Hydrogen-fueled Gas Turbine Research Articles

Deep learning-based source term estimation of hydrogen leakages from a hydrogen fueled gas turbine

Hydrogen fueled gas turbine is an efficient and environmentally friendly energy conversion equipment. However, it is prone to gas leakages from corrosion-prone components and pipe connections. In order to address gas leakage problems, source term estimation (STE) can be applied to estimate the location and intensity of the leakage sources. Traditional STE methods are based on an optimization procedure using an atmospheric transport and dispersion model, which requires considerable computation efforts and cannot meet the need of real-time implementation. The complex flow field around the gas turbine, the possible existence of multiple leakage sources, and the high-dimensional time series data further increase the difficulty of the STE problem. To address these challenges, in the present study, a deep learning based STE approach is proposed. The basic idea is to use long short-term memory auto-encoder (LSTM-AE) network to extract the encoded features of multi-sensor data and then use a deep neural network (NN) to establish the relationship between the encoded features and the source term parameters of hydrogen leakages. The multi-sensor data are generated using computational fluid dynamics (CFD) analysis to simulate relevant hydrogen leakage scenarios of concern. The results show that compared with other machine learning algorithms, the proposed approach has an overall best performance in terms of the STE accuracy. Specifically, its hydrogen leakage source localization accuracy is 0.9798, and the leakage strength estimation R-squared (R2) can reach 0.9632. When the training data proportion is only 20–30%, the proposed approach can still perform well, indicating the ability of the model to effectively predict the location and strength of the leakage source even with relatively less training data.

Combining Machine Learning, Embedded Sensor Networks and Additive Burner Design for Combustor Structural Health Monitoring

Abstract The crystAIr project is about sensitising burners for flame monitoring based on a discrete number of dynamic pressure sensors and a machine learning approach. The context is the development of better aircraft engines and the prospect of technical solutions for hydrogen-fuelled gas turbines. The combination of sensors and appropriate signal processing is designed to mimic a ‘feel’ for the state of the flame. The idea is to monitor the gas turbine's correct operation in real-time and anticipate impending problems such as flame blowout, combustion instability or flashback. Compared to conventional flame monitoring based on signal sampling, thresholding, band-pass analysis and time-lag measurement, this method should be less computationally intensive, more sensitive and more robust to artefacts. Not only should it be more responsive, but it should also anticipate problems based on a lessons-learned approach and outperform the conventional precursors. An unassisted machine learning method is used to achieve this. A custom-built AM burner designed for this experiment provides multiple instrumentation options. A powerful data acquisition system is set up to collect data on multiple channels, over a long time duration and at high speed to collect the learning signal chunks. The focus is on the detection of flames and, more specifically, the moment of their ignition and extinction, the operating conditions that are prone to flashback and the stability of the combustion. Additional measurement techniques are used to refine the learning method. The paper covers all these points and presents the first results.

Investigating the effect of using hydrogen as fuel on gas turbine performance operating under lean conditions at the Hassi R'mel gas site

This study evaluates the feasibility of using pure hydrogen as fuel for the MS5002C gas turbine at the Hassi R'mel gas site in Algeria. THERMOPTIM software was used to analyze key parameters, including compression ratio, excess air (λ), and climatic conditions, identifying an optimal excess air of 4.5. This configuration was validated over a year under local climatic conditions. The results indicate that at a harsh temperature of 50 °C, the hydrogen-fueled gas turbine increased thermal efficiency by 3.66% and power output by 6.18%, while reducing fuel consumption by 62% compared to an optimized natural gas turbine. Hydrogen use eliminated carbon emissions but caused a slight 1.17% increase in NOx emissions. Under reel climatic conditions, hydrogen fuel eliminated carbon footprint and mitigated the adverse effect of harsh climate on turbine performance, with a peak NOx emission of 1.891 ppm in August.

