Manfred Wirsum

RWTH Aachen University · Chair and Institute for Power Plant Technology, Steam and Gas Turbines

The substitution of conventional fossil fuels with synthetic CO2-neutral fuels, such as green hydrogen, represents a key measure to decarbonize sectors that are difficult to electrify. To implement large-scale fuel substitution, however, various issues related to the production, supply and use of hydrogen in energy applications need to be considere...

Due to the inherent volatility of renewable power generation technologies, dispatchable components, such as gas turbines (GT) will have to be used increasingly for residual load balancing. In addition, GTs are expected to operate fewer hours per year, more flexibly, and at lower capacities. However, fuel utilization in GT is inherently linked to em...

To accelerate progress toward sustainability, a fundamental shift from conventional to renewable energy sources is necessary, but insufficient on its own. Improving the efficiency of existing energy systems is equally important. One promising avenue for achieving this goal involves integrating previously overlooked devices, such as the vortex tube,...

The mitigation of climate change poses severe pressure on the rapid replacement of conventional power generation technologies by renewables. Due to the inherent volatility of renewable power generation technologies, dispatchable power generation units, such as gas turbines (GT) and gas-based reciprocating internal combustion engines (RICE), must be...

Kawasaki (KHI) has made various improvements and commercialized hydrogen gas turbines for existing diffusion combustors (0–100 vol.% H2, wet combustion) and lean pre-mixed DLE combustors (0–30 vol.% H2). However, it is challenging for conventional combustion technology to achieve dry low NOx emissions for 100 vol.% hydrogen. Kawasaki’s unique appro...

Secondary air systems in gas turbines provide a pressurized purge for the protection of highly-stressed components. The selection of an appropriate purge air mass flow seeks to sufficiently reduce the ingestion of hot annulus gas into the side wheel space with minimal impact on gas turbine efficiency. This paper describes a computational study of t...

Within the energy sector, the mitigation of climate change necessitates a paradigm change towards the replacement of conventional with sustainable power generation technologies. Due to the inherent volatility of renewable power generation technologies, dispatchable components, such as gas turbines (GT) will have to be used increasingly for residual...

Thermal loads play a major role in determining a turbocharger turbine’s lifecycle. The turbine wheel in particular is subject to varying thermal loads, which induce inhomogeneous temperature distributions causing thermo-mechanical stress. In order to calculate these thermal loads the mechanisms governing the heat transfer inside a turbocharger turb...

To combat climate change successfully, enhancing existing processes is imperative alongside exploring new regenerative technologies. For this purpose, new components must be considered to improve the efficiency of thermodynamic processes. A promising candidate is the Ranque–Hilsch vortex tube due to its low investment cost and maintenance. Previous...

Hydrogen and thermal storage can reduce cost of long-term and large-scale energy storage with high efficiency and low or even zero carbon emissions. Their potential in the low-carbon transition pathway of an energy system with rapid growth of energy demand, large shifting of energy supply structure and limited investment budget remains unclear. A l...

Renewable power generation capacities are mostly subject to inherent fluctuations. To maintain the security of supply in a regenerative-dominated energy system, flexible components must be increasingly implemented to balance the residual load. Among other options, gas turbines are eligible for this grid-serving task. However, fuel conversion in gas...

To achieve the climate goals and successfully mitigate climate change, the synthesis of fuels for hard-to-electrify sectors like transportation is crucial. Since biomass-based fuels are hard to scale up to the required dimensions, there is an exigency of alternative carbon sources to develop a carbon-neutral supply chain. The most prominent technol...

Renewable power generation capacities mostly underlay inherent fluctuations. To maintain the security of supply in a regenerative dominated energy system, flexible components must be increasingly implemented for balancing the residual load. Among other options, gas turbines are eligible for this grid-serving task. Special focus is set on hydrogen u...

For the decarbonisation of the steel industry, electric steelmaking using scrap is the most important technology as it produces 80 % less greenhouse gases than the blast furnace route. The electric arc furnace (EAF) is usually equipped with additional diffusion burners, so there are numerous efforts to replace natural gas with up to 100 % hydrogen....

Climate change intensifies stress on global potable water supply. Over 2 billion people still lack access to safe potable water, hindering social and economic development in arid regions. As a result, cost-effective desalination is important. The two main desalination technologies are thermal-based and membrane processes. The membrane-based desalin...

The mitigation of climate change poses severe pressure on the rapid replacement of conventional power generation technologies by renewables on a global scale. Due to the inherent volatility of renewable power generation technologies from solar and wind, dispatchable power generation units must be considered to maintain grid stability. Flexible gas-...

