Development and Optimization of a Small Scale Pellet Burner

2012 ◽  
Author(s):  
José Carlos Teixeira ◽  
Rui Ferreira ◽  
Eurico A. Seabra ◽  
Manuel Eduardo Ferreira
Keyword(s):  
Fossil Fuels ◽  
High Efficiency ◽  
Practical Interest ◽  
Direct Conversion ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Small Scale ◽  
Cylindrical Shape ◽  
Load Range ◽  
Air Supply

Environmental concerns and the drive to reduce the dependence on petroleum brought the use of renewable energies to the forefront. Biomass appears as a very interesting alternative for direct conversion into heat. In this context, densified forms of biomass such as pellets are of great relevance because of their easy of use, high efficiency and low emissions. The practical interest in pellet combustion has been driven by the domestic heating sector, which favors the characteristics that are intrinsic of this fuel, despite its relatively higher price. However, the growing costs of fossil fuels have extended the interest of pellet fuels into industrial applications, including co-firing in power stations. A fast growing market includes the retrofitting of existing fuel boilers and furnaces with alternative burners that can be fitted into existing combustion systems. Such an approach has proved very attractive due to the low installation cost and the growing existence of fuels produced in the vicinity of the end user. This involves in most cases a custom built application which requires a high level of flexibility to variable operating conditions. This work reports on the development of a 120 kW pellet burner. A prototype of the burner was built that enables the independent control of the air supply into various regions of the combustion chamber and an accurate supply of fuel. The burner was fitted into a testing furnace of cylindrical shape oriented horizontally. Its diameter is 0.5 m and is constructed in a modular fashion with a total length of 2.2 m. All the facility is fully instrumented and includes: temperature data in various locations inside the chamber, flue gases emissions (CO, CO2, NOx) measurements and flow rates. The objective of the test and development is to optimize the combustion over the thermal load range of the facility. The excess air, fuel supply (primary and secondary) and the shape of the furnace grate enable the optimization of the burner with CO emissions of approximately 50 ppm, well below the acceptable limits.

Optimization of a Small Scale Pellet Boiler

2010 ◽  
Author(s):  
Jose´ Carlos Teixeira ◽  
Rui Ferreira ◽  
Manuel Eduardo Ferreira
Keyword(s):  
Heat Dissipation ◽  
High Efficiency ◽  
Raw Materials ◽  
Direct Conversion ◽  
Pollutant Emissions ◽  
Small Scale ◽  
Air Supply ◽  
Wide Range ◽  
Great Relevance ◽  
Secondary Air

Environmental concerns and the drive to reduce the dependence on petroleum based fuels brought the use of renewable energies to the forefront. Biomass appears as a very interesting option for direct conversion into heat. In this context, densified forms of biomass such as pellets are of great relevance because of their easy of use, high efficiency and low emissions. Expected trends in the biomass market suggest that equipments should operate over a wide range of thermal loads and with fuels derived from lower quality raw materials; simultaneously, a high efficiency and low emissions are taken for granted. Currently, biomass domestic boilers prove to be very sensitive to fuel characteristics and load conditions. This work reports on the development of a 15 kW net pellet boiler. A prototype was built that enables the independent control of the air supply into various regions of the combustion chamber and an accurate supply of fuel. The test rig also includes: boiler and flue gases extraction system; feeding system; heat dissipation system; flue gas analyzer; data acquisition system and all sensors. In order to optimize the combustion conditions, pollutant emissions and their relation with feeding conditions, primary and secondary air flow rate and excess of air was analyzed. The results suggest that this burner is a promising for implementation in domestic boilers. The advantages are: CO emissions well below those observed in similar equipments and the capacity to maintain the emissions level constant under different loading conditions.

Solar Upgrading of Fuels for Generation of Electricity

2001 ◽  
Vol 123 (2) ◽  
pp. 160-163 ◽  
Author(s):  
Rainer Tamme ◽  
Reiner Buck ◽  
Michael Epstein ◽  
Uriyel Fisher ◽  
Chemi Sugarmen
Keyword(s):  
Gas Turbines ◽  
Large Scale ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Combined Cycle ◽  
Test Facility ◽  
Small Scale ◽  
Start Up ◽  
Efficiency Conversion ◽  
Solar Field

