The combined diesel-electric and gas turbine (CODLAG) plant is a new type of ship power plant combining the advantages of electric propulsion system and mechanical propulsion system. The requires about ship power grid is lower than full electric propulsion mode, at the same time it can gain the quiet of electric propulsion in the low working conditions and increase the mobility of the ship in the high working conditions. Unlike traditional mechanical propulsion methods and forward-looking all-electric propulsion methods, the CODLAG plant has a coupling between mechanical propulsion and electric propulsion mode. The cooperative working characteristics of two different nature systems is still need further research. For the in-depth research of CODLAG device’s characters, this study built a simulation model of CODLAG device based on Matlab/Simulink and C/C++ platform. A kind of torque-shaft speed double closed-loop control strategy based on PID was used on the CODLAG device. And the typical work condition of CODLAG, including merging, merging off and variable work condition, was simulated in this study. Through the simulation, the dynamic response of main parameters at typical condition have been got. Then, characters of CODLAG device with CPP was simulated at variable condition. And the thrust response was compared with FPP’s. Through comparative analysis, the effectiveness of integrated simulation method specifying to CODLAG device was verified, and some useful conference was provided for the future research.

A high flow coefficient centrifugal compressor was designed in a joint cooperation of DLR and MAN Diesel & Turbo SE Berlin. The main goal of this work is to increase the flow coefficient in the aerodynamic design point by 20% in comparison to the reference design. Besides a significant increase in flow coefficient, isentropic efficiency should be at least equal to the reference design. Design methods of the last decades are not able to reach a high flow coefficient without a reasonable compromise in efficiency. Furthermore, common design methods introduce splitter blades to gain a higher flow coefficient. Usually splitter blades lead to structural mechanical issues by introducing different eigenfrequencies. Reference impeller and vaned diffuser as well as the main design goals and constraints are provided by MAN Diesel & Turbo SE Berlin. DLR performed the design studies using their in-house design suite including TRACE as the CFD solver, PERMAS as the CSM program and AutoOpti for the multiobjective optimization tool. In preliminary design investigations it was found that a reduction of blade and vane number is necessary to avoid diffuser choking at high flow coefficients. Finally, a favorable geometry is chosen for a future test rig configuration at MAN Diesel & Turbo SE Berlin. The new design works totally in transonic conditions. The selected design fulfills all aerodynamic and structural mechanical design goals.

The air handling system for large diesel/gas engines such as those used on locomotive, marine, and power generation applications require turbochargers with a high reliability and with turbomachinery capable to adjust to different operating conditions and transient requirements. The usage of variable geometry turbocharging (VGT) provides flexibility to the air handling system but adds complexity, cost and reduces the reliability of the turbocharger in exchange for improved engine performance and transient response. For this reason, it was desirable to explore designs that could provide the variability required by the air handling system, without the efficiency penalty of a conventional waste gate and with as little added complexity as possible. The current work describes a new low-cost variable geometry turbine design to address these requirements. The new tandem nozzle concept proposed is applicable to both axial and radial turbines, and has been designed using conventional 1D models and 2D/3D CFD methods. The concept has furthermore been validated experimentally on two different test rigs. In order to avoid the long lead times of procuring castings, the nozzle for the axial turbine was manufactured using new additive manufacturing techniques. Both the axial turbine and the radial turbine designs showed that the concept is capable to achieve a mass flow variability of more than 15% and provide a robust and cost-effective alternative to conventional VGT designs by significantly reducing the number of moveable parts.

