Hydrogen burns with high flame front speed. This allows hydrogen engines to thermodynamically more closely approach the constant volume heat addition ideal cycle. This resemblance is adequate for stoichiometric mixture, when hydrogen engine runs lean to improve fuel economy and reduce nitrogen oxides, the flame speed slows down. However, it is still very much higher than the gasoline-air mixture flame speed  . Flame speed and maximum combustion temperature are of prime concern for thermal efficiency and emissions.
ABSTRACT: A Thermal power plant consist of various cycles and subsystems like air & flue gas cycle, main steam cycle , feed water & condensate water cycle , fuel & ash cycle, Equipment cooling water (ECW), auxiliary cooling water (ACW) system, Compressed air system ,Electrical auxiliary power & lighting system, HVAC system etc . In India , most thermal power plants employing sub critical technology are able to work only at 30 - 40 percent efficiency . The remaining 60 - 70 %is lost during generation, transmission and distribution out of which the predominant loss is in the form of heat . This paper demonstrates the major energy saving potential areas and methods to improve the overall efficiency of a thermal power plant .
Gas turbine cogeneration systems find applications in buildings, industry and others. The appropriate cogeneration system for a specific purpose is chosen with respect to some criteria such as efficiency, heat to power ratio and the grade of heat. Obtaining high efficiency depends on some factors such as reduced auxiliary power consumption, increased gas turbine inlet temperature, fuel preheating, advanced gas turbine cooling, inter-cooling, hydrogen cooled generators, low compressor inlet air temperature, high compressor inlet air pressure, high compressor inlet air humidity, multiple pressure cycle with reheat and better HRSG design [4, 5, 6]. There are many gas turbines cogeneration systems on the market, however they differ in efficiency, power output, pressure ratio, exhaust temperature, firing temperature, etc.
There is numerous classification of internal combustion engine which fall into types of ignition, basic design, numbers of cylinders, engine cycle and fuel used. Most of internal combustion engine are reciprocating engines where the pistons went back and forth in the cylinder. At closed end at each cylinder locates the combustion chamber. There can be a single cylinder or more than one cylinder which can reach more than 20 cylinders where the piston is connected to the crank shaft.
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Abstract: Biomass fuel as carbon neutral, abundant, domestic, cost effective is being reconsidered to fuel-up the power plant to produce electricity in clean way. But utilization of biomass fuel directly in existing conventional power plant causes problem in turbine such as erosion, hot corrosion, clogging and depositions . As such combustion of biomass fuel outside the primary cycle eradicates potential hazards for turbine. In such a case indirectly fired micro gas turbine opens a door to biomass fuel as this technology is free from negative aspects of direct combustion as well as making micro gas turbine feasible to generate electricity in small scale at non-grid areas for individual consumer or group of consumers. In this research, the effect of different types of biomass fuel on operating parameters as well as on output electrical power of externally fired micro gas turbine (EFmGT)has been analyzed. The biomass fuels are categorized on the basis of air to fuel ratio (AFR) using stoichiometry combustion theory. It is found from results that parameters like air mass flow rate, compression ratio, heat exchanger effectiveness, turbine inlet temperature, combustion temperature, and temperature difference in heat exchanger affect the performance of EFmGT. Also types of biomass fuel have substantial impacts on these performance parameters as well as on electrical power output of EFmGT cycle.
In this study a computational model to simulate the operation of a diesel engine fuelled by blends of 95% diesel oil + 5 % biodiesel (B5) and anhydrous ethanol was developed. The model was developed using the Engineering Equation Solver (EES) software and calculates fuel and air properties and the thermodynamic processes of the engine cycle. Ethanol injection was investigated by two different techniques: direct injection in the combustion chamber, together with B5, and indirect injection in the intake air system, with B5 being directly injected in the combustion chamber. Fuel/air mixture equivalence ratio, compression ratio, and the injected amount of ethanol were varied to obtain the cycle temperature and pressure diagrams, fuel consumption, indicated power, and exhaust gas composition. Fuel/air mixture equivalence ratio was varied from 0.7 to 0.9, compression ratio was varied from 15:1 to 19:1, directly injected ethanol concentration was varied up to 20 % of the total fuel amount injected, and intake system injected ethanol concentration was varied up to 50 % of the total fuel amount injected. The results demonstrate that the use of ethanol can reduce carbon monoxide (CO) and oxides of nitrogen (NO X ) emissions, slightly penalizing
The electric system of the Tu-154M aircraft is an out- dated system typical for aircraft being designed in the 1960s. Reversed design and analysis of GT40PCh6 main synchronous generators deliver important information on steady-state and transient performance of these ma- chines. Transient characteristics, especially short-circuit waveforms are very helpful in investigation of electric power system after crash. Credibility of flight parame- ters for electrical equipment and installation (Fig. 1.15) is questionable. There is not enough information how the recorded parameters have been secured, extracted and analyzed [13, 15]. It is now very difficult to find out if the electric power system was operating correctly in the last seconds of crash or not. According to [13, 15], the flight management system (FMS) lost electric power (memory freezing) at 10:41:05, i.e., at the time of colli- sion with ground. Table 1.3 show standard procedure for examination of electrical equipment and installation af- ter crash [18, 53]. The electrical equipment and wiring at the crash site was only inspected visually [13, 15]. There is still possible to examine synchronous genera- tors and induction motors for fuel pumps and for other on-board equipment, e.g., air conditioning system pro- vided that independent investigators will have access to the wreckage.
