bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of the Solar Energy-Heated Biogas Digester
Authors: Li Jin Yang , Li Jian , Liu Qing Yu , Zheng Hao
Published: June 2014

Heating biogas digester is essential in northern China, especially during the winter. Solar energy-heated biogas digester is a facility that radiates heat by the solar thermal, which maintains the temperature of the biogas digester. The working principle behind this facility is the division of the traditional biogas digester into three parts, namely, raw material storage section, biogas slurry storage section, and anaerobic digestion section. We only heat the anaerobic digestion section to decrease the heating volume and reduce the heat dissipating surface, thereby saving energy. Solar energy is unstable, and the anaerobic digestion section needs to be maintained at its best temperature, thus, we control the raw material inlet at its optimum temperature. This biogas digester improves the anaerobic digestion condition and enhances gas production rate, which enables the efficient function of the digester during winter.
Nano-Sized LiNi0.5Mn1.5O4 Spines Prepared by a Novel Sol-Gel Method
Authors: Li Shi You , Li Ling Xia , Cui Xiao Ling , Mao Li Ping
Published: June 2014

Nano-sized LiNi0.5Mn1.5O4 spines is prepared by a sol-gel reaction at 800 °C in air. Scanning electron microscopic (SEM) image indicates that LiNi0.5Mn1.5O4 has cubic spinel structure with small and homogeneous particles (about 300 nm). Electrochemical test shows that the prepared LiNi0.5Mn1.5O4 delivers up to 125 mAh g− 1at 0.2 C, and the capacity retains 110 mAh g− 1 at 0.5 C after 50 cycles.
Experimental Investigations of Transient and Daily Thermal Performances for a Balcony-Flat-Plate Solar Water Heater
Authors: Hu Fen E , Wei Sheng Xian , Li Dong Yu
Published: June 2014

Transient and daily thermal performances of the balcony-type solar water heater with a flat-plate collector were investigated under different weather conditions in Kunming. The results showed that the solar irradiance has a few influences on the thermal performance of the solar water heater. The system thermal efficiency is 50-57% when the daily total radiation varies from 5.3 to 22.2 MJ·m-2. The initial temperature of the water in the water tank has great effects on the thermal efficiency. The daily thermal efficiency decreases by 9% when the initial temperature increases by 10°C. The percentage (Useful energy/Energy need) exceeds 60% when the daily total solar radiation is more than 11.6 MJ·m-2. When the daily total solar radiation is larger than 21 MJ·m-2, the useful energy output of the solar water heater can meet the user requirement for hot water.
Study on the Structural Properties of Polycrystalline Er2O3 Films on SI(001) Substrates by Raman Spectra
Authors: Wang Jun Chao , Zhu Yan Yan
Published: June 2014

The Raman spectra of polystalline Er2O3 films on Si (001) substrates annealed at different temperatures in O2 atmosphere were investigated. Seven Raman lines are identified in annealed Er2O3 films on Si (001) substrates. Two broad peaks larger than 600 cm-1 are detected, and their origination is discussed. Raman spectroscopy is proved to be a simple and sensitive method to characterize the structures of Er2O3 films on Si substrates.
Indirect Preparation of Titanium Dioxide Oxidation Plating Layer as Photoelectrode Used in Dye-Sensitized Solar Cells
Authors: Zhang Jun , Wu Ya Han , Xue Fang , Yuan Meng Jun , Huo Yan , Yang Cai Xia , Liu Na , Wang Xiu Fang , Guo Wei
Published: June 2014

The structural morphology, arrangement of the nanocrystalline particles, porosity factor, surface state, crystalline phase and specific area of photoelectrode film have great influence on photoelectric performance of dye sensitized solar cells (DSSCs). At present, using TiO2 as the photoelectrode in the DSSC material has achieved very good photoelectric conversion efficiency. In this paper, the plating method is adopted to directly deposited the titanium coating on the conductive glass substrate, oxidizing the surface of titanium film, so that it is generated on the surface of titanium dioxide oxidation layer. Making it as the DSSC photoelectrode, obtained relative high photoelectric conversion efficiency.
Review on Microencapsulated Phase Change Materials (MPCM) Slurries: Materials, Rheological Behavior and Applications
Authors: Zhang Pan , Qiu Zhong Zhu , He Mei
Published: June 2014

Microencapsulated phase change materials (MPCM) slurries with high heat transfer and great latent heat can serve as both the heat transfer fluids and energy storage medias. Studies showed that the effective specific heat and heat transfer rate increased by 28.1% and 23.6% respectively as using MPCM slurries. The rheological behavior of slurries do not change as adding MPCM with low concentration, can be characterized by Newtonian fluid feature with mass fraction <0.25. MPCM particles have flow drag reduction effect under turbulent situation, which was applied to building energy efficiency and refrigeration, obtained remarkable energy conservation effect.
Experimental Studies on the Thermal Performance of the Balcony-Type Flat-Plate Solar Water Heater
Authors: Wei Sheng Xian , Hu Fen E , Li Dong Yu , Li Hui
Published: June 2014

