Optimisation of Support Fuel Consumption Burning Low Heat Value Gas Using Controlled Combustion Oscillations

2015 ◽  
Author(s):  
Fabrice Giuliani ◽  
Vanessa Moosbrugger ◽  
Markus Stuetz ◽  
Thomas Leitgeb-Simandl
Keyword(s):  
Landfill Gas ◽  
Combustion Process ◽  
Methane Emissions ◽  
Inlet Temperature ◽  
Technical Solution ◽  
Ambient Conditions ◽  
Pulse Combustion ◽  
Combustion Technology ◽  
Heat Value ◽  
Approach Zero

The purpose of this work is to develop a new combustion technology to reduce the operation costs of thermal systems that burn low heat value gases. Landfill methane emission is a greenhouse gas source which can be defined and reduced. Landfill managing companies in Austria have adapted the latest regulations on methane emissions primarily by collecting and flaring off landfill gas, sometimes with energy recovery. Their concern is related to long-term landfills where the methane concentration by volume falls well below 20%. The costs to flare-off these gases are mostly driven by the use of support fuel to ensure combustion. A technical solution using the programme MethaNull (to approach zero methane emissions) is proposed to extend the combustion domain of gases with low heat value so that the amount of support fuel can be significantly reduced. This solution should fit a large range of LHV gases, for combustion at ambient conditions as well as under pressure at elevated inlet temperature conditions. The process has similarities with pulse combustion, where the combustion process benefits from a higher energy density and better heat transfer rates. As the forced pulsation is generated by a separate module, the methodology can be easily adapted or retrofitted for existing facilities. This paper covers the MethaNull programme, the burner design, the flow pulsation technology and its operation. A systematic comparison between steady state and oscillating combustion is presented.

Pulse Combustion Technology

2006 ◽  
Author(s):  
Gene Plavnik
Keyword(s):  
Combustion Process ◽  
Industrial Applications ◽  
Waste To Energy ◽  
State Variables ◽  
Pulse Combustion ◽  
Combustion Technology

Pulse combustion has been used in a variety of ways since first being discovered in 1877. This a combustion process that occurs under oscillatory conditions with changing state variables, such as pressure, temperature and velocity. This paper looks at the historic uses of pulse combustion, and it provides an overview of this unique process. Pulse combustion has been used to amplify thrust power with the German V-1 rockets. Pulse combustion has been used to optimize flame efficiencies, and it is now reemerging in many new industrial applications including some for Waste to Energy.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

Characteristics of Preheated Bio-Oil Sprays Produced by an Air-Blast Injector

2010 ◽  
Author(s):  
Heena V. Panchasara ◽  
Ajay K. Agrawal
Keyword(s):  
Laser Sheet ◽  
Inlet Temperature ◽  
Mass Ratio ◽  
Ambient Conditions ◽  
Air Blast ◽  
Visualization System ◽  
Radial Profiles ◽  
Significant Difference ◽  
Bio Oil ◽  
Temperature And Pressure

In this study the vegetable oil (VO) is preheated to reduce the kinematic viscosity, and thus, improve atomization. A commercial air-blast atomizer is used to produce the VO spray at ambient conditions of temperature and pressure. Characteristics of the resulting spray are measured using a laser sheet visualization system and a Phase Doppler Particle Analyzer system. Experiments are conducted for VO temperatures varying from 40 C to 100 C and air to liquid mass ratio (ALR) of 2.0 and 4.0. Results show a decrease in Sauter Mean Diameter with an increase in VO temperature, regardless of the ALR. Radial profiles show larger droplets migrating towards the edge of the spray and smaller droplets in the interior spray region. Results show a significant difference in distributions of mean and root mean square axial velocity profiles as the VO inlet temperature is increased for a fixed ALR. Higher VO inlet temperature and higher ALR produced a narrower spray with smaller diameter droplets and higher peak axial velocities. Overall, this study has shown that preheating VO improves atomization by producing spray with smaller diameter droplets.

The Effects of Ambient Conditions on Gas Turbine Emissions—Generalized Correction Factors

1978 ◽  
Vol 100 (4) ◽  
pp. 640-646 ◽  
Author(s):  
P. Donovan ◽  
T. Cackette
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Correction Factors ◽  
Oxides Of Nitrogen ◽  
Ambient Conditions ◽  
Nitrogen Emission ◽  
Wide Range

A set of factors which reduces the variability due to ambient conditions of the hydrocarbon, carbon monoxide, and oxides of nitrogen emission indices has been developed. These factors can be used to correct an emission index to reference day ambient conditions. The correction factors, which vary with engine rated pressure ratio for NOx and idle pressure ratio for HC and CO, can be applied to a wide range of current technology gas turbine engines. The factors are a function of only the combustor inlet temperature and ambient humidity.

