bluuebunny/crossref_metadata_2025 huggingface dataset:
Measure of the Optical Properties of Semiconductor Pb3O4 Nano-Crystalline of Using Photo-Acoustic Technology
Authors: Lie Guang Hua , Tang Zhi Lie , Lie Gan Wen , Yang Ting , Tang Xiu Wen , Shao Le Xi
Published: October 2011

The application of new single-beam normalized photo-acoustic spectroscopy in semiconductor Pb3O4 nano-crystals photo-acoustic spectroscopy was carried out. The measured spectra of semiconductor Pb3O4 nano-crystals absorption coefficient of 0.95, and then measured the semiconductor Pb3O4 nano-crystals powders band gap is 2.3 . The TEM image shows the semiconductor Pb3O4 nano-crystals are round granular structure, while the XRD spectrum indicates that the semiconductor Pb3O4 nano-crystals are tetragonal. The grain size measured to be about 30nm, and the average particle size after the reunion is 100nm. Compared with the micron crystal, the optical properties of semiconductor nano-crystals and nano-particle size are closely related. By changing the size of semiconductor nano-crystals, doped to change shape and optical, electrical properties of the goal. Because the defense and photoconductive materials with very special properties, they were widely used in many areas of modern technology, especially in delay bombings and stealth coating.
Application Life Cycle Assessment to Diammonium Phosphate Production
Authors: Manjare Sampatrao , Mohite Rajendra
Published: October 2011

Abstract Diammonium Phosphate (DAP) is an important crop nutrient for plants and its use is increasing day by day with increase in population. Life cycle assessment (LCA) is an important tool in the evaluation of the environmental performance of the product/ system throughout the life cycle. In this paper, LCA has been used to evaluate the performance of the Diammonium Phosphate (DAP) fertilizer production. The system investigated includes DAP production process. The quantification of environmental emissions, material and energy usage are quantified and environmental effects are assessed. The impact categories most affected by the DAP production, are respiratory inorganics and terrestrial acid/nitrification. Interpretations have been made and recommendations are given for operational improvements in DAP production
Progress of Closed-Cycle OTEC and Study of a New Cycle of OTEC
Authors: Liu Wei Min , Chen Feng Yun , Wang Yi Qiang , Jiang Wei Jun , Zhang Ji Guang
Published: October 2011

OTEC has the advantages of large reserves, renewable, stable and clean without pollution. However the smaller ocean temperature-difference results in the lower thermal efficiency. Based on the research of Rankine cycle, Kalina cycle, Uehara cycle, a new closed-cycle system (GuoHai cycle) has been studied, this cycle system uses ammonia-water mixtures as working medium. Indirect regenerative cycle and poor ammonia solution regenerative cycle is adopted in order to improve the thermal efficiency of the system.
Interaction of CO with CuO and CuO/graphene: Reactions Mechanism and the Formation of CO2
Authors: Li Wen Yan , Chen Qiu Luan , Qin Wu , Wang Ning , Lai Jin Lin
Published: October 2011

CuO/graphene oxygen carrier models were built to investigate the reaction stoichiometry mechanism between the fuel gas CO and oxygen carrier CuO. The results show that the energy barrier of the single metal oxide CuO oxidation CO is 127.17kJ/mol, while energy barrier is only 42.64 kJ/ mol for the CuO/graphene. From the point view of chemical reaction dynamics, the oxidation activity of CuO/graphene much higher than single-metal oxide CuO, which indicate that graphene can improve the reaction performance of oxygen carrier. And analysis results for the oxidation of fuel gas CO has an important understanding of the process of scientific significance, and will promote the fundamental understanding and applications of the oxygen carrier CuO.
Experimental Investigation of the Influence of the Gas Type on the Heat Transfer in a High-Vacuum-Multilayer-Insulation Cryogenic Tank After Sudden, Catastrophic Loss of Insulating Vacuum
Authors: Zhu Ming , Xie Gao Feng , Wang Rong Shun
Published: October 2011

One of the worst accidents that may occur in a high-vacuum-multilayer-insulation (HVMLI) cryogenic tank is a sudden, catastrophic loss of insulation vacuum (SCLIV). it is obvious that the different gas leaking into the insulation jacket have some influence on the heat transfer process. However, this problem has not been studied systematically so far. In this paper, a test rig was built up and experiments were conducted on a SCLIV cryogenic tank by using the nitrogen, helium, oxygen, carbon dioxide and air as the leaking medium, respectively. Some important phenomena and heat transfer characteristics in a vacuum-lost HVMLI cryogenic tank have been obtained. The effects of the insulation layer numbers and the type of gases on venting rate and heat flux into the cryogenic liquid have been measured, analyzed and discussed. It indicates that the heat transfer performance of the HVMLI cryogenic tank after SCLIV is strong related to the type of gases leaking into the insulation jacket.
Thermodynamic Analysis of Magnesium Produced by CaC2 under Ordinary Pressure
Authors: Xia De Hong , Ren Ling , Shu Bin
Published: October 2011

