A New Approach to Maximize the Potential of Reciprocating Engines Operating on Bio-Fuel Energy

2011 ◽  
Author(s):  
Henry Lam ◽  
Mark Richter ◽  
Geoff Ashton
Keyword(s):  
Combustion Engine ◽  
Pressure Ratio ◽  
Waste Water Treatment ◽  
Pressure Sensors ◽  
Bulk Temperature ◽  
Lean Burn ◽  
Fuel Gas ◽  
Heating Value ◽  
Combustion Performance ◽  
Wide Range

Since the Industrial Revolution one of the oldest and “greenest” bio-fuel energy sources has been the byproduct of sewage and landfill. These biogases also known as Land Fill Gas or Digester Gas can be used as a fuel in an internal combustion engine, the clear choice for their efficiency in heat recovery and utility as a prime mover. The problem with bio-fuels is their unpredictable and varying fuel heating values which creates a challenge for maintaining air fuel ratio (AFR). If AFR is not controlled this can lead to engine instability and an increase in NOx, CO and THC emissions. With today’s ever increasing scrutiny of combustion pollutants this could spell the end of these types of fuels in combustion engines. AETC has embraced this challenge to provide a system that addresses the seasonal fuel gas quality, Low Heating Value (LHV) fluctuation to operate engines at best achievable emissions. This case study focuses on two Caterpillar 3516 Generator Engines rated 1000VA, at 1200 rpm, lean burn gas and turbocharged, running on renewable energy source supplementing power to a waste water treatment facility in California. The engines operate on wide range of fuel mixture including landfill, digester gas and air blended natural gas over a heating value range from 350–650 BTU. The fuel gas LHV constantly varies depending on fuel availability controlled by pressure switches within the individual fuel headers. Determining fuel heating values by using a gas calorimeter is not a viable option due to its high cost and poor reliability when operating in the environment of unfiltered Digester and landfill gas. AETC installed their Advanced Monitoring System (AMS) to utilize the engine as a calorimeter and to determine the fuels LHV. As part of the AMS functionality, the system acquired all the existing AFRC parameters such as kilo-Watt, RPM, Fuel Flow, Air Manifold Pressure and Temperature to determine the combustion performance. This simple approach offers surprisingly good performance while tying together basic thermodynamics, combustion performance and emissions. The system can also be used to parametrically determine engine emissions, based on the calculated combustion pressure without installing pressure sensors. The AMS monitors and determines emissions based on Trapped Equivalence Ratio, Effective Bulk Temperature or Pressure Ratio on single or multiple fuels providing a green/red light as an indicator of in/out of compliance accurately meeting today’s most stringent regulatory conditions.

Production of Simulated Gasified Biomass for Pilot Plant Applications

2001 ◽  
Author(s):  
Christophe Duwig ◽  
Jan Fredriksson ◽  
Torsten Fransson
Keyword(s):  
Steam Reforming ◽  
Gas Flow ◽  
Main Idea ◽  
Biomass Composition ◽  
Fuel Gas ◽  
Heating Value ◽  
Oil Refineries ◽  
Syngas Production ◽  
Numerical Predictions ◽  
Wide Range

The design of modern Low Heating Value (LHV) fuel combustion devices, such as gas turbine combustors, relies heavily on numerical simulations. In addition, numerical predictions are always validated by experimental tests. In this work, an experimental facility was built. The fuel input power of the combustor was 300 kW. Such facility requires a gas flow of typically 0.06 kg/s, so a syngas production at a reasonable cost was required to undertake tests under real working conditions. Within this work, an inexpensive and flexible syngas generator has been designed, produced and tested. The main idea was to use cheap available gas fuels and to crack it in order to obtain the syngas. Such conversion is heavily used in oil refineries and called “Steam Reforming”. Propane is used as a fuel and is cracked on a commercial steam reforming catalyst. To ensure the wanted ratio of C/H and C/O in the final product, CO2, H2O and air were added to the fuel gas. Catalytic cracking is needed as propane cracking kinetics are low at wanted operation temperatures, namely 900 to 1100 K. Care is taken to avoid carbon formation in the gasification device which may cause decomposition of the stainless steel reactor vessel. The gasification device was used to feed a 300kW combustor at 2.8 bar pressure. The device was successfully integrated into a test rig and used for a burner study. The obtained composition was quite close to a typical gasified biomass composition. A wide range of different compositions has also been explored. Hydrocarbon concentration range was investigated from 3 vol% up to 16 vol% (Methane equivalent). The CO2 concentration varied between 13 vol% and 20 vol%. The syngas temperature was kept at an interval between 900 and 1100 K. The device provided 0.06 kg/s of a 3 to 5 MJ/kg heating value fuel. The operating costs of the gasification device were found about one tenth of the bottled gas price.