Evaluation of the cooling flow rate of the cooled steam turbine for a novel H<sub>2</sub>/O<sub>2</sub> cycle

Evaluation of the cooling flow rate of the cooled steam turbine for a novel H<sub>2</sub>/O<sub>2</sub> cycle

A Literature Review of NOx Emissions in Current and Future State-of-the-Art Gas Turbines

Abstract Current U.S. government policy seeks to achieve a completely carbon-free economy by 2050, with a carbon-free electricity sector by 2035 (per executive orders #14008 and #14057). To address these goals, the U.S. Department of Energy is evaluating strategies and technologies that support the production, utilization, transport, and storage of hydrogen (via initiatives such as Department of Energy's (DOE) Energy Earthshot—Hydrogen and various DOE funding opportunity announcements). A carbon-free fuel such as hydrogen cannot be overvalued in a dynamic electric energy sector seeking to decarbonize. One of the most important technologies needed to achieve the goal of a carbon-free electricity sector is a 100% hydrogen-fueled gas turbine. Accommodating hydrogen-based fuels has been a key goal for various original engine manufacturers (OEMs) for many years, but much more research and development (R&D) is needed. The purpose of this paper is to highlight the current state-of-the- art of hydrogen turbine technology, especially regarding nitrogen oxide (NOX) emissions compared to natural gas-fueled turbines. NOX is the primary criteria pollutant from thermally driven combustion turbines and should be controlled to levels that are equivalent to or below existing standards (as reported “existing standards” for hydrogen-fueled gas turbines may need to be rebaselined). This paper will provide an overview of hydrogen as a fuel and various NOX emissions control techniques that are relevant for hydrogen-based fuels. A conclusion from this overview is that, with some level of R&D, NOX emissions from hydrogen-fueled gas turbines can be controlled to levels similar to those produced by state-of-the-art (SOTA) natural gas-fueled combustion turbines while remaining competitive in terms of performance and efficiency.

Assessment of paper industry decarbonization potential via hydrogen in a multi-energy system scenario: A case study

Green hydrogen is currently regarded as a key catalyst for the decarbonization of energy-intensive industries. In this context, the pulp and paper industry stands out as one of the most demanding, given the simultaneous need for large amounts of heat and electricity usually satisfied via cogeneration systems. Given the urgent need for cost-effective solutions in response to the climate crisis, it is crucial to analyze the feasibility of retrofitting existing power plants to operate carbon-neutral. The aim of this work is to provide a techno-economic analysis for the conversion of a conventional cogeneration system to run on locally produced hydrogen. Building on the energy consumption of the paper mill, the operation of a hydrogen-fuelled gas turbine is modelled in detail. Based on these results, a multi-energy system model for the production of green fuel is presented, considering production via solar-powered PEM electrolyzers, storage in tanks and final use in the gas turbine. An optimal configuration for the system is defined, leading to the definition of a solution that ensures a cost of 6.41 /kg for the production of green hydrogen. Finally, a sensitivity analysis highlights the close dependence of the economic profitability of the Power-to-X system on the natural gas price. The results indicate that although positive performance is achieved, the cost of investment remains still prohibitive for systems of this size, and the high initial capital expenditure needs to be supported by incentive policies that facilitate the adoption of hydrogen in industrial applications making it competitive in the short term.

The Life Cycle Assessment and Merit Order Effect of Green Hydrogen-Fueled Gas Turbine Power Plant

The Life Cycle Assessment and Merit Order Effect of Green Hydrogen-Fueled Gas Turbine Power Plant

Life Cycle Assessment of Greenhouse Gas (GHG) and NOx Emissions of Power-to-H2-to-Power Technology Integrated with Hydrogen-Fueled Gas Turbine