In this paper, a new process of using high grade ores, such as magnesite and water magnesium stone etc, to produce magnesium is proposed from the thermodynamic point of view. For the ores, the main component of calcined products is MgO. Considering the reaction activity, price and material stability, CaC2 is chosen as the reductant in the new process. Furthermore, the optimal reaction is determined as the reduction of MgO by CaC2 adding SiO2 based on the principle of Gibbs free energy. It is found that the initial reaction temperature is 947°C under ordinary pressure showing the reaction taking place without vacuum condition. Compared with the traditional silicothermic process, the new process is not only simple but also can achieve continuous production due to the thermal reduction under ordinary pressure, as a result that it is easy to industrial application in the present technological level and conditions.
The Relationship between the Wall Temperature and the Boiling Rate of the Biomass Boiler Economizer and Calculation Program Design
Authors: Lv Wei , Wang Xin Hai , Zhang De Li , Sun Hong Wei , Li Rui Yang
Published: October 2011

After the temperature medium voltage coal boiler changed to burn biomass, the quantity of the smoke greatly increased, the economizer heat increased and the boiling rate rose, which tends to cause the economizer’s tuber wall to overheat. In this article, the calculation formula of the economizer’s tube’s outside surface temperature and the average temperature are deduced based on the basic thermal law. Besides, by measuring the economizer’s wall temperature, the relation between the wall temperature and the boiling rate is attained and two limit boiling rate concepts which judge the safe work of the economizer are also put forward. What’s more, the window procedure which calculates the wall temperature and the limit boiling rate is also compiled. In the end, the authors summarize the rapid- increasing change rule of the wall temperature between the two limit boiling rates and hold that the biomass boiler boiling rate should be controlled below the first boiling rate.
Adsorption Equilibrium and Kinetics of Copper from Aqueous Solutions on Steel Slag
Authors: Li Jian Yun , Hua Quan Xian , Niu Jun Ling , Tang Jian Wei , Xu Ke
Published: October 2011

The adsorption of copper in aqueous solutions by steel slag was studied in batch adsorption experiments. The adsorption equilibrium data fitted best with Langmuir and Freundlich equations. The adsorption was preferential type. A comparison of the kinetics models on the apparent adsorption rate showed that the adsorption system was best described by the pseudo-second-order kinetics. The adsorption rate was controlled by both liquid film diffusion and intraparticle dispersion.
Research Based on the Mid-Point Enthalpy of Supercritical Unit Feed-Water Control Circuit
Authors: Li Xiao Ning , Zhang Lei Qiong
Published: October 2011

Introduced the supercritical unit boiler feed-water supply system of once-through boiler’s structure and characteristics, and the feed-water supply system control principle and control strategy. Analysis of the system all controlled object and based on the interaction between the mid-point in the feed-water supply system enthalpy control of the regulatory process and problems, and put forward the corresponding optimization measures, and simulation research, the simulation results show that the feed-water supply system to improve the quality of the feed-water supply system adjustment, the main adjust the parameter of good quality, safety and economy got the reliable guarantee.
The Effects of Low Flow Rate Gas Involvement on Oil-Water Flow in Horizontal Pipes
Authors: Wang Hai Qin , Zhang Lei , Wang Yong , Li De Xuan
Published: October 2011

The experiments were conducted in a horizontal multiphase flow test loop (50mm inner diameter, 40m long) to investigate the flow of oil/water and the influence of an involved gas phase with low flow rate in horizontal pipes, specifically including oil/water flow patterns, cross-section water holdup and pipe flow pressure gradient. The experimental results indicated that the involved gas with low flow rate had a considerable effect on oil/water flow characteristics, which shows the complexity of gas/oil/water three-phase flow. Thus, this effect could not be ignored in design and operation management of oil/gas gathering and transportation system.
The Design of HCNG Engine Fuel System with Making Hydrogen by Sliding Electric Arc
Authors: Xiong Shu Sheng , Yao Hong , Shi Wei , Liu Zhen Tao , Xu Jin , Xie Lian , Wu Xi Jiang , Li Wei , Ren Xiao Shuai , Lu Guang Cheng , Mei Yao Xin
Published: October 2011

This paper will put forward a device installed into the fuel system, which can use the sliding electric arc to electrolyze the natural gas to make hydrogen and then blend them in the fuel pipe for final combustion. This device can help to make a new type of HCNG engine fuel system, which electrolyses the single fuel (natural gas) partly to make appropriate-rate hydrogen for combustion. And in this paper, this new fuel system will be described in detail. The picture of sliding electric arc is shown in the end of this paper.
Modeling Spray Formed by Spring Nozzle Using Volume-of-Fluid Method
Authors: Wang Bo , Huang Yan , Yuan Yi Chao
Published: October 2011

Spring nozzles are widely used in deaerators. The spray issued from a spring nozzle was studied numerically with an adapted volume of fluid method combined with a continuous surface force model to capture the gas–liquid interface dynamics. The present analysis focuses on the formation of a water film and the generation of droplets near the spring nozzle outlet. The numerical simulation results show that the water film breaks up to droplets at the location 20~25cm from the nozzle exit vertically. The vortical structures are formed due to the interaction between the liquid film and the surrounding air, which leads to air recirculation and water film instability. When the inlet water velocity decreases from 5.33m/s to 4.1m/s, it results in a slightly reduced spray angle. But the vertical break up length is not obviously influenced. The water sheet disintegration is probably at the transition state between Rayleigh and first wind-induced breakup regimes.
Simulation of Low NOx Combustion with Heating Fuel in Diesel Engine
Authors: Wang Qian , Zhang Cheng Cheng , He Zhi Xia , Wang Jing
Published: October 2011