Gas Turbine Corrected Parameters Control: Humidity Correction – Sensors Evaluation and Selection

2002 ◽  
Author(s):  
Malath I. Arar
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Specific Humidity ◽  
Inlet Temperature ◽  
Ambient Conditions ◽  
Humidity Measurement ◽  
Nox Abatement ◽  
Test Criterion ◽  
Control Methodology ◽  
Performance Enhancing

Gas Turbine, GT, control methodology applied to power generation is being evaluated. Corrected parameter control methodology has been adopted for this purpose. This method uses the corrected physical ambient conditions such as pressure, temperature and humidity in controlling the GT operations. Humidity correction becomes increasingly important in this control scheme. The following are the reasons for accurate and robust humidity measurement: (1) Humidity measurement is important to the operation control of the dry low NOX, DLN, combustor system. (2) GT inlet performance enhancing devices, such as evaporative coolers and inlet foggers, depend upon the accurate humidity measurement to determine the amount of water needed for inlet temperature depression. (3) Humidity measurement is used to determine the amount of water to be injected in the combustor for NOX abatement when running on liquid fuel as an alternative to natural gas fuel. In order to obtain accurate and reliable humidity readings, several commercially available humidity sensors were extensively tested and evaluated in a controlled laboratory environment. The sensors were tested for their measurement accuracy, saturation conditions, power interruption and surge, sudden temperature changes and medium air speed. Test ambient temperature ranges from −30 °C to 50 °C. This covers the operating ambient conditions range for the Gas Turbine. The test criterion is that the error in the response of the sensor shall not exceed ±1 °C from the test reference for all the tests conducted on the sensors. The combustion requirements for Dry Low NOX operations and mode transfer dictate this criterion. Also, as a DLN requirement, error in specific humidity shall not exceed 0.904 g/g of air. This test criterion also satisfies the water injection requirements for NOX abatement and inlet performance enhancing devices. The results show that for ±1 °C error in the sensor measurement, the resulting error in NOX calculation is less than 0.2 ppm. The test results show that all sensors except the current one in use have met the test criterion. The current sensor, General Eastern DT-2, has a large measurement error in the order of ±5 °C. Programs have been launched to field test and evaluate these sensors in order to replace the current one.

Numerical Simulation on Moisture Influence to MSW Combustion

2014 ◽  
Vol 1006-1007 ◽  
pp. 181-184
Author(s):  
Zhu Sen Yang ◽  
Xing Hua Liu ◽  
Shu Chen
Keyword(s):  
Numerical Simulation ◽  
Moisture Content ◽  
Flue Gas ◽  
Combustion Process ◽  
Average Temperature ◽  
Excess Air ◽  
Heat Value ◽  
Moisture Influence ◽  
Excess Air Coefficient ◽  
Combustible Gases

The combustion process of municipal solid waste (MSW) in a operating 750t/d grate furnace in Guangzhou was researched by means of numerical simulation. The influence of MSW moisture content on burning effect was discussed. The results show that: with the moisture content dropped from 50% to 30%, the heat value could be evaluated from 13.72% to 54.91% and the average temperature in the furnace could be promoted 90-248°C. However, the combustible gases and particle in the flue gas of outlet would take up a high proportion since lacking of oxygen would lead to an incomplete combustion. The excess air coefficient should be increased to 2.043~2.593 in order to ensure the flue gas residence time more than 2s and temperature in the furnace higher to 800°C.

scholarly journals Hydrogen application in internal combustion engines

2020 ◽  
Vol 21 (1) ◽  
pp. 14-19
Author(s):  
Arthur R. Asoyan ◽  
Igor K. Danilov ◽  
Igor A. Asoyan ◽  
Georgy M. Polishchuk
Keyword(s):  
Burning Rate ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Hydrocarbon Fuel ◽  
Internal Combustion ◽  
Technical Solution ◽  
Combustion Engines ◽  
Environmental Friendliness ◽  
Petroleum Origin ◽  
Order Of Magnitude

A technical solution has been proposed to reduce the consumption of basic hydrocarbon fuel, to improve the technical, economic and environmental performance of internal combustion engines by affecting the combustion process of the fuel-air mixture with a minimum effective mass fraction of hydrogen additive in the fuel-air mixture. The burning rate of hydrogen-air mixtures is an order of magnitude greater than the burning rate of similar mixtures based on gasoline or diesel fuel, compared with the former, they are favorably distinguished by their greater detonation stability. With minimal additions of hydrogen to the fuel-air charge, its combustion time is significantly reduced, since hydrogen, having previously mixed with a portion of the air entering the cylinder and burning itself, effectively ignites the mixture in its entirety. Issues related to the accumulation of hydrogen on board the car, its storage, explosion safety, etc., significantly inhibit the development of mass production of cars using hydrogen fuel. The described technical solution allows the generation of hydrogen on board the car and without accumulation to use it as an additive to the main fuel in internal combustion engines. The technical result is to reduce the consumption of hydrocarbon fuels (of petroleum origin) and increase the environmental friendliness of the car due to the reduction of the emission of harmful substances in exhaust gases.

scholarly journals Optimizing Pulse Combustion Parameters in Carbon Anode Baking Furnaces for Aluminum Production