Hydrogen is expected to play an important role in renewable power storage and the decarbonization of the power sector. In order to clarify the environmental impacts of power regenerated through hydrogen-fueled gas turbines, this work details a life cycle model of the greenhouse gas (GHG) and NOx emissions of the power regenerated by power-to-H2-to-power (PHP) technology integrated with a combined cycle gas turbine (CCGT). This work evaluates the influences of several variables on the life cycle of GHG and NOx emissions, including renewable power sources, hydrogen production efficiency, net CCGT efficiency, equivalent operating hours (EOH), and plant scale. The results show that renewable power sources, net CCGT efficiency, and hydrogen production efficiency are the dominant variables, while EOH and plant scale are the minor factors. The results point out the direction for performance improvement in the future. This work also quantifies the life cycle of GHG and NOx emissions of power regenerated under current and future scenarios. For hydro, photovoltaic (PV) and wind power, the life cycle of the GHG emissions of regenerated power varies from 8.8 to 366.1 gCO2e/kWh and that of NOx emissions varies from 0.06 to 2.29 g/kWh. The power regenerated from hydro and wind power always has significant advantages over coal and gas power in terms of GHG and NOx emissions. The power regenerated from PV power has a small advantage over gas power in terms of GHG emissions, but does not have advantages regarding NOx emissions. Preference should be given to storing hydro and wind power, followed by PV power. For biomass power with or without CO2 capture and storage (CCS), the life cycle of the GHG emissions of regenerated power ranges from 555.2 to 653.5 and from −2385.0 to −1814.4, respectively, in gCO2e/kWh; meanwhile, the life cycle of NOx emissions ranges from 1.61 to 4.65 g/kWh, being greater than that of coal and gas power. Biomass power with CCS is the only power resource that can achieve a negative life cycle for GHG emissions. This work reveals that hydrogen-fueled gas turbines are an important, environmentally friendly technology. It also helps in decision making for grid operation and management.

Laser powder bed fusion technique of hydrogen–fueled gas turbine: Role of advanced materials and its challenges

Aviation accounts for 1.9% of greenhouse gas emissions, decarbonization is not straightforward as electrification is not feasible, and biofuels only partially address the issue. Therefore, aero-engine manufacturers are looking towards hydrogen as a clean fuel source as the emissions would majorly be water with no lasting greenhouse gasses. The major challenge with hydrogen-firing engines would be high firing temperatures, corrosive exhaust gasses and adverse reactions with structural components. The design flexibility of additive manufacturing (AM) and advanced materials development, such as high entropy alloys (HEAs) can be combined to produce gas turbines with higher turbine inlet temperatures and power output. This paper discusses the advantages and issues with hydrogen as fuel, the role of AM and advanced materials suitable for hydrogen-firing engines.

Analysis of a Multi-Generation Renewable Energy System With Hydrogen-Fueled Gas Turbine

Abstract Solar energy is considered one of the most affordable renewable resources for meeting current energy demands and mitigating environmental problems. However, the exploitation of solar energy is challenging because of both diurnal and seasonal variations. Power-to-hydrogen technologies can play a key role to counterbalance the variation of solar irradiance. Moreover, hydrogen-fueled gas turbines are considered promising technologies to decarbonize the electricity sector. To tackle these concerns, this paper presents a multigeneration energy system operated in island mode in which a hydrogen-fueled gas turbine is coupled with a solar photovoltaic plant, an electrolyzer, an absorption chiller, electric and thermal energy storage, as well as a hydrogen storage. Therefore, the energy system is 100% based on renewable energy. The sizes of the components are optimized by maximizing the exploitation of renewable energy sources, while the supply of electricity from the national grid must be null. Moreover, the effect of ambient conditions on the optimal sizing is also investigated by considering the thermal, cooling, and electrical energy demands of two case studies located in two different climatic zones. The paper demonstrates that the adoption of hydrogen-fueled gas turbines coupled with power-to-hydrogen technologies can effectively support the transition toward a clean energy supply. Moreover, this study provides a procedure for the optimal sizing of a multigeneration energy system fully based on solar energy, by also demonstrating that both photovoltaic (PV) panel area and hydrogen storage volume are feasible, if compared to the considered district layout.