Based on sensitivity of fuel physicochemical property to temperature,in order to study the effects of fuel injection temperature on spray and combustion performance of diesel engine, commercial CFD software STAR-CD is used to simulate the spray and combustion processes of diesel engine with heating fuel spray. Through compared with experimental results, calculation models are proved to be validity. The effects of different fuel injection temperatures on in–cylinder air motion, temperature field and exhaust emissions are researched in the CA6DL1-30 diesel engine. The results show that there is a valid temperature range for fuel injection in diesel engine. And it’s possible to implement Low NOx Combustion with heating fuel spray.
Research on the Combustion and Emission Characteristics of Lean Burn CNG Engine
Authors: Guan Lei , Wang Tian You , Zhang Hai Yan , Zhang Zhi Jin
Published: October 2011

The study on combustion characteristics of different excess air ratios (λ) and ignition timings was conducted on a lean-burn spark-ignition CNG engine, and the corresponding emission characteristics was also analyzed. The results show that the curve of cylinder pressure moves towards TDC, and the CoVimep decreases with the advance of ignition timing. With the excess air ratio increasing, the CoVimep increases while the cylinder pressure decreases firstly, and then increases. The flame development duration increases with the ignition timing advanced, but the rapid flame duration decreases, the total combustion duration basically keep constant, and all of them increase with the increasement of excess air ratio. Best fuel economy was gotten at λ=1.2. With the excess air ratio increasing, the CO and NMHC emissions decrease, the NOx emission firstly reaches to a peak value, which is about 3000ppm at λ=1.2, and then decreases. Both of the THC and CH4 emissions have opposite trends to NOx emission. All the emissions mentioned above increases with the advance of ignition timing.
A Novel Ultrasonic Motor Using Longitudinal Vibration of Bar with Varying Section
Authors: Huang Wei Qing , Wang Yin
Published: October 2011

Ultrasonic motors adopting longitudinal vibration of bar were widely studied for their considerable thrust, high efficiency and reliability. A novel ultrasonic motor using longitudinal vibration of bar with varying section was proposed in this paper. This ultrasonic motor features with two varying section bars connected by semi-circumferential structure. Elliptical trajectories of particles are formed on top of the semi-circumferential structure outer surface where driving foot located and a mover is pushed to move when the driving foot is pressed onto it. FE model of its stator was built and results of harmonic analysis verified its principle. Testing of prototype shows that this motor was capable of a 10N load with speed 100mm/s.
Numerical Simulation on Catalytic Combustion of Hydrogen inside Micro Tube
Authors: Chen Jun Jie , Wang Qian , He Zhi Xia , Pan Jian Feng
Published: October 2011

Catalytic combustion of hydrogen/air mixture inside micro-tube was numerically investigated with detailed gas phase and surface catalytic chemical reaction mechanisms. Combustion characteristics for different reaction models, the influence of wall thermal conductivity, inlet velocity, and tube diameter on surface catalytic combustion reaction were discussed. The Computational results indicate that the surface catalytic combustion restrains the gas phase combustion. The higher wall temperature gradient for low wall thermal conductivity will promote the gas phase combustion shift upstream and will result in a higher temperature distribution. The micro-tube can be divided into two regions. The upstream region is dominated by the surface catalytic reaction and the downstream region is dominated by the gas phase combustion. With increasing inlet velocity, the region dominated by surface catalytic reactions expanded downstream and finally occupied the whole tube. The temperature of the flame core decreases with the decrease of tube diameter. Decreasing the tube diameter will enhance the surface catalytic reactions. Some theoretical evidences are provided for the application of catalytic combustion to Micro-electromechanical System (MEMS) and the extension of the combustion limits.
Liquid Film Features Analysis on Mechanical Seals with Micro-Pore Face by CFD
Authors: Zhang Wei Zheng , Yu Shu Rong , Wang Yan , Ding Xue Xing
Published: October 2011

The six kinds of different models were simulated by FLUENT software under certain circumstances. As a result, their pressure distributions and liquid film opening force with different thickness were obtained. The relationship between liquid film thickness and opening force was obtained by least square fitting. And then the relationship between stiffness and liquid film thickness was calculated and analyzed. The result shows that: seal opening force and liquid film stiffness decrease as the liquid film thickness increase, this simulation results is identical with the theoretical data. In larger film thickness range, the opening force is larger, and so was the liquid film stiffness, which provide the basis for seal optimization design and the stable operation.
Deposition Process of Droplets Impacting on a Horizontal Surface
Authors: Li Jing Yin , Han Qiang , Zhao Yan Jie , Yuan Xiao Fang
Published: October 2011

The results of the experimental investigations and numerical simulations of droplet impact on a stationary horizontal surface are presented. The impact process of a droplet with high impact energy on a horizontal surface was photographed by a high-speed CCD. In addition, two-dimensional numerical simulation of the impact process was also performed using the VOF model. Comparison between the experimental and numerical results shows that the chosen computational model is suitable to simulate such impact processes. Furthermore, the effect of the droplet impact velocity and diameter on the impact process was studied in detailed. The numerical results show that the variation in droplet impact velocity has a significant effect on the maximum spread factor and spread speed, whereas, the variation in droplet diameter considerably influences the maximum spread factor and the oscillation of the drop in the receding phase.
Analysis on Effects of the Blade Wrap Angle and Outlet Angle on the Performance of the Low-Specific Speed Centrifugal Pump
Authors: Li Wei , Shi Wei Dong , Jiang Ting , Xu Yan , Li Tong Tong
Published: October 2011