In the last years, the increased demand of the energy market has led to the increasing penetration of renewable energies in order to achieve the primary energy supply. However, natural gas is expected to still play a key role in the energy market, since its environmental impact is lower than other fossil fuels. It is mainly employed as gaseous fuel for stationary energy generation, but also as liquefied fuel, as an alternative to the diesel fuel, in vehicular applications. Liquefied Natural Gas is currently produced mainly in large plants directly located at the extraction sites and transported by ships or tracks to the final users. In order to avoid costs and environmental related impact, in previous studies Authors developed a new plant configuration for liquefied natural gas production directly at filling stations. One of the main issues of the process is that in various sections the working fluid needs to be cooled by external fluids (such as air for compressor inter and after-cooling or chilling fluids), in order to increase the global performances. As a consequence, an important amount of heat could be potentially recovered from this Liquefied Natural Gas production process. Thus, based on the obtained results, in this study the integration between the liquefaction process and an organic Rankine cycle is proposed. In fact, the heat recovered from the Liquefied Natural Gas production process can be used as hot source within the organic Rankine cycle. The aim of the work is the identification of the optimal integrated configuration, in order to maximize the heat recovery and, as a consequence, to optimize the process efficiency. With this purpose, in this study different configurations — in terms of considered organic fluid, architecture and origin of the recovered heat — have been defined and analyzed by means of a commercial software. This software is able to thermodynamically evaluate the proposed process and had allowed to define the optimal solution.

Geographical characteristics give the island of Heuksando no choice but to use diesel power generation. This option is not economical, and more than half of the generated energy is released through exhaust gas, cooling water, and other sources of energy loss. In order to reduce these losses and improve power generation efficiency, this research studied Organic Rankine Cycle systems that use waste heat from diesel power plants as a heat source. Unlike previous Rankine cycles, electric power generation and operation are possible because of low heat source and capacity. Cycle design and demonstration-operation logic are required to set the range of waste heat temperature and capacity. In addition, as the overall efficiency may change substantially depending on the efficiency of each component, the operating conditions of various BOPs should be optimized. It is necessary to obtain the optimization and operating conditions of each element of the system through modeling and numerical study of the whole system. In this research, heat source analysis and BOP design were conducted in order to apply the 20kW/30kW ORC systems to the Heuksando Island 1MW diesel power plant. A heat-connecting technique that thermally connects the heat exhaust end piping and the evaporator of the ORC system was developed in this study. The demonstration experiment was conducted sharing the waste heat source with the 20kW and 30kW ORC systems. This paper presents the waste heat analysis and the demonstration operation results of the Heuksando island power plant.

The combustion of conventional fuels (Diesel and Jet A-1) with 10–20% vol. oxygenated biofuels (ethanol, 1-butanol, methyl octanoate, rapeseed oil methyl ester, diethyl carbonate, tri(propylene glycol)methyl ether, i.e., CH 3 (OC 3 H 6 ) 3 OH, and 2,5-dimethylfuran) and a synthetic paraffinic kerosene was studied. The experiments were performed using an atmospheric pressure laboratory premixed flame and a four-cylinder four-stroke Diesel engine operating at 1500 rpm. Soot samples from kerosene blends were collected above a premixed flame for analysis. Polyaromatic hydrocarbons (PAHs) were extracted from the soot samples. After fractioning, they were analyzed by high-pressure liquid chromatography (HPLC) with UV and fluorescence detectors. C 1 to C 8 carbonyl compounds were collected at the Diesel engine exhaust on 2,4-dinitrophenylhydrazine coated cartridges (DNPH) and analyzed by HPLC with UV detection. The data indicated that blending conventional fuels with biofuels has a significant impact on the emission of both carbonyl compounds and PAHs adsorbed on soot. The global concentration of 18 PAHs (1-methyl-naphthalene, 2-methyl-naphthalene, and the 16 US priority EPA PAHs) on soot was considerably lowered using oxygenated fuels, except 2,5-dimethylfuran. Conversely, the total carbonyl emission increased by oxygenated biofuels blending. Among them, ethanol and 1-butanol were found to increase considerably the emissions of carbonyl compounds.