Based on the test methods for solar water heating systems, the unsteady thermal efficiency, the daily thermal efficiency and the daily water temperature rise of the balcony-type solar water heating system with a flat-plate solar collector fixed at a large tilt angle (≥60o) have been discussed by the experimental test in Kunming. The results indicate that the average daily thermal efficiencies of the solar collector installed at 60o, 70o, 80o and 90o are around 0.35, 0.39, 0.34 and 0.40. The intercept and the slope of the unsteady thermal efficiency equations are about 0.36~0.44 and 1.62~4.01W·°C-1·m-2. The average daily water temperature rise is 25.2°C, 20.1°C, 18.2°C and 17.4°C for the solar collector fixed at 60o, 70o, 80o and 90o.
Kinetics Studies on a Novel Decomposition Method of Zircon Sand
Authors: Liu Jing Chong , Song Jing , Wang Yu , Wang Qian Qian , Qi Tao , Zhang Chang Qiao , Qu Jing Kui
Published: June 2014

A novel method was proposed for preparing oxychloride octahydrate by the two – step decomposition of zircon sand concentrate in sodium hydroxide system. The effect of decomposition temperature and NaOH – to – zircon mass ratio of each stage on the decomposition of zircon sand was investigated. The macrokinetics of the two – step decomposition process was also examined. The experimental date showed that the shrinking core model with diffusion through the residual layer is most applicable for the first step decomposition process with the apparent activation energy of 42.9 kJ/mol, but the second step process was controlled by chemical reaction with the apparent activation energy of 30.1 kJ/mol.
Template-Free Synthesis of Single Crystal MoO3 Nanobelts and its Potocatalytic Properties
Authors: Li Jing , Zhen Yan Zhong , Fu Feng , Wang Dan Jun , Gao Xiao Ming , Xue Gang Lin
Published: June 2014

Uniform 1D MoO3 nanobelts were synthesized via a facile template-free hydrothermal process using (NH4)6Mo24·4H2O as raw materials. XRD, FE-SEM, HR-TEM techniques were employed to investigate the phase composition, morphology, and microstructure of as-synthesized samples. The MoO3 nanobelts have single crystalline orthorhombic phase structure, preferentially grow in [001] direction. The photocatalytic properties were evaluated by the photodegradation of Rhodamine-B under visible light irradiation. The experimental result illustrated that the compound exhibits good photocatalytic performance for degradation of RhB under visible light irradiation.
Experimental Studies on the Thermal Performance of the Wall-Type All-Glass Evacuated Tube Solar Water Heater
Authors: Wei Sheng Xian , Hu Fen E , Shi You Ming , Yan Cui Qiong
Published: June 2014

Based on the test methods for solar water heating systems, the useful energy output, water temperature rise and thermal efficiency of the wall-type all-glass evacuated tube collectors fixed at a large tilt angle (≥60o) have been conducted by the experimental test in Kunming. The results show that the average thermal efficiency varies from 35% to 50%, the useful energy output decreases from 13.1MJ to 8.8MJ and the water temperature rise decreases from 31.3 °Cto 20.9°C when the tilt angle increases from 60o to 90o. These results can provide some useful experimental data support for the application of the all-glass evacuated tube solar collector integrated into the wall of the high-rise buildings.
Investigations on the Thermal and Acid Treatment of Graphite Felt for Vanadium Redox Flow Battery Application
Authors: Cui Xu Mei , Ding Hu Biao , Chen Xiao E , Zeng Zhi Yong , Wang Jun , Huang Zai Chun
Published: June 2014

In this paper, the effects of thermal treatment and acid treatment on the performance of graphite felt for vanadium redox flow battery (VRB ) were investigated by cyclic voltammograms, polarization curves and AC impedance measurements. Both thermal treatment and acid treatment can improve the activity of graphite felt and the thermally treated graphite felt exhibited better activity and reversibility for both positive and negative electrodes of vanadium redox flow batteries. Results from polarization curves analysis showed that the polarization resistivity of thermally treated graphite felt was reduced by 45.5% compared to raw graphite felt while the polarization resistivity of graphite felt became larger after acid treatment. The results of AC impedance measurement revealed that charge transfer process were the control step of the electrode reaction and the thermally treated graphite felt had a lower reaction resistance compared to graphite felt with acid treatment.
Energy Efficiency Assessment and Exergy Analysis for Lignite Pyrolysis Process System
Authors: Wang Kai , Sun Rong Feng , Zhang Guo Peng
Published: June 2014

The exergy calculation model was established to evaluate the energy consumption and exergy assessment of a typical coal pyrolysis process system with a capacity of 1000 kg/h for raw lignite. The results indicate that although the drying unit consumes more energy, it is the pyrolysis unit that exist the maximum exergy loss because of great temperature gradient at the first reaction stage. In addition, the energy quality factor of fuel was defined to evaluate the pyrolysis yield grade. It is found the tar energy quality factor is higher than that of semi-coke and syngas. Besides, the waste steam from drying unit contains plenty of exergy, which could be used to preliminary heat raw lignite in order to reduce the energy consumption and exergy loss of drying unit.
Mathematical Analysis on a Special Adsorption Refrigeration System Suitable for Solar Energy System
Authors: Liu Yan Ling , Shi Xue Zeng , Yu Yuan
Published: June 2014

s. In this paper, a new adsorption refrigeration system is designed and calculated. In this system, there are two beds, two condensers and two evaporators. The working principle is explained and specified in this paper. And mathematical models are also set up and through calculation, the system performance is analyzed and evaluated.Theory study results demonstrate that the new system nearly has the same cooling capacity as conventional system and this kind of system can be adopted in actual use.
Fractal Characteristics of Soot Particles in Ethylene/Air inverse diffusion Flame
Authors: Lv Jian Yi , Cao Xin , Meng Cheng Long
Published: June 2014

