0.2% increase in the entire mass balance of Garolim Bay relatively inadequate to mitigate the environmental impact.
Prospect and Suggestions on the Development of Wave Energy Resource in the South China Sea
Authors: Zheng Chong Wei , Pan Jing , Li Chong Yin
Published: October 2014

Against the background of many countries and regions in the world facing energy crisis in the modern society, the development of renewable energy is an inevitable choice. As a non-polluting, renewable, large reserve, widely distributed energy, the development and utilization of renewable wave energy will become the focus. In order to cast a brick to attract jade, this article intends to a preliminary research on the advantage of wave energy, the evaluation on wave energy resource. At last, we also assess the characteristic of wave energy resource in the South China Sea. We hope this study can provide reference for the evaluation of developing wave energy, especially the sustainable development of remote islands.
Electrical Performance Results Comparison of Photovoltaic Module between Two ISO 17025 Certified Laboratories
Authors: Liu Hai Tao , Zou Xin Jing , Zhai Yong Hui
Published: October 2014

The goal of I-V characteristic measurement of photovoltaic (PV) module is to reduce uncertainty not only for PV laboratories but also for manufacturers. This paper presents the results comparison and data analysis between two PV laboratories. Even though both laboratories have obtained the ISO 17025 certificate, the I-V results show inevitable deviation. The cause of deviation depends on photovoltaic scale traceability of laboratory, system bias, internal quality control measures and other uncertainty sources. The analysis also shows that the PV scale traceability is the most important factor to reduce result deviation among laboratories and measurement uncertainty. The various contributions to the result deviation are critically illustrated for different traceability chains. Besides, the calibration method of reference photovoltaic devices (reference cell or module), spatial uniformity of irradiance and I-V data acquisition unit should be paid more attention as well.
A Study on Supply with Consideration on Expectation Level of Energy-Saving Technology and Consumption Pattern of Consumers – Focusing on Boilers
Authors: Won An Na , Hong Won Hwa
Published: October 2014

With To obtain implications for supply of high efficiency home appliance, this study focused on boilers in the household sector to analyze efficiency grade, replacement cycle and usage condition of boilers and to examine possibility for introduction of high efficiency boiler and energy conservation.As a result, about 40% of households had grade 1 boiler, about 54% of households had grade 4 boiler, and remaining 6% had other grades. This did not differ much from the product ratio for each efficiency registered on [Efficiency Comparison], an energy efficiency management system. Increasing ratio of consumers are expected to purchase high efficiency boiler as development and supply of high efficiency products are institutionally reinforced.Also, general replacement cycle of boilers was investigated as 9 years based on living conditions, environment and marketing survey on the market. Energy conservation from sequential replacement of boilers other than grade 1 into grade 1 boilers during this life cycle of 9 years was calculated to be 6%.
Study on Door & Window Energy-Saving Technology at Hot-Summer and Cold-Winter Zone
Authors: Li Jie , Wang Fang
Published: October 2014

By combining the climate conditions of hot-summer and cold-winter zone, this paper has analyzed the characteristics for energy saving of windows and doors, and the approaches for energy-saving design are proposed in accordance with the functions of thermal insulation in summer, heat preservation in winter and lighting. Through the material of glass and window frame, it can provide reference to material selection for doors and windows, and various door & window energy-saving technologies are proposed, such as the structure and measures which can improve the thermal performance of window and the reasonable area ratio of window to wall.
Energy Performance of External versus Internal Shading Devices in Residential Buildings
Authors: Ye Yun Yang , Xu Peng , Mao Jia Chen
Published: October 2014

In the traditional concept, the performance of internal shading system is inferior compared with that of external one. In actual projects, however, external shadings are subject to severe limitations due to the damage of artistic appearance in building design, the high initial investment and the difficult maintenance in the late stage. Besides, in residential buildings the shading measures are single, mainly including external and internal shadings, and the window types are quite similar. Therefore, through theoretical calculation and experimental test in this paper, the feasibility of substituting the internal shading system with high reflectivity for the external one in residential buildings was analyzed. Such replacement can reduce the cost of shading system and maintain the artistic appearance of building facades. Thus, there are few limitations on the appearance design of a building considering the shading performance.
Energy Saving at Home
Authors: Vatin Nikolay , Gamayunova Olga
Published: October 2014

