Exergy analysis of a turboprop engine at different flight altitude and speeds using novel consideration

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Dinc ◽  
Yousef Gharbia

Abstract In this study, exergy efficiency calculations of a turboprop engine were performed together with main performance parameters such as shaft power, specific fuel consumption, fuel flow, thermal efficiency etc., for a range of flight altitude (0–14 km) and flight speeds (0–0.6 Mach). A novel exergy efficiency formula was derived in terms of specific fuel consumption and it is shown that these two parameters are inversely proportional to each other. Moreover, a novel exergy efficiency and thermal efficiency relation was also derived. The relationship showed that these two parameters are linearly proportional to each other. Exergy efficiency of the turboprop engine was found to be in the range of 23–33%. Thermal efficiency of the turboprop engine was found to be around 25–35%. Exergy efficiency is higher at higher speeds and altitude where the specific fuel consumption is lower. Conversely, exergy efficiency of the engine is lower for lower speeds and altitude where the specific fuel consumption is higher.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Dinc ◽  
Yousef Gharbia

AbstractIn this study, exergy efficiency calculations of a turboprop engine were performed together with main performance parameters such as shaft power, specific fuel consumption, fuel flow, thermal efficiency etc., for a range of flight altitude (0–14 km) and flight speeds (0–0.6 Mach). A novel exergy efficiency formula was derived in terms of specific fuel consumption and it is shown that these two parameters are inversely proportional to each other. Moreover, a novel exergy efficiency and thermal efficiency relation was also derived. The relationship showed that these two parameters are linearly proportional to each other. Exergy efficiency of the turboprop engine was found to be in the range of 23–33%. Thermal efficiency of the turboprop engine was found to be around 25–35%. Exergy efficiency is higher at higher speeds and altitude where the specific fuel consumption is lower. Conversely, exergy efficiency of the engine is lower for lower speeds and altitude where the specific fuel consumption is higher.


2021 ◽  
Vol 8 (1) ◽  
pp. H16-H20
Author(s):  
A.V.N.S. Kiran ◽  
B. Ramanjaneyulu ◽  
M. Lokanath M. ◽  
S. Nagendra ◽  
G.E. Balachander

An increase in fuel utilization to internal combustion engines, variation in gasoline price, reduction of the fossil fuels and natural resources, needs less carbon content in fuel to find an alternative fuel. This paper presents a comparative study of various gasoline blends in a single-cylinder two-stroke SI engine. The present experimental investigation with gasoline blends of butanol and propanol and magnesium partially stabilized zirconium (Mg-PSZ) as thermal barrier coating on piston crown of 100 µm. The samples of gasoline blends were blended with petrol in 1:4 ratios: 20 % of butanol and 80 % of gasoline; 20 % of propanol and 80 % of gasoline. In this work, the following engine characteristics of brake thermal efficiency (BTH), specific fuel consumption (SFC), HC, and CO emissions were measured for both coated and non-coated pistons. Experiments have shown that the thermal efficiency is increased by 2.2 % at P20. The specific fuel consumption is minimized by 2.2 % at P20. Exhaust emissions are minimized by 2.0 % of HC and 2.4 % of CO at B20. The results strongly indicate that the combination of thermal barrier coatings and gasoline blends can improve engine performance and reduce exhaust emissions.


2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Murugan Kuppusamy ◽  
Thirumalai Ramanathan ◽  
Udhayakumar Krishnavel ◽  
Seenivasan Murugesan

The effect of thermal-barrier coatings (TBCs) reduces fuel consumption, effectively improving the engine efficiency. This research focused on a TBC with a thickness of 300 µm insulating the combustion chamber of a direct ignition (DI) engine. The piston crown, inlet and exhaust-valve head were coated using air-plasma-spray coating. Ceramic powder materials such as molybdenum (Mo) and aluminum oxide titanium dioxide (Al2O3-TiO2) were used. A performance test of the engine with the coated combustion chamber was carried out to investigate the brake power, brake thermal efficiency, volumetric efficiency, brake specific fuel consumption and air-fuel ratio. Also, an emission-characteristic test was carried out to investigate the emissions of unburned hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NO, NO2, NO3) and smoke opacity (SO). The results reveal that the brake thermal efficiency and brake specific fuel consumption show significant increases because of these coating materials. The effect of the Al2O3-TiO2 coating significantly reduces the HC and CO engine emissions.


