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Showing papers in "Journal of Chinese Society of Power Engineering in 2010"


Journal Article
TL;DR: In this paper, the heat transfer and resistance characteristics of single or double H-type finned tube banks were analyzed using fluent software, during which variation laws of the heat transferred and resistance properties obtained.
Abstract: Based on general conditions of boiler economizer in large power plant,experimental tests were performed to the heat transfer and resistance characteristics at air-side of single or double H-type finned tube banks,while corresponding numerical simulation performed to the flow and temperature field using Fluent software,during which variation laws of the heat transfer and resistance characteristics obtained.Results show that the heat transfer and resistance characteristics of H-type finned tube banks are influenced by the Reynolds number of gas,i.e.with the growth of Re,the air-side Nu will rise gradually,meaning the heat transfer performance will get better and better,whereas the air-side Eu will drop step by step,and will finally get to a fixed value.In the case of a same Re,the air-side Nu of single H-type finned tube banks will be larger than that of double ones,and for air-side Eu,the variation law is just the opposite.Results of numerical simulation agree well with that of the experimental test,indicating that the numerical calculation method may be used for analysis of flow and heat transfer characteristics of H-type finned tube banks.

17 citations


Journal Article
TL;DR: In this article, a quantitative calculation and comparison was made on water consumption before and after reduction of inlet flue gas temperature, and relevant experimental results were listed, which showed that flue gases desulfurization reaction happens in the tower at saturated steam temperature; when inlet gas temperature changes,corresponding saturated steam temperature changes also, which subsequently results in different desulfureization temperatures of fluegas in the desulfURization tower.
Abstract: Variation law of steam temperature in wet desulfurization system was analyzed,while saturated steam temperatures influenced by various inlet gas temperatures calculated.A quantitative calculation and comparison was made on water consumption before and after reduction of inlet flue gas temperature,and relevant experimental results were listed.Results show that the flue gas desulfurization reaction happens in the tower at saturated steam temperature;when inlet gas temperature changes,corresponding saturated steam temperature changes also,which subsequently results in different desulfurization temperatures of flue gas in the desulfurization tower.Adding flue gas cooler to the desulfurization system can effectively reduce water consumption for lowering flue gas temperature,and therefore water-saving purpose is(achieved.)

8 citations


Journal Article
TL;DR: In this paper, a 660 MW power unit's inlet flue duct and guide vanes were optimized to increase the velocity uniformity at both the ammonia-injection grid (AIG) section and the catalyst inlet section, which is believed to be beneficial to performance improvement of SCR reactors.
Abstract: In order to improve denitrification performance of selective catalytic reduction(SCR) reactors,factors influencing the performance and how these factors function were analyzed.For performance improvement of SCR reactors,the importance of flow field uniformity was stressed and the way of flow field optimization was believed to effective.Taking a 660 MW power unit as an example,simulation optimization was carried out on design of the SCR reactor's inlet flue duct and guide vanes,based on which optimized flow field design obtained.Results show that the optimized design may help to raise the velocity uniformity at both the ammonia-injection grid(AIG) section and the catalyst inlet section,which is believed to be beneficial to performance improvement of SCR reactors.

5 citations


Journal Article
TL;DR: In this paper, the development history and prospects of advanced power plant materials in major countries of the world, and the development status of materials for USC boilers, steam turbines and nuclear power plants are presented.
Abstract: An introduction is being presented to the development status of China's Electric Power Industry(especially the manufacturing industry for ultra supercritical(USC) and nuclear power plants in recent few years),the development history and prospects of advanced power plant materials in major countries of the world,and the development status of materials for USC boilers,steam turbines and nuclear power plants.The development tendency of China's power plant materials is forecasted.It is believed that China is already able to manufacture materials for both 600 ℃ USC and nuclear power plants.

