Table of Content

05 February 2020, Volume 53 Issue 2

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Analysis on the Improvement Path of Non-fossil Energy Consumption Proportion and Terminal Electrification Rate under the New Energy Security Strategy

ZHANG Yunzhou, LU Gang, WANG Peng, WENG Yuyan, WU Shengyu, LIU Jun, ZHANG Chenglong

2020, 53(2):  1-8.  DOI: 10.11930/j.issn.1004-9649.201912106

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In order to implement the new national energy security strategy and resolve three energy issues, the first thing is to study and explore an energy revolution path that breaks the pattern of inertial development. Focusing on the goal of promoting clean and low-carbon energy development and maintaining the improvement of energy self-sufficiency in China, the energy transition path characterized by a significant increase in non-fossil energy consumption proportion and terminal electrification rate is analyzed quantitatively, the trend of key energy development indicators is given, the connotation elements of this path are emphatically interpreted, the dominant position of electric power in energy transition is revealed and suggestions on policies and key measures for high-quality power development during the "14th Five-Year Plan" period are put forward.

Research on Differentiated Price Package Based on Power Customer Evaluation

YU Xiaobao, TAN Zhongfu, QU Gaoqiang

2020, 53(2):  9-19.  DOI: 10.11930/j.issn.1004-9649.201803194

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With the advancement of the demand side reform, the electricity market is gradually expanding. While studying how to reduce the purchase cost in the wholesale market, the electricity retailers should pay attention to the research of the electricity users in the retail market. The paper built a power customer evaluation index system by introducing a weight design model of multi-objective optimization, and classified electricity users based on the assessment results, and designed a corresponding differential package. A case study shows that among the weights of various indicators, the weight of the electricity consumption in the revenue index is the highest. The electricity users are divided into three categories, and the evaluation results are matched with the users classification.

Scenario Prediction of Provincial Primary Energy Supply under Low Carbon Background: A Case Study of Zhejiang Province

WEN Fan, LIU Jun, NIU Dongxiao, SUN Ze, LIANG Yi, XIAO Yao

2020, 53(2):  20-28,163.  DOI: 10.11930/j.issn.1004-9649.201811093

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With the rapid development of China's economy, carbon emissions are increasing and environmental damage is becoming more and more serious. It is of great practical significance and practical value to study the evolution trend of regional energy supply from the perspective of low carbon development. Therefore, Zhejiang Province is used as an example to set three scenarios: routine development scenario, policy development scenario, and technology development scenario for the primary energy supply trend of coal, oil and natural gas. Based on the scenario prediction of low-carbon energy supply in Zhejiang Province by multivariate linear regression models, it can be concluded that low-carbon development will affect the structure of regional energy supply, which is conducive to the planning of primary energy supply in the region.

Risk Management for Wind Power Trading Based on Expected Utility-Entropy

ZHANG Wei, QIN Yanhui, LING Jing, CHEN Ning, DU Xizhou, SUN Yiqian, GAO Bingtuan

2020, 53(2):  29-35,82.  DOI: 10.11930/j.issn.1004-9649.201804147

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In a gradually deregulated electricity market, a power producer can minimum risk by reasonably allocating trading electricity in different markets such as the contract market and spot market. In this context, the paper addresses the electricity allocation issue of wind power producers in the power market under the premium mechanism. Considering the uncertainties of the spot electricity prices, the volatility of the wind power output and the risk preference of the wind power producers, an expected utility-entropy-based electricity allocation decision-making model is proposed, based on which, the electricity allocation of the wind power producers is calculated respectively in such three markets as annual contract market, monthly contract market and spot market. The results show that the model can not only reflect the decision-making characteristics of the wind power producers when their preference of the market risk changes, but also reduce the trading risk of wind power producers while obtaining expected return level.

