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Kyprianidis, KonstantinosORCID iD iconorcid.org/0000-0002-8466-356X
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Publications (10 of 91) Show all publications
Zaccaria, V., Stenfelt, M., Sjunnesson, A., Andreas, H. & Kyprianidis, K. (2019). A MODEL-BASED SOLUTION FOR GAS TURBINE DIAGNOSTICS: SIMULATIONS AND EXPERIMENTAL VERIFICATION. In: Proceedings of the ASME Turbo ExpoVolume 6, 2019: . Paper presented at ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition, GT 2019; Phoenix; United States; 17 June 2019 through 21 June 2019; Code 154121. , Article ID GT2019-90858.
Open this publication in new window or tab >>A MODEL-BASED SOLUTION FOR GAS TURBINE DIAGNOSTICS: SIMULATIONS AND EXPERIMENTAL VERIFICATION
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2019 (English)In: Proceedings of the ASME Turbo ExpoVolume 6, 2019, 2019, article id GT2019-90858Conference paper, Published paper (Refereed)
Abstract [en]

Prompt detection of incipient faults and accurate monitoring of engine deterioration are key aspects for ensuring safe operations and planning a timely maintenance. Modern computing capabilities allow for more and more complex tools for engine monitoring and diagnostics. Nevertheless, an underlying physics-based approach is often preferable, because not only the “what” but also the “why” can be identified, providing an effective decision support tool to the service engineer. In this work, a physics-based adaptive model is used to evaluate performance deltas and correct the data to reference conditions (gas turbine load and ambient conditions), while a data-driven correlation algorithm identifies the most likely matches within a fault signatures database. Possible faults are ordered from the highest correlation in the decision support system and the most likely fault can be selected based on the number of occurrences and the associated correlation. Gradual engine degradation can also be monitored by displaying performance deltas trends during time. The diagnostics tool was tested on a validated performance model of a single-shaft industrial gas turbine and subsequently on experimental data. This paper presents the diagnostics system structure, the model adaptation scheme, and the results obtained from simulated and real fault data. Accurate fault isolation and severity identification were achieved in all cases, demonstrating the tool capability for decision support system.

National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-45905 (URN)10.1115/GT2019-90858 (DOI)2-s2.0-85075526028 (Scopus ID)9780791858677 (ISBN)
Conference
ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition, GT 2019; Phoenix; United States; 17 June 2019 through 21 June 2019; Code 154121
Projects
DIAGNOSIS
Available from: 2019-11-04 Created: 2019-11-04 Last updated: 2019-12-02Bibliographically approved
Kavvalos, M., Xin, Z., Schnell, R., Aslanidou, I., Kalfas, A. & Kyprianidis, K. (2019). A Modelling Approach of Variable Geometry for Low Pressure Ratio Fans. In: : . Paper presented at International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 27 September 2019 Paper No. ISABE-2019-24382.
Open this publication in new window or tab >>A Modelling Approach of Variable Geometry for Low Pressure Ratio Fans
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2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents the development and application of a modelling approach of variable geometry conceptsfor low pressure ratio fans; namely Variable Area Nozzle and Variable Pitch Fan. An enhanced approachfor Outlet Guide Vane pressure loss predictions and an aerothermodynamic analysis of variable pitchconcept are developed and integrated into a multi-disciplinary conceptual engine design framework. Astreamline curvature algorithm is deployed for the derivation of the off-design fan performance map,alleviating scaling issues from higher pressure ratio fan designs. Correction deltas are derived through thevariable pitch analysis for calculating the re-shaped off-design fan performance map. The aforementionedvariable geometry concepts are evaluated in terms of surge margin at engine and aircraft level for a lowpressure ratio aft-fan of a hybrid-electric configuration. Performance assessments carried out suggest thata +8° closing of fan blade cascades leads to a 33% surge margin improvement (with reference being thesurge margin without variable geometry) compared to a 25% improvement achieved by +20% opening thenozzle area at end of runway take-off conditions. Although weight and complexity implications of variablegeometry are not considered, the integrated modelling approach is shown to be able to assess and comparesuch novel engine technologies for low pressure ratio fans in terms of operability.