Evaluation of the performance and economy for a hybrid energy storage system using hydrogen and compressed carbon dioxide as the energy carrier

A green concept of hybrid energy storage system with hydrogen and compressed carbon dioxide as the energy carrier has been proposed in this paper. The integration of the two energy storage methods leads to a hybrid efficient storage way, which can have higher energy density and lower pressure tank volume compared to the compressed carbon dioxide, and has higher energy storage efficiency compared with the hydrogen one. The ratio of the two energy storage is determined by the hydrogen consumption way. In this paper, the hydrogen fueled gas turbine with carbon dioxide as the working fluid (Allam cycle) is used for large amounts of the hydrogen consumption, and the mass flow rate ratio of hydrogen and CO2 is 0.0048 at the design point. The combined system can be used for inter-regional power dispatching, peak and frequency modulation and so on. A basic system form is firstly introduced, and the round trip efficiency (RTE) and levelized cost of electricity (LCOE) are 42.41% and 0.2075 $/kWh at the design point, respectively. In addition, two improved types are proposed. The effect of key parameters, including the CO2 compressor outlet pressure, the CO2 compressor inlet pressure and the CO2 mass flow rate, on the system performance is performed. The multi-objective optimization is also conducted. The comparison reveals that the improved form-I performs with a lower LCOE and a weaker RTE. In contrast, the improved form-II owns a better RTE but a higher LCOE. It can be concluded that the improved form-I can improve the economic performance of the energy storage system through the optimization of the compressed carbon dioxide high pressure storage subsystem. And the improved form-II can enhance the thermodynamic performance by adding the transcritical carbon dioxide cycle branch. Potential solutions to improve the system economic performances are also discussed and the results indicate that technology development, subsidies and electricity market transaction premium would be beneficial for the large-scale promotion of the system in practical.

Preliminary Analysis of Compression System Integrated Heat Management Concepts Using LH2-Based Parametric Gas Turbine Model

The investigation of the various heat management concepts using LH2 requires the development of a modeling environment coupling the cryogenic hydrogen fuel system with turbofan performance. This paper presents a numerical framework to model hydrogen-fueled gas turbine engines with a dedicated heat-management system, complemented by an introductory analysis of the impact of using LH2 to precool and intercool in the compression system. The propulsion installations comprise Brayton cycle-based turbofans and first assessments are made on how to use the hydrogen as a heat sink integrated into the compression system. Conceptual tubular compact heat exchanger designs are explored to either precool or intercool the compression system and preheat the fuel to improve the installed performance of the propulsion cycles. The precooler and the intercooler show up to 0.3% improved specific fuel consumption for heat exchanger effectiveness in the range 0.5–0.6, but higher effectiveness designs incur disproportionately higher pressure losses that cancel-out the benefits.

A review of research and development on hydrogenfueled gas turbine power plants

A review of research and development on hydrogenfueled gas turbine power plants

Materials challenges in hydrogen-fuelled gas turbines

ABSTRACT With the increased pressure to decarbonise the power generation sector several gas turbine manufacturers are working towards increasing the hydrogen-firing capabilities of their engines towards 100%. In this review, we discuss the potential materials challenges of gas turbines fuelled with hydrogen, provide an updated overview of the most promising alloys and coatings for this application, and highlight topics requiring further research and development. Particular focus is given to the high-temperature oxidation of gas turbine materials exposed to hydrogen and steam at elevated temperatures and to the corrosion challenges of parts fabricated by additive manufacturing. Other degradation mechanisms such as hot corrosion, the dual atmosphere effect and hydrogen diffusion in the base alloys are also discussed.