5 citations


Journal Article
TL;DR: In this article, a new concept,characteristic flow area (CFA) of steam turbines is proposed with a specific expression, which has following features: the area will remain nearly constant with high accuracy under various working conditions if there are no changes in geometric parameters at relevant stages.
Abstract: As a new concept,characteristic flow area(CFA) of steam turbines is being proposed with a specific expression,which has following features: the area will remain nearly constant with high accuracy under various working conditions if there are no changes in geometric parameters at relevant stagesOn the other hand,if there are any changes found in CFA,it must come from the changes of geometric parameters at relevant stagesCFA can be used for analyzing thermal characteristics of relevant flow passages,establishing precise files of thermal parameters,performing accurate calculation of off-design conditions and for monitoring and diagnosis of steam turbine operationsIn the process of exploring CFA,the widely used Flugel formula was found to have some deviationsIn order to solve this problem,a new formula with higher precision is proposed

5 citations


Journal Article
TL;DR: In this paper, the influence of number of tube rows and longitudinal space on heat transfer coefficient of H-type finned tube is analyzed, and a calculation formula was obtained and verified.
Abstract: Using Realizable model,numerical simulation on heat transfer characteristics of H-type finned tube was carried out by software Fluent.The influence of number of tube rows and longitudinal space on heat transfer coefficient of H-type finned tube is analyzed.Based on the calculation,a calculation formula was obtained and verified.Results show that the heat transfer coefficient increases with the increase of gas velocity and longitudinal space,and the decrease of the number of longitudinal tube rows.The maximum error of calculation results is 8.3%,and the minimum error 5.6%.Calculation results by the formula coincide well with the results of the verification case,experiment data of literatures and existed formulas.

5 citations


Journal Article
TL;DR: In this paper, the active-disturbance-rejection control (ADRC) was introduced to the main steam temperature control system of circulating fluidized bed boiler, and the niche quantum genetic algorithm based on chaotic mutation operator was put forward for the parameter optimization of the active disturbance rejection controller.
Abstract: Aiming at the features of main steam temperature of circulating fluidized bed boiler such as time dependence,large lag and big inertia,as well as the phenomenon that it is greatly affected by the flow rate of feed water,the active-disturbance-rejection control(ADRC) was introduced to the main steam temperature control system of circulating fluidized bed boiler,and the niche quantum genetic algorithm based on chaotic mutation operator was put forward for the parameter optimization of the active-disturbance-rejection controller.Simulation results show that the optimized ADRC system has good control effect and strong robustness.It is still able to obtain good control result when the object characteristics are changed.

4 citations


Journal Article
TL;DR: Using the identification experimental method and corresponding identification algorithm, a dynamic mathematical model of the combustion system of a coal-fired boiler was set up and calculation results show that this identification method has good modeling effect for the multi-input and multi-output system.
Abstract: Aiming at the multi-input and multi-output characteristic of the thermal system,the basic principle of identification and modeling for multi-input and multi-output system was introduced,and the detail derivation process of simplifying the multi-input and multi-output system as multi-input and single-output system was analyzed.Then the identification experimental method and corresponding identification algorithm were studied for the multi-input and multi-output system which adopts independent pseudo-random signal as input signal.Using the above-mentioned identification method,a dynamic mathematical model of the combustion system of a coal-fired boiler was set up.Calculation results show that this identification method has good modeling effect for the multi-input and multi-output system.

4 citations


Journal Article
TL;DR: In this article, a flue gas deep cooler for heat recovery of exhaust gas in domestic power boilers was introduced, and the feasibility was analyzed by building up the thermodynamic calculation and analysis model, selecting the structural parameters and the operational parameters which affect the heat transfer effect and investment cost as the analyzing object.
Abstract: Aiming at the general high temperature of exhaust gas in domestic power boilers,a flue gas deep cooler for heat recovery of flue gas was introduced,and the feasibility was analyzed.By building up the thermodynamic calculation and analysis model,selecting the structural parameters and the operational parameters which affect the heat transfer effect and investment cost as the analyzing object and taking the heat transfer coefficient and conversion cost as design reference,the design parameters of the flue gas deep cooler were optimized.Results show that by selecting reasonable structural parameters and operational parameters,the heat transfer effect can be effectively improved,and the investment cost and payoff period can be reduced so as to ensure the economy of the energy saving retrofit.