Author(s):  
P.S. Kumar ◽  
S.A. Kannan ◽  
A. Kumar ◽  
K.A.V. Geethan

In this study, for the first time analysis of a low heat rejection engine was carried out along with the addition of oxidation inhibitors. If the combustion chamber components of the engine such as piston, cylinder head, and inlet and outlet valves are insulated with a thermal barrier material, then the engine will be referred as low heat rejection engine. In this study yttria stabilized zirconia was coated on the combustion chamber components for a thickness of about 150 microns. Then the analysis of performance parameters such as brake thermal efficiency and specific fuel consumption and emission characteristics such as emission of carbon monoxide, hydrocarbon and nitrogen oxide was carried out in single cylinder four stroke diesel engine with electrical loading using diesel and pongamia methyl ester as the fuels. The major problem associated with the usage of biodiesels and low heat rejection engine is the increased NOX emission than the normal engine operated with the diesel. This problem has been overcome by the usage of oxidation inhibitors such as ethyl hexyl nitrate (EHN), tert-butyl hydroquinone (TBHQ). The results showed that addition of oxidation inhibitors leads to increase in brake thermal efficiency, reduced specific fuel consumption and reduced NOX emission.


2011 ◽  
Vol 142 ◽  
pp. 103-106
Author(s):  
Wen Ming Cheng ◽  
Hui Xie ◽  
Gang Li

This paper discusses the brake specific fuel consumption and brake thermal efficiency of a diesel engine using cottonseed biodiesel blended with diesel fuel. A series of experiments were conducted for the various blends under varying load conditions at a speed of 1500 rpm and 2500 rpm and the results were compared with the neat diesel. From the results, it is found that the brake specific fuel consumption of cottonseed biodiesel is slightly higher than that of diesel fuel at different engine loads and speeds, with this increase being higher the higher the percentage of the biodiesel in the blend. And the brake thermal efficiency of cottonseed biodiesel is nearly similar to that of diesel fuel at different engine loads and speeds. From the investigation, it is concluded that cottonseed biodiesl can be directly used in diesel engines without any modifications, at least in small blending ratios.


Author(s):  
O. K. Fadele ◽  
M. B. Usman ◽  
O. C. Ariyo ◽  
U. U. Emeghara ◽  
D. O. Adelani ◽  
...  

In this study, an electrically aerated stove was developed using locally available materials. The performance of the stove was evaluated by utilizing briquettes produced from pyrolyzed jatropha shell and Eucalyptus camadulensis wood shavings. Thermal parameters such as thermal efficiency, power output, specific fuel consumption and burning rate were determined. The mean values obtained for the thermal efficiency, power output, specific fuel consumption and burning rate were 7.62 %, 1685 J/s, 0.2377 g/g, 330.90 g/hr respectively. The performance of the briquette stove was considered to not be suboptimal. The thermal efficiency can further be improved by proper insulation and adequate utilization of the heat generated in the combustion chamber.


Many researchers have been working on bio-based lubricant which is complete or partial replacement for mineralbased lubricant. Mineral-based lubricant is highly pollutant and possesses environmental threat as it is not biodegradable, in the initial days of the industrial revolution bio-based lubricants were widely used, later it was replaced by more sustainable and easily available but environmental polluting mineral oils, currently due to environmental concerns and scarcity of mineral oils, bio-based lubricant has gained importance. Bio-based lubricants are now a day’s used for various applications such as transformer oil and processes where there is complete loss of lubricants. They possess very good properties in such applications, whereas bio-based lubricants are also used internal combustion engines, pure biobased lubricant may not be suitable for long-duration, but genetically and chemically modified bio-based lubricants will be suitable for IC engine. Though bio-based lubricant possesses many good properties as a lubricant for IC engine and various other application, it is still at large to become commercial, more study is required for checking performance of such pure and modified bio-based lubricants oils, in this paper such study of cotton seed Trimethylolpropane (TMP) ester oil and its effects on performance of brake specific fuel consumption (BSFC), brake thermal efficiency (BTh) and emission of gases like hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2 ) nitrogen oxides (NOx ) are studied, bio-based have poor cold flow properties and oxidation stability to improve these additives are added. The experimental study shows that Cottonseed Trimethylolpropane Ester (CSTE) displays similar characteristics of thermal efficiency, brake specific fuel consumption and emission of gases as compared to mineralbased lubricating oil hence can be used in the IC engine instead of mineral-based lubricants


