bluuebunny/crossref_metadata_2025_split huggingface dataset:
The development and application of voltage summation method with voltage transformers for determining ratio errors in power frequency
Authors: Wang L R 
Published: October 2019

Abstract
The ratio error of a standard voltage transformer must be determined by metrological method. This article introduces and illustrates the principles of series-parallel summation method in 1954, and the bilateral series summation method in 1988 along with the bilateral series summation method with series type voltage transformers in 2006 and 2008. Benefited from the improvement of voltage summation circuits and facilities the errors of voltage ratios at 1000 kV/√3 and below have been derived in this way. The uncertainties of all ratios at and below 1000 kV/√3 are less than 4×10−5 (P=95%). For eliminating the errors caused by imperfect shielding and proximity effect, the theory of response superposition with a three ports network was presented and realized in 2012 on voltage summation operation. The results obtained by response superposition method were satisfactory. For instance, the uncertainty at ratio 500kV/√3 over 100V/√3 decreased from 15×10−6 to 7×10−6 (P=95%).
Design and experimental study of thermal storage PV/T/PCM solar collector
Authors: He Y T , Xiao L X , Wang F Y , Wang J Q 
Published: October 2019

Abstract
In order to improve photoelectric thermal characteristics and practicability of PV/T collectors, a thermal storage PV/T/PCM solar collector was designed. Flexible copper indium gallium diselenide (CIGS) solar cells was applied in the collector to relieve the impact of operating temperature rise of the heat absorbing plate on the conversion efficiency of the solar cells, and solid phase change material was prepared to simplify integration process of the PV/T/PCM collector. In the meantime, PV/T/PCM solar collector system prototype was designed. The experimental results showed that the temperature of the absorber plate and solar cells of PV/T/PCM system was reduced by 15°C and 20°C respectively compared with PV/T system, while thermal efficiency was increased by 21%. Meanwhile, in PV/T/PCM, the absorber plate had a lower temperature than the solar cells, which thus achieved the purpose of reducing the influence of the absorber plate on solar cells temperature. In addition, the solar cells output power of the PV/T/PCM collector system was increased by 6.7% compared to PV/T collector system.
Establishment and analysis of micro-net model considering the enhancement of photovoltaic power utilization for air-source heat pump
Authors: Tian X Q , Xu T , Wang K X , Zhu T , Wang X L 
Published: October 2019

Abstract
Since the stability of the power grid and the quality of electricity supply can be affected, the intermittent and unpredictable features make the renewable energy generation cannot be absorbed by the power grid easily and completely. “Abandoning the wind and solar power” phenomenon also becomes more serious in recent years. As an efficient thermoelectric conversion device, the heat pump system can couple thermal energy and electricity to eliminate excess electricity of the system theoretically. However, the influence of the heat pump technology on the microgrid system which needs to be analysed case by case lacks a unified evaluation method. Therefore, based on the Energy PLAN, an energy microgrid model of an ecological region in Qingdao is established to study the impact on the renewable energy integration and the enhancement of renewable energy utilization through applying the air-source heat pump system. The simulation results showed that the maximum photovoltaic penetration rate in the region is 19.23% initially. After applying the air-source heat pump, the photovoltaic capacity corresponding to the critical point of 100% renewable energy utilization is in direct proportion to the heat pump capacity. Additionally, the maximum photovoltaic penetrations can reach 25%. In this paper, we also propose relevant suggestions for the designing and building of the micro-net energy system.
Effectiveness evaluation method on construction of active distribution network based on public service value model
Authors: Zhou Y J , Fang R C , Xu J Y , Wang Y X , Lei H , He J F 
Published: October 2019