The Identification and Correction Method of Grid Parameters Based on the State Estimation and Comprehensive Suspicious Index

WANG Shunjiang, SUN Qiao, HOU Yanqiu, LIN Jikeng

2020, 53(2):  36-42.  DOI: 10.11930/j.issn.1004-9649.201811132

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Errors lie in the grid parameters can reduce the reliability of advanced applications in the Energy Management System(EMS). Thus it is the basis for effective analysis and control on the grid to ensure the correctness of grid component parameters. For this purpose, this paper has proposed a parameter identification and correction scheme on the basis of Lagrangian multiplier method. Firstly, we have observed that local parameter errors can cause the Lagrangian multipliers and the measurement residuals to increase locally. And we define the suspicious measurement and parameter decision functions respectively. Furthermore, comprehensive suspicious index of each parameter is introduced based on the above two type of decision functions by which we can generate a so-called suspicious parameter set. Finally, for the suspicious parameters in the suspicious parameter set, a suspicious parameter modification scheme with varied step is proposed. The method can realize the dynamic correction of the parameter errors, and has high correction precision and no convergence problem.

Distribution of Electric Field in Three-Station Disconnecting Switch in Same Frequency and Phase AC Withstand Voltage Test of 110 kV GIS

ZHENG Yibo, XU Dangguo, QIN Yifan, MA Hao, LI Xuebao, SUN Yunsheng, NIU Zheng

2020, 53(2):  43-48.  DOI: 10.11930/j.issn.1004-9649.201812125

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The same frequency and phase AC withstand voltage test technology without GIS bus stop can enhance the power supply reliability. Therefore, it has been widely used in the GIS reconstruction and extension project in recent years. The three-phase cylindrical structure is generally adopted in 110 kV GIS devices. During the same frequency and phase test, there may be breakdown risk in the break-down or inter-phase of the three-station disconnecting switch. Hence, it is necessary to analyze the electric field distribution inside the three-station disconnecting switch. In this paper, the finite element method is used to analyze the internal electric field of three-station disconnecting switch in the 110 kV three-phase cylindrical structure during the GIS withstand voltage test. According to the voltage requirement and the corresponding boundary conditions during the actual test, the electric field distribution characteristics at different positions inside the three-station disconnecting switch are demonstrate in the simulation results. The positions with maximum values of electric field under different applying voltage modes are obtained. Furthermore, the influence of internal structure parameters of the three-station disconnecting switch on the distribution of electric field was analyzed. The presented results can provide theoretical and data support for the application of the same frequency phase withstand voltage test technology in 110 kV GIS devices.

Foreign Object Detection on Insulators Based on Improved YOLO v3

ZHANG Huankun, LI Junyi, ZHANG Bin

2020, 53(2):  49-55.  DOI: 10.11930/j.issn.1004-9649.201908009

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As an important component of transmission lines, insulator plays an essential role in the stable operation of the power grid. However, the outdoor environment in which the insulators are located can easily lead to the hanging of foreign objects. This paper proposes a novel method for foreign object detection on insulators based on the improved YOLO v3: Dense-YOLO v3. A dense network is designed to replace one of the convolutional layers of the original network in order to realize the multi-layer feature reuse and fusion of the insulator, which improves the detection accuracy. In addition, we amplify the training set to improve the training effect of the network and propose a wrong detection cost function to measure the risk of false detection. The experiment shows that the proposed algorithm has a detection precision rate reaching up to 94.54%. Meanwhile, the Dense-YOLO v3 outperforms YOLO v3 and Faster R-CNN, both in terms of detection accuracy and wrong detection cost. The result shows that the presented approach can be applied to the UAV inspection of transmission lines.

