Gas turbine power units,as an effective way to cope with the severe challenge of renewable energy accommodation in power grids,arouse the interest of power enterprises in the deep peak-load regulation performance.Two ...Gas turbine power units,as an effective way to cope with the severe challenge of renewable energy accommodation in power grids,arouse the interest of power enterprises in the deep peak-load regulation performance.Two common alternative load-control strategies including constant turbine inlet temperature(TIT)and constant turbine exhaust temperature(TET)regulations were taken into consideration.To comparatively investigate the part-load performance under these strategies,both mathematical and physical models were set up successively to serve as a validation and complementary to each other.For the mathematical model of compressor with inlet guide vane(IGV),combustor and turbine,stage-stacking method based on blade average geometric parameter,energy conservation and turbine stage model were adopted respectively.For the physical model,design and off-design analysis were carried out based on GT PRO and THERMOFLEX respectively.The simulation result of mathematical model validated the reliability of the physical model.Based on this,the influence of ambient temperature and different load-regulating strategies on the off-design performance of gas turbine power units was studied in THERMOFLEX.The results in the case of a PG 9351FA gas turbine show that the ambient temperature has a great impact on system performance,i.e.,every 5℃ increase in the ambient temperature produces a reduction of 3.7%in the relative full-load output and 1.1%in the relative efficiency respectively;when the gas turbine operates under constant TIT strategy,TET starts to rise till it reaches the maximum allowable value with the load rate decreasing,and IGV keeps at the minimum angle with both TIT and TET decreasing when the load rate is lower than 65%;when the gas turbine operates under constant TET strategy,TIT drops slightly at load rate of above 60%while both TIT and TET evidently decrease below 60%load rate operating along the constant corrected speed line at the minimum allowable IGV opening;gas turbine effi-ciency is greatly affected by load rate and the performance degradation is more obvious especially in lower load rate regions;constant TET strategy is superior in the operating efficiency to constant TIT strategy under part-load conditions.展开更多
In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Gen...In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Genetic Algorithm (SGA), connecting each population through immigrant operator and preserving the best individuals of every generation through elite strategy, MPGA can enhance the efficiency in obtaining the global optimal solution. In this paper, MPGA is applied to optimize the load dispatch of 3×390MW gas turbine units. The results of MPGA calculation are compared with that of equal micro incremental method and AGC instruction. MPGA shows the best performance of optimization under different load conditions. The amount of saved gas consumption in the calculation is up to 2337.45m3N/h, which indicates that the load dispatch optimization of gas turbine units via MPGA approach can be effective.展开更多
The main intention of the present study is to reduce wind, wave, and seismic induced vibrations of jacket- type offshore wind turbines （JOWTs） through a newly developed vibration absorber, called tuned liquid column...The main intention of the present study is to reduce wind, wave, and seismic induced vibrations of jacket- type offshore wind turbines （JOWTs） through a newly developed vibration absorber, called tuned liquid column gas damper （TLCGD）. Using a Simulink-based model, an analytical model is developed to simulate global behavior of JOWTs under different dynamic excitations. The study is followed by a parametric study to explore efficiency of the TLCGD in terms of nacelle acceleration reduction under wind, wave, and earthquake loads. Study results indicate that optimum frequency of the TLCGD is rather insensitive to excitation type. In addition, while the gain in vibration control from TLCGDs with higher mass ratios is generally more pronounced, heavy TLCGDs are more sensitive to their tuned frequency such that ill-regulated TLCGD with high mass ratio can lead to destructive results. It is revealed that a well regulated TLCGD has noticeable contribution to the dynamic response of the JOWT under any excitation.展开更多
An unsteady load calculation method for the support configuration of a monopile-supported offshore wind turbine is developed based on the Fluent software platform.Firstly,the water wave is generated by imposing the in...An unsteady load calculation method for the support configuration of a monopile-supported offshore wind turbine is developed based on the Fluent software platform.Firstly,the water wave is generated by imposing the inlet boundary conditions according to the exact potential flow solution.Then the wave evolution is simulated by solving the unsteady incompressible Navier-Stokes(N-S)equations coupled with the volume of fluid method.For the small amplitude wave with reasonable wave parameters,the numerical wave result agrees well with that of the given wave model.Finally,a monopile support configuration is introduced and a CFD-based load calculation method is established to accurately calculate the unsteady load under the combined action of wave and wind.The computed unsteady wave load on a small-size monopile support located in the small amplitude wave flow coincides with that of the Morison formula.The load calculations are also performed on a large-size monopile support and a monopile-supported offshore wind turbine under the combined action of small amplitude wave and wind.展开更多