Abstract
Evaluating the construction effectiveness of active distribution network is the key point of coordinated development of distribution network. At present, effectiveness evaluation on the distribution network in domestic only focuses on output performance while leaves out of consideration of utilization efficiency of investment. Therefore, this paper presents a kind of effectiveness evaluation method for construction and updating of the active distribution network based on public service value model which could make an overall evaluation in two dimensions of output performance and cost efficiency. The evaluation results are comprehensively analyzed on the four quadrant diagram, and the evaluation conclusions and suggestions are put forward according to the quadrant of the evaluation objects. Finally, it verifies this evaluation method is scientific, reasonable and feasible in guiding construction investment of the power grid by applying the method in evaluating construction effectiveness of distribution networks in some areas of Hubei Province in China.
Analysis of a latent heat thermal energy storage unit with metal foam insert in both the HTF and PCM sides
Authors: Chen X , Xia X L , Wang F Q , Sun C , Liu R Q 
Published: October 2019

Abstract
Latent heat thermal energy storage (LHTES) systems using phase change material (PCM) have received significant research attention in numerous engineering fields. The transient heat transfer phenomenon inside a vertical LHTES unit is numerically investigated, with the paraffin as the PCM and water as the heat transfer fluid (HTF). As a performance enhancement technique, the metal foam insert is applied in both the HTF and PCM sides. The conjugate thermal model for the HTF/foam-wall-PCM/foam system is built, considering the non-equilibrium effect between the solid and fluid phases with two-temperature energy equation and the natural convection inside the PCM with Boussinesq approximation. The enthalpy-based method is employed to account for the solid-liquid phase change problem. The overall performance is compared with other three cases: no foam insert, foam insert in HTF side and foam insert in PCM side. Besides, parametric study is also conducted on the melting features, including the foam structural parameters and inlet conditions of HTF. The results show that foam insert in both sides accelerates the PCM melting effectively. The foam porosity and HTF inlet temperature play important roles in the overall heat transfer, whereas the pore density and HTF inlet velocity have limited effects on the melting rate. The findings can provide referential information for the design of a LHTES system.
Experimental study on gasification of bituminutesous coal char with CO2 catalysed by Fe (NO3)3
Authors: Suo X L , Wang D Y , Zhang G 
Published: October 2019

Abstract
Effect of transition metal Fe(come from analytically pure Fe(NO3)3·9H2O) on Jin Jie coal char isothermal gasification by carbon dioxide in the condition of normal pressure is investigated in a self-built fixed bed reactor. Experimental results show that the gasification activity of Jin Jie coal char increases with the increment of Fe, and the loading saturation level of Fe is 3%. Adding 3% Fe can reduce the gasification temperature by 90°C, and shorten the coal char gasification time by 95 minutesutes. The higher the gasification temperature, the greater the increase in gasification activity factor K and average gasification rate Rm. The parameter K and Rm reach the maximum at 3% catalyst addition at the same gasification temperature. Under a regime constant by chemical reaction, the reaction activation energy and the pre-exponential factor and reaction rate constant are calculated. The reaction rate constan of char loaded Fe increases around three times, and the activation energy constants with the raw char.
Analysis of the stage group efficiency of steam turbine based on the unified model for coal-fired power unit
Authors: Guo J L , Chang H , Zhang R C , Shi Y 
Published: October 2019

Abstract
During actual operation of the unit, the group efficiency inevitably deviates from the design value and influences the unit heat consumption rate. This paper conduct a series of turbine stage efficiency analysis of the influence of unit energy consumption based on the basic equations for economic analysis, combined with the variable condition of steam turbine model. 1000 MW unit produced by DFSTW as the research object, this paper calculates the load of several groups of different stage group efficiency, and the amount of change of the unit coal consumption. Summarizing, this paper analyses the stage group efficiency influence on the power supply coal consumption rate of the unit, and the variation of stage group efficiency influence on the unit energy consumption with the load change. The results can provide great reference for the operation optimization of thermal power unit.
Core physics calculation study of miniature lead-bismuth cooled nuclear reactor
Authors: Lao X S , Lin Y S , Dai C H , Liu C L , Lyu W J 
Published: October 2019