In order to research the effect of the blade wrap angle and outlet angle on the hydraulic performance of the low-specific speed sewage pump, the Reynolds time-averaged Navier-Stokes equations was discretized based on the finite volume method, and the modified k-ε turbulence model were chosen in FLUENT. Numerical simulation of the internal flow within the centrifugal pump with the specific speed of 60 at different blade wrap angle and outlet angle is carried out. The analysis of the velocity and the turbulent kinetic energy distribution in different cases, and predicts the external characteristics of the several cases based on the loss analysis method. The study results show that the efficiency of pumps increase with decreasing the outlet angle and increasing the wrapping angle at the design of sewage pumps. According to the analysis, changing the blade outlet Angle has much more influence on the performance of the pump than changing the wrap angle.
Study on the Filtering Key Technology of Acrylic Solution Based on Polyflow
Authors: Gan Xue Hui , Liu Qiang , Ma Xiao Jian , Liu Na Na , Yang Chong Chang
Published: October 2011

The paper analyzes the status of acrylic filtration and describes a new filter, named KKF18, which filter viscose fiber. According to compare the parameters of acrylic solution fiber with viscose fiber’s and simulate by Polyflow, the results show that the KKF18 can be used in acrylic solution fiber. Then the paper builds mathematical model of acrylic liquid flow in cylindrical hole and conical hole, which belongs to KKF18.Using Polyflow to simulate respectively acrylic liquid flow in those hole, the results not only verify the correctness of the mathematical model ,but also illuminate the local pressure of cylindrical hole is smaller than conical hole. So cylindrical hole is more suitable for acrylic filter.
Numerical Study on Throat Tube Inlet Function of Pulsed Liquid Jet Pump
Authors: Wang Ling Hua , Gan Chao , Ning Pan Hua
Published: October 2011

In this paper, the performance parameters of time-average basic performance equation of pulsed liquid jet pump are studied in numerical methods. The change rules and its influence on performance of throat tube inlet function are quantitatively analyzed. The conclusion is obtained that pulsed jet could mainly make fluid of throat tube outlet more fully mixed and better improve optimal working parameters of liquid jet pump. Also, change rules of throat tube inlet function show the increasing of the entrainment rate is the reason why pulsed liquid jet pump could improve performance.
Numerical Simulation and Experimental Study on Deep-Well Centrifugal Pump with Small Rear Shroud Diameter
Authors: Shi Wei Dong , Zhou Ling , Lu Wei Gang , Li Hui
Published: October 2011

Choose the appropriate rear shroud diameter of impeller could get relatively small axial force and high pump performance. In this paper, a deep-well centrifugal pump impeller with a small rear shroud was studied by simulation and test. Two stages deep well centrifugal pump was simulated by means of a commercial CFD software that solved the Navier-Stokes equations for three-dimensional steady flow. The flow field and the static pressure distribution in the impellers obtained by steady numerical simulation were analyzed. By manufacturing and testing, the test results was acquired, and then compared with the predicting data of the numerical simulation. Results show that trimming the rear shroud could reduce the axial force, but too small rear shroud diameter lead to pump performance decline.
Research on Cushion of Boom Cylinder in Hydraulic Excavator
Authors: Shen Xiao Xia , Zhou Jun , Deng Jian Xin , Tan Hong Kui
Published: October 2011

In some circumstances, huge mass, if not cushioned, may pull the piston to a halt at rod side or head side at ease with a tremendous velocity causing huge impact. As a result of this issue, the boom cylinder of hydraulic excavator provides cushioning apparatus at the rod side stroke end. This paper discusses and analyses the cushioning apparatus structure of boom cylinder, and then proposes a numerical simulation model with SimulationX. It is known to us that many dynamic parameters of boom cylinder vary as mechanical structure or motion of excavator attachment changes. Thus in order to study the relationship between kinetic parameters and cushioning capability of boom cylinder, an excavator attachment model is built next. The last part of this paper is devoted to the obtained simulation results.
A CFD Study of an up- and a down-Pumping PBT Impeller in Solid-Liquid Stirred Tank
Authors: Wang Gui Chao , Zhou Shen Jie , Yang Feng Ling , Chen Song Ying
Published: October 2011

Particles concentration distribution in a stirred tank with pitched blade turbine was investigated using computational fluid dynamics. The effect of the pumping mode on the turbulent flow and particles concentration distribution was studied. The turbulent solid-liquid flow in a stirred tank was simulated using a two-fluid model with standard k-ε turbulence model. The multiple reference frames approach was used to simulate impeller rotation. Results show that different pumping modes create different flow field which decide the characteristics of the mixing quality. A further detailed discussion about particles mixing at the bottom of the stirred tank was made. The computational model and the predicted results discussed here would be useful for understanding the solid-liquid mixing process.
Kitchen and Toilet of the Residence Exhaust Flow Field Analysis
Authors: Wang Yue Ren , Xue Cong , Zhang Jing
Published: October 2011