2019 ◽  
Author(s):  
Abdul Raouf Tajik ◽  
Tariq Shamim ◽  
Ahmed F. Ghoniem ◽  
Rashid K. Abu Al-Rub
Keyword(s):  
Energy Efficiency ◽  
Response Surface ◽  
Oxygen Concentration ◽  
Fractional Factorial ◽  
Pollutant Emissions ◽  
Aluminum Production ◽  
Carbon Anode ◽  
Physical Parameters ◽  
Inlet Temperature ◽  
Pulse Combustion

Abstract Pulsating flame jets have been widely used in open-top carbon anode baking furnaces for aluminum electrolysis. Reducing energy consumption and pollutant emissions are still major challenges in baking (heat-treatment) carbon anode blocks. It is also of immense significance to bake all the anodes uniformly irrespective of their position in the furnace. Baking homogeneity can be enhanced noticeably by optimizing anode baking operational, geometrical, and physical parameters. In the present study, CFD simulations are combined with a response surface methodology to investigate and optimize the effects of pulse pressure, pulse frequency, and mainstream inlet oxygen concentration and mainstream inlet temperature. Two-levels half fractional factorial design with a center point is employed. It is perceived that pulse combustion with short pulse time and high momentum results in significant enhancement of the anode baking furnace energy efficiency. The temperature homogeneity is also significantly improved. It is found that the oxygen concentration is statistically the most significant parameter on NOx and soot formations, followed by the fuel flow rate. For NOx formation, air inlet oxygen concentration has a strong interaction with pulse duration. Coupling CFD models with the response surface methodologies demonstrated great potential in multi-objective optimization of the anode baking process with enhanced energy efficiency and baking uniformity.

scholarly journals A Thermodynamic Analysis of an Air-Cooled Proton Exchange Membrane Fuel Cell Operated in Different Climate Regions

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2611 ◽  
Author(s):  
Torsten Berning ◽  
Søren Knudsen Kær
Keyword(s):  
Fuel Cell ◽  
Thermodynamic Analysis ◽  
Operating Temperature ◽  
Flame Temperature ◽  
Combustion Process ◽  
Cell Voltage ◽  
Proton Exchange ◽  
Outlet Temperature ◽  
Flow Ratio ◽  
Ambient Conditions

A fundamental thermodynamic analysis of an air-cooled fuel cell, where the reactant air stream is also the coolant stream, is presented. The adiabatic cell temperature of such a fuel cell is calculated in a similar way as the adiabatic flame temperature in a combustion process. Diagrams that show the dependency of the cathode outlet temperature, the stoichiometric flow ratio and the operating cell voltage are developed. These diagrams can help fuel cell manufacturers to identify a suitable blower and a suitable operating regime for their fuel cell stacks. It is found that for standard conditions, reasonable cell temperatures are obtained for cathode stoichiometric flow ratios of ξ = 50 and higher, which is in very good agreement with manufacturer’s recommendations. Under very cold ambient conditions, the suggested stoichiometric flow ratio is only in the range of ξ = 20 in order to obtain a useful fuel cell operating temperature. The outside relative humidity only plays a role at ambient temperatures above 40 °C, and the predicted stoichiometric flow ratios should be above ξ = 70 in this region. From a thermodynamic perspective, it is suggested that the adiabatic outlet temperature is a suitable definition of the fuel cell operating temperature.

Design, Analysis, and Manufacture of an Axial Length-Saving Disk-Oriented Engine

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Bennett M. Staton ◽  
Brian T. Bohan ◽  
Marc D. Polanka ◽  
Larry P. Goss
Keyword(s):  
Gas Turbine ◽  
Axial Length ◽  
Electric Propulsion ◽  
Guide Vane ◽  
Combustion Process ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Turbine Engine ◽  
Power Extraction ◽  
Turbine Inlet

Abstract A disk-oriented engine was designed to reduce the overall length of a gas turbine engine, combining a single-stage centrifugal compressor and radial in-flow turbine (RIT) in a back-to-back configuration. The focus of this research was to understand how this unique flow path impacted the combustion process. Computational analysis was accomplished to determine the feasibility of reducing the axial length of a gas turbine engine utilizing circumferential combustion. The desire was to maintain circumferential swirl from the compressor through a U-bend combustion path. The U-bend reverses the outboard flow from the compressor into an integrated turbine guide vane in preparation for power extraction by the RIT. The computational targets for this design were a turbine inlet temperature of 1300 K, operating with a 3% total pressure drop across the combustor, and a turbine inlet pattern factor (PF) of 0.24 to produce a cycle capable of creating 668 N of thrust. By wrapping the combustion chamber about the circumference of the turbomachinery, the axial length of the entire engine was reduced. Reallocating the combustor volume from the axial to radial orientation reduced the overall length of the system up to 40%, improving the mobility and modularity of gas turbine power in specific applications. This reduction in axial length could be applied to electric power generation for both ground power and airborne distributive electric propulsion. Computational results were further compared to experimental velocity measurements on custom fuel–air swirl injectors at mass flow conditions representative of 668 N of thrust, providing qualitative and quantitative insight into the stability of the flame anchoring system. From this design, a full-scale physical model of the disk-oriented engine was designed for combustion analysis.

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