Abstract
Aiming at the application environment of small marine nuclear power platform, a 1MW Lead-Bismuth cooled nuclear reactor design scheme was proposed. The Monte Carlo method was used to calculate the reactor core physical parameters. 469 core fuel rods were arranged in 13 turns and 90% enriched UO2 fuel loading meet the power operation of nearly 10 years, and the core size meets the environmental requirements. The calculation results of fuel consumption show that after each loading, the reactor can run continuously for 1 year at 1 MW power. The radial density and axial flux density distribution and power distribution gradient trend of the core are reasonable, indicating that the design scheme can meet the requirements of small ships. Nuclear power platform use requirements.
The synthetic evaluation and analysis on technology of energy saving reform for existing public buildings in Shanghai Area
Authors: Qu Y , Liu Y D , Hu G X 
Published: October 2019

Abstract
Nowadays, a large proportion of old buildings in Shanghai area cannot satisfy the energy efficiency standards, thus the reform of existing buildings still plays an important role in the process of achieving energy saving target. However, the systematic study and evaluation of corresponding technology and those completed demonstration projects is lacked, which has affected the clear and reasonable understanding of government and related owners about the effectiveness of those reform projects as well as the investment payback. In view of this, a synthetic study was carried out to investigate the characteristic of energy consumption for public buildings in Shanghai firstly. Then a deep analysis was conducted on the energy-saving reform technologies involved in those projects, including usage frequency, energy-saving ratio and economic performance. The results show that the demonstration projects have good economic efficiency. The average static and dynamic payback period are 2.69 and 3.15 respectively. Among public buildings, hotel and shopping mall have a higher energy saving potential and better investment returns. Some involved technologies have good cost performance, such as LED light, pump frequency conversion, air source heat pump, glass filming and free cooling. This study could provide support for relevant owners and policy-making of governments.
Analysis on operation reliability of wind power units in China
Authors: Han Q , Liu Z L , Liu S L , Xu N 
Published: October 2019

Abstract
As an important direction of renewable energy, wind energy has developed rapidly, but there are also many problems. The reliability of wind turbines has received wide attention. This paper mainly studies and analyzes the development of wind turbines, basic structure, operation and maintenance of the unit, and then puts forward suggestions for improving the reliability of wind turbines in China.
Analysis of blockage reasons of air preheater based on big data
Authors: Gai Z J , Zhang G 
Published: October 2019

Abstract
With the rapid development of Internet and computer technology, the era of big data has arrived. With the increasingly high degree of automation in the power industry, data mining technology and cloud computing technology are continuously developing in the power industry to deal with massive operational data. Supervisory Information System (SIS) and Distributed Control System (DCS) have been widely used in power plants, which enables massive operation data of power plants to be saved. As data mining technology rises rapidly in the power industry, many scholars begin to use data mining technology to study and solve problems encountered in power plants. Air preheater is a kind of heat exchange equipment which USES the waste heat of flue gas to heat the air needed for boiler combustion. The air preheater can recover the heat of flue gas, reduce the temperature of smoke exhaust and improve the efficiency of boiler. In recent years, the phenomenon of air-preheater clogging is increasing. Based on big data theory, this paper investigated 26 thermal power generating units - a total of 52 air preheaters with a capacity of 300∼600MW, and applied the neural network Modeling method to the air preheater clogging reasons identification system. So we can find out the clogging reasons of air preheaters timely and accurately, slow down and avoid the clogging of air preheater.
Functional orientation analysis of primary frequency regulation and inertia control of DFIG
Authors: Liu H M , Yang S X , Zhu C L , Yin W Q , Hou Y H 
Published: October 2019