Keywords
Low Pressure Ratio Fan; Variable Area Nozzle; Variable Pitch Fan; Conceptual Design; Engine Performance;
National Category
Aerospace Engineering
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-46255 (URN)
Conference
International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 27 September 2019 Paper No. ISABE-2019-24382
Available from: 2019-12-08 Created: 2019-12-08 Last updated: 2019-12-08
Kavvalos, M., Xin, Z., Schnell, R., Aslanidou, I., Kalfas, A. & Kyprianidis, K. (2019). A Modelling Approach of Variable Geometry for Low Pressure Ratio Fans. In: International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 27 September 2019 Paper No. ISABE-2019-24382: . Paper presented at International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 27 September 2019 Paper No. ISABE-2019-24382.
Open this publication in new window or tab >>A Modelling Approach of Variable Geometry for Low Pressure Ratio Fans
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2019 (English)In: International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 27 September 2019 Paper No. ISABE-2019-24382, 2019Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents the development and application of a modelling approach of variable geometry conceptsfor low pressure ratio fans; namely Variable Area Nozzle and Variable Pitch Fan. An enhanced approachfor Outlet Guide Vane pressure loss predictions and an aerothermodynamic analysis of variable pitchconcept are developed and integrated into a multi-disciplinary conceptual engine design framework. Astreamline curvature algorithm is deployed for the derivation of the off-design fan performance map,alleviating scaling issues from higher pressure ratio fan designs. Correction deltas are derived through thevariable pitch analysis for calculating the re-shaped off-design fan performance map. The aforementionedvariable geometry concepts are evaluated in terms of surge margin at engine and aircraft level for a lowpressure ratio aft-fan of a hybrid-electric configuration. Performance assessments carried out suggest thata +8° closing of fan blade cascades leads to a 33% surge margin improvement (with reference being thesurge margin without variable geometry) compared to a 25% improvement achieved by +20% opening thenozzle area at end of runway take-off conditions. Although weight and complexity implications of variablegeometry are not considered, the integrated modelling approach is shown to be able to assess and comparesuch novel engine technologies for low pressure ratio fans in terms of operability.

Keywords
Low Pressure Ratio Fan; Variable Area Nozzle; Variable Pitch Fan; Conceptual Design; Engine Performance;
National Category
Aerospace Engineering
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-46288 (URN)
Conference
International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 27 September 2019 Paper No. ISABE-2019-24382
Available from: 2019-12-11 Created: 2019-12-11 Last updated: 2019-12-11
Zaccaria, V., Rahman, M. & Kyprianidis, K. (2019). A review of information fusion methodsfor gas turbine diagnostics. In: : . Paper presented at International Gas Turbine Congress IGTC2019.
Open this publication in new window or tab >>A review of information fusion methodsfor gas turbine diagnostics
2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

ABSTRACT The correct and early detection of incipient faults or severe degradation phenomena in gas turbine systems is essential for safe and cost-effective operations. A multitude of monitoring and diagnostic systems have been developed and tested in the last decades. The current computational capability of modern digital systems has been exploited for both accurate physics-based methods and artificial intelligence or machine learning methods. However, progress is rather limited and none of the methods explored so far seems to be superior to others. One solution to enhance diagnostic systems exploiting the advantages of various techniques is to fuse the information coming from different tools, for example through statistical methods. Information fusion techniques such as Bayesian networks, fuzzy logic, or probabilistic neural networks can be used to implement a decision support system. This paper presents a comprehensive review of information and decision fusion methods applied to gas turbine diagnostics and the use of probabilistic reasoning to enhance diagnostic accuracy. The different solutions presented in the literature are compared and major challenges for practical implementation on an industrial gas turbine are discussed. Detecting and isolating faults in a system is a complex problem under many uncertainties including integrity of available information. The capability of different information fusion techniques to deal with uncertainty are also compared and discussed. Based on the lessons learned, new perspectives for diagnostics and decision support system are proposed.

National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-45906 (URN)
Conference
International Gas Turbine Congress IGTC2019
Available from: 2019-11-04 Created: 2019-11-04 Last updated: 2019-11-22Bibliographically approved
Zimmerman, N., Kyprianidis, K. & Lindberg, C.-F. (2019). Achieving lower district heating network temperatures using feed-forward MPC. Materials, 12(15), Article ID 2465.
Open this publication in new window or tab >>Achieving lower district heating network temperatures using feed-forward MPC
2019 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 15, article id 2465Article in journal (Refereed) Published
Abstract [en]