3 citations


Journal Article
TL;DR: In this paper, three integrated modes of solar-coal hybrid power generation systems were presented: solar collector field connected in parallel with boiler, solar collectors field connected with boiler and heater, and solar collector fields connected with both boiler and heaters.
Abstract: Following three integrated modes of solar-coal hybrid power generation systems were presented: solar collector field connected in parallel with boiler,solar collector field connected in parallel with heater,solar collector field connected in parallel with both boiler and heater.Based on traditional economical indexes,such as the absolute electricity efficiency,coal consumption and solar power generation efficiency,the thermal economical indexes of solar-coal hybrid power generation system were calculated using heat balance method.Taking a 200 MW power unit as an example,the thermal economy was compared among three integrated modes,while the thermal economy variation law analyzed under different radiation intensity conditions,and hence an optimum mode obtained.Results show that in the solar-coal hybrid system,the thermal power generation efficiency of solar energy is larger than that in a pure solar power generation system,and simultaneously the hybrid system consumes less coal.The mode of solar collector field connected in parallel with boiler produces the highest thermal efficiency of solar energy and saves most coal among the three integrated modes.

3 citations


Journal Article
TL;DR: Aging and creep-rupture tests were carried out to domestic T92 steel tubes at 650 ℃ while study on corresponding microstructures performed as mentioned in this paper, which showed that after having experienced aging at 650(°C), following three phenomena may occur to the material: reduction of dislocation density, increase in sub-grain quantity and evolution of precipitates.
Abstract: Aging and creep-rupture tests were carried out to domestic T92 steel tubes at 650 ℃ while study on corresponding microstructures performed.Results show that after having experienced aging at 650(°C) and creep-rupture tests,following three phenomena may occur to the material: reduction of dislocation density,increase in sub-grain quantity and evolution of precipitates.After an aging time of 3 000 h,M_(23)C_6 precipitates will rapidly get coarsening while Laves phase form and get coarsening.M_(23)C_6 will stop growing and remain its morphology in the duration from 3 000 h to 10 000 h,due to precipitation and rapid coarsening of Laves phase from the matrix.Its martensite structure will still remain in lath morphology after aging up to 10 000 h,but partially transform to equiaxial sub-grains after creep-rupture test.

Journal Article
TL;DR: In this paper, a numerical analysis model was established for the spray cooling system of the air cooling unit, and three different types of spray cooling systems were designed, and software Fluent was adopted to perform the numerical simulation for the performance of the Spray cooling system.
Abstract: Taking certain domestic 300 MW direct air cooling unit as an example,the numerical analysis model was established for the spray cooling system of the air cooling unit.Three different types of spray cooling system were designed,and software Fluent was adopted to perform the numerical simulation for the performance of the spray cooling system.The internal and outlet temperature fields of the air cooling unit were obtained.Results show that the average air temperature at outlet of the air cooling unit is decreased by 2~5 K after spay.For spray system C,the outlet average air temperature is decreased by 5 K and the exhaust steam pressure is dropped by 6.7 kPa.The more uniform the spray is and the larger the spraying scope is,the better the performance of spray cooling system will be,the greater the exhaust steam pressure will drop,and the better the economy will be.For certain domestic 300 MW unit,spray system C is the best option if the demineralized water is sufficient,while spray system B should be selected if the amount of the demineralized water is limited.

Journal Article
TL;DR: Based on the analysis of internal mechanism of material balance of the circulating fluidized bed (CFB)boiler, it is considered that the reason of the fuel flexibility of CFB boiler was the certain solid suspension density distribution in the furnace.
Abstract: Based on the analysis of internal mechanism of material balance of the circulating fluidized bed(CFB)boiler,it is considered that the reason of the fuel flexibility of CFB boiler was the certain solid suspension density distribution in the furnaceIn order to achieve the particle concentration distribution required by boiler design,additional circulating material is necessary when the low-ash fuel is firedIt is presented that when the air velocity in the empty furnace is 5 m/s and the density of the sand is 2 650 kg/m3,the diameter of the sand should be less than 300 μm,and larger than d_ 99,the particle diameter responding to the separating efficiency of 99%Design was carried out on a 732t/h CFB boiler for Ajnomoto Coin ThailandResults shows that when the size of the sand is within above-mentioned range,the square separator can meet the requirement of material balance,and the carbon content in fly ash will be less than 1%,combustion efficiency will be more than 99%,as a result,boiler efficiency will reach 9362%(according to Japanese standard)However,since the density of sand is bigger than that of coal ash,the resistance of the fluidizing bed and the effect on primary air fan can't be ignored