Rising energy costs and increasing efforts to reduce greenhouse gas emissions strengthen the demand for highly efficient operation of centrifugal compressors. This applies both to new machines as well as to compressor units with long operation times. One possible measure to reduce drag in flow channels and thus increase compressor efficiency are mi...

In gas turbines, stressed components have to be protected against high temperatures, while at the same time minimizing the overall amount of secondary air. Decreasing safety factors in secondary air systems can be feasible with a better understanding of the underlying flow mechanisms. This paper focuses on the purging effect of the secondary air, w...

There are many different metrics used for characterizing the emission behavior of power generation units, making it difficult to compare different technologies, fuels, and cycle layouts comprehensively. The present study analyses and evaluates different metrics for emission quantification (e.g., relative, absolute, or performance-based values). Mix...

For the decarbonisation of the steel industry, electric steelmaking using scrap is the most important technology as it produces 80 % less greenhouse gases than the blast furnace route. The electric arc furnace (EAF) is usually equipped with additional diffusion burners, i.e. the process is not fully electrified. Numerous efforts are currently under...

Electric steelmaking using scrap generates 80% less greenhouse gases than the blast furnace route. The electric arc furnace (EAF) is usually equipped with natural gas (NG) burners that melt down the scrap and decarburize the melt. Many activities are underway to replace NG, at least to a large extent, with hydrogen. Hydrogen has complex combustion...

Kawasaki Heavy Industries, Ltd. (KHI), Aachen University of Applied Sciences, and B&B-AGEMA GmbH have investigated the potential of low NOx micro-mix (MMX) hydrogen combustion and its application to an industrial gas turbine combustor. Engine demonstration tests of a MMX combustor for the M1A-17 gas turbine with a co-generation system were conducte...

This paper presents different modeling approaches on rim seal flow in a 1.5-stage test turbine resulting in the analysis of numerical data in comparison to existing test data. The analysis focuses on a very simple axial sealing gap and a reference operation point which shows significant hot gas ingestion in the experiments. The presented model will...

Despite their similarity as gas-based power generation technologies, emissions from gas turbines (GT) and gas-based reciprocating internal combustion engines (RICE) are commonly regulated independently. Thus, the present study aims to provide a comprehensive emission footprint analysis of GT and RICE power plants using an apples-to-apples metric (i...

An important factor in the decarburization of the steel industry is to replace natural gas with hydrogen for use in the burners/injectors of an electric arc furnace. The interdisciplinary project Clusters4Future Hydrogen-Industrial burners for natural gas-hydrogen mixtures (HyInnoBurn) deals with industrial burners that can be used with mixtures of...

Digital twin is a core technology for smart power plants aiming to increase the safety and efficiency of power generation in low-carbon transitions. High-precision modelling of in-service power plant thermal systems plays a key role to develop digital twins, but remains a challenge. There is a lack of high-precision modelling for in-service power p...

Hydrogen-based energy storage has the potential to compensate for the volatility of renewable power generation in energy systems with a high renewable penetration. The operation of these storage facilities can be optimized using automated energy management systems. This work presents a Reinforcement Learning-based energy management approach in the...

Derzeit ist der Wärmesektor für mehr als die Hälfte des gesamten globalen Endenergiebedarfs verantwortlich, wobei aktuell nur ca. 10 % durch erneuerbare Energien bereitgestellt wird [1]. Der Großteil der Treibhausgasemissionen der Wärmebereitstellung kann zukünftig jedoch durch die Verwendung regenerativen Stroms mittels Sektorenkopplung und Elektr...

Zur Erreichung ambitionierter Klimaschutzziele ist neben einer Transformation der Stromerzeugungslandschaft auch eine Dekarbonisierung des Wärmesektors notwendig. Global gesehen ist der Wärmesektor für mehr als die Hälfte der CO2-Gesamtemissionen verantwortlich. Durch direkte Nutzung regenerativer Wärme mittels Geo- und Solarthermie oder durch die...

Hydrogen-fired gas turbines have the potential to play an important role in future CO2-neutral energy and industry sectors. A prerequisite for the operation of hydrogen-fired gas turbines is the availability of sufficient quantities of hydrogen. The combination of electrolysis and renewable power generation is currently considered the most relevant...

This paper presents the development and validation of a meanline model by means of numerical and experimental methods, to determine it's feasibility as an optimisation tool for turbocharger matching. Using a parametric turbine model, numerical experiments were conducted accounting for variations of several key turbine design parameters and a wide o...