A cogeneration plant can run at off-design due to change of load demand or ambient conditions. The cogeneration considered for this study is gas turbine based engine consists of variable stator vanes （VSVs） compress...A cogeneration plant can run at off-design due to change of load demand or ambient conditions. The cogeneration considered for this study is gas turbine based engine consists of variable stator vanes （VSVs） compressor that are re-staggered for loads greater than 50% to maintain the gas turbine exhaust gas temperature at the set value. In order to evaluate the exergetic performance of the cogeneration, exergy model of each cogeneration component is formulated. A 4.2 MW gas turbine based cogeneration plant is analysed for a wide range of part load operations including the effect of VSVs modulation. For loads less than 50%, the major exergy destruction contributors are the combustor and the loss with the stack gas. At full load, the exergy destructions in the combustor, turbine, heat recovery, compressor and the exergy loss with stack gas are 63.7, 14.1, 11.5, 5.7, and 4.9%, respectively. The corresponding first and second law cogeneration efficiencies are 78.5 and 45%, respectively. For comparison purpose both the first and second law efticiencies of each component are represented together. This analysis would help to identify the equipment where the potential for performance improvement is high, and trends which may aid in the design of future plants.展开更多
Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplant...Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplants. The cost and performance of various designs were estimated using the commercial software GT PRO. Improved GTCC output will increase the system efficiency which may induce total investment and will certainly increase the cumulative cash which then will induce the cost and the payback period. The relative annual fuel output increases almost in proportion to the relative GTCC output. China should select the gas turbine that provides the most economical output according to its specific conditions. The analysis shows that a GTCC power plant with a medium-sized 100 to 200 MW output gas turbine is the most suitable for Chinese investors.展开更多
The life cycle estimation of power plants is important for gas turbine operators.With the introduction of wind energy into the grid,gas turbine operators now operate their plants in Load–Following modes as back-ups t...The life cycle estimation of power plants is important for gas turbine operators.With the introduction of wind energy into the grid,gas turbine operators now operate their plants in Load–Following modes as back-ups to the renewable energy sources which include wind,solar,etc.The motive behind this study is to look at how much life is consumed when an intercooled power plant with 100 MW power output is used in conjunction with wind energy.This operation causes fluctuations because the wind energy is unpredictable and overtime causes adverse effects on the life of the plant–The High Pressure Turbine Blades.Such fluctuations give rise to low cycle fatigue and creep failure of the blades depending on the operating regime used.A performance based model that is capable of estimating the life consumed of an intercooled power plant has been developed.The model has the capability of estimating the life consumed based on seasonal power demands and operations.An in-depth comparison was undertaken on the life consumed during the seasons of operation and arrives at the conclusion that during summer,the creep and low cycle life is consumed higher than the rest periods.A comparison was also made to determine the life consumed between Load–Following and stop/start operating scenarios.It was also observed that daily creep life consumption in summer was higher than the winter period in-spite of having lower average daily operating hours in a Start–Stop operating scenario.展开更多
It has been made a proposal of new ideal cycle for power plants which is working by a turbine gas, for both closed and open systems. It has been designed a special device for adding heat at constant volume. The aim of...It has been made a proposal of new ideal cycle for power plants which is working by a turbine gas, for both closed and open systems. It has been designed a special device for adding heat at constant volume. The aim of special device is to decrease the amount of added heat for the new cycle. We have made a comparison between the simple gas turbine cycle & the new cycle. The results has been shown, that the efficiency of new cycle is greater than the simple cycle of gas turbine.展开更多
The paper discusses main aspects of low cycle fatigue influence on the lifetime ofengine parts.The importance and history of the problem,the main experiments and the effectsimpacting the low cycle fatigue of structura...The paper discusses main aspects of low cycle fatigue influence on the lifetime ofengine parts.The importance and history of the problem,the main experiments and the effectsimpacting the low cycle fatigue of structural materials are described.A hypothesis about theexistence of a thermomechanical surface of structural material,generalized to the case of acyclical loading was used to approximate the loops of cyclic nonisothermal elastoplasticdeformation curves.The cyclic deformation curve model is based on the following threeparameters:the elastic modulus during unloading,the Bauschinger effect and the conversionparameter of the nonlinear part of its first halfcycle.This model also accounts for theaccumulated plastic strain,as well as the testing temperature.The criterion of durability isformulated,based on the dependence between the number of halfcycles to failure and theaccumulated plastic deformation.Deformation theory of plasticity,generalized to the case ofcyclic deformation,in combination with the durability model and technology of"dying"elements is applied to the finite element analysis of low cycle fatigue of gas turbine engineparts.The results of calculations are demonstrated.展开更多
基金This work was supported by Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization(2013A061401005)by Guangdong Basic and Applied Basic Research Foundation(2020A1515011103)by research fund from Guangzhou Development Group Co.,Ltd.