Global potential of green ammonia based on hybrid PV-wind power plants

Ammonia is one of the most commonly used feedstock chemicals globally. Therefore, decarbonisation of ammonia production is of high relevance towards achieving a carbon neutral energy system. This study investigates the global potential of green ammonia production from semi-flexible ammonia plants utilising a cost-optimised configuration of hybrid PV-wind power plants, as well as conversion and balancing technologies. The global weather data used is on an hourly time scale and 0.45° × 0.45° spatial resolution. The results show that, by 2030, solar PV would be the dominating electricity generation technology in most parts of the world, and the role of batteries would be limited, while no significant role is found for hydrogen-fuelled gas turbines. Green ammonia could be generated at the best sites in the world for a cost range of 440–630, 345–420, 300–330 and 260–290 €/tNH3 in 2020, 2030, 2040 and 2050, respectively, for a weighted average capital cost of 7%. Comparing this to the decade-average fossil-based ammonia cost of 300–350 €/t, green ammonia could become cost-competitive in niche markets by 2030, and substitute fossil-based ammonia globally at current cost levels. A possible cost decline of natural gas and consequently fossil-based ammonia could be fully neutralised by greenhouse gas emissions cost of about 75 €/tCO2 by 2040. By 2040, green ammonia in China would be lower in cost than ammonia from new coal-based plants, even at the lowest coal prices and no greenhouse gas emissions cost. The difference in green ammonia production at the least-cost sites in the world’s nine major regions is less than 50 €/tNH3 by 2040. Thus, ammonia shipping cost could limit intercontinental trading and favour local or regional production beyond 2040.

A new pattern of flame/flow dynamics for lean-premixed, low-swirl hydrogen turbulent jet flames under thermoacoustic instability

This paper presents a phenomenological investigation of a new pattern of lean-premixed hydrogen-flame and flowfield dynamics under thermoacoustic instabilities (TIs) observed inside a low-swirl combustor (LSC) with two combustion chamber lengths of 300 and 500 mm. In this study, the initial bulk inlet velocity was set to Vm=15 m/s. The fuel flow rate was linearly increased while the air flow rate was kept constant, causing a transition from stable operation to TI. Simultaneous time-resolved electronically excited hydroxyl radical (OH*) chemiluminescence imaging and two-dimensional particle image velocimetry were performed along with pressure-fluctuation measurements to investigate spatiotemporal relationships between fluctuating quantities, i.e., OH* chemiluminescence, velocity fields, and pressure, before and after TI onset. A typical TI pattern characterized by a lifted, inverted conical flame caused by diverging, decelerating flow near the injector exit was observed in the long combustor. In contrast, the flame/flow dynamics pattern under TI in the short combustor had strong pressure oscillations and anomalous LSC flame structures which were characterized by a radially flat flame region and counter-rotating vortex pair (CVP) flame structures. In this case, the radial profile of the axial velocity assumed an atypical top-hat-like shape. This feature resulted in thermoacoustic coupling that satisfied the Rayleigh criterion over an almost entirely flat flame region and further strengthened the TI. Thermal expansions of CVP structures served as “converging nozzles” constricting the central flow region. Periodic appearances of this Venturi-like effect caused an alternating diverging (decelerating) and converging (accelerating) flowfield, with a significant peak-to-peak velocity-oscillation amplitude of 15 m/s, equivalent to Vm. These pioneering observations regarding LSCs provide further insights into TI mechanisms in hydrogen-fueled gas turbine combustors.

Investigation of a pure hydrogen fueled gas turbine burner

Hydrogen can represent an option for a low emission gas turbine if low NOx combustion systems are developed. This paper describes the design and the investigations carried out on a lean premixed burner 100% hydrogen supplied. An existing heavy-duty gas turbine burner was modified with a new axial swirler and a co-flow injection system. The designed prototype presents the interesting feature where the variable premixing level permits a wide-ranging case studying. The burner prototype was investigated during a test campaign performed on an atmospheric test rig. Flame control on burner prototype, fired by pure hydrogen, was achieved by managing the premixing degree and the flow velocity. NOx emissions, flash-back limit, and burner pressure drop were measured over a wide range of the main operating parameters: equivalence ratio, premixer discharge velocity and thermal input. Results of the measurements outline as higher velocity flow (depending on the burner arrangements and operating conditions) is necessary to avoid flame positioning inside the premixer duct when hydrogen is used. The best arrangement can limit the NOx emissions to 17 ppm but with an outlet velocity about 120 m/s. The numerical activity integrates the information on the flame shape, and it improves the knowledge of the NOx emissions and their chemical path. Anyway, the study confirmed the operability of the system and great perspective regarding NOx emission containment.