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The fuel life-cycle is the core concept of this study. If hydrogen is to be used as a transportation fuel, it must be produced, and the production of hydrogen requires both resources and energy. This is the reason why comparing the fuel life-cycle and not just the vehicle emissions is vitally important when discussing hydrogen. To demonstrate how fuel life-cycles work, the conventional fuel life-cycle pathway of gasoline is evaluated. First, crude oil must be extracted from the ground. Second, the crude oil must be transported from the location of extraction to a refining facility. In the U.S. the majority of oil comes from outside the country in the form of crude oil and is refined upon arrival to the U.S. The crude oil is then refined and processed into gasoline. Gasoline is then distributed to refueling stations all over the U.S. via pipeline or tanker trucks. And finally, gasoline is consumed in the light-duty transportation sector by internal combustion engines. Every step along the pathway has some associated emissions that make up fuel life-cycle emissions beginning with extraction of the crude oil and ending with combustion of gasoline.
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Ashes can cause a lot of problems in gasifiers. The compounds may melt and agglomerate producing clinker and causing slagging. This slag has to be removed which increases the need for workforce, causes a break for operation and thus increases costs. The occurrence of slagging depends on the ash content of the fuel, the melt- ing characteristics of the ash and the temperature profile of the gasifier. Usually slagging causes no troubles if the ash content of the fuel is lower than 5% - 6% . Bamboo contains approximately 3% - 5% of ash so slag- ging should not be a major problem but still the ash melting needs to be looked out for.
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The selected volume of the pilot fuel injection (5- 10% of the maximum fuel supply) was adopted in view of the conditions for achieving the maximum economic feasibility. But at such values of fuel delivery rate, at heavy loads there is a problem of high heat density of the injection nozzle. There are two possible ways to reduce the thermal load on the injection nozzle. The first way is to increase the diesel fuel delivery rate (in this case, the method is not acceptable). The second is to increase the expiration time of the minimum value of fuel delivery rate. The second way can be implemented by reducing the pressure in the fuel rail.
produced from agricultural feed stocks, such as sugarcane and also from forestry wood wastes and agricultural residues. It can also be derived chemically from ethylene or ethane. Ethanol has a simple molecular structure with well- defined physical and chemical properties. Ethanol can be employed as a transportation fuel even in its original form and can also be easily blended with other fuels, such as gasoline and diesel. Currently, there is a lot of interest in ethanol production from renewable feed stocks, to minimize the emissions of carbon dioxide, which is a greenhouse gas that contributes to global warming. The addition of ethanol to gasoline results in the enhancement of the octane number in blended fuels and changes the distillation temperature, as well as reducing CO 2 emissions.
Fig.4 shows that pressure ratio is directly proportional to the cycle thermal efficiency. Increasing the pressure ratio will improve the thermal efficiency of the cycle since the net work produced by the flue gases when they expand at higher pressure in the turbine is higher compared to the same at lower pressure. At pressure ratio of 53% of designed PR the GT gives 30.75% thermal efficiency which is the minimum value that the cycle can be allowed to operate at.
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An internal combustion engine is a device that converts chemical energy (fuel) to heat energy (combustion of fuel) to pressure energy (pressure forcing the piston down) to mechanical energy (movement of piston) [1-6]. Throughout these conversions process, it is desirable to maximize the efficiency of these conversions. All this is done within the engine itself, hence the name internal combustion engine. There are generally two types of internal combustion engine; spark ignition engines also known as Otto, gasoline or petrol engines, and compression ignition engines also known as a diesel engine [7-12]. The high energy density of the fuel used and the simplicity, ruggedness and high power to weight ratio of the internal combustion engine secured its wide application in the transportation (land, sea and air) and power generation sector. This project is focused on a new approach to designing and manufacturing cylinder heads for a low volume production using CNC machining instead of the conventional method like die and sand casting. As the cylinder head will be CNC machined, it will be designed with varying thickness with channels to direct more coolant to the hotspots such as the valve seat, valve stem and sparkplug. This will minimize the temperature variation over the cylinder head. The above approach will include bolting and sealing the 3 major parts of the cylinder head to the cylinder block. The placement of inlet and outlet of the coolant will be controlled by the packaging of the engine. CFD analysis will not be part of the scope of this project.