Adopting the k-ε standard model, the CFD simulation software to simulate the indoor kitchen and toilet different row of indoor air volume air distribution in natural ventilated circumstance, by comparison results show that different row of indoor air volume changes in the rate of secondary pollution rate, and then to provide the change rule of indoor air quality protection reference basis.
Experimental Study on Condensation of R134a inside Horizontal Inner-Micro-Fin Tubes
Authors: Chen Qi Wei , Ouyang Xin Ping
Published: October 2011

An experimental study of condensation heat transfer of R134a on horizontal inner enhanced tubes was conducted. The tested tubes were inner-micro-fin tubes, named tube A and tube B, respectively. The tested pieces were double-pipe condensers. The glycol solution flowed in the space between outer surface of the enhanced tube and inner surface of outer tube. In the experiment, condensing temperature inside the enhanced tube was 51°C, and the flow velocity of glycol solution was 3.35m/s. The inlet temperature of glycol solution changed according to mass velocity of refrigerant, to maintain certain degree of undercooling of outlet refrigerant. The research showed that the condensation heat transfer coefficient of both tubes increased with the increasing mass velocity of refrigerant. when the mass velocity of refrigerant increased from 300kg/m2s to 700kg/m2s, the condensation heat transfer coefficient in tube A was 1.87% to 6.28% higher than that of tube B. However, the flow resistance of the refrigerant in tube B was 9.56% to 11.05% higher than in tube A. The structure of tube A was superior to that of tube B.
Ground-Source Heat Pump Performance Analysis Based on Building-Integrated Renewable Energy Demonstration Projects
Authors: Yao Chun Ni , Hao Bin
Published: October 2011

Renewable energy, which is drawing more and more attentions in low global warming potential research area, has been applied in a large area of China for the past decade. In 2004, the overall application area of ground-source heat pump (GSHP) as a typical renewable energy is less than 8 million m2, while the overall application area increased dramatically to 100 million m2 till 2009. The present work did an in-depth research of coefficient of system performance (COPs) of GSHP based on the test results of around 70 building-integrated applications over 5 million m2. After comparison of different cool/heat source types and analysis of the collected existing application problems, the present paper provides some suggestions on the sustainable application of GSHP in China.
Comparing and Analyzing Influence of Basalt and Carbon Fibers on the Cement Mortar
Authors: Yang Jiu Jun , Guo Jun Hua , Zhang Lei , Guo Lei
Published: October 2011

Basalt fiber is a kind of Environment-friendly inorganic fiber material. Compared with Carbon fibers, studied the influence on cement mortar compressive, flexural, anti-shrinkage properties between different content and lengths of basalt fiber. The results showed that mechanical properties of Basalt fibers cement mortar are better than that of Carbon fibers cement mortar at a certain content, It is well for basalt fibers as reinforcement of cement based materials. Basalt fibers reduce the fluidity of mortar and have a certain enhancement to cement mortar early strength, and short fiber is more obvious than long fiber mortar. Basalt fibers cement mortar improved anti-shrinkage of cement mortar between different age, but decreased it’s 28d strength
An Online LS-SVM Prediction Model of Building Space Cooling Load
Authors: Cao Shuang Hua , Zhang Jiang Tao , Liu Fang , Li Min Si
Published: October 2011

Building space cooling load affected by lots of factors,was transient, multi-dimensional and highly interactive. A model of online least squares support vector machine (LS-SVM) was established to forecast the space cooling load of building, and correlation analysis was used to find out the main influencing factors, such as, dry-bulb temperature, solar irradiance, and so on. As an example, the hourly space cooling load of an office building in shanghai was investigated. The hourly space cooling load was firstly calculated by the simulation software of DEST, and then, an online LS-SVM model was presented to forecast the load. The simulation results showed that the online LS-SVM model was effective for space cooling load prediction.
The Performance Improvements of a Ground-Coupled Heat Pump System for both Building Heating and Cooling Modes
Authors: Qi Zi Shu , Gao Qing , Liu Yan , Yan Y.Y. , Spitler Jeffrey D.
Published: October 2011

The objective of the paper is to describe the performance of ground-coupled heat pump (GCHP) system in 20 years. A mathematical model for simulation of GCHP system is built based on long time-step Eskilson’s theory. The design methodology is based on a simulation that predicts the temperature response of the ground heat exchanger (GHE) to monthly heating and cooling loads and monthly peak heating and cooling demands over a number of years. The temperature response also has a secondary impact on the predicted energy consumption of the system, as the coefficient of performance (COP) of the heat pump varies with entering fluid temperature. This paper presents GCHP system can achieve better energy performance in building that heating and cooling loads are balanced all the year round. It is illustrated by performing a GHE for a 300 m2 building located in Changchun, China.
Study on Expander-Auxiliary Compressor Unit Used in Refrigeration System
Authors: He Tao , Wang Zhi Yuan , Xue Yu Qing
Published: October 2011