Journal Article
Pan Qi-wen1
TL;DR: In this article, the influence of catalyzing temperature and catalyst quantity on the product distribution and bio-oil components was studied in a fixed bed reactor using HZSM-5 as the catalyst.
Abstract: Direct catalytic cracking experiments on vapors from biomass fast pyrolysis were carried out in a fixed bed reactor using HZSM-5 as the catalyst so as to study the influence of catalyzing temperature and catalyst quantity on the product distribution and bio-oil components.Results show that when the catalyzing temperature is kept at 375 ℃ with a catalyst volume of 30 mL,higher liquid yield(36.4%),lower gas yield(20.4%) and lower coke yield(13.9%) will be resulted during the catalytic process,under which condition,the components containing higher oxygen content in the refined oil will drop substantially,such as organic acids,esters,ketones,aldehydes and furan derivatives etc, whereas those containing lower oxygen content will rise observably,like phenolic and non-oxygenated hydrocarbon etc.

Journal Article
TL;DR: In this article, the basic design scheme of a 1, 000 MW ultra-supercritical lignite-fired boiler is presented, including the selection of coal and steam parameters, furnace type and main characteristic parameters,furnace waterwall,combustion and coal-pulverizing system,superheater, reheater and economizer system,temperature controlling method, start-up system, steel of pressure parts, etc.
Abstract: Based on the existed domestic ultra-supercritical boiler technology,the necessity of developing and designing large capacity ultra-supercritical lignite-fired boiler is discussed.The basic design scheme of a 1 000 MW ultra-supercritical lignite-fired boiler is presented,including the selection of coal and steam parameters,furnace type and main characteristic parameters,furnace waterwall,combustion and coal-pulverizing system,superheater,reheater and economizer system,temperature controlling method,start-up system,steel of pressure parts,etc.

Journal Article
Zhu Min1
TL;DR: In this article, five typical mechanisms, used for numerical simulation of NO_x emission from methane combustion, were analyzed and compared, with focus on simulation features of the detailed, quasi-steady simplified and empirical three categories of mechanisms.
Abstract: Five typical mechanisms,used for numerical simulation of NO_x emission from methane combustion,were analyzed and compared,with focus on simulation features of the detailed,quasi-steady simplified and empirical three categories of mechanisms.Using models based on these mechanisms,turbulent combustion of gas turbine combustors were also simulated.By verifying simulation models with existing experimental results,influence of model parameters and pressure etc.on temperature and NO_x emission is analyzed.Results show that the simulation results agree well with that of the experiments,indicating that the calculation efficiency and accuracy may be raised by adopting reasonable chemical reaction,turbulent and combustion models.

Journal Article
TL;DR: Simulation results show that the proposed controller has better load set point tracking performance compared with the PID controller reduced from robust H_∞ one, which has also good robustness.
Abstract: A parameter optimization method is being proposed for a multivariable robust PID controller based on genetic algorithm with respect to the boiler-turbine control system of a thermal power plant.By taking set point tracking performance as the optimization goal and robustness as the punishment constraints,the controller parameters can be optimized by using genetic algorithm.Simulation results show that the proposed controller has better load set point tracking performance compared with the PID controller reduced from robust H_∞ one,which has also good robustness.

Journal Article
TL;DR: In order to improve the efficiency of mist eliminator and reduce the blockage of gas-gas heat-exanger (GGH) in desulfurization system, the water equilibrium method was used to analyze the performance of a mist elimination in a cold-state test-bed as mentioned in this paper.
Abstract: In order to improve the efficiency of mist eliminator and reduce the blockage of gas-gas heat-exanger(GGH) in desulfurization system,the water equilibrium method was used to analyze the performance of a mist eliminator in a cold-state test-bed.Results show that the optimal mist velocity increases with reducing space between the plates of single-stage mist eliminator.For eliminators with fold line shaped or curved barbed plates,the highest demisting efficiency is achieved for a plate space of 26 mm,between which the latter one has a slightly higher efficiency.Performance test results of two-stage mist eliminator indicate that the first stage has a far higher efficiency than the second stage.The average efficiency of the combination of "curved 26 fold line 20" can reach 84.2% within a flue velocity range of 3-10 m/s,and the best demisting efficiency(91%) is to be obtained in a velocity range of 4-8 m/s.The combination of "curved 26 fold line 20" has the best demisting efficiency.