A Three-Phase Linear Power Flow Calculation Method for Distribution Networks Considering PV Nodes

LIU Kuan, WANG Chun, YIN Fagen, CHEN Yujie, WU Huicheng

2020, 53(2):  56-62.  DOI: 10.11930/j.issn.1004-9649.201808184

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In order to meet the needs of rapid analysis of distribution system, a three-phase linear power flow calculation method is proposed in this paper for distribution networks with PV nodes. According to the characteristics of the distribution networks, the nonlinear terms in the node power equation in the form of polar coordinates are linearly approximated. And a linear node power equation is obtained by using the properties of the admittance matrix to simplify the node power equation. Based on the linear node power equation, a three-phase linear power flow calculation model is established for the distribution networks considering PV nodes, which not only considers the PV nodes, but also applies to the weak-loop distribution networks, and has a strong universality. Finally, using the calculation results of Newton-Raphson method as a benchmark, a case study is made on a 33-bus distribution system, and the results show that the calculation error of the proposed method meets the requirements for rapid analysis of the distribution system. Compared with the existing linear power flow calculation method, the proposed method has higher accuracy.

The Safety Monitoring and Warning System for Live Working Based on ToF Technology

LI Wen, GU Su, WANG Zhigang, ZHOU Chenmeng, MAO Dun, ZHENG Li

2020, 53(2):  63-68.  DOI: 10.11930/j.issn.1004-9649.201808168

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Aiming at the deficiency of security monitoring and early warning means and methods for live working in China, a ToF (Time of flight)-based real-time safety monitoring and warning system is proposed for live working. The ToF camera is used for real-time 3D reconstruction of the space around working staff, and to obtain the coordinate information of topographic features surrounding the staff for further testing the distance information of staff and nearby objects, and when the distance between the staff and the charged body such as wires exceeds the set value, the alarm system will be triggered to remind the operators. The testing results show that the system can accurately monitor the distances in real time and provide reliably alarms about the dangerous situations.

Application of Auxiliary Transformer Series Compensation Technology in Voltage Compensation of Power Voltage Transformer

LI Xuan, LIU Kun, LIU Xichao, DING Jiajing, AI Bing, SHI Qiang

2020, 53(2):  69-75.  DOI: 10.11930/j.issn.1004-9649.201812034

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In view of the fact that the supply voltage of power voltage transformer varies with load, this paper introduces a method of supply voltage compensation based on series compensation technology of auxiliary transformer. Taking a single-phase power supply voltage transformer with rated primary voltage of 110 / 3 kV and rated capacity 60 kV·A as an example, this paper calculates the variation rate of power supply voltage and capacity with load capacity and power factor. According to the rate of change, an automatic compensation circuit of power supply voltage is designed based on auxiliary transformer, which can realize the compensation of power supply voltage (+4.4 V, +8.8 V, +13.2 V, +17.6 V, +22 V, +26.4 and +30.8 V). The power factor cosφ=1 and cosφ=0.89 (inductive) are used to verify the power supply voltage compensation effect under different load capacities. The experimental results show that the power supply voltage change rate of the power supply voltage transformer increases from -1.8% ~ + 11.36% to -3% ~ + 0.045% after adding the automatic series compensation circuit of the auxiliary transformer, and the requirements for the quality of single-phase 220 V power supply voltage can be satisfied. The automatic series compensation technology of auxiliary transformer can be used to compensate the supply voltage of power supply voltage transformer, which solves the problem of low power factor of rural load and low supply voltage in peak load period, and can provide a guarantee for improving the voltage quality of users.

Optimizing Method for Key Parameters of Under-frequency Load Shedding for Power System Penetrated with Hydropower

PAN Xiaojie, FAN Maosen, ZHANG Wenchao, LI Pengwang, ZHANG Liwei

2020, 53(2):  76-82.  DOI: 10.11930/j.issn.1004-9649.201906007

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Under-frequency load shedding is an important part of the last defense line for power grid. However, the under-frequency load shedding device is prone to overcutting when large power shortage disturbance occurs in the grid system with high penetration of hydropower. Based on an analysis of the frequency variation characteristics following power shortage fault of power system penetrated with hydropower, an optimization method is proposed with appropriate step size for the key parameters of under-frequency load shedding, according to the water hammer effect principle and with consideration of the frequency characteristics of the power grid after disturbance and the water hammer effect. The simulation test has proved that the method can be effectively applied to the power grid with high penetration of hydropower to reduce the overcutting problem following the extreme power shortage disturbance.