available for both takeoff and cruise conditions. We chose to compare takeoff level static condition (SLS), dry] for this survey because data are available for this operating condition. The figure Many military engines use afterburners to boost the takeoff thrust level as much as 80%. However, analyzing data for military jet engines with their afterburners turned off east 20 times more powerful. These data also show a dramatic enhancement in thrust 1980s as a result of many factors. For example, in the civil sector the worldwide boom in air travel created a market rust engines to propel them. Also, in the United States, the IHPTET program initiated in October 1987 led to a coordinated effort between government and industry to significantly enhance military turbo propulsion emperature composite materials and the computer revolution also made possible the
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In the experiment, maintain constant fuel injection pressure 4 bar and air pressure 3 bar and vary the flow rate of fuel from 10ml/min to 60 ml/min and air 2 LPM to18 LPM. For find out quenching diameter use copper pipe having length 150mm and different inside diameter (5,7,9,11,15 mm) and pass the flame of different cross section pipe maintaining the same fuel and air pressure for diesel ,J10 and J20.
Apart from that, growing population and overuse of fossil fuel is also a critical problem nowadays. Improvement of technology had led to a greater use of hydrocarbon fuels. Thus, it is necessitates the search for alternative oil as energy source to replace or reduce the usage of hydrocarbon fuels [9, 10]. Besides, renewable energy sources are greatly developed all around the world due to attractive oil prices and limited greenhouse gas emissions. Biodiesel is an alternative fuel with esters of vegetable oils and animal fats act as the renewable sources to made biodiesel [9, 11]. Biodiesel has more beneficial combustion emission profile compared to the petroleum-based diesel such as low emissions of particulate matter, unburned hydrocarbons and carbon monoxide (CO). Photosynthesis process has taken part to recycle the carbon dioxide produced by the combustion of biodiesel in order to minimize the influences of biodiesel combustion on the greenhouse effect [12-14].
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The EQL0D procedure is a MATLAB ® - and Serpent- based burn-up calculation tool with specific features for the simulation of MSR fuel cycles . It uses the Serpent Monte-Carlo code  to obtain and update neutron reac- tion rates then used by the MATLAB ® script to compute fuel evolution using the Chebyshev Rational Approxi- mation Method (CRAM, ) and criticality. EQL0D can perform the necessary changes to fuel composition (removal of FPs, refueling, criticality control by compo- sition adjustments, etc.) in a batch-wise or continuous (on-line) manner to simulate various fuel cycles. Finally, it possesses both standard finite-step burn-up and equi- librium search modes. In the calculations shown in this paper, insoluble and volatile FPs are removed with a 30 s removal time.
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It is equally important to control for proper airflow. To event process disturbances causes by airflow disruptions originating outside the boiler a cascade system must be established. Such an airflow control loop would consist a flow transmitter measuring airflow and sending its signal directly to an air flow controller as the measured variables. The boiler master thus originates the signal used as flow demand; it becomes the set point of the air flow controller in turn, the air flow controller’s output goes to an inlet line or a speed control on the forced draft fan, establishing combustion air flow.
A fully three-dimensional flow, heat transfer and combustion computer model was developed by Boyd et al  for tangentially fired pulverized fuel furnaces. The complete model solves equations for gas momentum and mixing, particle trajectories and combustion and energy conservation with radiation transfer. Zheng et al.  presented numerical and experimental study on reduction of NOx emissions in the furnace of a tangentially fired boiler under different operating conditions using a simplified NOx formation mechanism model.
injector and found that combustion efficiency, depending on injector arrangement, is directly related to characteristic chamber length L*. Efficiency of characteristic velocity ηc* decreases with increase in characteristic chamber length .In order to increase ηc* at increased chamber length additional chamber insulation required. They found that without the implementation of combustion chamber insulation the swirl coaxial injector arrangements requires shorter L* to achieve higher efficiencies. A higher value of L* actually resulted in decreased ηc*, mainly due to heat loss through the chamber walls which can be minimize by combustion chamber insulation. James f. Driscoll et al, (1991) demonstrates how to maximize the amount of coaxial air that can be provided to a nonpremixed jet flame without causing the flame to blow out by optimizes different parameters. They investigated that in order to minimize NO x emission and size of combustor, coaxial