This paper presents a novel process comprising solar upgrading of hydrocarbons by steam reforming in solar specific receiver-reactors and utilizing the upgraded, hydrogen-rich fuel in high efficiency conversion systems, such as gas turbines or fuel cells. In comparison to conventionally heated processes about 30% of fuel can be saved with respect to the same specific output. Such processes can be used in small scale as a stand-alone system for off-grid markets as well as in large scale to be operated in connection with conventional combined-cycle plants. The complete reforming process will be demonstrated in the SOLASYS project, supported by the European Commission in the JOULE/THERMIE framework. The project has been started in June 1998. The SOLASYS plant is designed for 300 kWel output, it consists of the solar field, the solar reformer and a gas turbine, adjusted to operate with the reformed gas. The SOLASYS plant will be operated at the experimental solar test facility of the Weizmann Institute of Science in Israel. Start-up of the pilot plant is scheduled in April 2001. The midterm goal is to replace fossil fuels by renewable or non-conventional feedstock in order to increase the share of renewable energy and to establish processes with only minor or no CO2 emission. Examples might be upgrading of bio-gas from municipal solid waste as well as upgrading of weak gas resources.

scholarly journals An Introduction Into the Clearance Management of Ansaldo GT36 From Development to Validation

2018 ◽  
Author(s):  
S. Boeller ◽  
B. Feuillard ◽  
G. Filkorn ◽  
S. Olmes ◽  
F. Prou ◽  
...  
Keyword(s):  
Gas Turbine ◽  
High Efficiency ◽  
Evaluation Process ◽  
3D Models ◽  
Operating Conditions ◽  
Active Management ◽  
Test Plant ◽  
Pinch Point ◽  
Load Range ◽  
Clearance Prediction

The optimization and evaluation of blading clearance is important for gas turbine efficiency and performance. The Ansaldo GT36 gas turbine offers high efficiency together with outstanding flexibility across a large load range. Active management of engine clearances during the complete development process followed by a thorough validation on the Ansaldo test plant facility in Birr, Switzerland enables the GT to attain ambitious clearance targets. The clearance at baseload must be minimized but is limited by the pinch point clearance during cold, warm and hot start-ups — including normal and fast ramp-up and/or shutdown. Therefore transient analysis is necessary for covering the different operating conditions. A well-established process of 2d finite element modelling of the whole engine model (WEM) comprised of axis-symmetric and plane stress elements was used during the design process from concept to detailed design to optimize the clearances. It delivers the transient stator and rotor deformation and together with the compressor and turbine airfoil deformation based on 3D models the basic clearance evaluation process is defined. The GT engine design was significantly influenced, starting with a simplified version of the WEM for identification of the most promising variants. Subsequently a detailed WEM was developed which is fully validated against measurements on the test engine. Different 3D effects are considered separately at identified critical transient conditions and overlaid on the 2d clearances which lead to the final optimized clearances. In addition to this, limitations from each step of the manufacturing process were identified and improved to reduce tolerances and uncertainties to their minimum. The results of the calculation and clearance prediction process are compared against clearance measurements during all kinds of GT operation and cooldown. Passive clearance indicators showing the remaining gap till rubbing would occur and rub marks, in areas that tolerate it, further validate the clearances and clearance prediction process.

Data-Driven Predesign Tool for Small-Scale Centrifugal Compressor in Refrigeration

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Mounier Violette ◽  
Picard Cyril ◽  
Schiffmann Jürg
Keyword(s):  
Centrifugal Compressor ◽  
High Efficiency ◽  
Design Procedure ◽  
Integrated System ◽  
Operating Conditions ◽  
Data Driven ◽  
Small Scale ◽  
Centrifugal Compressors ◽  
Starting Point ◽  
Isentropic Efficiency

Domestic scale heat pumps and air conditioners are mainly driven by volumetric compressors. Yet the use of reduced scale centrifugal compressors is reconsidered due to their high efficiency and power density. The design procedure of centrifugal compressors starts with predesign tools based on the Cordier line. However, the optimality of the obtained predesign, which is the starting point of a complex and iterative process, is not guaranteed, especially for small-scale compressors operating with refrigerants. This paper proposes a data-driven predesign tool tailored for small-scale centrifugal compressors used in refrigeration applications. The predesign model is generated using an experimentally validated one-dimensional (1D) code which evaluates the compressor performance as a function of its detailed geometry and operating conditions. Using a symbolic regression tool, a reduced order model that predicts the performance of a given compressor geometry has been built. The proposed predesign model offers an alternative to the existing tools by providing a higher level of detail and flexibility. Particularly, the model includes the effect of the pressure ratio, the blade height ratio, and the shroud to tip radius ratio. The analysis of the centrifugal compressor losses allows identifying the underlying phenomena that shape the new isentropic efficiency contours. Compared to the validated 1D code, the new predesign model yields deviations below 4% on the isentropic efficiency, while running 1500 times faster. The new predesign model is, therefore, of significant interest when the compressor is part of an integrated system design process.

scholarly journals Integrated Geothermal Energy Systems for Small-Scale Combined Heat and Power Production: Energy and Economic Investigation

