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Chen, X., Tang, Y., Huang, X., Wang, W., Guo, J., Lin, F., . . . Zhu, Y. (2025). Automation and synchronisation on electro-hydraulic lifting system of tunnel boring machine segment assembly. International Journal of Hydromechatronics, 8(1), 94-120
Open this publication in new window or tab >>Automation and synchronisation on electro-hydraulic lifting system of tunnel boring machine segment assembly
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2025 (English)In: International Journal of Hydromechatronics, ISSN 2515-0464, Vol. 8, no 1, p. 94-120Article in journal (Refereed) Published
Abstract [en]

Segment lifting, performed by an electro-hydraulic system including two cylinders, is a crucial step in segment grasping, transporting, and assembly in tunnel boring machines. Due to heavy and uneven loading, large vibration, uncertainty of parameters, and nonlinear friction, it is difficult to develop an accurate physical model. This paper presents a comprehensive procedure to achieve two-cylinder automation and synchronisation according to the actual engineering requirements and environments. An improved deviation compensation recursive least squares identification algorithm with a forgetting factor was used to identify the key parameters of the model. To achieve synchronous control and precise control of the lifting system, SMC with improved sliding mode approach rate and the deviation coupling method of fusion single neuron PID were designed and verified by simulation. A full-scale bench test was also performed to show that the tracking steady-state error is below 4 mm, and the synchronisation error is below 2 mm.

Place, publisher, year, edition, pages
Inderscience Publishers, 2025
Keywords
automation, parameter identification, segment assembly, synchronous control, tunnel boring
National Category
Geology Vehicle and Aerospace Engineering
Identifiers
urn:nbn:se:kth:diva-361782 (URN)10.1504/IJHM.2025.144951 (DOI)2-s2.0-86000757815 (Scopus ID)
Note

QC 20250331

Available from: 2025-03-27 Created: 2025-03-27 Last updated: 2025-03-31Bibliographically approved
Xu, R., Zhu, Y., Wu, J., Huang, P., Wu, M., Wang, W., . . . Yang, H. (2025). Hybrid high-temperature wear mechanisms of additive manufactured Ti-6Al-4V alloy. Tribology International, 205, Article ID 110559.
Open this publication in new window or tab >>Hybrid high-temperature wear mechanisms of additive manufactured Ti-6Al-4V alloy
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2025 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 205, article id 110559Article in journal (Refereed) Published
Abstract [en]

This study investigates the high-temperature wear of additive-manufactured Ti6Al4V alloy against GH2132. The wear mechanism transitioned from abrasive and adhesive wear to oxidative wear with rising temperatures. The microstructure characteristics reveal the special hybrid high-temperature wear mechanisms: shear deformation-induced wear hardening and dynamic recrystallization-induced wear softening. At lower temperatures, the thinner oxide layer was easily removed and the worn surface in contact underwent work hardening, reducing the negative effects of thermal softening. At higher temperatures, the thicker oxide layer slightly reduced adhesive of the substrate but failed due to cracking and spalling. Combined with intensified thermal softening, recrystallization softening on the worn surface not only eliminated surface hardening but led to a sharp decline in wear resistance.

Place, publisher, year, edition, pages
Elsevier Ltd, 2025
Keywords
Additive manufacturing, Dry sliding, Recrystallization, Shear deformation, Ti6Al4V, Tribo-oxide layer
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:kth:diva-359880 (URN)10.1016/j.triboint.2025.110559 (DOI)001417279500001 ()2-s2.0-85216479046 (Scopus ID)
Note

QC 20250226

Available from: 2025-02-12 Created: 2025-02-12 Last updated: 2025-02-26Bibliographically approved
Ma, Y., Xie, G. & Wang, W. (2025). Influences of wall materials on flow and thermal performance of S-CO2 at high pressure and heat flux. International journal of thermal sciences, 214, Article ID 109899.
Open this publication in new window or tab >>Influences of wall materials on flow and thermal performance of S-CO2 at high pressure and heat flux
2025 (English)In: International journal of thermal sciences, ISSN 1290-0729, E-ISSN 1778-4166, Vol. 214, article id 109899Article in journal (Refereed) Published
Abstract [en]