Performance Prediction of a Transport Gasifier–Based IGCC System with CO2 Capture under Uncertainties

In this study, a transport gasifier–based integrated gasification combined cycle (IGCC) with 90% CO2 capture rate was analyzed to predict possible net power output and net efficiency distributions in the system under uncertainties. Moreover, the influence of each parameter on the total model output uncertainty was quantified and displayed using Pareto charts. Uncertainties in parameters of the gasifier, Selexol-CO2 capture process, hydrogen-fueled gas turbine, compressors, steam turbines, and pumps were considered and quantitatively represented in uniform, triangle, or normal distributions. Monte Carlo simulation was adopted to propagate the parameters through process modeling. Results showed that the predicted median net plant efficiency of the system was 37.71% with a standard deviation of 0.41%. The unconverted carbon rate in the gasifier and the gas turbine combustor temperature (gtCMBT) exhibited the greatest effect on predicting uncertainties in efficiency and power output, respectively. Thus, future work should focus on reducing these parameter uncertainties. Comparisons are conducted between the transport gasifer–based system and the dry-feed entrained flow gasifier–based system with similar configuration. The results indicate that, even in the worst case scenario, IGCC with the oxygen-blown gasifier has a similar net efficiency to IGCC with the dry-feed entrained flow gasifier.

Design and Testing of a Micromix Combustor With Recuperative Wall Cooling for a Hydrogen Fueled μ-Scale Gas Turbine

For more than 1 decade up to now, there is an ongoing interest in small gas turbines downsized to microscale. With their high energy density, they offer a great potential as a substitute for today’s unwieldy accumulators found in a variety of applications such as laptops, small tools, etc. But microscale gas turbines could not only be used for generating electricity, they could also produce thrust for powering small unmanned aerial vehicles or similar devices. Beneath all the great design challenges with the rotating parts of the turbomachinery at this small scale, another crucial item is in fact the combustion chamber needed for a safe and reliable operation. With the so-called regular micromix burning principle for hydrogen successfully downscaled in an initial combustion chamber prototype of 10 kW energy output, this paper describes a new design attempt aimed at the integration possibilities in a μ-scale gas turbine. For manufacturing the combustion chamber completely out of stainless steel components, a recuperative wall cooling was introduced to keep the temperatures in an acceptable range. Also a new way of an integrated ignition was developed. The detailed description of the prototype’s design is followed by an in depth report about the test results. The experimental investigations comprise a set of mass flow variations, coupled with a variation of the equivalence ratio for each mass flow at different inlet temperatures and pressures. With the data obtained by an exhaust gas analysis, a full characterization concerning combustion efficiency and stability of the prototype chamber is possible. Furthermore, the data show full compliance with the expected operating requirements of the designated μ-scale gas turbine.

Numerical simulation of a hydrogen fuelled gas turbine combustor

The interest for hydrogen-fuelled combustors is recently growing thanks to the development of gas turbines fed by high content hydrogen syngas. The diffusion flame combustion is a well-known and consolidated technology in the field of industrial gas turbine applications. However, few CFD analyses on commercial medium size heavy duty gas turbine fuelled with pure hydrogen are available in the literature. This paper presents a CFD simulation of the air-hydrogen reacting flow inside a diffusion flame combustor of a single shaft gas turbine. The 3D geometrical model extends from the compressor discharge to the gas turbine inlet (both liner and air plenum are included). A coarse grid and a very simplified reaction scheme are adopted to evaluate the capability of a rather basic model to predict the temperature field inside the combustor. The interest is focused on the liner wall temperatures and the turbine inlet temperature profile since they could affect the reliability of components designed for natural gas operation. Data of a full-scale experimental test are employed to validate the numerical results. The calculated thermal field is useful to explain the non-uniform distribution of the temperature measured at the turbine inlet.