The throttling valve used in the refrigeration system always causes energy loss. In this paper, an energy recovery device in the refrigeration system which was composed of an expander-auxiliary compressor unit to replace the throttling valve was investigated. On the basis of thermodynamic analysis, two typical arrangements which the auxiliary compressor was connected to the main compressor of the refrigeration system were compared and the system performance parameters were discussed. A prototype of an expander-auxiliary unit was manufactured to observe the expander performance using R410A as refrigerant. The results showed the reliability of the unit working in the two-phase flow condition with the rotation speed up to 21020 rpm. And the maximum increases in the cooling capacity by 3.9% and COP by 3.2% could be obtained under the testing condition.
Regression Test of Stainless Steel Stamping Well-Pump Based on Numerical Simulation
Authors: Wang Chuan , Shi Wei Dong , Lu Wei Gang , Xu Yan , Zhou Ling
Published: October 2011

In order to develop stamping well pump with high efficiency, 4SP14 stainless steel stamping well pump was set as an example. Combined with the features of stamping technology, this research was taken on raising the efficiency of stamping well pump, using hydraulic design of impeller and CFD and regression test method. The experiment was designed with four factors including impeller inlet angle Δβ1, impeller outlet angle β2, and impeller outlet width b2 and inlet width of guide vane B3. 30 groups of programs were designed according to CCD central composite test method. The whole flow field of well pump at the operating point was simulated by FLUENT using the standard k-ε model, SIMPLE algorithm, first-order upwind scheme. 30 group of efficiency were obtained. Use regression equation to fit the function relationship between the efficiency value and each factor. Through the analysis of the regression equation, the optimal combination of geometric parameters can be found as inlet angle 4º, outlet angle 27.5º, outlet width 9.5mm and inlet width of guide vane 11.5mm. After manufactured and tested according to the above geometric parameters, the efficiency of the optimal model pump reaches 60.28%, which reaches the international advanced level.
Research on a Current Direct Control Method
Authors: Li Yan , Li Gang
Published: October 2011

A current direct control is proposed in the paper. The topology structure of a hybrid filtering equipment is presented. The traditional current detecting and controlling method for the structure is discussed. The relationship between the grid current and harmonic suppressing current is educed, which proves that the step of harmonic detection be left out in theory. A current direct control based on the grid current error is proposed, which is simple. It is not necessary to detect harmonic and reactive current. So influence factors on the real time and precision of the filter are reduced. The simulating model of the hybrid filtering equipment is constructed and the new current direct control is applied in the model. The simulating results show that the good performance of harmonic suppression and reactive compensation is obtained with the current direct control.
Water Source Determination of Mine Inflow Based on Non-Linear Method and Hydrochemical Characteristics
Authors: Zuo Wen Zhe , Wang Guo Hua , Li Jing , Gao Lian Feng
Published: October 2011

Nonlinear methods can be used to identify inrush water rapidly. Yet to identify the mixture water must be combined with water chemistry analysis. Take 9 levels inrush water in Tangshan Mine as an example, according to routine water test data, nonlinear methods, including gray correlation analysis, stepwise distinguishing, neural network, were used to determine water supply quickly, and the results were compared. On the basis, the indicators of piper three-line graph, SI, PCO2 determine the composition of the mixed water and supply channels. The results showed that the main recharge sources of 9th levels inrush water are alluvial and Ordovician limestone water, and infiltrating surface water. Possible ways to supply water are the tectonic fracture, gob, leakage shaft, closed adverse drilling.
The Development of Software of Self-Healing Analysis Base on the Analysis of Power Supply Path in Regional Power Network
Authors: Zhao Lin , Bao Hai , Dong Xiao Yu
Published: October 2011

At present, dispatchers analyze the power transmission from change of operation modes always by their own experiences, so currency of the result cannot be proved. Also, because these works depend on recognize of dispatcher to electrical system, objective of the result cannot be proved. For this problem, we developed this software based on the analysis of power supply path. It reveals inherent laws of power transmission in network and provides an analyzing and assisting tool for dispatchers.
Study on the Supporting System for Smart Grid Control Center
Authors: Yang Sheng Chun , Yao Jian Guo , Wang Ke , Huang Kun
Published: October 2011

The chief technical characteristics of the supporting system for smart grid control center include: wide area, panorama, distribution, integration, sensitivity, foresight and risk defense. The essential element in real-time monitor, control and early warning is to realize early warning and preventive control. The dispatch planning is to realize unified, coordinated and refined plan compilation and its close loop safety check at different levels, with multiple targets, multiple obligations, and multiple periodes. The dispatch management shall focus on enhancing flexibility, standardize business flow and integration of different levels coordination . This paper first presents the general system design, compared it with current technical support means to introduce the system framework and key features. In the end, several key technical issues are discussed and described with the application prospects.
Root-Cause Analysis Based on Time Delay Estimation for Alarm Systems in Power Grids
Authors: Zhao Yi Shu , Li Xi Nong , Li Ke Jun
Published: October 2011

This paper studies the root-cause analysis based on the time delays among various signals, for reducing nuisance alarms in modern industrial systems including power grids. Time delays are estimated via the revised nearest neighbor imputation method, and are validated via the subsequent consistency check. Numerical examples including the IEEE 5-node system as a prototype power grid are provided to demonstrate the effectiveness of the proposed time delay estimation method and the subsequent consistency check.
Research on High Order Resonance Hybrid APF
Authors: Li Gang , Fan Xiao Ping , Hu Shang
Published: October 2011

