Emissions produced by the aviation industry are currently a severe environmental threat;therefore,aviation agencies and governments have set emission targets and formulated plans to restrict emissions within the next ...Emissions produced by the aviation industry are currently a severe environmental threat;therefore,aviation agencies and governments have set emission targets and formulated plans to restrict emissions within the next decade.Hybrid aircraft technology is being considered to meet these targets.The importance of these technologies lies in their advancements in terms of aircraft life cycles and environmental benignity.Owing to these advancements,hybrid electric systems with more than one power source have become promising for the aviation industry,considering that the growth of air traffic is projected to double in the next decade.Hybrid technologies have given future hybrid fans and motor-fan engines potential as alternative power generators.Herein,Turboelectric Distributed Propulsion(TeDP)is discussed in terms of power distribution and power sources.The fundamentals of turbofan and turboshaft engines are presented along with their electricitygeneration mechanism.TeDP is discussed from a design viewpoint,with a detailed discussion of different types of hybrid electric and turboelectric systems.Examples of proposed TeDP aircraft models and numerical modelling tools used to simulate the performance of TeDP models are reviewed.Finally,innovative turboelectric systems in which electric power savers and mechanical gear changers have been discarded for weight optimisation are presented along with other prospective models,engines,approaches,and architectures.The findings of this review indicate the knowledge gaps in the field of numerical modelling for NASA’s TeDP and its capability to increase the efficiency by up to 24%with a 50%reduction in emissions relative to those of conventional gas turbines.展开更多
There is an increasing concern that current trends of consumption of natural resources cannot continue.It is imperative that major targeted investments are made into economical and reliable environment friendly propul...There is an increasing concern that current trends of consumption of natural resources cannot continue.It is imperative that major targeted investments are made into economical and reliable environment friendly propulsion and power solutions.Many novel and promising concepts are being proposed.The selection of the best candidates to pursue for investment becomes a very difficult choice.A detailed TERA(techno-economic environmental risk analysis) framework is described here to quantify risks and to compare and rank competing schemes on a formal and consistent basis.This technique is based on detailed and rigorous thermodynamic representations of power plants.A layer of environment,economic,weather and other models to describe the appropriate local conditions is superimposed to this.The outcome is a techno-economic environmental risk analysis framework with appropriate detail of each power plant as applied to the appropriate conditions.The results for each concept can then be compared and contrasted to make appropriate selections.展开更多
Typically, crude oil production in Nigeria always accompanied by surface production of associated gas. With little associated gas recovery facilities in place, majority of associated gas is continuously flared with fe...Typically, crude oil production in Nigeria always accompanied by surface production of associated gas. With little associated gas recovery facilities in place, majority of associated gas is continuously flared with few portions re-injected into the reservoir for enhance oil recovery (EOR). In addition to environmental hazards, wasting substantial amount of produced associated gas is deemed detrimental to a country currently generating less than 54% of its electric power requirement. Onsite power generation as one of the many means of utilization of associated gas has been conceived. Conversely, the availability and performance of the gas turbine engine for onsite associated gas utilization requires evaluation owing to variations in associated natural gas composition globally and the dependency of associated gas production on reservoirs and oil production activities. This paper presents an analytical investigation of gas turbine engine inspired by GE LMS100 frame engine for onsite utilization of associated gas in Nigeria. Gas turbine performance results are presented and performance parameters are compared against typical commercial natural gas grade.展开更多
This paper focuses on investigations encompassing comparative assessment of gasturbine cycle options.More specifically,investigation was caried out of technical performanceof turboshaft engine cycles based on existing...This paper focuses on investigations encompassing comparative assessment of gasturbine cycle options.More specifically,investigation was caried out of technical performanceof turboshaft engine cycles based on existing simple cycle(SC)and its projected modifiedcycles for civil helicopter application.Technically,thermal efficiency,specific fuel consump-tion,and power output are of paramount importance to the overall performance of gas urbineengines.In course of carrying out this research,turbomatch software established at CranfieldUniversity based on gas turbine theory was applied to conduct simulation of a simple cycle(baseline)two-spool helicopter turboshaft engine model with free power turbine.Similarly,some modified gas urbine cycle configurations incoporating unconventional components,such as engine cycle with low pressure compressor(LPC)zero-staged,recuperated enginecycle,and intercooled/recuperated(ICR)engine cycle,were also simulated.In doing so,designpoint(DP)and off-design point(OD)performances of the engine models were established.Thepercentage changes in performance parameters of the modified cycle engines over the simplecycle were evaluated and it was found that to a large extent,the modified engine cycles withunconventional components exhibit better performances in terms of thermal efficiency andspecific fuel consumption than the traditional simple cycle engine.This research made use ofpublic domain open source references.展开更多
This paper considers comparative assessment of simple and advanced cycle small-scale aero-derivative industrial gas turbines derived from helicopter engines.More particularly,investigation was made of technical perfor...This paper considers comparative assessment of simple and advanced cycle small-scale aero-derivative industrial gas turbines derived from helicopter engines.More particularly,investigation was made of technical performance of the small-scale aero-derivative engine cycles based on existing and projected cycles for applications in industrial power generation,combined heat and power concept,rotating equipment driving,and/or allied processes.The investigation was done by carrying out preliminary design and performance simulation of a simple cycle(baseline)two-spool small-scale aero-derivative turboshaft engine model,and some advanced counterpart aero-derivative configurations.The advanced configurations consist of recuperated and intercooled/recuperated engine cycles of same nominal power rating of 1.567 MW.The baseline model was derived from the conversion of an existing helicopter engine model.In doing so,design point and off-design point performances of the engine models were established.In comparing their performances,it was observed that to a large extent,the advanced engine cycles showed superior performance in terms of thermal efficiency,and specific fuel consumption.In numerical terms,thermal efficiencies of recuperated engine cycle,and intercooled/recuperated engine cycles,over the simple cycle at DP increased by 13.5%,and 14.5%respectively,whereas specific fuel consumption of these cycles over simple cycle at DP decreased by 12.5%,and 13%respectively.This research relied on open access public literature for data.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