This study examines the viability of electrochemical solid-state nitric oxide sensors as an alternative to CEM (Continuous Emission Monitoring) instruments for use in monitoring the emissions of a 60 kW gas turbine. While CEM equipment is used regularly at large scale centralized power plants, it is not cost effective for small generators used for distributed power generation. Yet in areas with poor air quality, assessment of the emissions generated by such generators is an important question. A commercial and inexpensive potential alternative to the complex CEM systems used in power plants comes from the automotive industry, which employs solid-state sensors to monitor and control emissions in diesel vehicles. In the present study, two models of commercial solid-state sensors (UniNOx ® and NTK) were evaluated in the exhaust stream of the Capstone C-60 gas turbine engine. A referee instrument (Horiba PG-350) using the EPA approved NO measurement method, chemiluminescence, was used in the study as a reference point. Over 8 months of testing, it was found that both solid state sensors followed the general NO trends measured by Horiba PG-350 analyzer. Both solid-state sensors responded to small incremental changes in engine load with high-resolution changes in NO ppm. It was determined that the NTK sensor had more favorable performance over test period than the UniNOx ® sensor with regards to Accuracy, Lower Detectable Limit (LDL), and Rise Time and Fall Time. The UniNOx ® sensor was found to have higher precision than the NTK sensor.

Extension of gas fuel flexibility of a current production standard SGT-400 industrial gas turbine combustor is reported in this paper. A successful development program has increased the capability of the standard production dry low emissions burner configuration to burn a range of fuels covering a temperature corrected wobbe index from 30 to 49 MJ/m 3 . A standard SGT-400 13.4 MW dry low emission double skinned combustor can was tested with a standard production gas burner for a cannular combustion system. Emissions, combustion dynamics, fuel pressure and flashback monitoring via measurement of burner metal temperatures, were the main parameters used to evaluate the impact of fuel flexibility on combustor performance. High pressure rig tests were carried out to demonstrate the capabilities of the combustion system at engine operating conditions across a wide range of ambient conditions. Variations of the fuel heating value were achieved by blending natural gas with CO 2 as diluent. The standard SGT-400 combustion system employs proven dry low emissions technology for natural gas and liquid fuels such as diesel within a specified range of fuel heating values. With the aid of novel intelligent control software, the gas fuel capability of the SGT-400 standard dry low emissions burner has been extended, with the engine, achieving stable operation and reduced emissions across the load range despite variations of the composition of the fuel supply. This, combined with previous experience from high pressure rig and engine testing of the different burner configurations that covered this range, resulted in a reduction in the number of hardware configurations from three burners to two. Testing showed that the standard production burner can reliably operate with a fuel temperature controlled wobbe index as low as 30 MJ/m 3 which corresponds to 20% CO 2 (by volume) in the fuel. The performance of four different fuels with heating values in terms of temperature controlled wobbe index: 30, 33, 35 and 45 MJ/m 3 (natural gas), is presented for the current production hardware. Test results show that NO x emissions decrease as the fuel heating value is reduced. Also note that a decreasing temperature controlled wobbe index leads to a requirement to increase the fuel supply pressure. The tests results obtained on the Siemens SGT-400 combustion system provide significant improvement for industrial gas turbine burner design for fuel flexibility.

In light of the potential of butanol as an alternative fuel for blending with petroleum fuels such as gasoline, diesel or Jet A, experimental data regarding the burning characteristics of these blends are required in order to better understand their combustion process. In this study, freely-falling droplets of butanol, Jet A, and their mixtures (10, 20 and 50% butanol by volume) were examined in a combustion chamber which provides representative conditions of real flames, both in terms of temperature and oxygen availability. The combustion characteristics reported here include evolution of droplet sizes, burning rates, soot measurements, and the occurrence of microexplosions and soot shells. Results show that the evolution of droplet diameter for butanol, Jet A and their blends are very similar, regardless of the obvious compositional differences. Sooting behaviors are found to be quite different, with a clear reduction in the sooting propensity as the butanol content in the fuel increases. These results are consistent with a previous study in a gas turbine showing similar performance among Jet A and its blends with butanol, suggesting that such mixtures are promising alternative fuels with very similar combustion characteristics to Jet A, but with much less propensity to soot. Moreover, this study provides new results on the combustion properties of Jet A/butanol blends, for which very scarce data exist in the open literature.

