Gas Engine Research Articles

Numerical Investigation of the Operating Characteristics of the Passive and Active Prechamber Jet Ignition in a Natural Gas Engine.

Prechamber jet ignition is a promising technology that enables stable ignition and fast combustion by combining thermal effects, chemical kinetics, and turbulent disturbance. The development and application of the prechamber ignition require a comprehensive and in-depth understanding of the operating characteristics of the prechamber ignition in the real engine working cycle. Therefore, numerical simulations are conducted to explore the operating performance of the prechamber ignition applied to a large-bore natural gas engine in this study. The differences between the passive prechamber (PPRE) and active prechamber (APRE) near the lean burn limit are compared. The results show that the jet ignition performance of the PPRE is hampered by the high residual gas coefficient and lean mixture in the prechamber under lean burn conditions. The ignition mode of the PPRE is similar to torch ignition, and the combustion process in the main chamber is mainly turbulent flame propagation. The ignition mechanism of the APRE is flame jet ignition. The main chamber combustion process presents a two-stage heat release characteristic, which can be subdivided into three phases: the initial flame development phase, the rapid combustion phase, and the late combustion phase. The heat release rate during the initial flame development phase depends on the physical and chemical properties of the prechamber jet and the mixture conditions in the main chamber. During the rapid combustion phase, the flame propagation along the radial direction of the jet largely depends on the time scale of the chemical reaction. The heat release rate depends on the coverage area of the jet, the jet residual momentum, and the turbulent flame speed. During the late combustion phase, the flame propagation is mainly affected by the turbulent flame speed. These results provide theoretical guidance for the subsequent application of prechamber ignition systems in various powertrains.

Analysis of effects of pre-chamber orifices on torch flame behaviours in lean-burn gas engines

Fuel conversion from heavy oil to natural gas is favoured as a quick remedy for GHG re-duction from industrial engines in ship propulsion and power generation fields thanks to fewer carbon contents in natural gas. In medium-speed gas engines, the ejection of torch flame from a pre-chamber is often used to promote flame propagation within a main com-bustion chamber. Although orifice specifications affect the ejection behaviour of the torch flame and the following combustion in the main chamber, the effects are difficult to fully understand. Some of the authors developed a constant-volume combustion vessel that simu-lated the combustion chamber around the top dead centre of a pre-chamber type gas engine and observed the effects of orifice specifications on the torch flame ejection and the com-bustion in the main chamber. Still, the correlation was not concluded due to the lack of physical examination. In the paper, the above measurement results were confirmed by using RANS-type CFD considering the larger scale of the target engines, and the physical back-ground of the effects of orifice specifications was successfully reproduced.

Ultra-fast polarity switching GC-IMS for the analysis of volatiles in biogas

The Renewable Energy Act 2023 (§39i) requires reducing corn silage in biogas plants from 40 % to 30 % in 2026. Since corn silage yields the highest biogas per weight unit of all biogas feedstocks, this poses new challenges for biogas plant operators. However, alternative biogas feedstocks not harvested directly from the field may contain siloxanes due to the use of care products and disinfectants. The conversion of siloxanes into silicon dioxide during the combustion process seriously threatens the lifetime and efficiency of the used gas engine, even in very low concentrations. Consequently, we present a highly sensitive measurement system for monitoring biogas. Detection limits down to 0.037 mg/m³ for the tested siloxanes have been reached. Furthermore, ketones can be detected down to 0.002 mg/m³, alcohols down to 0.001 mg/m³. The device combines an ultra-fast polarity switching ion mobility spectrometer with a switching time of 12 ms and a resolving power of RP = 70, a gas chromatographic pre-separation, and a non-dispersive infrared sensor for methane. In this context, we analyzed the biogas composition for volatile substances and siloxanes, whereby we only found the volatile substances. For demonstration, biogas was analyzed at three different stages during the gas purification process.