文摘Gas turbine power units,as an effective way to cope with the severe challenge of renewable energy accommodation in power grids,arouse the interest of power enterprises in the deep peak-load regulation performance.Two common alternative load-control strategies including constant turbine inlet temperature(TIT)and constant turbine exhaust temperature(TET)regulations were taken into consideration.To comparatively investigate the part-load performance under these strategies,both mathematical and physical models were set up successively to serve as a validation and complementary to each other.For the mathematical model of compressor with inlet guide vane(IGV),combustor and turbine,stage-stacking method based on blade average geometric parameter,energy conservation and turbine stage model were adopted respectively.For the physical model,design and off-design analysis were carried out based on GT PRO and THERMOFLEX respectively.The simulation result of mathematical model validated the reliability of the physical model.Based on this,the influence of ambient temperature and different load-regulating strategies on the off-design performance of gas turbine power units was studied in THERMOFLEX.The results in the case of a PG 9351FA gas turbine show that the ambient temperature has a great impact on system performance,i.e.,every 5℃ increase in the ambient temperature produces a reduction of 3.7%in the relative full-load output and 1.1%in the relative efficiency respectively;when the gas turbine operates under constant TIT strategy,TET starts to rise till it reaches the maximum allowable value with the load rate decreasing,and IGV keeps at the minimum angle with both TIT and TET decreasing when the load rate is lower than 65%;when the gas turbine operates under constant TET strategy,TIT drops slightly at load rate of above 60%while both TIT and TET evidently decrease below 60%load rate operating along the constant corrected speed line at the minimum allowable IGV opening;gas turbine effi-ciency is greatly affected by load rate and the performance degradation is more obvious especially in lower load rate regions;constant TET strategy is superior in the operating efficiency to constant TIT strategy under part-load conditions.
文摘In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Genetic Algorithm (SGA), connecting each population through immigrant operator and preserving the best individuals of every generation through elite strategy, MPGA can enhance the efficiency in obtaining the global optimal solution. In this paper, MPGA is applied to optimize the load dispatch of 3×390MW gas turbine units. The results of MPGA calculation are compared with that of equal micro incremental method and AGC instruction. MPGA shows the best performance of optimization under different load conditions. The amount of saved gas consumption in the calculation is up to 2337.45m3N/h, which indicates that the load dispatch optimization of gas turbine units via MPGA approach can be effective.
文摘The main intention of the present study is to reduce wind, wave, and seismic induced vibrations of jacket- type offshore wind turbines （JOWTs） through a newly developed vibration absorber, called tuned liquid column gas damper （TLCGD）. Using a Simulink-based model, an analytical model is developed to simulate global behavior of JOWTs under different dynamic excitations. The study is followed by a parametric study to explore efficiency of the TLCGD in terms of nacelle acceleration reduction under wind, wave, and earthquake loads. Study results indicate that optimum frequency of the TLCGD is rather insensitive to excitation type. In addition, while the gain in vibration control from TLCGDs with higher mass ratios is generally more pronounced, heavy TLCGDs are more sensitive to their tuned frequency such that ill-regulated TLCGD with high mass ratio can lead to destructive results. It is revealed that a well regulated TLCGD has noticeable contribution to the dynamic response of the JOWT under any excitation.
基金supported partly by the National Basic Research Program of China("973"Program)(No.2014CB046200)the National Natural Science Foundation of China(No.11372135)the NUAA Fundamental Research Funds(No.NS2013005)
文摘An unsteady load calculation method for the support configuration of a monopile-supported offshore wind turbine is developed based on the Fluent software platform.Firstly,the water wave is generated by imposing the inlet boundary conditions according to the exact potential flow solution.Then the wave evolution is simulated by solving the unsteady incompressible Navier-Stokes(N-S)equations coupled with the volume of fluid method.For the small amplitude wave with reasonable wave parameters,the numerical wave result agrees well with that of the given wave model.Finally,a monopile support configuration is introduced and a CFD-based load calculation method is established to accurately calculate the unsteady load under the combined action of wave and wind.The computed unsteady wave load on a small-size monopile support located in the small amplitude wave flow coincides with that of the Morison formula.The load calculations are also performed on a large-size monopile support and a monopile-supported offshore wind turbine under the combined action of small amplitude wave and wind.