Journal Article
TL;DR: In this article, numerical simulation on gas flow field in two cyclones with different inlet height-width ratios was performed using Reynolds stress model (RSM), while calculation for particle trajectory inside the cyclone was made using Lagrangian model.
Abstract: Numerical simulation on gas flow field in two cyclones with different inlet height-width ratios was performed using Reynolds stress model(RSM),while calculation for particle trajectory inside the cyclone was made using Lagrangian model.Results show that both the collection efficiency and gas flow field obtained by numerical simulation basically agree with the experimental results.For a fixed area of inlet section,the collection efficiency of cyclone B with higher inlet height-width ratio is 2%-8% larger than that of cyclone A,but the pressure drop of cyclone B is higher than that of cyclone A.Higher collection efficiency of cyclone B results from larger tangential velocity,lower average entering position of particles and shorter distance for particles to move to the wall.However,larger shortcut flow and eccentric circumfluence near dust outlet in cyclone B are unfavorable to the improvement of collection efficiency.

Journal Article
TL;DR: Based on a dynamic simulation model of two-stage circulating fluidized bed (CFB), a dynamic mathematic model was established for the CFB with breeches-legs considering the effect of the cross exchange of air flow and solid material between the two furnaces as mentioned in this paper.
Abstract: Based on a dynamic simulation model of two-stage circulating fluidized bed(CFB),a dynamic mathematic model was established for the CFB with breeches-legs considering the effect of the cross exchange of air flow and solid material between the two furnaces of the CFB with breeches-legs on the dynamic characteristics of the fluidized bed.Computational fluid mechanics software was used to simulate the air and gas flow inside the cold CFB with breeches-legs,and a calculating method was obtained for the cross exchange amount of the air when the flow rate of the feed air of the two furnaces were different.The relationship of the cross exchange amount of the air and material varying with the flow rate of the feed air of the two furnaces was analyzed with emphasis.And a formula was set up for the relationship between cross exchange amount of the material and gas.The simulated pressure drop of the bed material and variation of bed temperature were compared with the variations during actural "bed overturn".Results show that the model results can correctly reflect the "bed overturn" process of the CFB with breeches-legs.

Journal Article
TL;DR: In this article, a single blade and a circle of blades were calculated under different rotating speeds, and the characteristics of the dry friction damping of the blade with zigzag shrouds were analyzed.
Abstract: Based on the hysteretic spring friction model,the natural frequencies and modal characteristics of the single blade and a circle of blades were calculated under different rotating speeds,and the characteristics of the dry friction damping of the blade with zigzag shroud were analyzedThe influence of rotating speed on the blade with zigzag shroud was analyzedThrough analyzing the internal contacting status of the blade shrouds,the friction force and the relative sliding distance between the blade shrouds were obtained,thus the equivalent damping and the equivalent stiffness between the blade shrouds were calculated The element of MATRIX 27 in finite element analysis software was introduced as a spring damping element to simulate the internal damping and stiffness in the contacting area between the blade shrouds,and to analyze the dynamic stress for the blade with the zigzag shroudResults show that the damping effect is obviously for the dry friction between the blade's zigzag shrouds,and can efficiently control the system vibration

Journal Article
TL;DR: In this paper, the Runge-Kutta method was used to solve the vibration response of integrally shrouded blades and the effects of the clearance, contact angle and the normal rigidity between blade tips on the impact damping were analyzed.
Abstract: An equivalent model of spring and dry friction damping for contact impact in shrouds with clearance was set up by harmonic balance method.Then the three degree-of-freedom lumped-parameter model that can reflect main dangerous vibration mode of steam turbine shrouded blades was obtained.The Runge-Kutta method was used to solve the vibration response of integrally shrouded blades. Meanwhile,the effects of the clearance,contact angle and the normal rigidity between blade tips on the impact damping were analyzed.Results show that the integrally shrouded blades of steam turbine has a good advantages of vibration reduction because of contact-impact between shrouds,but the phenomenon of multi-spectrum characteristics and right-shift of resonance frequency appears.The effect of impact damping for the shrouded blade becomes better with reducing the clearance.The vibration reduction effect of compact-impact between shrouds to the first order vibration is better than that to the second order vibration.The larger contacting angles between the shrouds make the effect of the vibration reduction to the tangential vibration better.The larger normal contacting rigidity between the shrouds may make the vibration reduction effect of the contact-impact between the shrouds well enough.