A parametric study on syngas production by adding CO2 and CH4 on steam gasification of biomass system using ASPEN Plus

Abstract Biomass gasification technology is increasingly employed as an environmentally friendly energy source, primarily due to its minimal impact on the environment and its ability to mitigate pollution. This technology excels in producing gas with exceptionally high hydrogen content, making it a valuable source for both fuel and energy carriers. Hydrogen (H2), renowned for its stability and lack of detrimental environmental effects, holds great significance in various applications related to energy utilization and sustainability. In the current work, wood sawdust was utilized as the biomass feedstock for syngas production. The research focused on examining the impact of introducing carbon dioxide (CO2) and methane (CH4) gases into the Gibbs reactors. The steam gasification process was modeled by the ASPEN Plus software, allowing for comprehensive analysis and simulation of the gasification reactions. According to the obtained results, the modeling performed in this study demonstrates good predictive capability when compared to the experimental data. It was shown that when the ratio of CO2 to biomass (C/B) increases, the MFR (mass flow rates) of H2 as well as CH4 decrease, whereas the flow rates of CO2 and carbon monoxide (CO) increase. These findings indicate the influence of the C/B ratio on the distribution of different gases within the gasification process. The reduction in MFR of hydrogen when transitioning from C/B = 0 to C/B = 1 in modes a and b is quantified as 17.51 % and 16.39 %, respectively. These percentages represent the magnitude of the decrease in hydrogen MFR for each specific mode when comparing two carbon dioxide to biomass ratios. When the CH4 to biomass (M/B) ratio increases, the mass flow rates of H2 exhibit a consistent upward trend, while the MFR of CO2 displays a descending form. Specifically, when in the Gibbs reactor, M/B rises from 0 to 1 for modes a and b, the mass flow rates of H2 experience significant increases of 265 % and 243 %, respectively. These findings underscore the direct relationship between the M/B ratio and hydrogen production, highlighting the potential for enhanced hydrogen yields with higher M/B ratios in the studied modes.

Composition and Structural Characteristics of Coal Gasification Slag from Jinhua Furnace and Its Thermochemical Conversion Performance

Gasification technology enables the clean and efficient utilization of coal. However, the process generates a significant amount of solid waste—coal gasification slag. This paper focuses on the Jinhua furnace coal gasification slag (fine slag, FS; coarse slag, CS) as the research subject, analyzing its composition and structural characteristics, and discussing the thermochemical conversion performance of both under different atmospheres (N2 and air). The results show that the fixed carbon content in FS is as high as 35.82%, while it is only 1% in CS. FS has a large number of fluffy porous carbon on its surface, which wraps around or embeds into smooth and variously sized spherical inorganic components, with a specific surface area as high as 353 m2/g, and the pore structure is mainly mesoporous. Compared to the raw coal (TYC), the types of organic functional groups in FS and CS are significantly reduced, and the graphitization degree of the carbon elements in FS is higher. The ash in FS is mainly amorphous and glassy, while in CS, it mainly has crystalline structures. The weight loss rates of TYC and FS under an inert atmosphere are 27.49% and 10.38%, respectively; under an air atmosphere, the weight loss rates of TYC and FS are 81.69% and 44.40%, respectively. Based on the analysis of the thermal stability of FS and its high specific surface area, this paper suggests that FS can be used to prepare high-value-added products such as porous carbon or high-temperature-resistant carbon materials through the method of carbon–ash separation.

Thermodynamic and life cycle assessment analysis of polymer-containing oily sludge supercritical water gasification system combined with Organic Rankine Cycle

With the development of polymer flooding technology, polymer-containing oily sludge (PCOS) has become a major pollutant on offshore oil platforms. Supercritical water gasification system is an efficient and pollution-free technology compared to conventional PCOS treatment. However, the system model for PCOS has not yet been established and the theoretical model for system optimization is insufficient. In this work, a novel auto-thermal system is established based on supercritical water gasification technology for the treatment of PCOS. Through the thermodynamic analysis, an optimization plan is concluded and used for the establishment of a modified system with Organic Rankine Cycle. Results show that the two-stage reactor reduces the gasification reaction temperature from 652 °C to 502 °C, and the Organic Rankine Cycle system using Isopropanol recover 9.1 % chemical exergy of feedstock with the optimal parameters (superheat, evaporation temperature and circulating pressure). The energy and exergy efficiency of the modified system has increased by 52.4 % and 42.4 % compared to the original system. Besides, a life cycle assessment is adopted for the environment analysis. The results show that the increasing gasification temperature and PCOS slurry concentration can reduce system unit exergy loss. Global Warming Potential reaching the minimum value of 26.1 at 65 wt%.