Soot is produced in incomplete combustion of fuels, it is harmful to human health and the environment. Sampling points were set along the flame height of different air-fuel ratios in ethylene/air IDF and samples were tested by transmission electron microscopy (TEM). MATLAB software was used to process TEM images, calculated the fractal dimensions of soot samples and analyzed the fractal features. With the increasing of air-fuel ratio, the soot fractal dimension decreases, the size and the number of primary particles included in aggregates increase. With the increasing of flame height, the fractal dimension value decreases, and the size of primary particle increases, the aggregating soot particles are united loose.
Fundamental Study on Steam Gasification Reactivity of Typical Different Metamorphic Grade Coals
Authors: Tian Hui Ying , Li Yang , Zhang Ying Dou , Liu Quan Sheng , Zhi Ke Duan , He Run Xia , Zhang Xiao Rong
Published: June 2014

The steam gasification experiment of FJC lignite, BL lignite, SH bituminous and TT anthracite were carried out by using an own design WFSM-3060TL Catalyst Evaluation Unit apparatus. The infulence of coal rank on the steam gasification activity was investigated. Experiment conditions: heating rate:15°C/min (25°C-500°C), 2°C/min (500°C-850°C). The resuts show that gasification of lignite is better. With the deepening of coal rank, the steam gasifiction reactivity of coal samples decreases obviously, the higher the coal rank is, the worse the gasification reactivity is.
Low-Temperature Oxidation Gas Products and Spontaneous Combustion Tendency of Shengli Lignite
Authors: Ban Yan Peng , Li Yang , Tang Yan Hua , Wang Jie , Liu Quan Sheng , Zhi Ke Duan , Wu Ya Jie , Fan Yuan
Published: June 2014

Oxygen adsorption and CO2 produced of samples at different adsorption temperatures was investigated, Combined with thermal analysis method, the combustion properties of coal samples was determined. The results show that the oxygen adsorption capacity and CO2 produced of the samples increase and later decrease with the enhanced of pyrolysis degree. In the process of low-temperature oxidation, coal molecular side chains break, then H2O, CO, CO2 and so on are detected in turn; with the enhanced of pyrolysis degree, it reveals that combustion reaction activity decreased and spontaneous combustion tendency weakened.
Spontaneous Formation of CTAB/SLS Vesicles
Authors: Cui Lin Lin
Published: June 2014

Cetyl trimethyl ammonium bromide/sodium dodecyl sulfate (CTAB/SLS) complex formulation of scale effect on the spontaneous formation of vesicles and the influence of different factors on the stability of vesicles were discussed, structure and morphology of vesicles were observed.
Modeling of a Ten-Particle Char Cluster Interactive Combustion
Authors: Liu Xiang Jun , Fan Yu Jiao
Published: June 2014

Char-cluster interactive combustion occurs widely in practical combustors. A 3-D mathematical model for char-cluster combustion is established. The combustion and gas-solid drag properties of a ten-particle char cluster are numerically studied. Detailed results regarding velocity vector, mass component, temperature distributions around and inside the cluster are revealed. Gas-solid drag forces acted on each combusting char particle are obtained and comparatively studied.
The Investigation on Fragmentation Behavior of Lignite Coal during Fluidized Bed Pyrolysis
Authors: Li Chao , Xia Zhi Xiang , Qiao Xing Long , Li Wen Bang , Fang Meng Xiang
Published: June 2014

This paper reported the fragmentation behavior of lignite coal particles during coal pyrolysis in fluidized bed reactor at temperature of 300°C,350°C,600°C,650°C. The particles with size of 2-4mm,4-6mm and 7-10mm pyrolyzed under N2 atmosphere. The fragments were recovered by hopper, cooled to the ambient temperature and sieved in different ranks. Experimental results show that with the increasing of temperature and initial coal size due to internal overpressure induced by volatiles releasing and thermal stress caused by thermal gradient of coal intra-particles the intensity of fragmentation was enhanced monotonously, the number of fragments increased sharply and the average size of fragments declined.
A Method for Calculation the Effective Adsorption Capacity of a Long Adsorption Band-Filled Column
Authors: Liu Yan , Guo Jin Xin
Published: June 2014

Long adsorption band can result in negative effective adsorption capacity; in this paper, a calculation method for effective adsorption capacity is put forward for an adsorption band with fδ>L. A safety coefficient of adsorption capacity, g, was defined, which, it was proven, could be calculated out using the similarity law between the adsorption capacity-height distribution curve of a filler and the leakage-exhaustion curve of an adsorption column.
The Photovoltaic Efficiency of the Dye-Sensitized Solar Cells at Different Annealing Temperatures
Authors: Wang Xiu Fang , Wu Ya Han , Yang Cai Xia , Yuan Meng Jun , Huo Yan , Liu Na , Zhang Jun , Guo Wei
Published: June 2014