Journal Article
TL;DR: In this article, the heat transfer boundary of the rotor's blade groove in finite element analysis for temperature and thermal stress fields of supercritical and ultra-supercritical steam turbine rotors is determined.
Abstract: A calculation method of the heat transfer coefficient of blade grooves for supercritical and ultra-supercritical steam turbine rotors is presented: firstly the heat transfer thermal resistance of blade roots is calculated by using the model of monolayer cylinder wall,multilayer cylinder wall and multilayer plane wall;then the total transfer thermal resistance of the blade roots is calculated by the addition principle of series transfer thermal resistance;after that the heat transfer coefficients of blade grooves are calculated by use of the total transfer thermal resistance of blade roots and the surface area of the teeth in blade groove which suffered the centrifugal forcesThe calculation method of the heat transfer coefficient for the inverted T-type blade groove,the double inverted T-type blade groove,the fork-type blade groove and the fir-treetype blade groove are introducedThe calculating results of quantification for the heat transfer coefficient of the high pressure rotor's blade grooves of a supercritical 600 MW steam turbine are givenThe proposed method supplies the basis for determining the heat transfer boundary of the rotor's blade groove in finite element analysis for temperature and thermal stress fields of supercritical and ultra-supercritical steam turbine rotors

Journal Article
NI Wei-dou1
TL;DR: In this paper, a scenario analysis has been carried out to study the total emission of SO_2 and NO_x from domestic coal-fired power plants in 2030, during which total SO 2 and NO x emission as well as total SO2 emission were calculated respectively with different emission standards and different operation rates of desulfurization equipment.
Abstract: General conditions of China's thermal power plants in 2006-2007 are being reviewed on the aspects of air pollutant emission and the emission control.A scenario analysis has been carried out to study the total emission of SO_2 and NO_x from domestic coal-fired power plants in 2030,during which total SO_2 and NO_x emission as well as total SO_2 emission were calculated respectively with different emission standards and different operation rates of desulfurization equipment.Based on above study results,some suggestions are proposed for policy preparation on energy saving and environmental protection for coal-fired power plants before 2030.

Journal Article
TL;DR: In this article, the design features of the first domestic 690 t/h super-pressure reheating circulating fluidized bed (CFB) boiler without external heat exchanger are presented, while technical features of CFB boiler with same capacity levels at home and abroad compared.
Abstract: Design features of the first domestic 690 t/h super-pressure reheating circulating fluidized bed(CFB) boiler without external heat exchanger are being presented,while technical features of CFB boiler with same capacity levels at home and abroad compared.Moreover,the operation regulating characteristics,the performance evaluation test results under the different loads,and the main problems occurring during operation as well as corresponding solutions are analyzed.Operational and experimental results show that the main operating parameters of the boilers are in agreement with the design parameters,and the main performance indexes exceed or reach the guaranteed value.The problem of excessive desuperheater spray and slag-leakage from funnel cap may be effectively solved by changing the superheated panel into water-cooled evaporating panel,and simultaneously by applying new type structure and reducing the number of the funnel caps.This may serve as a reference for optimized design and operation of large-scale CFB boilers.

Journal Article
TL;DR: In this article, a variable pitch control strategy combining nonlinear feed forward and fuzzy PID control is proposed to overcome the deficiency of conventional PID controller that can't achieve satisfactory performance above rated speed.
Abstract: Aiming at the strong non-linear and time-delay characteristics of wind turbine-generator set,a new variable pitch control strategy combining nonlinear feed forward and fuzzy PID control is being proposed,so as to overcome the deficiency of conventional PID controller that can't achieve satisfactory performance above rated speed.According to aerodynamic characteristics of its blade,the nonlinear relationship between pitch angle and wind speed was obtained by way of numerical calculation and least square polynomial fitting method,based on which a nonlinear feed forward controller was designed.Simulation results on a 300 kW variable pitch wind turbine-generator set show that with the new pitch control strategy,the system's overshoot can be effectively reduced at different wind speed ranges above the rated speed,while the regulation time shortened and satisfactory control effect achieved.