The chemical kinetic and heating effects decoupling of pilot diesel in a diesel ignited natural gas engine under various pilot diesel injection timing

The diesel ignited natural gas engine suffers from low load low thermal efficiency and high load knocking problems. The solution to these problems requires control of the combustion process. The combustion of pilot diesel plays an important role in the natural gas combustion process. The combustion of pilot diesel not only provides heat for the natural gas combustion process (heating effect), but also provides highly intermediate chemicals for the chemical reaction of natural gas (chemical kinetic effect). However, the mechanism of this effect under various pilot diesel injection timing is unclear. To decouple the heating effect and chemical kinetic effect of pilot diesel, a detailed study was conducted by numerical simulation combined with chemical inertness method. A 6-cylinder turbocharged intercooler diesel/natural gas dual fuel heavy-duty engine was used in this study, and the pilot diesel injection timing was controlled over a very wide range. The result shows that the chemical kinetic effect of pilot diesel increases while the heating effect shows the opposite trend with the advance of injection timing. When the fuel injection timing is 40° CABTDC, the pilot diesel chemical kinetic effect begins to exceed 50%. This may serve as judging the start timing of RCCI combustion mode. The low concentration and wide distribution of pilot diesel at the beginning of natural gas combustion is the leading reason for the increase of chemical kinetic effect. When the fuel injection timing is advanced, the high concentration area and distribution of highly active intermediate CH2O show an increasing trend, while the high-temperature area decreases and the low-temperature area gradually increases. There is a strong correlation between strong chemical kinetic effect and low-temperature combustion.

Influence of In-Cylinder Turbulence Kinetic Energy on the Mixing Uniformity within Gaseous-Fuel Engines under Various Intake Pressure Conditions

To explore the potential for further enhancing the gas mixing uniformity of natural gas (NG) engines, this paper identifies turbulent kinetic energy (TKE), which has an essential impact on gas mixing, as the entry point of the research. After establishing a computational fluid dynamics (CFD) model for NG engines’ direct injection and mixing processes, the inlet pressure is selected as the experimental variable to investigate the influence of TKE on gas mixing uniformity. In particular, by proposing the theoretical concept of the core mixing stage, the numerical variation rule between the best mixture concentration region (BMCR) percentage and the mean turbulent kinetic energy (MTKE) of the core mixing stage is analyzed under certain injection timing conditions. The results indicate that, with identical intake pressures, an advanced gas injection timing elevates the total turbulence kinetic energy (TTKE) during the core mixing stage, thereby amplifying the uniformity of the gas mixture at the ignition. In specific scenarios, as the intake pressure increases, the decreasing trend in the BMCR proportion closely resembles the diminishing trend in the MTKE during the core mixing stage. Scrutinizing the variation trend in either parameter allows for an approximate prediction of the variation trend in the other parameter. When the intake pressure is gradually raised from the naturally aspirated state, the adequacy of the gas jet development is progressively reduced by the increasing back pressure in the cylinder.

Study on Cracking/Oxidation/Integrated Reforming Reaction for Efficient Conversion of Biomass to High‐Quality Syngas

AbstractThe advanced gasification technology of coal is mainly based on oxidation reaction and high temperature but is not suitable for biomass conversion. High tar and CO2 content are the two main issues that affect the efficiency of biomass gasification. In order to deeply convert hydrocarbons/tar and CO2 simultaneously, and enhance syngas yield, the cracking/partial oxidation/reforming reactions and their integrated reaction routes are investigated from an interrelated view. The effects of each reaction on the distribution of C/H elements in hydrocarbons/tar and syngas are illustrated. By cracking and oxidation reaction, the syngas yield can only reach 0.93 Nm3 kg−1, about 58 % of the theoretical maximum value; a large proportion of residual C/H atoms existing in stable hydrocarbons/tar/CO2/H2O are not converted. Based on the concept of lattice O oxidation combined with dry reforming, it realizes syngas yield (CO+H2) 1.56 Nm3 kg−1 with 91.6 % concentration, demonstrating that tar/hydrocarbons and CO2/H2O are converted to syngas efficiently. The effects of [O]/C ratio on gas yield represent a synergistic coordination between lattice Os oxidation and catalytic reforming reaction. Oxidation‐reforming is the optimum route for biomass conversion to high‐quality syngas.

Biomass Energy Gasification Technology and Application

Globally, the dual challenges of energy crisis and environmental pollution encourage people to seek sustainable energy solutions. Biomass energy, with its renewable and environmentally friendly characteristics, has gradually become an important choice to replace the traditional energy. Biomass gasification technology, as an advanced thermochemical process to convert biomass energy into combustible gas, not only improves the efficiency of energy utilization, but also shows great potential in the field of energy conversion and environmental protection due to its cleanliness and operability. In this paper, we deeply analyze the basic principles of biomass gasification technology, including the key steps such as pyrolysis, gasification and gas purification, and explore the application strategies of this technology in biomass energy conversion. In particular, the paper details the innovative practice of Shanghai Diyan Environmental Protection Technology Co., Ltd. in the field of biomass gasification, including its technological breakthrough in printing and dyeing sludge treatment, as well as the national utility model patent obtained. The successful cases of the company not only show the advantages of biomass gasification technology in practical industrial applications, but also provide valuable experience and inspiration for the same industry. Through these studies and practices, this paper aims to provide theoretical basis and technical support for the efficient and environmental protection utilization of biomass energy, in order to promote the further development and application of biomass energy gasification technology.