Abstract
With the penetration of wind power increasing continuously, the inertia and the capability of primary frequency regulation of grid are declining. To deal with this problem effectively, additional primary frequency regulation control and inertia control adopted in wind turbines are necessary. However, at present, the functional orientation of primary frequency regulation control and inertia control is still unclear. It is urgent to clarify the difference between the two kinds of control methods and to make clear the demand of power grid for them. In this paper, based on analysis of main methods of primary frequency regulation and inertia control of doubly-fed induction generators (DFIG), the functional orientation distinction between inertia support function and primary frequency regulation function is studied from perspective of control principles and control results. The different effectiveness of different control functions on the frequency regulation process in different scenarios are analyzed by simulations.
Building’s solar chimney: The performance of width and inlet to in tropical country
Authors: Abraham S B , Ming T Z 
Published: October 2019

Abstract
The main purpose of the passive solar design strategy is to maximize the potential for abundance of solar radiation to improve the heating/cooling of buildings. One of them is by utilizing the stack ventilation strategy. Solar Chimney (SC) is a technology that utilizes this effect. Further simulation of Abraham’s research on buildings with SC such as widening the chimney and the opening/closing strategy of the inlet to test the performance of the inlet. The results showed that changes in the variation in width and angle of the solar chimney effectively increased the value of indoor wind speed by 10%. Whereas through the inlet open/close strategy it can be seen which inlet has the best performance.
Photovoltaic-thermal (PVT) technology: Review and case study
Authors: Ramos C A F , Alcaso A N , Cardoso A J M 
Published: October 2019

Abstract
Nowadays, solar technology converts solar energy into electricity and heat separately. For electricity generation, the main obstacle is the fact that the photovoltaic cells produce less energy as the temperature increases. To overcome this, cooling techniques can be used to raise the efficiency of solar cells, in order to obtain greater power generation. The photovoltaic-thermal hybrid solar collector (or PVT) is an equipment that integrates a photovoltaic (PV) module, for the conversion of solar energy into electrical energy, and a module with high thermal conversion efficiency (T), which employs a thermal fluid. This optimization of solar conversion technology has the main objective of cooling the photovoltaic cells, for increased generation of electricity, while also resulting in useful thermal energy from the working fluid, therefore constituting a cogeneration equipment. The present work reviews the development and global panorama of PVT technology. Afterwards, a case study of a PVT system is presented, together with a theoretical and experimental study. A thermography analysis performed in this PVT system is also examined, which allows for a real-time study of its operating regimes in different conditions, mainly of its thermal behaviour, and for the diagnosis of hot spots that signal potential defects in the cells.
Study on environmental legal systems of different regions in China and impact on energetic cooperation
Authors: Zhang J D 
Published: October 2019

Abstract
Based on the present situation of China’s environmental law system under the rapid economic development, this paper expounds the significance of regional environmental law research. Through the comparison of regional environment and legal system between China and the United States, this paper analyzes the impact of domestic environmental legal system on energy cooperation under the background of Belt and Road Initiative.
The joint simulation of doubly-fed wind turbines
Authors: Xiao Y C , Chen W J 
Published: October 2019

Abstract
As a clean and safe renewable energy, wind power has been rapidly commercialized in recent years. In order to analyse some faults in wind turbines by software, a joint simulation model of 1.5 MW doubly-fed wind turbine is built in this paper. In the system, the 3D model of the transmission system was established by SolidWorks, which was imported into Adams to build the virtual prototype model. The other parts of the system are built by MATLAB/Simulink. Thus the advantages of Adams in mechanical multibody dynamics and MATLAB/Simulink in wind turbines control system are combined. The simulation result of the wind turbine output power under natural wind speed proves the validity of the model.
Experimental study on heat transfer resistance of condensation heat transfer in high efficiency heat transfer
Authors: Ma L X , Lu K 
Published: October 2019