Since supercritical carbon dioxide (S-CO2) systems usually have to work at both high temperature, high pressure and high heat flux, selecting appropriate solid materials is of great important to their system safety. In this study, the thermofluidic characteristics of supercritical carbon dioxide (S-CO2) in a horizontal rectangular channel have been investigated under high pressure and one-side-wall heated with high heat flux. Four different solid wall materials (253 MA, Inconel 617, Haynes 230 and Haynes 233) and three different heat flux values (1.5 MW/m2, 2.0 MW/m2 and 2.5 MW/m2) are selected for analyzing the impacts of wall material and heat flux boundary conditions. The results showed that the maximum wall temperature difference of all four wall materials can generally exceed 100 K under the minimum heat flux, and can reach 500 K for Haynes 233 at the heat flux of 2.5 MW/m2. Considering the maximum allowable stress and creep characteristics, Inconel 617 has more obvious advantages as a solid material at the heat flux below 2 MW/m2, while Haynes 230 is a better choice at the heat flux beyond 2 MW/m2 because of the stronger mechanical properties. By exploring the effect of inlet temperature, it is found that the inlet temperature close to the pseudo-critical temperature is conducive to flow and heat transfer. Taking the effect of buoyancy into account, it is shown that the temperature of the heating surface is decreased, the deterioration of heat transfer is weakened and occurs early, and the difference on the cross sections of the wall temperature decreases.

Place, publisher, year, edition, pages
Elsevier BV, 2025
Keywords
Buoyancy, Refractory alloys, Solid wall material, Supercritical carbon dioxide (S-CO ) 2, Thermal performance
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-362027 (URN)10.1016/j.ijthermalsci.2025.109899 (DOI)001459210600001 ()2-s2.0-105000888675 (Scopus ID)
Note

QC 20250520

Available from: 2025-04-03 Created: 2025-04-03 Last updated: 2025-05-20Bibliographically approved
Ruan, T., Wang, W. & Laumert, B. (2025). Potential of Wall-Mounted Solar PV Panel in high-latitude areas-A case study in Swedish contexts. In: Energy Proceedings: . Paper presented at 16th International Conference on Applied Energy, ICAE 2024, Niigata, Japan, Sep 1 2024 - Sep 5 2024. Applied Energy Innovation Institute (AEii), 51
Open this publication in new window or tab >>Potential of Wall-Mounted Solar PV Panel in high-latitude areas-A case study in Swedish contexts
2025 (English)In: Energy Proceedings, Applied Energy Innovation Institute (AEii) , 2025, Vol. 51Conference paper, Published paper (Refereed)
Abstract [en]

To catch up with the sustainability transition progress, the global capacity of PV system is predicted to grow dramatically in the following decades, including high-latitude regions. To effectively use the urban space resource for PV power generation in the high-latitude areas, wall-mounted PV system is becoming an attractive solution. This paper evaluates the potential of wallmounted PV system in the high-latitude areas with a case study in Swedish contexts through a PV power generation model by considering weather conditions (including snowfall, icing and melting), orientation, and economics. The key performances are compared with rooftop fixed-tilt angle PV systems in Swedish contexts. Although the annual power generation of the wallmounted PV system is around 5% lower under heavy snow conditions, its power generation during the snow season (from October to April) increases significantly. In general, the power generation in March almost doubled and the increase could be more than 25% in April. Therefore, wall-mounted PV system can contribute to the winter electricity supply in high-latitude areas, when the electricity price is high.

Place, publisher, year, edition, pages
Applied Energy Innovation Institute (AEii), 2025
Keywords
High-latitude areas, Snow conditions, Techno-economic analysis, Wall-mounted PV
National Category
Energy Systems Fusion, Plasma and Space Physics Other Engineering and Technologies
Identifiers
urn:nbn:se:kth:diva-356946 (URN)10.46855/energy-proceedings-11449 (DOI)2-s2.0-85209574607 (Scopus ID)
Conference
16th International Conference on Applied Energy, ICAE 2024, Niigata, Japan, Sep 1 2024 - Sep 5 2024
Note

QC 20241129

Available from: 2024-11-28 Created: 2024-11-28 Last updated: 2025-04-17Bibliographically approved
Lyu, X., Ruan, T., Wang, W. & Cai, X. (2024). A bibliometric evaluation and visualization of global solar power generation research: productivity, contributors and hot topics. Environmental Science and Pollution Research, 31(5), 8274-8290
Open this publication in new window or tab >>A bibliometric evaluation and visualization of global solar power generation research: productivity, contributors and hot topics
2024 (English)In: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 31, no 5, p. 8274-8290Article in journal (Refereed) Published
Abstract [en]

The demand for sustainable energy is increasingly urgent to mitigate global warming which has been exacerbated by the extensive use of fossil fuels. Solar energy has attracted global attention as a crucial renewable resource. This study conducted a bibliometric analysis based on publication metrics from the Web of Science database to gain insights into global solar power research. The results indicate a stable global increase in publications on solar power generation and a rise in citations, reflecting growing academic interest. Leading contributors include China, the USA, South Korea, Japan, and India, with the Chinese Academy of Sciences emerging as the most prolific institution. Multidisciplinary Materials Science, Applied Physics, Energy and Fuels, Physical Chemistry, and Nanoscience and Nanotechnology were the most used and promising subject categories. Current hot topics include the systematic analysis of photovoltaic systems, perovskite as a solar cell material, and focusing on stability and flexibility issues arising during photovoltaic-grid integration. This study facilitates a comprehensive understanding of the status and trends in solar power research for researchers, stakeholders, and policy-makers.