CO2 emission mitigation of a hybrid photovoltaic and cogeneration system in computer hardware manufacturing industry: A case study in Thailand

Abstract In the wake of COP26 and the growing urgency of addressing climate change, achieving carbon neutrality by 2050 has become a central global objective. This imperative extends to industries like computer hardware manufacturing, which are now actively pursuing decarbonization strategies through the strategic adoption of renewable energy sources and energy efficiency enhancements. This research paper assessed the CO2 emission mitigation potential of a hybrid system of photovoltaic (PV) roof and cogeneration where a large factory of computer hardware manufacturing in tropical Thailand was selected as a study site. On one hand, a one-Megawatt photovoltaic system was installed over the roof of the production building to generate electricity from solar radiation to serve the building. On the other hand, a twenty-four-Megawatt cogeneration system of gas engines as the prime mover was used to supply power to meet the building’s electricity demand. Waste heat from the gas engine was used by the absorption chiller to generate chilled water for cooling inside the building. Based on the system equipment specifications, the annual simulation using Thailand’s solar radiation showed that the installed photovoltaic system could generate electricity of 1,412.4 MWhelec/year while the implementation of the absorption chillers for cooling helped to reduce the electrical energy consumed by the traditional electric chiller by 10,211.4 MWhelec/year. In our study case where the CO2 emission of the grid power was 0.4758 kgCO2/kWhelec in the year 2022 and was reduced to 0.350 kgCO2/kWhelec in the year 2050, the total CO2 emission mitigation from the hybrid photovoltaic and cogeneration system with the genset efficiency of 50% and the waste heat recovery of 60% could reduce approximately 207,388.5TonCO2 for over 20 years as compared to the scenario where the grid electricity alone powered the building. These findings underscored the critical role of the proposed hybrid system in addressing the climate crisis and exemplified how the industry could make meaningful strides toward more environmental sustainability.

From hydratable alumina bonded high chrome castables to shaped product for coal water slurry gasifier

The gasifier is a key equipment of coal gasification technology, enabling efficient and clean utilization of coal resources. However, the aluminum phosphate bonded high chrome brick lining in the gasifier experienced premature failure due to the migration of phosphate in reducing gases such as H2 and CO, as well as increased slag penetration and thermal spalling. In this study, a high chrome castable was prepared using hydratable alumina as a binder and fired at 1600 ℃ to replace the traditional phosphate bonded high chrome brick. The impact of curing temperatures (25℃, 40 ℃, and 60 ℃) on the properties of the high chrome castable was investigated, with corresponding hydrates examined through XRD, FTIR, TG-DSC, and SEM analyses. Results revealed that higher curing temperatures accelerated the hydration process of hydratable alumina. At higher curing temperatures, more well-developed micro-nano sized boehmite and bayerite phases were formed within the castables, filling their pores effectively and enhancing their properties after drying at 110 ℃. Moreover, during heat treatment these micro-nano sized hydrates decomposed into submicron/nano sized alumina which readily reacted with Cr2O3 to form (Cr-Al)2O3 solid solution. This phenomenon facilitated the sintering of castables fired at 1600 ℃ and optimized internal structure, ultimately leading to the enhanced mechanical properties and improved slag resistance.