Multiphysics Numerical Investigation of an Aeronautical Lean Burn Combustor

2019 ◽  
Author(s):  
D. Bertini ◽  
L. Mazzei ◽  
A. Andreini ◽  
B. Facchini
Keyword(s):  
Fluid Dynamics ◽  
Pressure Ratio ◽  
Computational Cost ◽  
Engine Performance ◽  
Pollutant Emissions ◽  
Strong Interactions ◽  
Inlet Temperature ◽  
Test Case ◽  
Lean Burn ◽  
Wide Range

Abstract The importance of the combustion chamber has been underestimated for years by aeroengine manufacturers that focused their research efforts mainly on other components, such as compressor and turbine, to improve the engine performance. Nevertheless, stricter requirements on pollutant emissions have contributed to increase the interest on combustor development and, nowadays, new design concepts are widely investigated. To meet the goals of ACARE FlightPath 2050 and future ICAO-CAEP standards one of the most promising results is provided by the Lean Burn technology. As this combustion mode is based on a lean Primary Zone, the air devoted to liner cooling is restricted and advanced cooling systems must be exploited to obtain higher overall effectiveness. The pushing trends of Turbine Inlet Temperature and Overall Pressure Ratio in modern aeroengine are not supported enough by the development of materials, thus making the research branch of liner cooling increasingly relevant. In this context, Computational Fluid Dynamics is able to predict the flow field and the complex interactions between the involved phenomena, supporting the design of modern Lean Burn combustors in all stages of the process. RANS approaches provide a solution of the problem with low computational cost, but can lack in accuracy when the flow unsteadiness dominates the fluid dynamics and the strong interactions, as in aeroengine combustors. Even if steady simulations can be easily employed in the preliminary design, their inaccuracy can be detrimental for an optimized combustor design and Scale-Resolving methods should be preferred, at least, in the final stages. Unfortunately, having to deal with a multiphysics problem as Conjugate Heat Transfer (CHT) in presence of radiation, these simulations can become computationally expensive and some numerical treatments are required to handle the wide range of time and space scales in an unsteady framework. In the present work the metal temperature distribution is investigated from a numerical perspective on a full annular aeronautical lean burn combustor operated at real conditions. For this purpose, the U-THERM3D multiphysics tool was developed in ANSYS Fluent and applied on the test case. The results are compared against RANS and experimental data to assess the tool capability to handle the CHT problem in the context of scale-resolving simulations.

Development of a Lean Burn Methane Number Measurement Technique for Alternative Gaseous Fuel Evaluation

2013 ◽  
Author(s):  
Daniel M. Wise ◽  
Daniel B. Olsen ◽  
Myoungjin Kim
Keyword(s):  
Natural Gas ◽  
Landfill Gas ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Liquefied Petroleum Gas ◽  
Lean Burn ◽  
Pressure Transducers ◽  
Wide Range ◽  
Gas Fueled ◽  
Methane Number

A wide range of fuels are used in industrial gas fueled engines. Fuels include well-head gas, pipeline natural gas, producer gas, coal gas, digester gas, landfill gas, and liquefied petroleum gas. Many industrial gas fueled engines operate at high power density and at ultra-lean air-fuel ratios for low NOx emissions. Engines operate in a narrow air-fuel ratio band between misfire and knock limits. To utilize this wide range of fuels effectively it is important to understand knock properties. Methane number determination for natural gas blends is traditionally performed with research engines at stoichiometric conditions where the onset of knock is identified through subjective audible indication. The objective of this paper is to develop a process to determine knock onset through direct indication from pressure transducer data at lean operating conditions characteristic of lean-burn industrial gas engines. Validation of the method is provided with methane number determination and comparison of pipeline natural gas. A Waukesha F2 Cooperative Fuel Research (CFR) engine is modified to incorporate piezoelectric pressure transducers at the cylinder head and conversion from natural aspiration to boosted intake and variable exhaust back pressures (to simulate turbocharger operation). The new pressure sensors enable Fast Fourier Transform calculation of pressure data to calculate amplitude at characteristic knock frequency.