Research on Temperature Control of Trough Solar Collector

XU Hui, LI Xin, XU Ershu

2020, 53(2):  83-91.  DOI: 10.11930/j.issn.1004-9649.201808155

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In order to control the outlet temperature of the heat transfer fluid within reasonable range, it is necessary to develop a fast-response and effective control system for the outlet temperature in the parabolic trough solar plants. In this paper, a dynamic mathematical model of parabolic trough collector loop was established first, which took the solar field of a 1 MW solar parabolic trough power plant as the research object. And then an internal model controller (IMC) for the outlet temperature of the heat transfer fluid was proposed based on the developed mathematical model. Afterwards the IMC control system and PID control system were built respectively on the Simulink platform such that. the control effects under multiple disturbances were compared and analyzed accordingly. The results show that: under the disturbances of solar radiation, inlet temperature and ambient temperature, the IMC controller demonstrates better control effect with less time duration for control setting and less overshoot in contrast with the PID controller.

Effectiveness Analysis of Three-dimensional Effect Correction Formulas Based on the CFD and Wind Tunnel Experiment of the Scaled Wind Turbines

XU Xiaoming, YUAN Zhiqiang, LI Qingyu, YAN Shunlin, HUANG Chenwu, YANG Ke

2020, 53(2):  92-98.  DOI: 10.11930/j.issn.1004-9649.201812136

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Based on the NREL Phase VI and its scaled wind turbines, and combined with 3D CFD numerical simulations and 2D airfoil wind tunnel experiments, the correction effects of four three-dimensional effect correction formulas including Snel, Lindenburg, Du & Selig, Chaviaropoulos & Hansen in low Reynolds number are compared and analyzed. The results show that their effectiveness differs from each other while the correction value is generally larger than the real value. Specifically from the comprehensive comparison, Du & Selig formula demonstrates the best effect, and the performance can be ranked in descending order as Lindenburg, Snel and Chaviaropoulos & Hansen. Regarding the correlation between the correction effect and the blade scale from small to large when λ=5.39 in the whole blade area, it can be ordered as Snel, Chaviaropoulos & Hansen, Lindenburg, Du & Selig; when λ=8.00 in the whole blade area and λ=10.00 in the middle or outboard blade area, the order is Du & Selig, Lindenburg, Snel, Chaviaropoulos & Hansen; while when λ=10.00 in the root blade area, it goes like Lindenburg, Snel, Chaviaropoulos & Hansen, Du & Selig.

Discussion of Distributed Energy Resources Utility Mode and Its Application in China

HONG Bowen, FENG Kaihui, MU Yunfei, DONG Xiaohong, LIANG Yi, YAN Hu, HE Yongsheng

2020, 53(2):  99-104.  DOI: 10.11930/j.issn.1004-9649.201903096

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Based on a systematic review of the definition and characteristics of distributed energy resources(DER) at home and abroad, several typical utility modes of distributed energy resources are summarized for rural areas with consideration of the main problems existing in the development of distributed energy resources in China. Based on the features of resources and demand in different applications scenarios, an in-depth analysis is made of the basic characteristics, applicable scope as well as application conditions of the different utility modes. Finally, typical case studies are carried out focusing on distributed energy resources utility modes in the three application scenarios, and suggestions are given on the promotion of distributed energy resources utility modes suitable for the rural areas in China.