Upconversion NaYF4:Yb3+Er3+@TiO2 are synthesized and used to compose the photoelectrode (PE) of dye-sensitized solar cells (DSSCs). The morphology, structure, photoluminescence characterization of the NaYF4:Yb3+, Er@TiO2 and the photoelectric performance, alternating current impedance spectroscopy of DSSCs are characterized using transmission electron microscopy, CHI660C electrochemical analyzer, 720 nm long wave pass filter, the infrared laser light, upconversion spectra. Comparing the output power of the DSSC with upconversion performance at different annealing temperatures, the DSSCs under annealing temperature (330°C) show a better photovoltaic efficiency.
Effects of Static Magnetic Field on Phosphate Buffer Solution
Authors: Li Jin Yang , Wang Ai Jie , Ren Nan Qi , Zhou Sheng
Published: June 2014

Phosphate buffer solution (PBS) was exposed for different times to static magnetic field (MF) generated from six neodymium magnet (B=250mT) at flow conditions. The PBS conductivity and DO were measured as a function of time following the application of MF. It was found that the MF increases the PBS conductivity, and decreases the DO; they all have largest effect at the flow rate of 3m/s. Besides electrochemical reasons, this maybe can explains why the MFC have good performance by exposure to MF.
Methanol Electro-Oxidation Using RuRh@Pt/C
Authors: Wang Guang Ying , Fang Li , Li Fei Fei , Saipanya Surin
Published: June 2014

A core-shell structure RuRh@Pt/C nanoparticles was prepared by using a two-step reduction method under ultrasonic promotion. The catalytic performance was tested in methanol electrooxidation. X-ray diffraction (XRD), scanning electron microscope (SEM) combined with cyclic voltammetry (CV) were used to characterize the obtained catalyst. The results showed that there was no alloy formed between the core RuRh and the shell Pt. The electrocatalytic activity of RuRh@Pt/C varied with the Ru/Rh ratio in the bimetallic core, among which the catalyst with the Ru/Rh ratio 1:2 and the Pt-shell thickness of 1.5 (Ru1Rh2@Pt1.5/C) showed the highest catalytic activity for methanol. With this catalyst, the current density of the oxidation peak for methanol electro-oxidation reached 2.3 times as that of Pt1.5/C while the corresponding peak potential shifted 60 mV negatively in comparing to that of Pt1.5/C. In addition, the catalyst with the core-shell structure of RuRh@Pt/C possessed much higher CO-tolerance for methanol electro-oxidation, indicating its promising application in low temperature fuel cell.
Effect of Catalysts on Oxidation of Ruqigou Coal with NaOCl
Authors: Gong Gui Zhen , Di Bo , Hua Wei
Published: June 2014

The effect of molecular sieve, activated carbon, and nickel-based catalyst on oxidation of Ruqigou coal with NaOCl was investigated. The yields of diethyl ether-soluble fractions from reaction mixture are 67.3% for black test, 71.2% for molecular sieve, 68.6% for activated carbon and 70.3% for nickel-based catalyst, respectively. The results indicate that molecular sieve, nickel-based catalyst and activated carbon can all improve the oxidation reactivity of coal in aqueous NaOCl solution. Molecular sieve and nickel-based catalyst can convert most of the organic matters contained in coal into solvent-soluble species. The catalysis of molecular sieve is the highest, followed by nickel-based catalyst, activated carbon is relatively small.
A Novel Process Simulation Study of Coalbed Methane Enrichment by Solvent
Authors: Xuan Zi Run , Yang Zhi Yuan , Wang De Chao , Wang Si Tong , Cao Shui Jing
Published: June 2014

A type of novel solvent absorption method using propyl ether as absorbent was proposed, which the coalbed methane (CBM) was concentrated and simulated in the form of physical absorption. The reasonable process had been designed and analyzed by Aspen Plus v7.3 . Through the simulation method PSRK, effects of the number of theoretical stages and the optimal operating pressure, temperature, amount of fresh absorbent added were studied respectively. The optimal enrichment effect of CH4/N2 feed ratio was determined. Simulation results show that when the feed molar ratio of CH4/N2 is 3:7, it can improve methane concentration to 67.44% with a recovery ratio of 87.11%. When feeding methane concentration increased to more than 50%, it can be enriched to more than 80%, which is suitable for the CBM civil and industrial utilization value. The enrichment process designed can provide an idea for the enrichment of CBM.
Experimental Study on Using Solar to Improve Producing Methane in Northeast China
Authors: Li Bai , Zhou Xue Zhi , Yan Wang
Published: June 2014

It presents a new idea of producing methane with solar heating. In order to improve the temperature and promote production of methane, providing the run situation of solar digesters on every stage with the heat-transfer content and the temperature of digesters is shown in this article. It indicates that in this experimental study, according to processing and analysis the experimental data, it’s beneficial to improve the rates of biogas production, and it solve the problem of digester and safe operation in winter in the northeast of China.
Direct-Drive Permanent Magnet Synchronous Motor in the Application of New Energy Vehicles
Authors: Fei Yuan , Liu Quan
Published: June 2014

This paper introduces the new energy vehicles drive system for the future development trend, analysis and comparison in the new energy vehicles drive motor technical indicators. By Ansolf analysis software to optimize the motor rotor, to improve the air gap flux density and the electric potential sine.
Research on the Data Management of Electric Vehicle Charging Equipment Testing Platform
Authors: Yan Xiang Wu , Zhang He Chuan , Wang Li Na
Published: June 2014