State-of-the-art centrifugal compressor stages are required to provide both a flexible and a highly efficient operation. To extend the stable operating range and to improve the design-point polytropic total-to-total efficiency of an open impeller centrifugal compressor stage, three vaned contoured diffusers characterized by geometric modifications...

Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for a future hydrogen society. These projects comprise the complete hydrogen cycle, including the production of hydrogen gas, the refinement and liquefaction for transportation and storage, and finally the utilization in a gas turbine for electricity and heat supply. Within...

Hydrogen-fired gas turbines have the potential to play an important role in future CO2-neutral energy and industry sectors. A prerequisite for the operation of hydrogen-fired gas turbines is the availability of sufficient quantities of hydrogen. The combination of electrolysis and renewable power generation is currently considered the most relevant...

To mitigate its impact on global climate, the power generation sector must strive towards a transition to net-zero emissions of greenhouse gases. This can be achieved by a massive penetration of renewable power generation. However, a high share of renewable power generation requires dispatchable and flexible power generation technologies such as ga...

Highly efficient and concurrent flexible operation are heavy demands on today's centrifugal compressor units. Diffuser end wall contouring is a measure to delay the incipience of instability and therefore to extend the compressor's operating range while maintaining efficient performance. In the presented paper, a hub-side wall contouring, applied i...

One of the main challenges currently hindering the transition to energy systems based on renewable power generation is grid stability. To compensate for the volatility of wind- and solar-based power generation, storage facilities able to adapt to seasonal and short-term differences in energy production and demand are required. Liquid organic hydrog...

This paper presents a novel methodology for engine tailored optimisation of turbocharger turbine design. Both the turbine rotor and volute geometries for a turbocharger radial turbine were parameterised in order to enable CFD calculations for variations of predefined design parameters. The results of this analysis where used to develop and validate...

Hydrogen-fired gas turbines can play an important role in carbon neutral energy and industry sectors. However, the required demand-oriented supply of CO2-neutral hydrogen is technically and economically challenging. These challenges arise due to interdependencies between the volatility of renewable power generation, available hydrogen production ca...

Climate science shows that the limitation of global warming requires a rapid transition towards net-zero emissions of greenhouse gases (GHG) on a global scale. Expanding renewable power generation is seen as an imperative measure within this transition. To compensate for the inherent volatility of renewable power generation, flexible and dispatchab...

In this paper, the transient thermal and structural analyses of a 19-stage IP steam turbine in various start-up operating modes are discussed. The research utilises a hybrid (HFEM - numerical FEM and analytical) approach to efficiently determine the time-dependent temperature distribution in the components of the steam turbine. The simulation strat...

Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for a future hydrogen society. Within the development of the hydrogen gas turbine, the key technology is stable and low NOx hydrogen combustion, namely the Dry Low NOx (DLN) hydrogen combustion. KHI, Aachen University of Applied Science, and B&B-AGEMA have investigated the...

Highly efficient and concurrent flexible operation are heavy demands on today’s centrifugal compressor units. Diffuser end wall contouring is a measure to delay the incipience of instability and therefore to extend the compressor’s operating range while maintaining efficient performance. In the presented paper, a hubside wall contouring, applied in...

Hydrogen-fired gas turbines have the potential to play an important role in decarbonized energy sectors. However, a demand-oriented supply of CO2-neutral hydrogen for the operation of gas turbines is technically and economically challenging. These challenges mainly arise due to various interdependencies between the volatility of renewable power gen...

Adaptability of coal-based power generating units to accommodate renewable energy sources is becoming increasingly important. In order to improve flexibility, reduce start-up time and extend the life cycle, General Electric has developed solutions to pre-warm/warm-keep steam turbines using hot air. In this paper two main contributions to optimize t...

Motivated by the urgent need for flexibility and start-up capability improvements of conventional power plants in addition to extending their life cycle, General Electric provides its customers with a product to pre-warm steam turbines using hot air. In this paper, the transient thermal and structural analyses of a 19-stage IP steam turbine in vari...

This paper presents the development and validation of a meanline model by means of numerical and experimental methods, to determine it’s feasibility as an optimisation tool for turbocharger matching. Using a parametric turbine model, numerical experiments were conducted accounting for variations of several key turbine design parameters and a wide o...

Climate science shows that the limitation of global warming requires a rapid transition towards net-zero emissions of green house gases (GHG) on a global scale. Expanding renewable power generation in a significant way is seen as an imperative measure within this transition. To compensate for the inherent volatility of wind- and solar-based power g...