文摘Emissions produced by the aviation industry are currently a severe environmental threat;therefore,aviation agencies and governments have set emission targets and formulated plans to restrict emissions within the next decade.Hybrid aircraft technology is being considered to meet these targets.The importance of these technologies lies in their advancements in terms of aircraft life cycles and environmental benignity.Owing to these advancements,hybrid electric systems with more than one power source have become promising for the aviation industry,considering that the growth of air traffic is projected to double in the next decade.Hybrid technologies have given future hybrid fans and motor-fan engines potential as alternative power generators.Herein,Turboelectric Distributed Propulsion(TeDP)is discussed in terms of power distribution and power sources.The fundamentals of turbofan and turboshaft engines are presented along with their electricitygeneration mechanism.TeDP is discussed from a design viewpoint,with a detailed discussion of different types of hybrid electric and turboelectric systems.Examples of proposed TeDP aircraft models and numerical modelling tools used to simulate the performance of TeDP models are reviewed.Finally,innovative turboelectric systems in which electric power savers and mechanical gear changers have been discarded for weight optimisation are presented along with other prospective models,engines,approaches,and architectures.The findings of this review indicate the knowledge gaps in the field of numerical modelling for NASA’s TeDP and its capability to increase the efficiency by up to 24%with a 50%reduction in emissions relative to those of conventional gas turbines.
文摘There is an increasing concern that current trends of consumption of natural resources cannot continue.It is imperative that major targeted investments are made into economical and reliable environment friendly propulsion and power solutions.Many novel and promising concepts are being proposed.The selection of the best candidates to pursue for investment becomes a very difficult choice.A detailed TERA(techno-economic environmental risk analysis) framework is described here to quantify risks and to compare and rank competing schemes on a formal and consistent basis.This technique is based on detailed and rigorous thermodynamic representations of power plants.A layer of environment,economic,weather and other models to describe the appropriate local conditions is superimposed to this.The outcome is a techno-economic environmental risk analysis framework with appropriate detail of each power plant as applied to the appropriate conditions.The results for each concept can then be compared and contrasted to make appropriate selections.
文摘Typically, crude oil production in Nigeria always accompanied by surface production of associated gas. With little associated gas recovery facilities in place, majority of associated gas is continuously flared with few portions re-injected into the reservoir for enhance oil recovery (EOR). In addition to environmental hazards, wasting substantial amount of produced associated gas is deemed detrimental to a country currently generating less than 54% of its electric power requirement. Onsite power generation as one of the many means of utilization of associated gas has been conceived. Conversely, the availability and performance of the gas turbine engine for onsite associated gas utilization requires evaluation owing to variations in associated natural gas composition globally and the dependency of associated gas production on reservoirs and oil production activities. This paper presents an analytical investigation of gas turbine engine inspired by GE LMS100 frame engine for onsite utilization of associated gas in Nigeria. Gas turbine performance results are presented and performance parameters are compared against typical commercial natural gas grade.
文摘This paper focuses on investigations encompassing comparative assessment of gasturbine cycle options.More specifically,investigation was caried out of technical performanceof turboshaft engine cycles based on existing simple cycle(SC)and its projected modifiedcycles for civil helicopter application.Technically,thermal efficiency,specific fuel consump-tion,and power output are of paramount importance to the overall performance of gas urbineengines.In course of carrying out this research,turbomatch software established at CranfieldUniversity based on gas turbine theory was applied to conduct simulation of a simple cycle(baseline)two-spool helicopter turboshaft engine model with free power turbine.Similarly,some modified gas urbine cycle configurations incoporating unconventional components,such as engine cycle with low pressure compressor(LPC)zero-staged,recuperated enginecycle,and intercooled/recuperated(ICR)engine cycle,were also simulated.In doing so,designpoint(DP)and off-design point(OD)performances of the engine models were established.Thepercentage changes in performance parameters of the modified cycle engines over the simplecycle were evaluated and it was found that to a large extent,the modified engine cycles withunconventional components exhibit better performances in terms of thermal efficiency andspecific fuel consumption than the traditional simple cycle engine.This research made use ofpublic domain open source references.
文摘This paper considers comparative assessment of simple and advanced cycle small-scale aero-derivative industrial gas turbines derived from helicopter engines.More particularly,investigation was made of technical performance of the small-scale aero-derivative engine cycles based on existing and projected cycles for applications in industrial power generation,combined heat and power concept,rotating equipment driving,and/or allied processes.The investigation was done by carrying out preliminary design and performance simulation of a simple cycle(baseline)two-spool small-scale aero-derivative turboshaft engine model,and some advanced counterpart aero-derivative configurations.The advanced configurations consist of recuperated and intercooled/recuperated engine cycles of same nominal power rating of 1.567 MW.The baseline model was derived from the conversion of an existing helicopter engine model.In doing so,design point and off-design point performances of the engine models were established.In comparing their performances,it was observed that to a large extent,the advanced engine cycles showed superior performance in terms of thermal efficiency,and specific fuel consumption.In numerical terms,thermal efficiencies of recuperated engine cycle,and intercooled/recuperated engine cycles,over the simple cycle at DP increased by 13.5%,and 14.5%respectively,whereas specific fuel consumption of these cycles over simple cycle at DP decreased by 12.5%,and 13%respectively.This research relied on open access public literature for data.
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.