The focus of this work is to present the feasibility of lowering the supply and return temperatures of district heating networks in order to achieve energy savings through the implementation of feed-forward model predictive control. The current level of district heating technology dictates a need for higher supply temperatures, which is not the case when considering the future outlook. In part, this can be attributed to the fact that current networks are being controlled by operator experience and outdoor temperatures. The prospects of reducing network temperatures can be evaluated by developing a dynamic model of the process which can then be used for control purposes. Two scenarios are presented in this work, to not only evaluate a controller's performance in supplying lower network temperatures, but to also assess the boundaries of the return temperature. In Scenario 1, the historical load is used as a feed-forward signal to the controller, and in Scenario 2, a load prediction model is used as the feed-forward signal. The findings for both scenarios suggest that the new control approach can lead to a load reduction of 12.5% and 13.7% respectively for the heat being supplied to the network. With the inclusion of predictions with increased accuracy on end-user demand and feed-back, the return temperature values can be better sustained, and can lead to a decrease in supply temperatures and an increase in energy savings on the production side.

Place, publisher, year, edition, pages
MDPI AG, 2019
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-45030 (URN)10.3390/ma12152465 (DOI)000482576900126 ()31382435 (PubMedID)2-s2.0-85070601468 (Scopus ID)
Available from: 2019-08-22 Created: 2019-08-22 Last updated: 2019-10-14Bibliographically approved
Rahman, M., Avelin, A. & Kyprianidis, K. (2019). An Approach for Feedforward Model Predictive Control of Continuous Pulp Digesters. Processes, 7(9), 602-622
Open this publication in new window or tab >>An Approach for Feedforward Model Predictive Control of Continuous Pulp Digesters
2019 (English)In: Processes, ISSN 2227 9717, Vol. 7, no 9, p. 602-622Article in journal (Refereed) Published
Abstract [en]

Kappa number variability at the continuous digester outlet is a major concern for pulp and paper mills. It is evident that the aforementioned variability is strongly linked to the feedstock wood properties, particularly lignin content. Online measurement of lignin content utilizing near-infrared spectroscopy at the inlet of the digester is paving the way for tighter control of the blow-line Kappa number. In this paper, an innovative approach of feedforwarding the lignin content to a model predictive controller was investigated with the help of modeling and simulation studies. For this purpose, a physics-based modeling library for continuous pulp digesters was developed and validated. Finally, model predictive control approaches with and without feedforwarding the lignin measurement were evaluated against current industrial control and proportional-integral-derivative (PID) schemes. 

Keywords
pulp and paper; Kappa number; pulp digester; modeling; feedforward; predictive control
National Category
Energy Engineering
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-45217 (URN)10.3390/pr7090602 (DOI)000489121800055 ()2-s2.0-85072222936 (Scopus ID)
Projects
FUDIPO
Available from: 2019-09-16 Created: 2019-09-16 Last updated: 2019-10-24Bibliographically approved
Kavvalos, M. & Kyprianidis, K. (2019). Compressor Characteristics for Transient and Part-load Performance Simulation. In: Proceedings of the ASME Turbo Expo, American Society of Mechanical Engineers (ASME), 2019: . Paper presented at ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition, 17-21 June 2019, GT2019-90457. American Society of Mechanical Engineers (ASME)
Open this publication in new window or tab >>Compressor Characteristics for Transient and Part-load Performance Simulation
2019 (English)In: Proceedings of the ASME Turbo Expo, American Society of Mechanical Engineers (ASME), 2019, American Society of Mechanical Engineers (ASME) , 2019Conference paper, Published paper (Refereed)
Abstract [en]