State-of-the-art centrifugal compressor units utilised in pipeline and in energy storage applications face the challenge of flexible and highly efficient operation. Geometric contouring on the hub side near a vaned diffuser affects the flow in a way which increases operational flexibility by delaying the incipience of instability and thereby increa...

In turbocharger design, the accurate determination of thermally induced stresses is of particular importance for life cycle predictions. An accurate, transient, thermal finite element analysis (FEA) of turbocharger components requires transient conjugate heat transfer (CHT) analysis. However, due to the vastly different timescales of the heat trans...

Unshrouded industrial centrifugal compressor impellers operate at high rotational speeds and volume flow rates. Under such conditions impeller blade excitation is dominated by high frequency interaction with stationary parts, i.e. vaned diffusers or inlet guide vanes. In a previous study conducted on two full compression units of the original equip...

The changing energy landscape leads to a rising demand of more flexible power generation. A system for steam turbine (ST) warm-keeping provides the ability to shutdown conventional power plants during periods with a high share of renewable power. Simultaneously, these power plants are ready for grid stabilization on demand without an excessive cons...

In pursuit of flexibility improvements and extension of lifetime, a concept to pre-warm steam turbines using hot air was developed. In order to further optimize the pre-warming operation, an extensive numerical investigation is conducted to determine the time-dependent temperature and stress fields. In this work, the transient thermal and structura...

Emission measurements are a valuable source of information regarding the condition of gas turbine combustors. Aging of the hot gas path components can lead to an emission increase, which may ultimately require a readjustment of operational settings and accordingly impacts plant availability and maintenance. While NOx emissions may become crucial in...

In pursuit of flexibility improvements and extension of lifetime, a concept to pre-warm steam turbines using hot air was developed. In order to further optimize the pre-warming operation, an extensive numerical investigation is conducted to determine the time-dependent temperature and stress fields. In this work, the transient thermal and structura...

The changing energy landscape leads to a rising demand of more flexible power generation. A system for steam turbines warm-keeping provides the ability to shutdown conventional power plants during periods with a high share of renewable power. Simultaneously, these power plants are ready for grid stabilization on demand without an excessive consumpt...

Increasing load ramps and temperature gradients in steam turbines, especially during start-ups, have a high impact on the component lifetime. Calculation models are commonly used to predict the lifetime consumption during such start-up procedures. However, the changing energy landscape requires innovative solutions to increase the power plant flexi...

Combined cycle power plants (CCPP) have many advantages compared to other fossil power plants: high efficiency, flexible operation, compact design, high potential for combined heat and power (CHP) applications and fewer emissions. However, fuel costs are relatively high compared to coal. Nevertheless, major qualities such as high operation flexibil...

A stereo vision system for deep-sea operations is presented. The system consists of cameras in pressure bottles, which are daisy-chained to a computer bottle. The system has substantial computation power for on-board stereo processing as well as for further computer vision methods to support autonomous intelligent functions, e.g., object recognitio...

The sustainable energy transition (Energiewende) is a multidisciplinary challenge. While for technical disciplines, the focus is on the development of technologies which can supply, transmit and store energy in a sustainable way, economic research focuses for example on the analyses of costs and risks of different asset portfolios. Yet another pers...

Recent studies have shown that in a prewarming, respectively, warm-keeping operation of a steam turbine, the blades and vanes transport most of the heat to the thick-walled casing and rotor. Thereby, a thermal bottle-neck arises at the connection between the blade root and the rotor. The thermal contact resistance (TCR) at these interfaces affects...

Flexible steam turbines play an important role within the future energy market. Start-up times and lifetime consumption can be reduced due to steam turbine pre-warming. The consideration of the thermal contact resistance (TCR) is important especially during an operation with low rotational speed. Several analytical approaches for the determination...

Many energy supply systems around the world are currently undergoing a phase of transition characterized by a continuing increase in installed renewable power generation capacities. The inherent volatility and limited predictability of renewable power generation pose various challenges for an efficient system integration of these capacities. One ap...

In pursuit of flexibility improvements, General Electric has developed a product to warm-keep high/intermediate pressure steam turbines using hot air. In order to optimize the warm-keeping operation and to gain knowledge about the dominant heat transfer phenomena and flow structures, detailed numerical investigations are required. For the sake of t...