Compared with common switching power supply, EV charger has more functional requirements, more severe demands on electrical performance, and wider range of output voltage and current value, what will make the test more complex. Variety of conditions will be set to test the electrical performance of the charger completely, and a large amount of test data will be generated. This article describes the data management platform of EV charging equipment test, which uses real-time database to manage the data. It also detailed introduce data collection and storage, data analysis and report generation and database design of the test platform. The test results show that this system can manage the test data safely, quickly and reliably, providing a convenient and fast way to achieve rapid automated charger test.
A Two-Step Method of Optimal Planning for Electric Vehicle Charging Stations Location
Authors: Li Zong Feng , Guo Chun Lin , Chen Jun , Tang Zhe Ci , Chen Wen , Wang Ya Ling , Li Xiang Zhen , Ou Qing Hai
Published: June 2014

As a promising transport in the future, electric vehicles plays an important role in people's lives and energy conservation. Planning of electric vehicle charging stations has a far-reaching significance for the popularity of electric vehicles. In this paper, we discuss the siting problem of electric vehicle charging station and propose a two-step method of optimization method. Firstly, we establish a charging station location model, then use Voronoi diagram to determine the preliminary zone, finally we get this problem optimally solved by immune algorithm.The example verifies feasibility of this model.
Considering the Demand Side Response of Electric Vehicle to Grid
Authors: Xu Dan , Liu Wei , Wei Tao , Zong Wei
Published: June 2014

When electric vehicles switch on power grid largely, it will impact on the operation of power system if there aren’t any management and control. This paper compared different characteristics of electric vehicles in charge and discharge from different regions. It divided the situations into three areas: residential area, commercial district, industrial zone; And established avoidable load model, transferable load model and combined load model based on different types of users. Through the analysis of the examples, verified that different load model can effect on loads from different regions, and finally concluded that, the models can play the role of “cut a peak to fill valley”. Therefore, it is very important to transfer part of the electro-demand from the peak period to low period through reasonable price guide.
Research of Time-of-Use Tariff Considering Electric Vehicles Charging Demands
Authors: Chen Wen , Guo Chun Lin , Li Zong Feng , Jia Dong Ming , Chen Jun , Li Xiang Zhen , Zhuang Guo Zhong , Liu Zhu
Published: June 2014

With the large-scale EV(electric vehicle) integrating into the power system, new challenges has been brought to the planning as well as the security of the network. There will be a great impact on the system if the system operator ignores the vast quantity of EV charging at the same. Thus, taking measures, e.g. the multiple tariff, is of vital importance to give the guidance to the EV owners to charging wisely to save the daily cost on charging, as well as reduce the gap between peak load and valley load. A model for TOU has been presented in this paper. In the model , an objective function is declared to describe the purpose of TOU, and the optimal solution is gained according to the response of EV when the price of electricity changes. Finally , a case based on the daily load curve of a certain place is calculated with the model in this paper.
Based on Adaptive Fuzzy PI DTC of Double Wheeled Electric Vehicle Drive Control
Authors: Han Ya Jun , Du De Yin , Chen Bao Fan
Published: June 2014

In order to improve the stability of an electric vehicle on different road conditions, this paper puts forward a fuzzy PI direct torque control of an adaptive, through the electronic differential control, the parameters of two high torque motor is adjusted dynamically, so as to replace the traditional mechanical differential. Analysis for system stability, the simulation results show that, with Matlab/Simulink, in a different way, this method can obtain good steady-state tracking accuracy and small dynamic error integral.
The Heating Coefficient Experimental Analysis of Solar Water-Assisted Low Temperature Air Source Heat Pump System
Authors: Wu Jin Shun , Hu Yue Bo , Hu De Zhi , Liu Hong Wei
Published: June 2014

In winter,Many families use air source heat pump because of the low evaporation temperature of the system, resulting in lower heating efficiency of system. To solve this problem, the low temperature solar assisted hot water was added to the project which is on the basis of air source heat pump, and the system has been tested. After analysis of the collection efficiency of solar collectors at low temperatures and comparative analysis of the temperature cycle, pressure, energy consumption of the low-temperature solar-assisted systems and air source heat pump system, the optimal collector temperature and law of heat pump refrigerant cycle changes of the system were obtained. Theoretically, comparative analysis of low temperature air source heat pumps and solar hot water secondary air source heat pump compression ratio and COP. It gives the key parameters affecting the compression ratio and COP, pointing out ways to improve the heat pump COP. Finally, a key measure to improve the thermal performance of the unit system is proposed, to provide a reference for future practical applications and research.
Foreword
Air source heat pump in ambient air contains rich low grade solar potential as a source of heat, it has inexhaustible characteristics [1] . The main reason for restricting the use of air source heat pump in northern area of our country is when the outdoor air temperature is low in winter, the outdoor coil frost severe heating efficiency air source heat pump is greatly reduced. Martinez suggested experimental study on the application of solar radiant floor heating systems , solar water temperature is 50-60°C, low efficiency, especially when overcast snow lower system efficiency [2] .In view of the outdoor coil frosting problem, direct expansion solar assisted heat pump water heater system using the proposed by Li Yuwu, from a certain extent alleviated the problem of heat in winter for coil winter fros, improving the heating coefficient and improved the operating characteristics of the unit. However, this system requires the direct absorption of heat in air tube, and the specific heat of air is small, difficult to heat storage, illumination by solar radiation impact, unstable system operation [3].
Based on the above issues, for the low-level office building , the new rural residential , this study presents low temperature solar auxiliary air source heat pump system , the device uses low-temperature solar hot water heat pump system as low , both full use of solar energy , but also eliminates the original system frost problems and improve the efficiency of solar collectors and heat set to improve the evaporation temperature of the evaporator , thereby increasing the compression ratio of the heat pump unit .
The Impact of Charging Plug-In Electric Vehicles on Distribution System Considering Spatial and Temporal Distribution
Authors: Wang Dong Hua , Mao Cheng Xiong , Wang Min Wei , Lu Ji Ming , Fan Hua , Wang Dan
Published: June 2014