Coordinative Dispatch and Development of Renewable Energy and Nuclear Power Generation

BAI Qingfeng

2020, 53(2):  105-111.  DOI: 10.11930/j.issn.1004-9649.201812114

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For the period from 2016 to 2017, substantial abandonment of wind and light took place in China. The average utilization hours of nuclear power declined significantly with serious curtailment of nuclear power generation. For those regions with limited clean energy consumption capacity, it is becoming increasingly urgent to optimize the dispatch and coordinate the development of renewable energy power generation and nuclear power. According to China's current energy-saving power generation dispatching guidelines, wind power and photovoltaic power generation are given higher priorities than nuclear power. In this paper, in consideration of the maximization of the overall society benefit as the starting point,, the author conducted the analysis and comparison of the dispatching sequence of wind power, photovoltaic power and nuclear power from the point of view of economy, environmental protection, grid friendliness, security as well as the past experience from different countries. It is advised that the relevant departments should optimize the existing dispatching priorities appropriately and privilege nuclear power units over wind power units. Also it is suggested that for those nuclear power provinces the wind power development should be managed reasonably when formulating the clean energy plan in order to solve the dilemma of clean energy absorption.

Configuration and Operation Optimization of Circulating Water Pumps for 660 MW Ultra-supercritical Unit

WANG Du, LIU Yuxian, WAN Mingyuan, ZHAO Siwei, JIANG Jianming

2020, 53(2):  112-119.  DOI: 10.11930/j.issn.1004-9649.201905133

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The configuration schemes and operation modes of the circulating water pump of the thermal power unit have significant impacts on the efficiency of the unit. In this paper, the simulation model of the 2×660 MW ultra supercritical unit with the four circulating water pumps are constructed by using the EBSILON platform. Then regarding three different circulating water pump configuration schemes, a variety of operation modes were established accordingly under different loads and circulating water temperatures. Considering the operation cost of the unit and the payback period of investment, different circulating water pump configuration schemes of the unit have been analyzed and compared both technically and economically. The simulation results show that the scheme configured with variable frequency speed control in two circulating water pumps is the optimal solution such that the annual operation income will increase by 5.377 million yuan and the investment payback period is expected to be about 1.741 years.

Effect of Heat Storage Device on Primary Frequency Regulation Capacity of Thermal Power Unit

SONG Chongming, TIAN Xueqin, XU Tong, WANG Xinlei

2020, 53(2):  120-128.  DOI: 10.11930/j.issn.1004-9649.201809044

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High penetration of renewable energy has brought great challenges to the stability of power systems. Meanwhile, in the era of knowledge economy, higher requirements are put forward for power supply quality such that the issues of power system frequency regulation will gradually become prominent. Since the thermal power unit is the main power source for the peak-load regulation of power system, the thermal storage device equipped with the unit has been studied both theoretically and practically regarding its influence on the peak-load regulation capability of power system. This paper takes a 300 MW unit as the example to analyze the effect of different thermal storage device configurations on the unit's primary frequency regulation capacity. The results show that different configurations have different effects on the primary frequency regulation capacity of thermal power units at different time intervals. This study has positive reference significance for the analysis of the influence of thermal power flexibility transformation and the assessment of generation deficit of primary frequency regulation of power system.

Feasibility Study on the Preparation of Contact Materials of High-Voltage Disconnector by Powder Metallurgy

ZHANG Xiuli, YANG Zhiyuan, PENG Bo, WANG Yinggao, CHEN Cunguang, MA Guang, CHEN Yunxiang

2020, 53(2):  129-136.  DOI: 10.11930/j.issn.1004-9649.201907019

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In this paper, the contact materials with copper substrate covered by silver coating is fabricated for high-voltage disconnector by adopting powder metallurgy (PM) techniques. Through comparative tests on the performance of electroplated silver coating and the PM silver-coated layer in terms of corrosion and sulfur resistance, adhesion strength and micro-Vickers hardness, the feasibilities of using PM techniques to produce contact materials are studied. The test results indicate that the interface between the silver-coated layer and the copper matrix is tightly coupled without any noticeable defects and the adhesion strength meets the requirements of GB/T 5270—2005. The corrosion resistance of the PM silver-coated layer is close to that of the electroplated silver layer while the sulfur tolerance of the PM silver-coated layer is basically identical to the electroplated silver coating, but the surface hardness of the PM silver-coated layer is significantly higher than that of the electroplated silver layer, which is helpful to improve the wear resistance to some extent. The research in this paper shows that the method of powder metallurgy technology to produce high-voltage switch contacts is feasible theoretically, but to further promote practical applications, more research on engineering applications should be carried out.