MFIX–DEM simulation of gas-solid flow dynamics in a dual fluidized bed system

Abstract To overcome the operational difficulties associated with bubbling and circulating fluidized bed gasifiers, a new gasification technology termed dual fluidized bed gasification (DFBG) has evolved. To strengthen the understanding of the gasification and combustion processes in the DFBG system, a thorough analysis of bed hydrodynamics is of paramount importance. Furthermore, the complexity of the hydrodynamics escalates while incorporating diverse fuels like biomass and coal, along with bed materials fluidized in a single reactor due to its nonlinearity and transience. As a result, the study of hydrodynamics in such a system is indispensable. The present study focuses on the discrete element model (DEM) simulation of the bed hydrodynamic behaviour within the gasifier of a DFBG system. The simulation was conducted using Multiphase Flow with Interphase eXchanges (MFiX) software. The influence of superficial velocity on the number of particles in a gasifier was analyzed using the 2-D discrete element model (DEM). In this numerical investigation, transient variation of pressure drop, axial and radial solid volume fraction, and particle velocity was evaluated, and the data were analyzed using the ParaView software. The simulation results of the gasifier indicated an increase in the bed pressure drop with the rise in inlet air velocity. The effective height of solid volume fraction also increased with the surge in superficial velocity. The solid velocity profile and streamlines were also investigated to understand its variation pertaining to the location within the fluidized bed.

Теоретические исследования процесса топливоподачи газового двигателя

This article is devoted to theoretical studies of the fuel supply process of a gas engine. It examines the main aspects of the functioning of the fuel supply system, the influence of fuel supply parameters on the efficiency of the engine, as well as problems and solutions. The authors analyze various theoretical models, describe the basic principles of fuel injection systems and discuss current trends in the development of this field. The article is intended for specialists in the field of automotive, mechanics and thermal engineering, as well as for anyone interested in modern technologies in the field of motor transport. Theoretical studies of the gas engine fuel supply process are of great importance in the modern automotive industry. The efficiency of a gas engine depends directly on the correct selection of fuel supply parameters, which makes this topic relevant for research and development. The article analyzes in detail various aspects of the fuel supply process, such as fuel dosing, spraying, system pressure, as well as interaction with other engine systems So, the presented article is a valuable contribution to the field of gas engine fuel supply research and can be useful both for specialists involved in the development of gas engines and for a wide range of readers interested in modern technologies and innovations in the field of automotive technology. Keywords: GAS ENGINE, FUEL SUPPLY, FUEL INJECTION SYSTEM, AGROENGINEERING, INNOVATIONS IN THE FUEL SUPPLY SYSTEM, AGROTECHNICS, FUEL SUPPLY PARAMETERS

Interconnected pyrolysis and activation with in-situ H3PO4 activation of biochar from pear wood chips in a pilot scale dual fluidized bed

Interconnected pyrolysis and activation is a novel technology for combustible gas and biochar production in dual fluidized bed (DFB). The study proposed one-step and two-step methods for pyrolysis and activation of biomass in a pilot scale DFB with capacity of 100 kg/h. Physical and chemical activation occurred simultaneously in DFB system by phosphoric acid (H3PO4) impregnation pretreatment of pear wood chips, and flowing hot flue gas and steam. Stable operating parameters were observed for both methods. The one-step method was superior to the two-step method in terms of the pyrolysis gas quality, biochar pore distribution, micro- and meso-pores structures of biochar, while one-step method reduced the biochar yields. As an activation agent, H3PO4 increased the yields of biochar and pyrolysis gas, promoted formation of micropores and enriched the surface functional groups of biochar with increasing ratio of H3PO4. H3PO4 to biomass ratio of 1:5 reached the maximum biochar yield of 42.3 wt% and highest iodine adsorption value of 648.5 mg/g, increasing by 70.6 % and 90.3 % compared to the biochar without H3PO4 pretreatment, respectively. This DFB system facilitated the diversified use of fluidized beds and the co-production of biochar and product gas with energy saving and CO2 emission reduction.

A Review of Research on Marine Main Propulsion Systems

Ship power, as an essential component of ship engineering, directly affects the navigation performance, economy, and environmental friendliness of ships. This article reviews the development history of ship power, introduces the main propulsion devices including internal combustion engines, steam engines, and electric motors, and discusses the structure and optimization design of ship power systems. Modern ship power technology includes traditional diesel and gasoline engines, as well as new power devices such as liquefied natural gas (LNG) engines, hybrid power systems, and fuel cells. Electric ships are gaining attention due to their efficiency and environmental benefits. In the future, ship power technology will develop towards green environmental protection, intelligence, integration, diversification, and digitization, providing more reliable and efficient power support for the shipping industry and the advancement of ship engineering.

Experimental Study on Oil-Gas Interaction Mechanism during Offshore Heavy Oil Gas Injection.