Journal Article
TL;DR: In this paper, the dynamic eccentric exciting force at the flow path of the rotor blade was analyzed based on the principles of steam doing work, and the results showed that the rotor will be subjected to larger static exciting force in asymmetric inlet condition.
Abstract: Taking a rotor of 600MW supercritical steam turbine as studying object,the dynamic eccentric exciting force at the flow path of the rotor blade were analyzed based on the principles of steam doing work.The forces excited by steam flow were identified by simulating the 3-D viscous flow field with CFD software for whirling rotor's steam leakage at shroud steam seal.Calculation results show that the rotor will be subjected to larger static exciting force in asymmetric inlet condition.In symmetric inlet condition,the exciting force is quite little, that is benefit to rotor stability.Compared with the rated conditions,there is a big increase in radial force but a less increase in tangential force and leakage under the valve wide open(VWO) conditions.Consequently,for the large scale steam turbine,the stability of rotor system will be enhanced in symmetric inlet condition.

Journal Article
TL;DR: In this article, a model for uncertainty evaluation on performance tests of complicated industrial systems was established, while the definition of influence factor (IF) and specific evaluation way described, based on analysis of IF, the selection and arrangement of measuring instruments were suggested.
Abstract: A model for uncertainty evaluation on performance tests of complicated industrial systems was established,while the definition of influence factor(IF) and specific evaluation way described.Based on analysis of IF,the selection and arrangement of measuring instruments were suggested.A new method named uncertainty pre-evaluation(UP) was proposed for control of the test uncertainty.Taking the heat rate performance test of a 600 MW ultra-supercritical steam turbine as an example,a case study including a complete procedure of uncertainty evaluation has been performed,after which the measuring points which may have large influences on the uncertainty evaluation are pointed out,while corresponding countermeasures proposed.

Journal Article
TL;DR: The steady and unsteady full 3D steam flow fields in the main stop and control valve system of a 1, 000 MW ultra-supercritical steam turbine were simulated and analyzed by using CFD numerical method and commercial fluent software as discussed by the authors.
Abstract: The steady and unsteady full 3-D steam flow fields in the main stop and control valve system of a 1 000 MW ultra-supercritical steam turbine were simulated and analyzed by using CFD numerical method and commercial fluent software Results show that under stable working conditions with valves in fully open position,the total pressure loss of the whole valve system accounts for about 123% of the total inlet pressure,in which 5752% loss comes from the control valveFor stop and control valves of the quick opening type,their flow rates are basically unadjustable when corresponding relative lifts get more than 30%The unsteady steam flow fields of the control valve fast switched from fully open to close position were calculated and analyzed using Fluent dynamic mesh,during which dynamic curves of the valve lift,mass flow rate and downstream pressure varying with closing time presented

Journal Article
TL;DR: X-ray fluorescence (XRF) analysis was performed for the raw petroleum coke and the incinerated petroleum CO 2 of certain aluminum plant in China by analyzing the scanning electron microscope (SEM) of the sample tube made from the economizer and X-ray diffraction(XRD) of corrosion layer, the formation and mechanism of low temperature corrosion on the wall of the economiser of the waste heat boiler were discussed as mentioned in this paper.
Abstract: X-ray fluorescence(XRF) analysis was performed for the raw petroleum coke and the incinerated petroleum coke of certain aluminum plant in ChinaBy analyzing the scanning electron microscope(SEM) of the sample tube made from the economizer and X-ray diffraction(XRD) of the corrosion layer,the formation and mechanism of low temperature corrosion on the wall of the economizer of the waste heat boiler were discussedResults show that the main component of the corrosion layer was FeSO_4·H_2O,and the low temperature corrosion of waste heat boiler in aluminum plant was caused by higher concentration of SO_2 produced by coking and large amounts of steam produced by natural gas combustionLow temperature corrosion can be prevented by increasing the wall temperature of the economizer