A new topology of high order resonance hybrid APF(HORHAPF) is proposed, which can be adopted in high voltage system. The corresponding electric models were constructed and controlling strategies was presented. The harmonic suppressing function was used to analyze the harmonic suppressing performance of HORHAPF with the changing parameters based on the controlling strategies in MATLAB. The reactive power compensating performance of the system was also gotten. The simulating results prove the validity of HORHAPF. The reactive power and harmonics are suppressed well.
Characterization of a Rhizobium larrymoorei FJ Exhibiting High Level Cr(VI) Reduction Potential
Authors: Zhang Jun Hui
Published: October 2011

The investigation was conducted to evaluate mechanism of Cr(VI) resistance and reduction by a bacterial strain named FJ under different conditions. This strain, identified as a member of Rhizobium larrymoorei by analysis of its 16S rRNA gene sequence was previously isolated from a paddy soil contaminated by e-waste recycling. Good Cr(VI) reduction ability catalyzed by growing cells of R. larrymoorei FJ was observed in batch cultures conducted at different initial Cr(VI) concentrations. Up to 83.23% reduction was shown in LB medium supplemented with 2.50 mM Cr(VI). Cr(VI) was transformed to some soluble form of Cr(III) due to anaerobic respiration. Biosorption was also observed in the process of bioreduction. But only loosely cell-surface binding Cr(VI) was detected in cells grown in medium supplied with different concentrations of Cr(VI). Present of yeast or citrate could enhance Cr(VI) reduction of resting cells. However, Cr(VI) reduction by resting cells was only observed at Cr(VI) concentration lower than 0.25 mM. R. larrymoorei FJ exhibited a high efficiency of Cr(VI) reduction at temperatures from 28°C to 37°C and pH values from 6.0 to 7.0.
Human Interference of the Soil Nematodes Community and Flora Influence
Authors: Tang Hai , Ji Ya Qi Du
Published: October 2011

For human interference residential areas under around the prairie soil nematodes community meadow spatial and temporal features were studied, and the results showed that soil nematodes to capture residential sample article 4658No./100 g dry soil, fence of soil nematodes in capture of article 6622/100 g dry soil ，Human interference effect of advantage of the temporal and spatial distribution of residential areas, around sample of Bursapbrelenchus umbrella slippery blade, smooth the blade of Aphelenchoides, slippery blade of Aphelenchus, spiral of Helicotylenchus for advantage of; The fence of small stem of Rhabditis, head of Cephalobus leaves, Liz axon Acrobeles, class of short body of Pratylenchoicles for advantage of nematode, the floristic analysis showed around residential food nets by certain degree disturbance, fence of interference in smaller, food nets stable mature.
Study on Operation Optimal Control of Double Impeller Underwater Aeration Machine
Authors: Li Wei Bin , Shi Wei Dong
Published: October 2011

Under water aerator is one of the most important biological wastewater treatment equipments, and it is one of the main power of the sewage treatment plant equipments as well, therefore, effects of aeration is good or bad just as oxygenation capacity is good or bad that is the main basis for the under water aerator . In this paper fuzzy control theory and frequency control principle are used to research running method of the double-impeller underwater aerator and by the demand for dissolved oxygen in water through the aerator variable frequency control, the aerator is controlled to adjust the operating speed, so that to achieve energy savings.
Removal of Pollutants from High Polychlorinated Biphenyl Level Contaminated Soil at Different Thermal Treated Time
Authors: Wu Hai Long , Lu Sheng Yong , Li Xiao Dong , Yan Jian Hua
Published: October 2011

High contaminated level of polychlorinated biphenyl (PCBs) in soil could not be easily removed by routine method. Since thermal treatment technology becomes a promising method especially for removal of volatile organic compounds, it has not yet been widespread in China for some technical and economic reasons. Experiments were conducted in a horizontal quartz tube furnace with nitrogen as the unique carrier gas, and heating temperature was set at 500oC with retention time of flue gas desorbed from soil was about 1 min. It has been found that total removal efficiency of PCBs from soil increased with the heating time was prolonged. Thermal treated time of 60 min seems suitable for the removal of PCBs, with the removal efficiency of 95.8% in solid phase. It has also been concluded that the removal mechanism of PCBs from soil endures dechlorination and destruction reactions with anticipation of catalytic metals. Normal gaseous pollutants desorbed from soil were also studied, H2O evaporation was favored with at the beginning of thermal process; after H2O evaporation, the organic matters began to decompose; when the thermal treated time was longer than 20 min, the desorption of the normal gaseous pollutants were almost finished (except for NH3).
Hypochlorous and Urea Modifications on Carbon Fiber Surface and Effects on Microorganism Immobilization
Authors: Bao Yan Ling , Dai Guang Ze , Jiang Chuan
Published: October 2011

PAN-based carbon fiber (CF) was modified by hypochlorous and urea in current treatments. The CF surface morphology and natures were characterized by specific facilities, such as scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and the degree of moisture. On the other hand, the biocompatibility nature was indicated by immobilization results of microorganisms on CF. The results show that the surface hydrophilicity and roughness of CF surface would contribute greatly to improve the immobilization ability of microorganisms on CF surface, and the produced oxygen on CF has more effect on microorganism immobilization than nitrogen.
Cadmium Stress on Wheat Morphology: Germination and Growth
Authors: Chen Zhong Shan , Zhang Hua Yong , Guo Wei , Zhang Lu Yi , Tian Yong Lan , Wei Xiao Feng
Published: October 2011