文摘A cogeneration plant can run at off-design due to change of load demand or ambient conditions. The cogeneration considered for this study is gas turbine based engine consists of variable stator vanes （VSVs） compressor that are re-staggered for loads greater than 50% to maintain the gas turbine exhaust gas temperature at the set value. In order to evaluate the exergetic performance of the cogeneration, exergy model of each cogeneration component is formulated. A 4.2 MW gas turbine based cogeneration plant is analysed for a wide range of part load operations including the effect of VSVs modulation. For loads less than 50%, the major exergy destruction contributors are the combustor and the loss with the stack gas. At full load, the exergy destructions in the combustor, turbine, heat recovery, compressor and the exergy loss with stack gas are 63.7, 14.1, 11.5, 5.7, and 4.9%, respectively. The corresponding first and second law cogeneration efficiencies are 78.5 and 45%, respectively. For comparison purpose both the first and second law efticiencies of each component are represented together. This analysis would help to identify the equipment where the potential for performance improvement is high, and trends which may aid in the design of future plants.
文摘Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplants. The cost and performance of various designs were estimated using the commercial software GT PRO. Improved GTCC output will increase the system efficiency which may induce total investment and will certainly increase the cumulative cash which then will induce the cost and the payback period. The relative annual fuel output increases almost in proportion to the relative GTCC output. China should select the gas turbine that provides the most economical output according to its specific conditions. The analysis shows that a GTCC power plant with a medium-sized 100 to 200 MW output gas turbine is the most suitable for Chinese investors.
文摘The life cycle estimation of power plants is important for gas turbine operators.With the introduction of wind energy into the grid,gas turbine operators now operate their plants in Load–Following modes as back-ups to the renewable energy sources which include wind,solar,etc.The motive behind this study is to look at how much life is consumed when an intercooled power plant with 100 MW power output is used in conjunction with wind energy.This operation causes fluctuations because the wind energy is unpredictable and overtime causes adverse effects on the life of the plant–The High Pressure Turbine Blades.Such fluctuations give rise to low cycle fatigue and creep failure of the blades depending on the operating regime used.A performance based model that is capable of estimating the life consumed of an intercooled power plant has been developed.The model has the capability of estimating the life consumed based on seasonal power demands and operations.An in-depth comparison was undertaken on the life consumed during the seasons of operation and arrives at the conclusion that during summer,the creep and low cycle life is consumed higher than the rest periods.A comparison was also made to determine the life consumed between Load–Following and stop/start operating scenarios.It was also observed that daily creep life consumption in summer was higher than the winter period in-spite of having lower average daily operating hours in a Start–Stop operating scenario.
文摘It has been made a proposal of new ideal cycle for power plants which is working by a turbine gas, for both closed and open systems. It has been designed a special device for adding heat at constant volume. The aim of special device is to decrease the amount of added heat for the new cycle. We have made a comparison between the simple gas turbine cycle & the new cycle. The results has been shown, that the efficiency of new cycle is greater than the simple cycle of gas turbine.
文摘The paper discusses main aspects of low cycle fatigue influence on the lifetime ofengine parts.The importance and history of the problem,the main experiments and the effectsimpacting the low cycle fatigue of structural materials are described.A hypothesis about theexistence of a thermomechanical surface of structural material,generalized to the case of acyclical loading was used to approximate the loops of cyclic nonisothermal elastoplasticdeformation curves.The cyclic deformation curve model is based on the following threeparameters:the elastic modulus during unloading,the Bauschinger effect and the conversionparameter of the nonlinear part of its first halfcycle.This model also accounts for theaccumulated plastic strain,as well as the testing temperature.The criterion of durability isformulated,based on the dependence between the number of halfcycles to failure and theaccumulated plastic deformation.Deformation theory of plasticity,generalized to the case ofcyclic deformation,in combination with the durability model and technology of"dying"elements is applied to the finite element analysis of low cycle fatigue of gas turbine engineparts.The results of calculations are demonstrated.