Injection of water into a combustor is a proven method for reducing emissions of particulate and nitrogen oxide emissions beyond what can be achieved by reducing firing temperature through fuel lean operation. However, the added complexity and cost associated with a standalone water injection circuit makes this method less desirable. A method for reducing the complexity of water injection is to premix the fuel with water as an emulsion and injecting this mixture through the existing liquid fuel circuit. In the present study, the gaseous fuel injectors of a commercial micro gas turbine generator were modified to operate on both water-in-oil emulsions and gas fuel. These injectors were installed in an otherwise unmodified engine. The original air-blast injector was modified by adding a central fuel tube and blocking the original gas fuel passages. Dual-fuel operation was achieved by injecting gaseous fuel through the annular passage surrounding the liquid fuel tube. This gas fuel passageway is used for both gas fuel delivery and for introduction of air that is used to assist in the liquid fuel atomization. The atomization behavior of these injectors has been characterized using laser diffraction and high speed video for water mass fractions of between zero and 0.5, and air-to-liquid ratios between zero and one. Additionally, pollutant emissions were measured from an engine equipped with these modified injectors and operated over the same range of water mass fraction and air-to-liquid ratio. The results confirmed viability of the modified injectors for introducing water in form of an emulsion. It was also observed that, while atomization performance was altered in a minor way, the complex interaction between evaporation and subsequent mixing resulted in non-monotonic impact on NO x emissions.

Particulate matter (PM) emitted by the combustion of liquid fuels consist of both ash and soot particles. For installations fired on heavy fuel oil, ash particles represent a substantial fraction of the PM emitted. However, when one burns distillate oil, soot accounts for more than 95% of the PM emission. There is currently a marked move towards the reduction of particles emitted by combustion installations. This includes gas turbines operated in cogeneration or in simple/combined cycle. This trend is driven namely by the EU BREF (Best Available Techniques Reference Document) and IED (Industrial Emission Directive), which recommend more stringent PM limitations for the combustion of gaseous and liquid fuels. Due to the proposed regulations GE has performed testing to evaluate the efficiency of catalysts mobilized in the form of fuel additives on soot emissions of heavy duty gas turbines (“GT”) fired on # 2 diesel oil (#2 DO) also known as gasoil. In the framework of a collaboration between EDF and GE, a full-scale test has been performed at the Jarry Sud power plant in Guadeloupe (West Indies), involving a Frame 6B, with three types of benign oxidation catalyst additives: cerium (IV), cerium (III) and iron (III). The results of this trial proved successful with a PM abatement level up to 80% attained at full load. The paper summarizes the preparation and execution of this field test with emphasis placed on the activity of cerium that appeared efficient at concentrations as low as a few ppm. The performances of iron and cerium are also compared.

The effect of the chamber pressure on combustion of a twin-fluid-atomized spray of straight vegetable oil (VO) in a swirl stabilized combustion system is experimentally studied. A system with high pressure capabilities was developed, and flame and emissions characteristics of VO are investigated at elevated pressures, up to about 5 bars, different heat release rates and atomizing air to liquid ratios (ALR) by mass. An image analysis technique was developed to infer flame and soot characteristics from visual images acquired by a digital camera. An increase in the ALR improved combustion characterized by blue flames, lower CO and NOx emissions, and minimal soot formation. For a given fuel flow rate, an increase in the chamber pressure resulted in smaller volume flames with lower CO levels but higher NOx emissions. Compared to diesel, as pressure increased, straight VO flames produced lower NOx and more voluminous flames characterized by distributed combustion with less soot formation. Overall, straight VO could be atomized and combusted at elevated pressures using the twin-fluid atomizer of the present study, and the resulting VO flames exhibited less sensitivity to chamber pressure variations.