In this study, the morphological responses of wheat to Cd during the whole growth stage were investigated in pot experiment with substrates containing 0, 1, 5, 10, 50 and 100 mg Cd/kg soil. The results showed that wheat was moderately tolerant to Cd stress, and the most sensitive endpoint to Cd toxicity was tiller number. The seed germination was not effected by Cd at all concentrations. The No Observed Adverse Effect Concentration (NOAEC) was 10 mg Cd/kg, and the Low Observed Adverse Effect Concentration (LOAEC) was 50 mg Cd/kg for the wheat.
A Novel PIV Interrogation Algorithm
Authors: Xu Lian Feng , Chen Gang
Published: October 2011

Based on the thoroughly analysis of two conventional PIV algorithm, a new velocity extracting methods called Pre-estimate Searching Algorithm(PESA) is presented in this paper which combines the superiorities of the two conventional PIV algorithms. And the realization procedure of this new algorithm is provided also. Both the synthetic images and real PIV images experiments show that the new algorithm has the advantage of high accuracy and fast computing speed.
Modeling of PVA Modified Non-Woven for Submerged Membrane Bioreactor Treating Synthetic Wastewater
Authors: Zhang Chun Hua , Dong Yu Ying , Zhang Feng Jie
Published: October 2011

In this study, a mathematical model has been developed for the submerged membrane bioreactor (SMBR). Polyvinyl alcohol (PVA) Modified Non-woven model is immerged in MBR to be used for synthetic wastewater treatment. The results show that membrane fouling resistance is mostly cake resistance occurring during filtration. Based on the concept of specific fouling resistance and Darcy law that describes the relationship between flux and resistance during filtration driven by pressure, a module is established to explain the relationship between specific fouling resistance and time during filtration controlled by cake resistance in SMBR. The decline trend of flux can be predicted by the model. The model is used to predict the decline trend of flux during pharmaceutical wastewater treatment. Compared with experimental data, the relative error is less than 10% at t>b, the relative error is less than 5% at t>2b. It shows that the model can predict the decline trend of flux during stable operation of SMBR. But the relative error is bigger during unstable operation at initial stage (t<b). The model developed in this study would provide a useful tool in optimizing operation conditions as well as design parameters for a SMBR system.
Construction and Application of Suspending Combination Ecological Filter Bed
Authors: Liu Xue Mei , He Feng Biao
Published: October 2011

A new kind of suspending combination ecological filter bed was constructed, which took floating baskets as basic units and took flyash cenospheres and attapulgite clay ultra light filter material as loading material. It integrated plant absorption, filter material adsorption with biofilm colonization to purify wastewater. Experiment showed that by the use of filter bed, TP, TN and COD can be removed effectively. Three kinds of plants, including green vegetables, spinach and American-four-season-green grass were cultivated in the filter bed and grew better than those planted in soils. Germination rate and speed of growth were faster than the controlled group. The application of filter bed didn't need land occupation and civil engineering construction. Meanwhile, it can restore the polluted water, reduce the operation costs and fulfill the recycling of eutrophia water.
Deposited Sediment Dredging to Reduce Internal Pollutant Loading for a Waterfront Shallow Lake in Zhenjiang of China
Authors: Wang Hua , Pang Yong
Published: October 2011

Due to the geographical location, sediment deposition resulted in a heavy internal pollutant loading and destroied the ecological system in Neijiang, a typical waterfront shallow lake. Based on the field investigation and laboratory experiment the characteristics of deposited sediments including deposition thickness, pollutant contents and pollutant release intensity were analyzed and then the sediment dredging schemes for Neijiang were proposed. Finally the impacts of sediment dredging on internal pollutant loading were quantificationally evaluated. It was found that:(1) the deposition thickness, pollutant contents and release intensity of sediments in Neijiang were all distibuted asymmetrically; (2) sediment dredging significantly decreased the basal elevation of Neijiang and cut down the internal pollutant sources by removing the surface contaminated sediments; (3) After dredging the internal pollutant loading under different hydrological conditions in Neijiang was evidently reduced.
Kinetic Calculations for the Calcination Reaction of Limestone Modified by Alkaline Industrial Wastes
Authors: Liu Hong Tao , Han Kui Hua , Niu Sheng Li , Lu Chun Mei
Published: October 2011

The enhancement of alkaline industrial wastes on the desulfurization performance and utilization of limestone has already been found. In order to explore the reason of this phenomenon from the kinetic point of view, two typical alkaline wastes, carbide slag with a high calcium content and Bayer process red mud with more metal impurities, were adopted to research. Kinetic behavior of calcination reaction was calculated using the isoconversional method of Kissinger-Akahira-Sunose method (a differential method) and Flynn-Wall-Ozawa method (an integral method) at four different heating rates: 10, 20, 40 and 80 K•min-1. Values calculated by these two methods are very close, and the calculated result shows that calcination rate constant of modified limestone is obviously greater than that of original limestone, under the same calcination temperature, which means that alkaline wastes are advantageous to the thermal decomposition of limestone.