2020 ◽  
Vol 10 (19) ◽  
pp. 6639 ◽  
Author(s):  
Pietropaolo Morrone ◽  
Angelo Algieri
Keyword(s):  
Geothermal Energy ◽  
Energy Demand ◽  
High Efficiency ◽  
Energy Performance ◽  
Combined Heat And Power ◽  
Integrated System ◽  
Operating Conditions ◽  
Economic Viability ◽  
Small Scale ◽  
Partial Load

In recent years, an increasing interest in geothermal energy has been registered in both the scientific community and industry. The present work aims to analyse the energy performance and the economic viability of an innovative high-efficiency geothermal-driven integrated system for a combined heat and power (CHP) application. The system consists of a heat exchanger (HEX) and a transcritical organic Rankine cycle (ORC) that work in parallel to exploit a high-temperature geothermal source (230 °C) and satisfy the energy demand of a commercial centre located in Southern Italy. The ORC and HEX sub-units can operate at partial load to increase the system flexibility and to properly react to continuous changes in energy request. A lumped model was developed to find the proper operating conditions and to evaluate the energy production on an hourly basis over the whole year. In particular, a multi-variable optimisation was implemented to find the most suitable configuration and a 101.4 kWel ORC was selected while the HEX nominal power was 249.5 kWth. The economic viability of the integrated system was evaluated in terms of net present value and payback period and different operating strategies were compared: thermal-driven, electric-driven, and a mixed strategy. The latter turned out to be the best solution according to both energy and economic criteria, with electric and thermal self-consumptions larger than 90%, with no heat dumping and a payback time close to five years.

Study of a Concrete Mixer Hybrid Truck

2013 ◽  
Author(s):  
Ferdinando Luigi Mapelli ◽  
Davide Tarsitano ◽  
Davide Annese ◽  
Nicola Pirri ◽  
Emanuele Zorzi
Keyword(s):  
Hydraulic System ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Control Strategies ◽  
Simulation Models ◽  
Operating Conditions ◽  
Hybrid Powertrain ◽  
Conventional Concrete ◽  
Electrical Drives ◽  
Concrete Mixer

Decrease of availability of fossil fuels and environment issues, push research towards the development of high efficiency power trains for vehicles that transport people, goods and mobile operating machines, like the concrete mixer trucks considered in this paper. Conventional concrete mixer trucks use diesel engine to move the truck and a hydraulic system which keep spinning the concrete drum. A hybrid powertrain based on battery-powered electrical drives can replace the conventional hydraulic system assuring an efficiency improvement. Furthermore, thanks to the reversibility of the electrical drives, it is possible to recover kinetic energy during the braking phases of the truck. Aim of this paper is to study and develop a hybrid powertrain for the concrete mixer drum. The study is based on a full energetic model of the vehicle developed for sizing the components and designing the control strategies. A model of the conventional hydraulic mixer truck has also been proposed in order to evaluate the benefit introduced by the proposed hybrid system. Simulation models have been validated comparing experimental data collected on a conventional mixer truck in different operating conditions.

Experimental Study of Turbulent Burning Velocity of Premixed Biogas Flame

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Ahmad Ayache ◽  
Madjid Birouk
Keyword(s):  
Turbulence Intensity ◽  
Equivalence Ratio ◽  
Fossil Fuels ◽  
Isotropic Turbulence ◽  
Burning Velocity ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Velocity Versus ◽  
Carbon Dioxide Co2 ◽  
Turbulent Burning Velocity

Biogas is a renewable source of energy produced by anaerobic digestion of organic material and composed mainly of methane (CH4) and carbon dioxide (CO2). Despite its lower heating value, biogas can still replace fossil fuels in several engineering stationary power generation and other industrial applications. Although numerous published studies were devoted to advance our understating of biogas combustion, experimental data of some parameters such as turbulent burning velocity (St) under certain operating conditions is still lacking. The present study aims to experimentally determine biogas turbulent burning velocity under normal temperature and pressure conditions. Turbulent premixed biogas–air flame was ignited at the center of a 29 L fan-stirred spherical combustion chamber of nearly homogeneous and isotropic turbulence. Test conditions consisted of varying turbulence intensity and biogas surrogate composition. Outwardly propagating biogas flames were tracked and imaged using Schlieren imaging technique. The results showed that, by increasing turbulence and reducing methane percentage in the surrogate, the flammability of the mixture shrinked. In addition, the curve fits of biogas turbulent burning velocity versus the equivalence ratio exhibited two different trends. The peak of turbulent burning velocity shifted away from nearly lean equivalence ratio toward the stoichiometric at a fixed turbulence intensity and higher CH4 percentage in the surrogate. However, for the same biogas surrogate composition, the peak of turbulent burning velocity shifted away from stoichiometric toward leaner equivalence ratio with increased turbulence intensity.