Compressor performance tests are mainly focused on the typical range of operation, resulting in limited knowledge of compressor behavior in the low-speed region. The main target of this work comprises the generation of compressor characteristics at low part-load by giving particular insight into the physical aspect of this operating condition. It is necessary for running transient and part-load performance simulation and can be considered as the first crucial step toward an optimal engine starting schedule. Modelling the low part-load operating regime requires accurate component performance maps extended to the low-speed area, where engine starting and altitude relight occur. In this work, a robust methodology for generating compressor maps in the low part-load operating regime is developed. Compressor geometry and typical operation range compressor map are required as inputs. Two different modelling processes are incorporated within this methodology. Extrapolation based on the principle of similarity laws with modified law exponents constitutes the first modelling process, which seems inaccurate when predicting compressor performance at fixed-rotor conditions. Interpolation based on the fixed-rotor characteristic constitutes the second modelling process, which can be either linear or adaptive. The adaptive interpolation scheme was developed by the authors and generates low-speed characteristics using the same allocation trend as the one obtained from given performance data. It is observed that performance data points of each β-line follow an exponential trend in mass flow differences while increasing rotational speed, with a calculated average relativized Root Mean Square (RMS) error of less than 5%. Adapting the same trend in mass flow to the low-speed region, a compressor performance map with continuous exponential trend in all characteristics (for part- and full-load conditions) can be achieved. Implementing the developed methodology on the High Pressure Compressor (HPC) of the Energy Efficient Engine (E3) project is also presented, showcasing its applicability and the merit of it being incorporated into any conventional performance prediction tool. Furthermore, a sensitivity analysis for input variables, namely compressor exit effective area and pressure loss model coefficients is carried out, demonstrating the significant impact of the former on the shape of the low part-load characteristics. Generation of compressor characteristics at low-speeds with this methodology can be viewed as an enabler for running credible transient starting simulation and transient diagnostics, thereby defining an optimal starting schedule, applicable to both power generation and aerospace industry.

Place, publisher, year, edition, pages
American Society of Mechanical Engineers (ASME), 2019
Keywords
Aerospace industry, Alternative fuels, Energy efficiency, Engines, Hydrogen fuels, Interpolation, Mass transfer, Power generation, Rankine cycle, Sensitivity analysis, Speed, Turbomachinery, Adaptive interpolation, Compressor characteristics, Compressor performance, High-pressure compressors, Low-speed characteristic, Part-load characteristics, Performance prediction, Root-mean-square errors, Compressors
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-46217 (URN)10.1115/GT2019-90457 (DOI)2-s2.0-85075485942 (Scopus ID)9780791858608 (ISBN)
Conference
ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition, 17-21 June 2019, GT2019-90457
Available from: 2019-12-02 Created: 2019-12-02 Last updated: 2019-12-11
Papagianni, A., Kavvalos, M., Aslanidou, I., Kyprianidis, K. & Kalfas, A. (2019). Conceptual Design of a Hybrid Gas Turbine - Solid Oxide Fuel Cell System for Civil Aviation. In: : . Paper presented at International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 28 September 2019 Paper No. ISABE-2019-24214.
Open this publication in new window or tab >>Conceptual Design of a Hybrid Gas Turbine - Solid Oxide Fuel Cell System for Civil Aviation
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2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

A conceptual design of a hybrid Gas Turbine - Solid Oxide Fuel Cell (SOFC) system is presented for civil aviation applications. The system operates using hydrogen as fuel, for the aircraft’s propulsion, while at the same time produces electrical energy in the fuel cell. Hydrogen is produced during flight by reformation of methane. The motivation of the study is to investigate hydrogen’s use for aviation purposes, so the hybrid system’s operation characteristics need to be examined. A configuration is designed, where a SOFC and the burner is modeled as one and simulated, in a modern multidisciplinary programming environment, in order to analyze the thermodynamic characteristics of the hybrid system. The fuel cell sets into motion when the aircraft reaches top of climb. During operation, liquefied natural gas is converted to hydrogen in the fuel cell and part of it is used to produce electrical energy while the rest for combustion. To determine the efficiency of the system, its performance was simulated using two scenarios, one for longhaul flights and one for short-haul flights. Comparing the results, for long-haul flights, the hybrid system presents a reduction in fuel consumption and an increase in thermal efficiency. For flights of a short range, the existing conditions in the fuel cell inlet were found to be prohibitive for it’s operation and the use of the hybrid system ineffective. For the system’s efficiency, the larger the pressure in the SOFC’s inlet the better. However, SOFC’s pressure limits restrict the pressure range and the cell’s use only during flight. Concluding, according to the study’s results, the hybrid system can operate in flight conditions, making the use of hydrogen in civil aviation possible. As a result, a 12% and 35% benefit is achieved, in fuel saving and thermal efficiency respectively.