2021 ◽  
Author(s):  
Naveen Rana ◽  
Harikrishna Nagwan ◽  
Kannan Manickam

Abstract Indeed, the development of alternative fuels for use in internal combustion engines has become an essential requirement to meet the energy demand and to deal with the different problems related to fuel. The research in this domain leads to the identification of adverse fuel properties and for their solution standard limits are being defined. This paper outlines an investigation of performance and combustion characteristics of a 4-stroke diesel engine using different cymbopogon (lemongrass) - diesel fuel blends. 10% to 40% cymbopogon is mixed with diesel fuel and tested for performance characteristics like brake specific fuel consumption and brake thermal efficiency. To obtain emission characteristics smoke density in the terms of HSU has been measured. In result, it has observed that there is an increase of 5% in brake thermal efficiency and 16.33% decrease in brake specific fuel consumption. Regarding emission characteristics, a 12.9% decrease in smoke emission has been found.


Author(s):  
Konrad Vogeler

ABB has designed a new family of industrial gasturbines for power generation using a Sequential Combustion Cycle (SCC) on a large single shaft engine. This concept allows considerable increase in power density and efficiency by only increasing pressure without raising the maximum hot gas temperature of the cycle. Instead a second combustion after an HP-turbine is used to reheat the gas before the final expansion in an LP-turbine. This concept is applied to the analysis of a high bypass ratio jet engine. In an engine with a single combustor, thrust is a function of bypass ratio and the combination of maximum pressure and temperature in the cycle. The proposed SCC allows increased thrust without pushing technology on materials and cooling. A modern twin spool engine is taken as reference. When total inlet massflow is kept constant, increasing bypass ratio decreases core mass flow. This limits the fuel flow for the HP-spool and hence total energy input to the engine. Introduction of the SCC gives another parameter of freedom to the cycle design. However the twin spool concept is now a disadvantage. The low fuel flow for the HP-spool due to high bypass ratio means there is not enough energy available to build up the necessary pressure for an economical expansion in the LP-turbine after the second combustion. Specific fuel consumption will be unacceptable. It is proposed to apply the SCC concept in a single spool engine with a geared fan. Both turbines can now support the compression. The fan is operated as a constant speed propeller with variable blade pitch. This engine concept allows for a given inlet massflow a substantially higher bypass ratio and hence decreases specific fuel consumption while specific thrust can be kept on a level which will be considerably higher than it would be in todays engines with comparable bypass ratio.


2014 ◽  
Vol 984-985 ◽  
pp. 950-956
Author(s):  
S. Arumugam ◽  
N. Vasudevan ◽  
P. Saravanan ◽  
K. Pitchandi

The experimental work investigates performance, combustion and emission analysis for various combustion chamber geometry such as combustion, brake thermal efficiency, specific fuel consumption, and emission characteristics. The various combustion chamber namely Spherical chamber (SC), Toroidal chamber (TC), Re-entrant chamber (RC) were fitted in a 4.4 kW single cylinder air cooled Compression ignition (CI) engine and tests were conducted with standard diesel. The investigated of the combustion chamber geometry characteristics on combustion, performance and emissions. This investigation shows brake thermal efficiency for Re-entrant chamber and Toroidal chamber is slightly higher than Spherical chamber. And lower specific fuel consumption of Toroidal chamber, Re-entrant chamber than that of Spherical chamber. The enhancement in reduction of carbon monoxide, hydrocarbon is recorded for Re-entrant chamber compared to the Toroidal chamber and Spherical chamber. Oxides of nitrogen are reduced for Re-entrant chamber and Toroidal chamber than that of Spherical chamber. Combustion characteristics improved for Re-entrant chamber compared to Spherical chamber. The cylinder pressure for Re-entrant chamber and Toroidal chamber is higher than that of Spherical chamber. Also obtained maximum heat release rate for Re-entrant chamber than Toroidal chamber and Spherical chamber.


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