scholarly journals INDUSTRIAL BURNERS TESTING AND COMBUSTION EFFICIENCY ANALYSIS

2002 ◽  
Vol 1 (2) ◽  
pp. 03
Author(s):  
J. Pimenta ◽  
L.C. De Lima ◽  
J.B.F. Duarte ◽  
R. M. Macedo
Keyword(s):  
Combustion Chamber ◽  
Experimental Testing ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Industrial Applications ◽  
Thermal Capacity ◽  
Operating Conditions ◽  
Air Supply ◽  
Commercial Applications ◽  
Energy Balance Approach

This paper describes experimental procedures and techniques adopted for combustion analysis during the testing of burners for industrial applications. The tests were carried out in the Combustion Technology Laboratory (NTC) of the University of Fortaleza. The NTC facilities are composed basically of experimental testing hall, a monitoring room, a chromatography laboratory and a modeling and simulation studies room. In the lab testing hall, is installed a test bench composed basically of the following parts : a combustion chamber with nominal thermal capacity of 1.000.000 kcal/h, two fully instrumented gas and air supply sections, a gas analyzer for emissions measurement, a panel for monitoring of water supply to combustion chamber coil, a cooling tower for heat delivery of combustion chamber. A data acquisition and control system is available with all the hardware tools for monitoring of the combustion process. With all the acquired measurements of temperature, flow rate, pressures, emissions, etc., the First Law energy balance approach was used in order to evaluate the combustion efficiency of two different burners with 378.000 and 403.200 kcal/h nominal heat power. Analysis of preliminary results allows representing the burners efficiency according to different air and fuel operating conditions. The experimental data obtained are also compared with simulation results from the modeling of the combustion process, presented in another article linked with this work, where a discussion of such comparison is made. Future studies will be dedicated to the development of improved efficiency combustion systems for industrial and commercial applications.

scholarly journals Performance analysis and modeling of parabolic trough based concentrated solar facility using different thermal fluid mediums

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmed Ullah ◽  
◽  
Asim Mushtaq ◽  
Rizwan Ahmed Qamar ◽  
Zaeem Uddin Ali ◽  
...  
Keyword(s):  
Solar Energy ◽  
High Efficiency ◽  
Solar Power ◽  
Operating Conditions ◽  
Design Parameters ◽  
Small Scale ◽  
Concentrated Solar Power ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
Thermal Fluids

The significance of sustainable power source has expanded because of environmental change and worldwide cautioning concerns because of its renewing quality. Solar energy is the focal point of numerous examinations due to modern industrial applications and small scale local applications in emerging nations. Solar energy is being bridled, either specifically utilizing photovoltaic or secondarily utilizing concentrated solar power. This study aims to design and fabricate a small scale concentrated solar power (CSP) plant using linear parabolic trough. Linear parabolic trough collector is used because of high efficiency and exceedingly prescribed kind of CSP. The scope of this study is to develop a CSP plant and also study the properties of various thermal fluids and expect the best transfer medium. The study done in this research is based on carrying out a detailed energy balance scheme for a linear parabolic trough collector while observing twenty-six vital design parameters, including the geometric measurements and material properties of concentrator and receiver pipe, thermal fluids properties, and operating conditions. Modeling of the system is carried out for different thermal fluids that are deemed viable for use. It was found that the results obtained from the fabricated parabolic trough CSP were used to verify the model and compare with the theoretical results. The conclusions deduced from this study will help design both small and large scale applications of linear parabolic troughs.

scholarly journals The Operating Strategies of Small-Scale Combined Heat and Power Plants in Liberalized Power Markets

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3110 ◽  
Author(s):  
Pavel Atănăsoae
Keyword(s):  
Electricity Markets ◽  
Electricity Market ◽  
Power Plants ◽  
High Efficiency ◽  
Organic Rankine Cycle ◽  
Combined Heat And Power ◽  
Operating Conditions ◽  
Power Markets ◽  
Small Scale ◽  
Operating Strategies

Distributed generation is a good option for future energy systems with respect to sustainable development. In this context, the small-scale combined heat and power (CHP) plants are seen as an efficient way to reduce greenhouse gas emissions due to lower fuel consumption compared to the separate generation of the heat and electricity. The objective of this paper is to establish operating strategies of the small-scale CHP plants to reduce operational cost and increase revenue in liberalized electricity markets. It analyzes a cogeneration plant with organic Rankine cycle and biomass fuel under the conditions of the Romanian electricity market and the green certificates support scheme for electricity generated in high efficiency cogeneration and from renewable sources. The main finding is that choosing an appropriate mode of operation and using correlated prices of heat and electricity can increase the trading profitability of a CHP plant in liberalized power markets. This can be done by an analysis of the particularities and the specific operating conditions of the CHP plant. The results show that the operating strategies of the CHP plant can yield substantial net revenues from electricity and heat sales. The CHP plant can be economically operated to a useful heat load of more than 40% when operating strategies are applied.

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