The plug-in electric vehicles (PEVs) would exert inevitable impact on distribution system operation due to the spatial and temporal stochastic nature of the charging load. Based on the probability distributions of battery charging start time and the initial state-of-charge (SOC), the spatial and temporal charging loads of PEVs are analyzed on load nature and charging behaviors among different functional distribution areas. Taking IEEE 33-bus distribution system as an example, the Monte Carlo method is adopted to simulate charging load under different charging strategies and charging places for assess the impact on network loss and nodal voltage using standard load flow calculations. The results show that the choice of control strategies can improve the impacts of PEVs charging on distribution grid; a well-developed public charging infrastructure could reduce the stress on the residential distribution systems; optimal assignment of PEVs charging in residential area and industrial or commercial areas would provide a reference for charging infrastructure construction.
Experimental Research on Combustion Characteristics of PCCI–DI Engine Fueled with Dimethyl Ether
Authors: Li Wei , Li Yun Peng , Li Fan Bin
Published: June 2014

The use of clean alternative fuel and new combustion mode is one of the most effective methods of further reduction of NOx and smoke emissions at diesel engine. High thermal efficiency and ultra-low NOx and PM emission of engine in HCCI combustion mode can be realized at low and medium load. However, some problems such as hard control of ignition timing and narrow operating range still exist.For the sake of expanding the operating range of HCCI (Homogeneous Charge Compression Ignition) engines and explore the scientific methods to realize the ultra-low emission with DME (Dimethyl Ether) as alternative fuel. Experimental Research on the characteristics of PCCI-DI (Partial Premixed Charge Compression Ignition – Direct Injection) combustion is carried out on a single cylinder and naturally aspirated direct injection diesel engine. Results indicate that PCCI-DI DME engine has lower peak cylinder pressure and lesser rise rate of pressure. The engine also shows up an obvious two-stage heat-release characteristic. Compared with HCCI DME engine, peak value of two heat-releases reduces, the position of the first peak almost has no change and the position of the second peak shifts to the position later than TDC (Top Dead Center).
Influence of Compression Ratio, EGR Rate and Main Injection Fuel Quantity on Combustion and Emissions in a PCCI Diesel Engine
Authors: Xiao Sen Lin , Sun Wan Chen , Du Jia Kun , Li Guo Liang , Tan Man Zhi
Published: June 2014

In this study, simulation model on combustion process of a diesel engine was developed and the results were validated by experiments. Then the compression ignition was switched into PCCI (Premixed Charge Compression Ignition) in order to understand the effects of individual parameters on PCCI combustion and provide the reference for the further studies of testing and simulation. The results illustrate that the lower compression ratio extends the ignition delay and enhances fuel-air mixing and improves PCCI combustion. In addition, the oxygen concentration in cylinder is highly diluted as the EGR (Exhaust Gas Recirculation) rate increases and the NOx (Oxides of nitrogen) emissions are effectively depressed as EGR rate over 30%. Moreover, the reduction of main injection fuel quantity results in a decrease reactivity and peak heat release rate in combustion.
Active Disturbance Rejection Controller Design for Electric Vehicle Traction System
Authors: Wang Yu Min , Fan Qing
Published: June 2014

In some low velocity electric vehicle system, Brushless DC motor is used for the main traction motor. However, the low-velocity stability should be guaranteed, especially with the suddenly-changing load, the velocity response should be more quick and the overshoot should be small, all of above can make the vehicle more comfortable. The traction system is controlled by a current loop and a velocity loop, so a new method is proposed, that PI control strategy is in the current loop and the active disturbance rejection controller is in the velocity loop to restrain the bad effect results from suddenly-changing load. This active disturbance rejection controller is composed of a tracking differentiator, an extended state observer, a nonlinear state error feedback controller, and etc. The parameters of the controller are optimally designed, and the simulation results show that this control strategy can effectively restrain the suddenly-changing load and improve the vehicle’s low velocity performance.
Top-Down of Electric Vehicle Industry Development
Authors: Yang Shuang
Published: June 2014

This thesis focuses on the Top-down of electric vehicle promotion, conducted with Beijing as an example. First, Top-down of the electric vehicle development is gotten. By analyzing behaviors and roles of governments, enterprises and other social organizations in development, the thesis makes feasible recommendations respectively, then, based on which the thesis sums up the Top-down to promote the industry as a whole. Finally, the application of research findings in other cities is given. New ideas are given by the research findings to develop the industry, providing a great deal of inspiration to the development of the new and expanding green industry in China.
A Maximum Power Criterion of MPPT and its Application
Authors: Liu Shu Lin , Wu Feng Juan , Ma Yi Bo
Published: June 2014