Abstract
The condensation heat transfer experiment of R134a inside the horizontal enhanced tube was operated under the condensation temperatures of 35°C, 40°C and 45°C. Firstly, correlations were used to predict the heat transfer coefficient inside the tube to check the experimental data reliability. Then mass flux and condensation temperature were selected as the variables, and the total heat transfer coefficient K, the water heat transfer coefficient hw and the refrigerant heat transfer coefficient hr were seen as performance evaluation index to study the heat resistance of the enhanced tube. Experimental results show that: both the total heat transfer coefficient K and the refrigerant heat transfer coefficient hr increase with increasing mass flux, and get bigger with temperature decreasing. But the water heat transfer coefficient hw slightly decreases with mass flux increasing. And condensation temperature has a small influence on it. Analyze the thermal resistance and find that the water thermal resistance increases and the refrigerant thermal resistance decreases with mass flux increasing but the refrigerant thermal resistance is always less than the water thermal resistance. The difference between them gets bigger with the temperature decreasing.
Wind power control strategy based on high precision prediction technology
Authors: Liu Q , Zhao J , Zhang S F , Wu J , Fang JJ , Wang L H , Shao Y G 
Published: October 2019

Abstract
This paper proposes an active power control strategy for wind farms based on high-precision prediction technology. The aim of this study is to improve the absorptive capacity of large-scale wind farms, reduce network loss and promote the operation economy of wind farms. The strategy divides the active power dispatching into four layers. Based on the constraints of the safe operation of the power grid, the corresponding objective function and power allocation method for each layerare given. The result of this study shows that the strategy proposed can effectively improve the operation economy of the power grid and promote wind power consumption. Compared with the traditional control strategy, the proposed control strategy can well deal with the actual situation of large power fluctuation, and reduce the number of wind turbine start-up and shutdown.
Feasibility study of a coal-fired coupled to biomass power generation technology on a 300 MW unit boiler
Authors: Sun W , Wang Y , Liu G D , Li Y L 
Published: October 2019

Abstract
This paper describes the characteristics of a coal-fired coupled to biomass power generation technology on a 300 MW unit boiler, the characteristics of the coal-fired coupled to biomass fuel, and the problems and solutions that may occur in the process of coal-fired coupled biomass power generation, as well as the boiler technology transformation plan on the coal-fired coupled to biomass power generation. In terms of study on the characteristics of coal-burning coupled to biomass fuel, the main characteristics of the coal-burning coupled to biomass fuel, such as the combustion characteristics, the ignition characteristics, the burnout characteristics, the slagging characteristics, and the explosion characteristics of the coal-burning coupled to biomass fuel are described. The paper mainly describes the explosion prone problem of the pulverizing system, the pulverized coal hardening problem of the raw coal bunker and the boiler corrosion, and coking problem of the heating surface of the boiler. The explosion-proof transformation of the pulverizing system is described, and the technology transformation of the pulverizing system is carried out. After adopting the technical transformation scheme of sludge, the problems caused by sludge blending and burning are solved, and the power generation by sludge blending and burning is realized.
Selection of steam turbine bypass system
Authors: Sun W , Wang Y 
Published: October 2019

Abstract
This paper introduces the functions of steam turbine bypass system for the large coal-fired power units, the types of the steam turbine bypass system, the selections of the bypass system capacity and the current design situation of domestic units. About the functional design of the steam turbine bypass system, it is designed with the following functions: starting, protecting the reheater, tracking the main steam pressure, recovering working substance, quick opening when the steam turbine trips, relief valve and fast cut back etc.. About the type of bypass system, this paper introduces the application of the bypass system for large capacity units, which can be divided into four types: the high pressure one-stage large capacity bypass system, the high and low pressure two-stage series bypass system, the tertiary bypass system and the triple-purpose valve bypass system, and the advantages and disadvantages of the design for all kinds of the bypass system. In terms of the capacity selection of the bypass system capacity, the capacity of the bypass system should be selected to match the peak-regulation capacity of the unit, while taking into account the investment and maintenance costs. In view of the current design situation of domestic units, this paper expounds the design patterns and the characteristics of the bypass system of several large thermal power units.