A Thermodynamic Analysis for Detonation-Free Engine Performance

1970 ◽  
Vol 92 (3) ◽  
pp. 231-238 ◽  
Author(s):  
C. K. Powell ◽  
R. N. Alford ◽  
T. N. Chen ◽  
V. Kevorkian
Keyword(s):  
Thermodynamic Analysis ◽  
Combustion Engine ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Constant Volume ◽  
Analytical Prediction ◽  
Wide Range ◽  
Performance Map ◽  
Constant Volume Combustion ◽  
Detonation Limit

A method of thermodynamic analysis of power cycles incorporating more complete expansion and turbocharging with after-cooling is presented; it predicts the performance of constant volume combustion engines under detonation-free conditions. The analysis involves expressing the detonation limit in terms of the firing pressure and a theoretical adiabatic end-gas temperature. Expressing the detonation limit in this form, the performance map for any constant volume combustion engine can be predicted. The map yields detonation-free operation over a wide range of bmep and bsfc by identifying the required combinations of fuel-air ratio, compression ratio, expansion ratio, and blower pressure ratio. The analysis requires information on the combustion characteristics of the specific engine, namely, the deviations of the thermal efficiency and the firing pressure from those derived from the equivalent fuel-air cycle. Analysis showed that a significant gain of engine output can be realized without detonation occurring by employing higher blower pressure ratio and firing pressure. The lower limit of fuel consumption is determined directly by the performance of the turbocharger and indirectly by the heating of the inlet air and the detonation limit. Tests performed on a 17-in-bore single cylinder gas engine at two different expansion ratios verified the analytical prediction of detonation-free operation over a wide range of bmep, from 135 to 346 psi. The type of performance map resulting from this analysis is useful in the selection of engine performance and engine parameters for the development of new engines.

Stirring and aeration system for the upgrading of small waste water treatment plants

1994 ◽  
Vol 29 (12) ◽  
pp. 149-156 ◽  
Author(s):  
Marcus Höfken ◽  
Katharina Zähringer ◽  
Franz Bischof
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Large Scale ◽  
Waste Water Treatment ◽  
Water Treatment Plants ◽  
Waste Water Treatment Plants ◽  
Basic Fluid ◽  
Aeration System ◽  
Technical Realization ◽  
Wide Range

A novel agitating system has been developed which allows for individual or combined operation of stirring and aeration processes. Basic fluid mechanical considerations led to the innovative hyperboloid design of the stirrer body, which ensures high efficiencies in the stirring and the aeration mode, gentle circulation with low shear forces, excellent controllability, and a wide range of applications. This paper presents the basic considerations which led to the operating principle, the technical realization of the system and experimental results in a large-scale plant. The characteristics of the system and the differences to other stirring and aeration systems are illustrated. Details of the technical realization are shown, which conform to the specific demands of applications in the biological treatment of waste water. Special regard is given to applications in the upgrading of small compact waste water treatment plants.

Danube River Basin: Progress with the Environmental Programme

1999 ◽  
Vol 40 (10) ◽  
pp. 1-8 ◽  
Author(s):  
T. Botterweg ◽  
D. W. Rodda
Keyword(s):  
River Basin ◽  
Action Plan ◽  
Waste Water Treatment ◽  
Warning System ◽  
Danube River ◽  
The Black Sea ◽  
Research Activity ◽  
Global Environment Facility ◽  
Major Activity ◽  
Wide Range

An Internationally funded Programme, involving the European Commission, the Global Environment Facility managed by UN Development Programme, the World Bank and the European Bank for Reconstruction and Development, is addressing river basin problems in a unique situation. The solution of these should lead to the prevention of pollution and better water quality, protected ecosystems, sustainable water resources and more efficient sewerage and waste water treatment facilities for the 90 million population living in the region and the reduction of pollution impact on the Black Sea into which the Danube River flows. The paper introduces current Programme activities, the challenges being met and progress. Work is described for implementing a monitoring strategy, an accident emergency warning system and implementation of the 1994 Strategic Action Plan. The applied research activity is explained. The Programme is a major activity with many elements addressing a wide range of environmental problems in the catchment of a major international waterway.

ТЕХНОЛОГИЯ И ПРИМЕНЕНИЕ ЭЛЕКТРОХИМИЧЕСКИХ ПРЕОБРАЗОВАТЕЛЕЙ

2020 ◽  
Vol 96 (3s) ◽  
pp. 450-455
Author(s):  
В.Г. Криштоп ◽  
Д.А. Жевненко ◽  
П.В. Дудкин ◽  
Е.С. Горнев ◽  
В.Г. Попов ◽  
...  
Keyword(s):  
Pressure Sensors ◽  
Engineering Applications ◽  
Electrochemical Systems ◽  
Seismic Sensors ◽  
Microelectronic Technology ◽  
Wide Range ◽  
Electrochemical Transducers ◽  
Element Base ◽  
New Devices