Last years much attention is paid to energy efficiency and conservation in organizations. But energy saving at industrial scale starts with heat energy saving, electricity and water in each apartment and every home. The article describes the basic rules of saving heat, electricity and water at home. Also described the means of promoting energy saving and energy efficiency among the population. Special attention is paid to the training of the population and advanced training of specialists at field of energy conservation.
Autonomous Energy Efficient Co-Generation Units
Authors: Petrichenko Mikhail , Tseytin Dmitriy , Nemova Darya , Kharkov Nikita
Published: October 2014

The technology of application of the liquefied gas for the centralized providing with energy resources of a complex of building remote from network energy resources is considered in this work, the economic-mathematical model of the first approach of the concept of the device of the settlement, allowing to determine the cost of received energy and equipment payback periods is offered.
Fe-C-N Catalysts Prepared by Magnetron Sputtering for Oxygen Reduction Reaction in a Neutral Solution
Authors: Chen Jing Yan , He Xiao Guang , Qi Hai Yan , Shi Hao Chen , Gao Feng
Published: October 2014

Non-precious metal Fe-C-N thin films were prepared by magnetron sputtering at different sputtering currents applied on a Fe target. The films were subsequently heated at 700 °C in N2atmosphere. Fe-C-N thin films were investigated as an alternative cathode catalyst for the oxygen reduction reaction (ORR) in a neutral solution. The results indicated that the catalytic activity of Fe-C-N thin films for the ORR increased with the increase of the sputtering current. When the sputtering current was 0.2 A, limiting current density was 5.50 mA cm-2and onset potential was-0.10 V vs. Ag/AgCl, which were comparable with those of commercial Pt/C catalysts. The current density of films was unchanged in 5000 seconds in the chronoamperometric experiment, indicating that the catalytic activity was very stable in a neutral solution for potential use in microbial fuel cells.
High-Pressure Design of Composite Vessel for Hydrogen Gas
Authors: Badida Miroslav , Hurajt Marián
Published: October 2014

The article deals with of a hydrogen pressure vessel suitable for very high pressure of approximately 100 MPa. One of the goals is to design a vessel from materials whose strength will meet mechanical requirements a calculated in numerical ways. Another objective is the simulation of the design the pressure vessel with regard to safety and weight requirements.
Oxygen Reduction Reaction on Pt Surface in PEM Fuel Cell Cathode Based on the First-Principles Molecular Dynamics
Authors: Song Wen Shuai , Lian Li , Wang Xun , Sun Hong
Published: October 2014

In proton exchange membrane (PEM) fuel cell cathode, oxygen reduction reaction (ORR) behavior have important effects on fuel cell performance. In this paper, the dynamic oxygen adsorption model and then the redox reaction model for hydrogen and oxygen system were established on the surface of the electricity catalyst Pt. The reaction process of hydrogen and oxygen on the surface of Pt was simulated by first-principles molecular dynamics method, and the influence of temperature on oxygen reduction reaction characteristics was analyzed. The simulation results show that the oxygen atom adsorption on the Pt (111) surface and reaction with the first hydrogen atom are the control step of the oxygen reduction reaction; and the oxygen reduction reaction accelerates with increasing temperature, but the temperature does not affect the geometric structure of the products in the oxygen reduction reaction steps. The results of the simulation agree well with our previous first-principles calclation, and this will be helpful for understanding the mechanism of oxygen reduction reaction in PEM fuel cell cathode.
Study on Synthesis of Polycarboxylate Superplasticizer at Room Temperature
Authors: Wang Gang , Liang Ling Xun
Published: October 2014

Use TPEG and AA , Through free radical polymerization in normal temperature conditions, Synthesis of the high-performance polycarboxylate superplasticizer. The results showed that, Room temperature synthesis of polycarboxylate superplasticizer with high temperature (60°C) synthesis of polycarboxylate superplasticizer have same performance. The synthesis process without heating, Production water without deionized water, To save energy, To greatly reduce the cost.