Optimization on the Control Mode of Thermal Power Unit to Suppress Low Frequency Oscillation of Power System

ZHANG Bao, DING Yangjun, GU Zhenghao, YING Guangyao, FAN Yinlong

2020, 53(2):  137-141,149.  DOI: 10.11930/j.issn.1004-9649.201910033

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Due to the randomness of its occurrence in power system, currently there is no effective way to suppress the low frequency oscillations through the existing thermal control modes of generation units. Based on the two specific study cases, this paper analyzes the process of thermal power units participating in low-frequency oscillation and then summarizes them in common. Arising from the observation of significant discrepancies between the turbine speed signal and the power grid frequency signal during the oscillation, an optimization method is proposed to suppress the forced oscillation by virtue of the control mode of thermal power unit. Additionally, it is suggested to replace the speed signal with the power grid frequency signal for the primary frequency modulation.

PSO-SVM-Based Rolling Forecast of Coal Consumption Reference Value for the Power Plants Dispatched by Power Grid

LI Yikun, CHE Quan, ZHAO Huirong, PENG Daogang

2020, 53(2):  142-149.  DOI: 10.11930/j.issn.1004-9649.201909080

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The power grid dispatcher often uses the coal consumption reference value when making the research plan of the graded early warning system for coal-fired supply or the economic load distribution schedule for each power plant. It plays an important role in both monitoring the coal stockpiles in terms of days of burn in the power plant and formulating a reasonable power generation dispatch schedule. However, there are only few methods applicable so far, most of which simply process the historical data into the mathematical calculation as the forecast value for future coal consumption benchmark and hence may introduce considerable computation errors. By taking account of the actual demand, a method using the rolling calculation of unit coal consumption benchmark value is proposed on the basis of particle swarm optimization support vector machine for power grid scheduling.Three typical power plants in the power grid are selected in the case studies. Through detailed data analysis and comparison testing, from the results the support vector machine model based on particle swarm optimization has demonstrated satisfactory performance in rolling test and forecast update on coal consumption reference value, which means it can even provide further data support for the grid dispatch department to estimate the number of days of coal storage available, establish a coal storage early warning mechanism and formulate a power generation dispatch plan.

Coupling Design of Tower Concentrated Solar Power System and Coal-Fired Power Generation

ZHANG Jinsheng

2020, 53(2):  150-155.  DOI: 10.11930/j.issn.1004-9649.201902198

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A solar-coal collaborative complementary generation system is constructed by selecting the tower concentrated solar power system using water as working fluid, coupled with the water feeding and condensation system of conventional thermal power plant boiler to replace part of the function of high and low pressure heat exchangers. Based on the requirement of efficiency improvement without increasing the capacity, the system design and economic analysis are conducted. The new scheme can reduce the amount of regenerative steam in steam-water system, so that the main steam flow rate is reduced, the coal consumption is deducted, and the operation efficiency of the unit can be improved. Furthermore, with this new scheme, the pollutant emission is reduced as well and the comprehensive utilization of clean energy is finally achieved. The system provides a reference for the selection of other solar-coal coupling system loads and system design.

Identifying and Standardized Setting Method of Overlap Degree of DEH System Regulating Valve

WAN Zhonghai, CHEN Wen, CAI Wen, LU Jin, YAN Tao

2020, 53(2):  156-163.  DOI: 10.11930/j.issn.1004-9649.201907017

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According to the principle of steam turbine, the connotation and function of the overlap degree of the regulating valve of DEH system are analyzed in-depth with the overlapping measurement indices established. Then the stepping safety limit of the valve position is determined and verified as the critical constraint affecting the adjustment of the valve overlap. Moreover, an applicable valve overlap identification and normalization setting method with broader spectrum is proposed in high compliance with the established valve sequence characteristics, which is separated from the pressure overlap and closely related to the valve position of the regulating valve. The simulation and field tests have verified that the method meets the requirements for the linearity of the inlet flow in the overlap area of the regulating valve, the operation security of the DEH system as well as the need to reduce the throttling loss under the valve point operating condition.