A novel MPPT control strategy with only sampling the port voltage of the solar cell is presented in this paper. The principle of the MPPT system is analyzed and the criterion to reach the maximum power point is deduced. Based on the obtained criterion, a novel algorithm realizing MPPT is proposed. The feasibility of the proposed control strategy and the correctness of the theoretical analysis are verified by the experimental results.
The Optimal Operation Problem of Boilers
Authors: Sun Cong
Published: June 2014

Boiler optimum efficiency problem can be solved by optimum excess air coefficient model. It is the key to find the relationship between main factors and the excess air coefficient. These main factors are smoke exhaust heat losschemistry incomplete combustion heat loss and mechanical incomplete combustion heat loss.In this paper, we projected the relationship between the factors and the excess air coefficient by using the computational formulas of principles of boiler. Then we synthesized the three formulas to establish the excess air coefficient model. Finally, this paper geted the optimum excess air coefficient using extremum method.That is αp=1.152596.
Thermal Stress Analysis of Fiber Wrapped High-Pressure Hydrogen Vessel
Authors: Bie Hai Yan , Yang Meng Zhu
Published: June 2014

In order to reveal the influence of thermal on the stress distribution of fiber wrapped high-pressure hydrogen vessel, the strain and stress of the vessel in pure mechanical loads are studied firstly. Then thermal loads are taken into account, and the thermal stress distribution is given out. The results show that, the stress of the vessel liner changes little when the loads differ from pure mechanical loads to thermal mechanical coupling loads. While in the fiber-wrapped layer, stresses change significantly, and are non-monotonic. In addition, the deformation of the vessel decreases under thermal mechanical coupling loads.
Vortex Characteristics of Heliostats’ Surface Wind Pressure under Resting Condition
Authors: Wang Ying Ge
Published: June 2014

Flat rectangular heliostats’ surface wind pressure distribution under resting condition was analyzed via wind tunnel experiment results. The flow field characteristics of the mirror in parallel with the ground were combined to reveal the distribution cause of fluctuating pressure. Phenomena of columnar vortex and conical vortex formed from mirror’s flow field under wind angles 0° and 45° were aimed to explain their internal structure using theory of point vortex model. With power spectrum of peculiar points’ fluctuating wind pressure analyzed, the surface vortex characteristics were further elaborated. The above work revealed heliostats’ surface wind pressure characteristics under resting conditions, and established the theoretical basis of its design study.
Low-Yielding Wells Automatic Metering System
Authors: Li Guang Fu
Published: June 2014

When oil field entered into the high water content period, liquid production capacity of oil wells had large fluctuation and poor regularity, which leaded to the error of human reading and bottom water density in the measurement process, the difficulty of measuring oil wells is gradually increasing. Therefore, the measurement of low producing well has aroused extensive attention. How to research and establish a suitable measuring device for low producing well, improve measurement accuracy and management level of intermittent oil wells has become a serious problem in oil production. Using automatic oil measuring system can improve the accuracy of measurement, which achieved the automatic measurement for the fluid and gas production and moisture content of oil wells.
The Application of Low Voltage Dynamic Reactive Compensation Technology of Submerged Arc Furnace in Intelligent Industrial Park
Authors: Li Qiang , Song Ning Xi , Sun Qian , Liu Hao , Wang Da Peng
Published: June 2014

This paper introduces a kind of low-voltage dynamic reactive power compensation technology which is applied in intelligent industrial park. The system scheme, working principle, technical feature of the DCS-KB-2100 type low voltage power dynamic compensation device is recommended. According to the application result, the low voltage reactive power compensation technology has been greatly improved power quality, improve the power factor of the power grid. The advancement and stability of the low voltage reactive power dynamic compensation technology is verified. In the process of enterprise production, it gives full play to the role of energy saving and consumption reducing, points out the direction on the technological innovation of the industrial park electricity intellectualization, and provides a reliable technical support.
A Study on Sun Shading Reconstruction Design of Residential Buildings in Chongqing City
Authors: Jin Liu
Published: June 2014

Windows energy saving design of residential buildings has increasingly got the attention of people. Through a large number of surveys and analysis of residential buildings in Chongqing and consumers personal experience, the author finds problems and deficiency, and then proposes principles of residential buildings sun shading reconstruction in Chongqing city. Taking the high-rise residential building of one university in Chongqing as reconstruction sample, selecting a specific time period, the author recalculates sun shading coefficient with and without sun shading by using Ecotect software to do simulation analysis. Finally, the reasonable reconstruction design pattern is put forward through cases. Keywords: Buildings Sun Shading, Sun Shading Reconstruction, Energy Saving
A Finite Element Model was Established of Buried Pipeline without Frusta
Authors: Li Xiao Li , Li Ke
Published: June 2014

The finite element analysis of the underground buried pipes were done by being used ANSYS software. In order to improve or replace the traditional calculation method, basic information on buried pipeline without frusta was set up , stress and deformation were analyzed, a finite element calculation model was established.
Can Biological Fuels Replace Fossil Fuels? - A Critical Thinking
Authors: Li Lin Zi , Fu Ze Qiang
Published: June 2014