Waste heat recovery using Organic Rankine cycle (ORC) systems has been regarded as the most potential technology for diesel engine fuel economy improvement. The compactness of ORC system is very important, so reducing the total volume of heat exchangers of the ORC system is the main challenge for ORC applications in truck engines. This paper proposes a new ORC system for waste heat recovery of truck diesel engines. The ORC system uses the hot compressed intake air and the exhaust gas as heat sources. The conventional air intercooler is substituted with the pre-heater of the ORC system. Hence the condenser of the ORC system can be installed at the original place of the intercooler, which could make the system integration much easier. A one-dimension simulation model of the combined diesel engine and ORC power system is set up. In combined ORC-engine system the output power of turbine is combined with the output power of crack shaft at a specific gear ratio to increase effective power of the engine system. The combined ORC-engine system performance is analyzed at common operating conditions and compared with the original engine. Results show that the combined system thermal efficiency is increased by 8.38% and the brake special fuel consumption (BSFC) reduces by 7.82% at peak. In design point, net output power of ORC system is 28.72kW, which increases thermal efficiency by 9.31% and reduces BSFC from 199.76 g/(kW·h) to 182.76 g/(kW·h). In addition, the cost of ORC system is estimated, and Payback time is 4.92 years.

Using a mixture of water and diesel fuel is considered a way to reduce gas emissions including NOx and COx in the gas turbine. This paper presents experimental results on spray characteristics of the water-diesel fuel mixture in an air crossflow. A plain-orifice type injector of 0.508 mm in diameter is employed in the research. Pure water, pure diesel fuel, and water-diesel fuel mixtures with different mixing ratios are used to compare their spray characteristics. In order to observe spray behaviors in different breakup regimes, Weber numbers for water of 30 and 125 are chosen as the operating condition and the corresponding Weber numbers for diesel fuel at the same conditions are 92 and 382, respectively. Momentum flux ratios are 10 and 20. A tee connection and a subsequent static mixer are employed at upstream of fuel injector to mix two liquids. Phase Doppler Particle Analyzer (PDPA) measurement is performed to measure droplet distributions and mean drop size at various mixture ratios, and planar laser induced fluorescence (PLIF) technique with dyeing either diesel or water is used to look into the primary breakup process. PDPA data show that the spray characteristics of water-diesel fuel mixtures such as mean drop size and number density distribution can be predicted from the measured drop size distribution of pure fluids by weighting those quantities by mass fraction of each fluid, indicating that the water and diesel are injected alternately without significant mixing between the two fluids. A short transition of liquid flow from water-to-diesel or diesel-to-water produces small fraction of relatively bigger droplets.

The MT30 marine gas turbine has been developed specifically for 21st century naval propulsion using modern techniques and methods. Design and development of the MT30 began in 1999 and has since been qualified for naval service following extensive testing. Since then the engine has rapidly been adopted by progressive navies, in both its mechanical and electrical power generation configuration. The Lockheed Martin Littoral Combat Ship (LCS) is one of a new class of United States Navy (USN) fast combatants which has been at sea for more than six years and is powered by the MT30. A combined MT30-driven generator was selected for the new USN DDG1000 Zumwalt class of destroyer and has also been successfully installed into the Royal Navy’s Queen Elizabeth Class aircraft carrier. Most recently, the MT30 Compact Package has been selected to power the Royal Navy’s Type 26 Global Combat Ship which will be built by BAE Systems. The MT30 Compact Package has been designed with the aim of powering modern warship programmes, with the result that it is currently the World’s most power dense in-service marine gas turbine. This is an important factor in naval propulsion where delivering a high power output in a compact space is essential. In addition to the programmes stated above, the MT30 Compact Package was selected for the new Republic of Korea Navy’s (RoKN) frigate programme with a single-GT CODLOG hybrid arrangement consisting of propulsion motors and a Diesel-electric system. As a result, Rolls Royce was selected by the RoKN to deliver the MT30 Gas Turbine Unit and, from a preliminary Rolls-Royce compact package design, the engine and machinery division of Hyundai Heavy Industry (HHI-EMD) has developed the Compact Package for the New Korea Frigate. The MT30 GT was delivered to the HHI-EMD facility in 2014 with the surrounding Compact Package built at HHI-EMD before onward delivery to Daewoo Shipbuilding and Marine Engineering (DSME) where construction of the first frigate will take place. This paper provides the rationale for selection of the MT30 Compact Package for the New Korea Frigate Programme and also describes the development of the MT30 Compact Package; aspects of the design process, construction of the Compact Package and the factory acceptance test conducted at the HHI-EMD facility.