Comprehensive Comparison of Ultra-low Emission Coal-Fired Power Plants and Gas-Fired Power Plants

XU Jingxin, ZHU Fahua, WANG Sheng, ZHANG Ming, ZHAO Xiuyong, SUN Xueli, HU Yun, TIAN Wenxin

2020, 53(2):  164-172,179.  DOI: 10.11930/j.issn.1004-9649.201908027

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Coal-fired and gas-fired power generation are the two major types of thermal power generation in China. This paper compares ULE coal-fired power plants with the gas-fired power plants from three aspects, i.e., technologies, environmental effect and economic benefit. The comparison results show that firstly, the power generation and pollution control technologies for ULE coal-fired power plants have been developed and manufactured completely and independently with the overall technologies reaching the global advanced level, while for gas-fired power plants key technologies are still imported abroad such that the technology development including gas turbine manufacturing need to speed up. Secondly, in terms of environmental effects, ULE coal-fired power plants have achieved effective control over the gas, liquid and solid emission of conventional pollutants with very few impacts on the environment, which means they are even much more cleaner than gas-fired power plants as long as their standard coal consumption is not higher than the national average value. At last, in terms of economic benefits, ULE coal-fired power plants continue to maintain significant economic advantage over gas-fired power plants. These results can provide not only the theoretical reference for the evaluation of the pros and cons of the two types of power plants in an objective way, but also necessary basis and suggestions for the formulation of national polices.

Research and Application of Impacting Method for Liquid Droplet Testing in Wet Flue Gas Desulfurization System

TAO Ming, WANG Shaoliang, LIU Haipei, HE Yudong

2020, 53(2):  173-179.  DOI: 10.11930/j.issn.1004-9649.201904076

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The performance of mist eliminator in wet desulfurization system is critical to the flue gas emission level of coal-fired power plants. Appropriate analysis method should be adopted to analyze the liquid droplets carried in the flue gas of desulfurization. In this paper the impacting method was used to study the droplet size distribution in flue gas of wet desulfurization. The sampling principle, operation manual, data analysis and processing of impact method are introduced. The application examples and precautions in the testing process of impact method are also put forward. The results show that by using the microscope to observe and count the imprints of droplets carried by flue gas on the impact plate, the distribution of droplet size can be obtained according to the diameter and number of the imprint. At the same time, the mass concentration of droplets in flue gas can be calculated as well. Hence corresponding data support is provided from the derived calculation result for the research and optimization of the operation of the demister.

Experimental Study on Performance of Plume Abatement and Water-saving Cooling Tower with Condensate Method

JIA Mingxiao, HU Sanji, LI Hao, WANG Bin

2020, 53(2):  180-184.  DOI: 10.11930/j.issn.1004-9649.201902050

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The condensate cooling towers for plume abatement and water-saving have been installed and applied in China in the recent years. To assess its plume abatement and water-saving performance, related experimental studies were conducted on a cooling tower with designed circulating water rate of 4 000 m³/h, where the outlet air parameters and water saving rate of this cooling tower were tested. When the circulation water volume was close to the design value, the outlet air dry-wet bulb temperature and velocity distribution were presented with the winter plume abatement mode turned on. The testing result shows that at the exit of the condensate cooling tower, the air flow velocity is higher around the wall surface than at the tower center. The average weighted air relative humidity was 64.2% such that no visible plume will form since the outlet air plume dilution line always lies in the unsaturated region. The amount of condensate water recollected was 11.357 m³/h and the mass of water loss was 45.440 m³/h due to evaporation. The water-saving rate of this cooling tower was 25% under testing conditions. The results can provide beneficial reference for the performance research of plume abatement and water-saving cooling towers.