Keywords
Hybrid system; Solid Oxide Fuel Cell; Hydrogen; Fuel saving; thermal efficiency
National Category
Aerospace Engineering
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-46257 (URN)
Conference
International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 28 September 2019 Paper No. ISABE-2019-24214
Available from: 2019-12-08 Created: 2019-12-08 Last updated: 2019-12-08
Salman, C. A., Dahlquist, E., Thorin, E., Kyprianidis, K. & Avelin, A. (2019). Future directions for CHP plants using biomass and waste - Adding production of vehicle fuels. In: E3S Web of Conferences: . Paper presented at 2019 SUstainable PolyEnergy Generation and HaRvesting, SUPEHR 2019, 4 September 2019 through 6 September 2019. EDP Sciences, Article ID 01006.
Open this publication in new window or tab >>Future directions for CHP plants using biomass and waste - Adding production of vehicle fuels
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2019 (English)In: E3S Web of Conferences, EDP Sciences , 2019, article id 01006Conference paper, Published paper (Refereed)
Abstract [en]

In Northern Europe, the production of many biobased CHP plants is getting affected due to the enormous expansion of wind and solar power. In addition, heat demand varies throughout the year, and existing CHP plants show less technical performance and suffer economically. By integrating the existing CHP plants with other processes for the production of chemicals, they can be operated more hours, provide operational and production flexibility and thus increase efficiency and profitability. In this paper, we look at a possible solution by converting an existing CHP plant into integrated biorefinery by retrofitting pyrolysis and gasification process. Pyrolysis is retrofitted in an existed CHP plant. Bio-oil obtained from pyrolysis is upgraded to vehicle grade biofuels. Gasification process located upfront of CHP plant provides the hydrogen required for upgradation of biofuel. The results show that a pyrolysis plant with 18 ton/h feed handling capacity (90 MWth), when integrated with gasification for hydrogen requirement and CHP plant for heat can produce 5.2 ton/h of gasoline/diesel grade biofuels. The system integration gives positive economic benefits too but the annual operating hours can impact economic performance. 

Place, publisher, year, edition, pages
EDP Sciences, 2019
National Category
Energy Systems
Identifiers
urn:nbn:se:mdh:diva-45259 (URN)10.1051/e3sconf/201911301006 (DOI)2-s2.0-85071879296 (Scopus ID)
Conference
2019 SUstainable PolyEnergy Generation and HaRvesting, SUPEHR 2019, 4 September 2019 through 6 September 2019
Available from: 2019-09-19 Created: 2019-09-19 Last updated: 2019-09-19Bibliographically approved
Stenfelt, M. & Kyprianidis, K. (2019). Gas Turbine Mixer Modelling Strategies and Afterburner Liner Burn-Through Diagnostics. In: : . Paper presented at 24:th ISABE Conference, Canberra, September 22-27, 2019.
Open this publication in new window or tab >>Gas Turbine Mixer Modelling Strategies and Afterburner Liner Burn-Through Diagnostics
2019 (English)Conference paper, Published paper (Other academic)
Abstract [en]

A mixer may be damaged either by cracks or mechanical deformation causing a change in geometry. Only the latter case is, in some cases, possible to detect by shifts in physical measurements such as pressures and temperatures. In general, deformations of the geometry of a mixer due to damage is very hard to identify and quantify with the onboard measurements available, especially for turbofans with high bypass ratio (BPR) where a damaged mixer may cause a slight loss in thrust rather than shifts in measurable quantities.

A special case of mixer damage that may be detected is burn-through of the afterburner liner in low bypass afterburning turbofans. The liner is used to protect the outer casing of the gas turbine to the high temperatures during afterburner operation. For this, the liner need to be continuously cooled by bypass air to withstand the temperatures. A burn-through is generally caused by a local blockage of the cooling path, leading to temperatures the liner cannot withstand. In severe cases it may cause a burn-through of the gas turbine outer casing as well where it may cause a fire in the engine bay.

In this paper, two diagnostic routines are developed to identify a burn-through of an afterburner liner. The diagnostics is intended to be performed as a part of the startup check of the gas turbine to increase the confidence that no burn-through has occurred during the last operation. For these methods a mixer model of high enough fidelity is required, which is described in the paper. The main conclusion is that with enough data it is possible to detect a burn-through but the data collection time is so long that the methods need to be further enhanced to be of any practical use.

Keywords
Mixer, Modelling, Diagnostics, Afterburner, Burn-Through
National Category
Aerospace Engineering
Identifiers
urn:nbn:se:mdh:diva-45867 (URN)
Conference
24:th ISABE Conference, Canberra, September 22-27, 2019
Projects
DIAGNOSIS
Funder
Knowledge Foundation, 20160133
Available from: 2019-10-29 Created: 2019-10-29 Last updated: 2019-11-22Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8466-356X

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