In contrast to other alternative fuels, methanol offers a plethora of advantages; it can be produced from natural gas, coal or any organic biomass matter. Methanol is the cheapest of all alternative fuels and has a reduced likelihood of reacting to form pollutants such as soot, CO, NOx. Furthermore, methanol is a liquid at standard atmospheric conditions and can be stored and transported much more cheaply and safely than gaseous fuel. There are also drawbacks that impinge on its overall utility: Methanol has a lower energy density as compared to conventional fossil liquid fuels (kerosene, diesel oil etc.), it has the propensity to react to form aldehyde emissions and to dissolve in atmospheric moisture. Methanol also has a low vapor pressure that could lead to cold start problems in IC engines, at temperatures below 15°C. The objective of the present work is to perform an experimental investigation and a chemical kinetic comparison of combustion characteristics between methanol and kerosene & diesel fueled swirl stabilized burner. A special emphasis is given to the impact of fuel conversion of existing combustion systems from kerosene (or diesel) to methanol. The experimental set-up is based on a modified industrial burner with heating power of 50kW. In order to have a better control over the incoming air flow, the original blower is replaced with a larger and more stable industrial blower that allowed precise monitoring of the air flow rate. The combustion chamber consists of a stainless steel tube, 10cm in diameter and 80cm in length. The experiments include measurements of temperature distribution inside the combustor: wall temperature distribution is recorded with the use of thermocouples and a calibrated infra-red camera. The composition of the combustion pollutants is also monitored at the exhaust. A National Instruments cRIO 9074 controller is used in conjunction with a National Instruments LabView interface for data acquisition. The comparison between methanol and kerosene characteristics is carried out for equal heat release and equivalence ratios. Experimental results show that methanol burns slower than kerosene and therefore requires a longer combustor. It is found that the larger methanol droplet size and its larger volume flux contribute significantly to this extended length requirement for complete methanol combustion. The measured CO emission values for kerosene and methanol were 25 and 110 ppm respectively, and 40 and 10ppm for NOx. These results clearly indicate the reduced NOx emission during methanol combustion; however, the notable presence of CO indicates that methanol needs a longer combustor length to complete the combustion process.

Turbocharger turbines for diesel and gasoline engines work under pulsating inflow conditions. This paper discusses the influences of such unsteady conditions on turbine performance through a similarity analysis. First the assumptions for the analysis are described and key non-dimensional parameters are identified. Some of these parameters are further studied with the assistance from experimental and computational results in the open literature. Strouhal number, which expresses the relative importance of unsteady influences, is discussed in details regarding its definition, its application to experimental setup, and how it affects different components of the turbines. The analysis shows that Strouhal number should be scaled with the square root of turbine inlet total temperature.

In the last years, the increased demand of the energy market has led to the increasing penetration of renewable energies in order to achieve the primary energy supply. However, simultaneously natural gas still plays a key role in the energy market, mainly as gaseous fuel for stationary energy generation, but also as liquefied fuel, as an alternative to the diesel fuel, in vehicular applications. Liquefied Natural Gas (LNG) is currently produced in large plants directly located at the extraction sites. In this study, the idea of realizing plug & play solutions to produce LNG directly at vehicle’s filling stations has been investigated. A novel process of LNG production for filling stations has been analyzed, consisting in a single stage Joule-Thompson isenthalpic expansion process, with intercooled compression. Furthermore, the presented layout has been developed with the purpose of optimizing the energy consumption of the plant, obtaining moderately pressurized LNG. With the aim of investigating the feasibility of this novel LNG generation process, a thermodynamic analysis has been carried out and presented in this study. Moreover, the minimization of energy consumption has been investigated with a parametric analysis, in order to optimize the LNG production and to maximize the efficiency of the process. Furthermore, novel performance indicators have been defined, in order to account the efficiency of the LNG production process. Results of the optimization analysis show that, with the proposed layout, an energy consumption equal to about 1.9 MJ/kg of produced LNG can be achieved.