Biological fuels have triggered the heated controversy in recent years. This paper critically examined the potentials of biological fuels through the lens of Multi-Criteria Analysis (MCA) and Integrated Conservation and Development Projects (ICDP). Although MCA framework may possess the capability in making the right decision on land diversion to handle the intensifying competition for land between biofuels and food production, it is difficult to reach a balance among sufficient biofuels supply, biodiversity conservation and social equity from the perspective of ICDP. Despite biofuels could not totally displace fossil fuels in the near future, there might still be some possible policy designs that can help realizing the smooth transition to the biofuels era.
Indoor Environmental Quality (IEQ) Acceptance of Air Conditioned Buildings in Malaysia: Case Study of Universiti Tenaga Nasional
Authors: Asadi Iman , Hussein Ibrahim , Palanisamy Kumaran
Published: June 2014

Indoor environmental quality (IEQ) is an important topic which impacts on energy efficiency and also productivity of occupants. Thermal comfort, indoor air quality, visual comfort and aural comfort are four main physical parameters which are normally used to determine IEQ. In this paper, the results of field study on IEQ conducted in the offices and student study areas of 6 air conditioned buildings in Universiti Tenaga Nasional in Malaysia are presented. The study was conducted during the month of October and November 2013, collecting a full set of objective physical measurements and subjective assessments through questionnaires. The measured environmental parameters are indoor air temperature, relative humidity, air velocity, carbon dioxide concentration, sound pressure level and luminance. The subjective responses concern the judgment of the respondents about the IEQ parameters at the moment of measurements. The results obtained showed that 86% of the respondents found that the IEQ is acceptable and the environmental conditions are mainly within the limits set by the various guidelines and standards in Malaysia. The neutral IEQ values were also determined through linear regression analysis of the sensation votes.
The Urgency of Green Building’s Development from the Angle of Building Energy Consumption in China
Authors: Wu Dao Kai , Zhao Yu Hong , Ji Xu
Published: June 2014

Based on a building energy-consumption model, the building energy consumption from 2002 to 2011 in China was figured out. Analysis on building energy consumption trends showed that the building energy consumption would increase inevitably and drastically. Meanwhile, the analysis on green building presented its well energy-efficient performance. The results indicate that green building’s development is an urgent task in China.
Wall Energy-Saving Reconstruction of Existing Buildings of Tai’an City Ningyang County and Countermeasure Research
Authors: Hou Xin Ping
Published: June 2014

This paper analyzes the present situation of the existing buildings in Ningyang county of Tai'an city and researches problems faced by Ningyang in energy refurbishment for the existing buildings. it is concluded that the county wall energy saving renovation of obstacles, and then analyzes its countermeasures.
Comprehensive Method of Energy Efficiency of Residential House
Authors: Zadvinskaya Taisia Olegovna , Gorshkov Alexandr Sergeevich
Published: June 2014

The article describes a method of increasing the efficiency of heat energy. The method is based on installation of heat metering system and automatic controlled domestic heating plant in residential building. An example of comparative calculation of the heat input and estimation for heat energy in a typical residential building, according to different methods which are used for the calculation of extra charge by the energy supplier, in the presence of the heat metering system and automatic controlled domestic heating plant and without. Calculated payback period of the proposed activities.
The Approaches and Implementing Measures of Building Energy Conservation
Authors: Sun Xiao Lu , Zhang Liang , Zhang Yu Mei
Published: June 2014

Building energy consumption is huge, with the emergence of global energy crisis and environmental problems and the concept of low carbon environmental protection, in order to relieve the strained situation of world energy, energy-saving building began to get attention widely. By means of the reasonable design and material selection for architecture, energy-saving buildings reduce the operation energy consumption, through scientific methods and using environmental protection materials to raise science and technology content of construction, by internal control of building, such as temperature, lighting, noise within the range of suitable for human settlement, to provide a healthy, comfortable and ecological living space for residents.
Study on Energy Consumption Quotas Development Method of Colleges and Universities in Hubei
Authors: Xue Shi Hai , Li Yu Yun , Ma You Cai , Yu Yi
Published: June 2014

This paper analyzed characteristics of different energy consumption quotas development method focusing on building of green campus as our sustainable development demand and pointed out the development of energy consumption quotas by colleges and universities based on building area per student per stage by use of regression analysis, gaved out the corresponding ratings ,and proposed that correction coefficient should be developed based on properties, scientific research ability and scientific research funds of colleges and universities.
Study of Low Density and High Strength Slag MTC System
Authors: Ma Di Hui , Jia Wei Jiang
Published: June 2014

With the demand of improving the second interfacial bonding strength and environmental protection, MTC cementing technology has obvious technical and economic advantages. However, due to containing lots of low-density materials and slurry treating agents, which make low strength, the application of low-density slag MTC cementing slurry system is restricted in the cementing of deep wells and low-pressure leakiness formations. According to the theory of particle distribution and based on particle size analysis of floating bead, micro silicon and slag, solid-phase proportioning design of low-density (1.35~1.55 g/cm3) slag MTC was carried out in this paper. By adjusting the adding amount of micro silicon and activators, the slag MTC cementing fluid system with the 24-hour compressive strength greater than 21.6MPa which has the density range of 1.35 to 1.55g/cm3 was get. This system has small initial consistency, short thickening transition time, low water loss and good rheological property. And at last, the mechanism of improving the strength of low-density slag MTC cementing fluid system was analyzed.