Offshore heavy oil injection gas extraction is a highly scrutinized area in today's petroleum industry. However, the interaction mechanisms between oil and gas are not clear. To elucidate these mechanisms, an indoor experimental setup was established for research purposes. The effects of different types of gases on heavy oil expansion, mass transfer mechanisms between gas and heavy oil, the influence of gas injection on heavy oil phase behavior, and the testing of minimum miscibility pressures are investigated in this study. The results indicate that CO2 yields the best reduction in the heavy oil viscosity. Both forward and backward multiple contact mass transfer processes demonstrate nonmiscible multiple contact dynamic displacement mechanisms involving CO2 dissolution and condensation, as well as C1 extraction and coextraction. Nonmiscible multiple contact dynamic displacement of natural gas primarily involves limited dissolution and condensation of light hydrocarbon components and intermediate hydrocarbon components, with an extremely weak extraction effect. The minimum miscibility pressures are in the order of CO2 < natural gas < N2. This research provides important experimental evidence and theoretical guidance for further improving offshore heavy oil injection gas technology and practice.

Towards optimized excess air ratio and substitution rate for a dual fuel HPDI engine

The diesel-piloted high-pressure direct-injection (HPDI) natural gas engine is a significant application of natural gas in heavy-duty engines. However, there is limited research focusing on quantitative optimization of the excess air coefficient and natural gas substitution rate of HPDI engines. In order to support the design and development of HPDI engines, this article investigates the effects of excess air coefficient and substitution rate on a dual fuel HPDI engine combustion performance and emission characteristics. Results show that increasing the excess air coefficient results in higher cylinder pressure, but it has minimal effect on the heat release rate. A higher excess air coefficient can also lead to higher nitrogen oxides (NOx) emissions, lower soot emissions, methane (CH4) and total hydrocarbon (THC) emissions significantly decrease at 50% loads (Case2 and Case4), but these increase at 70% loads (Case1 and Case3). Furthermore, increasing the substitution rate markedly reduces greenhouse gas emissions, though it comes with the drawback of heightened combustion instability, and there is a trade-off between engine combustion cycle variations and greenhouse gas emissions as the substitution rate changes. The above research findings will provide optimization guidance for the engineering development of HPDI engines.

Evaluating potential of increasing flow intensity and reducing crevice volume to improve thermal efficiency and hydrocarbon emission in spark-ignition natural gas engines

Low thermal efficiency and high hydrocarbon emissions caused by slow combustion rates and high methane emissions hinder the development of natural gas (NG) engines. Engine structure modifications have always been an important means of improving the combustion effects of engines. This study investigates the effects of combustion chamber improvements on the thermal efficiency and hydrocarbon emissions of stoichiometric spark-ignition NG engines through numerical simulations. The improvements aimed to enhance squish flow, organize high tumble flow, and reduce crevice volume. The results indicate that strengthening the squish intensity by increasing the squish area of the piston can accelerate flame propagation and reduce exhaust loss. However, this improvement is hindered by a significant rise in heat transfer loss, which limits further gains in thermal efficiency. Compared to the traditional high swirl combustion chamber, a high tumble combustion chamber (dual straight intake port combined with a hemispherical piston) can promote flame propagation in the early stages of combustion and increase thermal efficiency by 1.43%. However, the accelerated flame propagation rate resulting from increased flow intensity has little potential to reduce hydrocarbon emissions due to the small contribution of flame quenching to unburned hydrocarbon production. The primary source of hydrocarbon emissions from NG engines is unburned methane in the piston crevice. Therefore, when addressing hydrocarbon emissions from NG engines, the first consideration should be to minimize the volume of the piston crevice, which will significantly reduce methane emissions and incomplete combustion loss.

Harnessing NOx emission management: A virtual sensor model for natural gas power generation engines with active pre-chamber

This paper presents a NOx Sensor machine learning model for a highly efficient 2MW power generation lean burn gas engine with an active pre-chamber. As gas power generation continues to evolve, engine efficiency and the accurate measurement of NOx emissions has taken on greater importance. However, the working life of existing NOx sensors pales in comparison to the lifecycle of an engine. This paper studies a series of machine learning NOx sensor models and carries out a comparative analysis. We introduce a predictive analytics model used for monitoring the emissions of active pre-chamber gas engines. This real deployment aims to detect the deviations in emissions across an entire fleet of gas engines, even when no physical sensors are installed in the engines. Finally, a model has been implemented that allows the prediction of NOx values, in engines that did not have them initially, with a 5–10 % precision. For example, with NOx at 120 ppm, the virtual sensor provides values close to +-10 ppm. It has been observed that such features as the setpoint value of the active pre-chamber gas pressure, in a lean burn gas engine with active pre-chamber, are among those parameters that have the greatest impact on the model estimation.