The Experts below are selected from a list of 1788 Experts worldwide ranked by ideXlab platform
Wang Pei-hong - One of the best experts on this subject based on the ideXlab platform.
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Economic Analysis for Parallel Manner of Solar Collector System and Low-pressure Heaters of Coal-Fired Units
East China Electric Power, 2010Co-Authors: Wang Pei-hongAbstract:The various parallel manners of solar collector system and low-pressure(LP) heaters of coal-fired units were analyzed by using equivalent Enthalpy Drop method.The corresponding equivalent Enthalpy Drop partial quantitative model was thus established.By using an illustrative example of 600MW power system,it verifies that the established equivalent Enthalpy Drop partial formula is feasible.Finally,it concludes that under the same heat-obtaining quantity of solar collector,the higher the pressure of LP heaters in parallel is,the more economic the combined system has.
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Research on the Algorithms for Analyzing Thermal Economy of Feedwater Bypass in High-Pressure Heater
East China Electric Power, 2010Co-Authors: Wang Pei-hongAbstract:In view of some abnormal operation modes,such as each level alone feedwater bypass,large feedwater bypass,each level alone feedwater bypass leakage,large feedwater bypass leakage in High-Pressure(HP) Heaters,the calculation models with the same formation of changes in equivalent Enthalpy Drop and absorption of heat and the quantitative analysis model of efficiency changes of abnormal operation modes,were respectively established based on the application law of system variable heat equivalent Enthalpy Drop.The Calculation models with the same formation of changes in equivalent Enthalpy Drop and absorption of heat and the quantitative analysis model of efficiency changes of abnormal operation modes are established,respectively.Particularly,some detailed analysis and proof of changes in equivalent Enthalpy Drop influenced by hyDrophobic were made in the case when the middle HP heaters are bypassed.The consistency between this calculation and thermodynamic calculation of positive and negative balance was verified through a given example.These results suggest that the contributions in this paper are significant for reducing energy consumption in power plant.
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Selection and analysis of relative change reference of efficiency for equivalent Enthalpy Drop methods
East China Electric Power, 2009Co-Authors: Wang Pei-hongAbstract:In calculating the relative change of efficiency for steam turbines,it is essential to select the right change reference.The tradition algorithm applies the net equivalent Enthalpy Drop as the reference,which takes the feed water pump′s Enthalpy rise and shaft sealing leakage loss into account but does not consider such common losses as heat loss and extraction steam pressure loss,and therefore the comparability in calculation of different types of losses was not satisfactory.In this paper,different calculation references were selected and the local-quantitative analysis model for the changes of feed water pump′s Enthalpy rise and heat loss was established respectively.Based on that,the different influences of the types of references on relative change analysis of unit efficiency were analyzed.Calculation example showed that selecting the gross equivalent Enthalpy Drop as reference is superior in comparability.
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Improving Algorithm Study on Drain Heat Utilization of Regenerative Heating System with Equivalent Enthalpy Drop Method
2009 International Conference on Energy and Environment Technology, 2009Co-Authors: Wang Quan, Wang Pei-hong, Peng Xianyong, Qian Jin, Zhao HuanAbstract:Drain heat utilization system is a key part of energy saving for the thermal system. The partial analysis models of drain heat utilization with traditional Equivalent Enthalpy Drop Method (EEDM) based a different basis, and the algorithms are not well comprehensive. Based on the research on integrated mixing heater and through the mathematical derivation, the paper presented a consistent and comprehensive partial quantitative analysis model of drain heat utilization with the definition of mixing heater; the model is simple for analysis and easy to understand. The regular and meaning of the correction term in traditional EEDM was not presented, in the process of the above research, the algorithm of partial correction was presented with the partial analysis model of drain heat recovering. The extraction steam efficiency of changed condition should be used in the model when extraction steam efficiency changed that caused by the changes of thermal system structure or heater parameter. The correction algorithm is common and highly accurate and consummates the partial analysis model of EEDM.