The objective of this study is to develop a theoretical basis for scalability considerations and design of a large scale combustor utilizing flow blurring (FB) atomization. FB atomization is a recently discovered twin-fluid atomization concept, reported to produce fine spray of liquids with wide range of viscosities. Previously, we have developed and investigated a small scale swirl-stabilized combustor of 7-kWth capacity. Spray measurements have shown that the FB injector’s atomization capability is superior when compared to other techniques, such as air blast atomization. However, despite these favorable results, scalability of the FB injector and associated combustor design has never been explored for large capacity, for example, for gas turbine applications. In this study, a number of dimensionless scaling parameters that affect the processes of atomization, fuel-air mixing, and combustion are analyzed, and scaling criteria for the different components of the combustion system are selected. Constant velocity criterion is used to scale key geometric components of the system. Scaling of the nonlinear dimensions and complex geometries, such as swirler vanes and internal parts of the injector is undertaken through phenomenological analysis of the flow processes associated with the scaled component. A scaled up 60-kW th capacity combustor with FB injector is developed and investigated for combustion performance using diesel and vegetable oil (soybean oil) as fuels. Results show that the scaled-up injector’s performance is comparable to the smaller scale system in terms of flame quality, emission levels, and static flame stability. Visual flame images at different air to liquid ratio by mass (ALR) show mainly blue flames, especially for ALR > 2.8. Emission measurements show a general trend of lower CO and NOx levels at higher ALRs, replicating the performance of the small scale combustion system. Flame liftoff height at different ALRs is similar for both scales. The scaled-up combustor with FB injector preformed robustly with uncompromised stability for the range of firing rates above 50% of the design capacity. Experimental results corroborate with the scaling methodology developed in this research.

In this work the ongoing development of a jet-stabilized FLOX ® (Flameless Oxidation)-type low-emission combustor for liquid fuels is described. The desired application of this concept is a micro gas turbine range extender for next generation car concepts. Diesel DIN EN 590 was used to operate the combustor, which is very similar to other fuels like bio-diesel, light heating oil and kerosene and therefore provides a link to other gas turbine applications in power generation. The investigation of flame stabilization of jet flames as well as fuel atomization, spray dispersion and evaporation is essential for the design of an effective and reliable combustor for liquid fuels. An axisymmetric single-nozzle combustion chamber was chosen for the initial setup. A variety of burner configurations was tested in order to investigate the influence of different design parameters on the flame shape, the flame stability and emissions. Two pressure atomizers and one air-blast atomizer were combined with two types of air nozzles and two different burner front plates (axisymmetric and off-centered jet nozzle). Finally, a twelve nozzle FLOX ® combustor with pre-evaporator was designed and characterized. The combustor was operated at atmospheric pressure with preheated air (300° C) and in a range of equivalence ratios φ between 0.5 and 0.95 (λ = 1.05–2). The maximum thermal power was 40 kW. For each combustor configuration and operating condition the flame shape was imaged by OH*-chemiluminescence, together with an analysis of the exhaust gas emissions. Laser sheet imaging was used to identify the spray geometry for all axisymmetric combustors. Wall temperatures were measured for two configurations using temperature sensitive paints, which will be utilized in future CFD modeling. The results show a dependence of NO x emissions on the flame’s lift-off height, which in turn is defined by the spray properties and evaporation conditions. The tendency to soot formation was strongly dependent on the correlation of the recirculation zone to the spray cone geometry. In particular, strong soot formation was observed when unevaporated droplets entered the recirculation zone.