Due to the growing share of volatile renewable power generation, conventional power plants with a high flexibility are required. This leads to high thermal stresses inside the heavy components which reduces the lifetime. To improve the ability for fast start-ups, information about the metal temperature inside the rotor and the casing are crucial. T...

Accurate monitoring of gas turbine performance is a means to an early detection of performance deviation from the design point and thus to an optimized operational control. In this process, the diagnosis of the combustion process is of high importance due to strict legal pollution limits as aging of the combustor during operation may lead to an obs...

Many energy supply systems around the world are currently undergoing a phase of transition characterized by a continuing increase in installed renewable power generation capacities. The inherent volatility and limited predictability of renewable power generation pose various challenges for an efficient system integration of these capacities. One ap...

In recent decades, the rising share of commonly subsidized renewable energy especially affects the operational strategy of conventional power plants. In pursuit of flexibility improvements, extension of life cycle, in addition to a reduction in start-up time, General Electric has developed a product to warm-keep high/intermediate pressure steam tur...

Reliable engine and emission models allow for an online monitoring of commercial gas turbine operation and help the plant operator and the original equipment manufacturer (OEM) to ensure emission compliance of the aging engine. However, model development and validation require fine-tuning on the particular engines, which may differ in a fleet of a...

Due to the growing share of volatile renewable power generation, conventional power plants with a high flexibility are required. This leads to high thermal stresses inside the heavy components which reduces the lifetime. To improve the ability for fast start-ups, information about the metal temperature inside the rotor and the casing are crucial. T...

Within the ongoing global transition process towards renewable energies, gas turbines can play a significant role due to their ability to provide flexible and dispatchable power that compensates for the inherent volatility of renewable power generation. While being important for the stability of the electricity grid, this flexible mode of operation...

The determination of the temperature distribution in the thick-walled components in steam turbines is increasing in relevance. Due to the growing share of volatile renewable power generation, power plants with a high flexibility and a high integral effciency are required. The current operational conditions lead to high thermal stresses inside the h...

Studies have shown that in a pre-warming respectively warm-keeping operation of a steam turbine, the blades and vanes transport most of the heat to the thick-walled casing and rotor. Thereby, a bottle-neck arises at the connection between the blade root and the rotor. The contact heat resistance at these interfaces affects the temperature distribut...

Steam turbines in conventional power plants have to deal with an increasing number of start-ups due to the high share of fluctuating power input in renewable power generation. As a result, the development of new methods for flexibility improvements such as reductions in start-up time and the effects these start-ups have on turbine lifetime-have bec...

Dampfturbinen in konventionellen Kraftwerken bilden aktuell, wie auch in näherer Zukunft das Rückgrat einer sicheren Energieversorgung im Kontext der Energiewende. Um dies zu gewährleisten ist es notwendig, die bestehenden Kraftwerke an die sich verändernden Anforderungen anzupassen. Die volatile Einspeisung aus Erneuerbaren Energien fordert von de...

Tangential endwall contouring is intended to improve the blading efficiency in turbomachinery. The present paper focusses on the influence of leakage flows on the performance of non-axisymmetric endwall contouring. All tests were conducted on a 2 stage axial turbine test rig at the Institute of Power Plant Technology, Steam and Gas Turbines (IKDG)...

Lean premixed combustion has become state of the art technology in gas turbines for power generation because of its very low emission potential in the context of tightening pollutant emissions regulations. Lean premixed combustion is yet also prone to combustion instabilities, resulting in thermo-acoustically induced acoustic pressure oscillations...

Accurate monitoring of gas turbine performance is a means to an early detection of performance deviation from the design point and thus to an optimized operational control. In this process, the diagnosis of the combustion process is of high importance due to strict legal pollution limits as aging of the combustor during operation may lead to an obs...

Nowadays, steam turbines in conventional power plants deal with an increasing number of startups due to the high share of fluctuating power input of renewable generation. Thus, the development of new methods for flexibility improvements, such as reduction of the start-up time and its costs, have become more and more important. At the same time, fas...

Many energy supply systems around the world are currently undergoing a phase of transition that is mainly characterized by a continuing increase in installed renewable power generation capacities. Aiming at a better integration of these additional capacities, operators of wind farms in Germany are obliged to bindingly forecast their power productio...

Addition of hydrogen (H2) to gas turbine fuel has recently become a topic of interest facing the global challenges of CO2 free combustion. As a drawback, Nitrogen oxide (NOx) emissions are likely to increase in hydrogen-rich fuel combustion which in return limits the use of the technology. In the course of this development, a model-based quantifica...