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Arithmetic Research of Local Quantitative Modificatory Model on Equivalent Enthalpy Drop
Turbine Technology, 2008Co-Authors: Wang Pei-hongAbstract:Basic parameters such as exhaust efficiency are needed in local quantitative analysis of equivalent Enthalpy Drop,which would be influenced by local change.With less consideration of this ruthless influence,traditional arithmetic model affected using effect of equivalent Enthalpy Drop method in different degree.In order to analyze influence on traditional local quantitative arithmetic by changes of steam extraction heat release quantity,drain water heat release quantity and feed water decalescence,this paper studied local quantitative model of extraction pressure change(two conditions),compared different influence on local quantitative model by Enthalpy changes of extraction steam,out flowing feed,and drainage,and advanced amendatory arithmetic.Validated result of thermal balance method showed the correctness of amendatory model.
Li Yong - One of the best experts on this subject based on the ideXlab platform.
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Improvements on the Equivalent Enthalpy Drop Method And Its Application in Thermal Economy Diagnosis of Thermal System of Steam Turbine
Challenges of Power Engineering and Environment, 2007Co-Authors: Li Yong, Cao LihuaAbstract:The equivalent Enthalpy Drop method is one of the thermal economy diagnosis methods. It is found that in calculating equivalent Enthalpy Drop, the exhaust steam of steam turbine and regenerative extraction steam Enthalpy need determining. But for condensing steam turbine, the exhaust steam Enthalpy and the Enthalpy of regenerative extraction steam in wet steam state region can’t be determined accurately. These cause the calculation results of equivalent Enthalpy Drop method with error. In addition, in analyzing the effect of the changing of some factors on thermal economy of steam turbine and auxiliary equipments, the equivalent Enthalpy Drop method can’t separate the effect of the changing of some factors on thermal economy of thermal system from the effect on thermal economy of steam turbine and auxiliary equipments, so it can’t help to diagnose the reasons and positions that cause the thermal performance of thermal system to be decreased. To counter the problems above, the defining method of ideal cycle thermal efficiency is improved firstly. Then based on the improved ideal cycle heat efficiency, the improved equivalent Enthalpy Drop method is proposed. With the improved equivalent Enthalpy Drop method, not only the difficulty of determining the exhaust steam Enthalpy can be avoid and the degrees of convenience and accuracy are improved, but also the reasons and positions that cause the economy of thermal system of steam turbine to be decreased can be analyzed.
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Precise Calculation Model on the Influence of Terminal Temperature Difference on Thermal Economy of Reheat Unit
Journal of Northeast Dianli University, 2007Co-Authors: Li YongAbstract:Based on the theory of equivalent Enthalpy Drop method and first law of thermodynamics,the authors adopt heat balance equation which can be understood and mastered easily by the engineers,distinguish the heater's location and connection model,and propose a precise calculation model of the effect of terminal tem- perature difference on the unit thermal economy.The paper points out that correlative model in equivalent heat Drop method is approximated.
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Study on Calculating Method of the Affection of Back Pressure to Electric Power of Turbo-generator Set
Turbine Technology, 2006Co-Authors: Li YongAbstract:There isn't a uniform method of calculating the affection of back pressure to electric power of steam turbine at present.In this paper,through calculating,four methods of engineering in common use are analyzed and compared.In this process,the value of the heat balance method of thermodynamic system is regarded as norm because of high precision in calculation.The result shows that the error of thermodynamics method and steam turbine theory method are very big except the equivalent Enthalpy Drop method.So the equivalent Enthalpy Drop method is suggested to calculate the change of electric power with back pressure changing in engineering.
Zhang Chun-fa - One of the best experts on this subject based on the ideXlab platform.
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The Application of Various Analytical Methods in Thermal Economic Analysis
Turbine Technology, 2008Co-Authors: Zhang Chun-faAbstract:For disturbance of the thermal effects of turbine unit,doing analysis in light of the actual situation of different units under different disturbance,Giving three calculation methods(the method of thermal balance,the method of equivalent Enthalpy Drop,the method of matrix analysis).