Электрохимические системы очень перспективны для разработки новой элементной базы для микроэлектроники и для использования в широком спектре инженерных задач. Мы разработали новую микроэлектронную технологию для изготовления электрохимических преобразователей (ЭХП) и новые приборы на основе новых электрохимических микроэлектронных чипов. Планарные электрохимические преобразователи могут использоваться в акселерометрах, сейсмических датчиках, датчиках вращения, гидрофонах и датчиках давления. Electrochemical systems are very promising for the development of a new element base for microelectronics, and for use in a wide range of engineering applications. We have developed a new microelectronic technology for manufacturing electrochemical transducers (ECP) and new devices based on new electrochemical microelectronic chips. Planar electrochemical transducers are used in accelerometers, seismic sensors, rotation sensors, hydrophones and pressure sensors.

scholarly journals Simulation of a Downdraft Gasifier for Production of Syngas from Different Biomass Feedstocks

2021 ◽  
Vol 5 (2) ◽  
pp. 20
Author(s):  
Mateus Paiva ◽  
Admilson Vieira ◽  
Helder T. Gomes ◽  
Paulo Brito
Keyword(s):  
Modeling And Simulation ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Fuel Gas ◽  
Heating Value ◽  
Downdraft Gasifier ◽  
Process Operation ◽  
Independent Parameters ◽  
Gasification Temperature ◽  
Main Operating

In the evaluation of gasification processes, estimating the composition of the fuel gas for different conditions is fundamental to identify the best operating conditions. In this way, modeling and simulation of gasification provide an analysis of the process performance, allowing for resource and time savings in pilot-scale process operation, as it predicts the behavior and analyzes the effects of different variables on the process. Thus, the focus of this work was the modeling and simulation of biomass gasification processes using the UniSim Design chemical process software, in order to satisfactorily reproduce the operation behavior of a downdraft gasifier. The study was performed for two residual biomasses (forest and agricultural) in order to predict the produced syngas composition. The reactors simulated gasification by minimizing the free energy of Gibbs. The main operating parameters considered were the equivalence ratio (ER), steam to biomass ratio (SBR), and gasification temperature (independent variables). In the simulations, a sensitivity analysis was carried out, where the effects of these parameters on the composition of syngas, flow of syngas, and heating value (dependent variables) were studied, in order to maximize these three variables in the process with the choice of the best parameters of operation. The model is able to predict the performance of the gasifier and it is qualified to analyze the behavior of the independent parameters in the gasification results. With a temperature between 850 and 950 °C, SBR up to 0.2, and ER between 0.3 and 0.5, the best operating conditions are obtained for maximizing the composition of the syngas in CO and H2.

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.

Investigation of the Combustion Performance in a Three-Nozzle RQL Combustor

2016 ◽  
Author(s):  
Bing Ge ◽  
Yongbin Ji ◽  
Shusheng Zang ◽  
Yongwen Yuan ◽  
Jianhua Xin
Keyword(s):  
Air Flow ◽  
Lean Burn ◽  
Uniformity Coefficient ◽  
Performance And Emission ◽  
Combustion Performance ◽  
Sector Model ◽  
Exhaust Temperature ◽  
Whole Process ◽  
Axial Temperature ◽  
Two Peaks

RQL (Rich-burn/Quick-quench/Lean-burn) is a candidate to support fuel flexible stationary power generation. The equivalence ratio of rich-burn zone (Φr) and the quench air flow are paramount for implantation of the whole process. In this paper, an experimental test stand with multi-sector model combustor was established. Rich premixed combustion were used in rich zone. The experiments which pay attention to the impacts of Φr and quench air flow on the combustion performance and emission are conducted. The results show that the flame in RQL combustor is segmented when Φr >1.4, presenting flameless combustion in rich zone and a pale blue flame in lean zone. Axial temperature distribution is M-type. Two peaks appear at the head and tail of the combustion chamber, and the valley is located in the quench zone. The concentration of CO decreases rapidly in quench zone because of the injection of quench air. However, the concentration of NOx increases quickly at the same time. The outlet emissions of CO and NOx in RQL combustor are maintained at low level (<20ppm@15%O2). With a decrease of Φr from 1.4 to 1.2, the emission of NOx increases, and the emission of CO decreases. With jet-to-mainstream mass-flow ratio increases from 1.28 to 2.22., the concentration of NOx in outlet declines gently, but the CO emission increase. The average exhaust temperature depresses gradually, and the uniformity coefficient of exhaust temperature increases.

Sign in / Sign up

Export Citation Format

Share Document