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Comparison of Equivalent Enthalpy Drop Method and Small Disturbance Theory in Thermal Efficiency Analysis
Jiangsu Electrical Engineering, 2007Co-Authors: Zhang Chun-faAbstract:Based on the combination of the matrix equation,the small disturbance theory and the fundamental equations of thermal efficiency analysis,the internal work and thermal analysis equations are educed,and then the quantitative analysis equations for the system energy saving analysis are built.Take 300 MW unit for instance,the influence of superheater and reheater′s spray desuperheating on thermal efficiency is computed using equivalent Enthalpy Drop method and small disturbance theory respectively.The results indicate that small disturbance theory can achieve all what equivalent Enthalpy Drop method can do.Beside of these,small disturbance theory has the merits that its matrix structure corresponds to the system structure and it is suitable for thermal efficiency analysis of unit.
Xinye Chang - One of the best experts on this subject based on the ideXlab platform.
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Numerical investigation on aerodynamic characteristics of exhaust passage with consideration of multi-factor components in a supercritical steam turbine
Applied Thermal Engineering, 2019Co-Authors: Xiaoqiang Jiang, Aqiang Lin, Adil Malik, Xinye ChangAbstract:Abstract Heat transfer and vacuum in the condenser are affected by the flow characteristics in the low-pressure steam turbine exhaust passage. In this study, the Eulerian-Eulerian equilibrium two-phase model is applied to investigate the contribution of multi-factor components on aerodynamic performance of twin exhaust passage. Results show that the share of steam phase is reduced in the exhaust passage with consideration of the built-in pipelines. Total-pressure loss in the exhaust hood is about four times of that in the throat. The sensitivity of local loss existing in the exhaust hood on the whole loss is higher than that in the throat. Considering the factors of LSBs and pipelines, both the static-pressure recovery coefficient of 15.44% and effective specific Enthalpy-Drop of 0.145% are the best performance. By evaluating the steam turbine economic, however, static-pressure recovery coefficient and specific Enthalpy Drop are 1.25 times and 0.475 times of that without pipelines, respectively, relative to built-in pipelines. Therefore, a recommendation on the consideration of twin exhaust passage, last stage blades, steam extraction pipelines, low-pressure heater, and wet steam can obtain a representative aerodynamic characteristic.
Yan Junjie - One of the best experts on this subject based on the ideXlab platform.
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calculation of electric power generation rate from thermification of heat supplying unit by using equivalent Enthalpy Drop method
Thermal Power Generation, 2007Co-Authors: Yan JunjieAbstract:A new method for calculating the electric power generation rate from thermification of heat-supplying unit by using equivalent Enthalpy Drop algorithm has been put forward,and a comparison calculation of the electric power generation rate from thermification of one NC 200/160-12.7/535/535 type double extraction heat-supplying unit being carried out by adopting the said new method,as well as the conventional heat-equilibrum algorithm and the cyclic function algorithm.Results show that the calculated result of equivalent Enthalpy Drop algorithm is completely identical with the results of other methods,proving the correctness of equivalent Enthalpy Drop algorithm.The equivalent Enthalpy Drop algorithm has more obvious superiority than other algorithms due to the localized calculation can be carried out by using this algorithm.
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QUANTITATIVE ANALYSIS ON THE INFLUENCE OF OPERATIONAL PERFORMANCE OF HEATERS IN HEATING NETWORK UPON THE COGENERATION UNIT IN ECONOMIC ASPECT
Thermal Power Generation, 2001Co-Authors: Yan JunjieAbstract:In view of the influence of terminal temperature difference during operation of heaters in heating network and departure of extraction pressure loss from standard value upon the extraction pressure for heating system, two mathematical models to quantitatively calculate the vaviation of unit′s economic condition are obtained respectively by using the equivalent Enthalpy Drop theory and the calculation method of performance under variable conditions. The calculation results from the two said models have been compared through practical examples, it is found that the calculation model by using the equivalent Enthalpy Drop theory can meet the practical engineering requirements.