Place, publisher, year, edition, pages
Springer Nature, 2024
Keywords
Solar power generation, Bibliometric analysis, Science mapping, Scientific production, Hot topics
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-344104 (URN)10.1007/s11356-023-31715-x (DOI)001151563300034 ()38175504 (PubMedID)2-s2.0-85184344791 (Scopus ID)
Note

QC 20240304

Available from: 2024-03-04 Created: 2024-03-04 Last updated: 2024-03-04Bibliographically approved
Ruan, T., Wang, F., Topel, M., Laumert, B. & Wang, W. (2024). A new optimal PV installation angle model in high-latitude cold regions based on historical weather big data. Applied Energy, 359, Article ID 122690.
Open this publication in new window or tab >>A new optimal PV installation angle model in high-latitude cold regions based on historical weather big data
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2024 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 359, article id 122690Article in journal (Refereed) Published
Abstract [en]

PV technologies are regarded as one of the most promising renewable options for the transition towards Net Zero. Despite the rapid development of PV systems in recent years, achieving the necessary goals requires more than a threefold increase in annual capacity deployment by 2030. However, current PV systems often fall short of optimal performance due to improper installation angles. In high-latitude cold regions, the actual PV generation capacity is frequently overestimated due to the omission of snow conditions. This study introduces a novel model designed for high-latitude regions to predict local optimal PV installation angle that maximizes PV power generation, utilizing historical weather big data, including snowfall and melting effects. A case study is presented within a Swedish context to demonstrate the implementation of these methods. The results highlight the crucial role snow conditions play in determining PV performance, resulting in an average reduction of 14.7% in annual PV power generation. Optimal installation angle could yield approximately a 4.8% improvement compared to common installation angles. The study also explores the application of snow removal agents, which could potentially increase PV generation by 0.1–2.3%. Additionally, the new PV installation angle successfully captures the impact of the local weather changes on PV power generation, potentially serving as a bridge between climate change adaptation and future PV power generation endeavors.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
High-latitude region, Optimal PV installation angle, Snow condition, Snow-PV yield model, Weather big data
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-344017 (URN)10.1016/j.apenergy.2024.122690 (DOI)001170659600001 ()2-s2.0-85185176041 (Scopus ID)
Note

QC 20240229

Available from: 2024-02-28 Created: 2024-02-28 Last updated: 2025-04-17Bibliographically approved
Choque Campero, L. A., Wang, W., Cardozo, E. & Martin, A. R. (2024). Biomass-based Brayton-Stirling-AGMD polygeneration for small-scale applications in rural areas. Energy, 304, Article ID 132033.
Open this publication in new window or tab >>Biomass-based Brayton-Stirling-AGMD polygeneration for small-scale applications in rural areas
2024 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 304, article id 132033Article in journal (Refereed) Published
Abstract [en]

The lack of access to electricity and clean water still affects a substantial proportion of rural areas worldwide, in particular the global south. This paper presents a sustainable polygeneration system that can provide electricity, heat, and drinking water by using agricultural residues in remote rural areas. This polygeneration system consists of a solid biomass-fueled Brayton-Stirling combined cycle system, a boiler, and an air-gap membrane distillation unit. Four different system operation modes were designed to examine the most ideal configurations for maximizing power output, overall efficiency, and/or clean water production, considering a polygeneration system designed for a rural village with daily demands of 13450 kWh electricity and 7.5 m3 drinking water. A thermodynamic analysis are employed to analyze and compare these modes, each operating under steady state conditions. The highest electricity output, up to 160 kW, while the highest clean water is up to 0.7 m3/h. The fuel consumption can reach 0.9 kWh/kg of solid fuel and provide up to 0.0045 m3 of freshwater. In addition, nonlinear multi-objective optimization is used to meet the power demands of typical day in rural areas by varying the polygeneration operation modes and turbine inlet temperature.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Biomass pellets, Brayton-Stirling cycle, Externally fired microturbine, Polygeneration, Rural electrification, Water desalination
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-348740 (URN)10.1016/j.energy.2024.132033 (DOI)001347394700001 ()2-s2.0-85196430828 (Scopus ID)
Note

QC 20241119

Available from: 2024-06-27 Created: 2024-06-27 Last updated: 2024-11-19Bibliographically approved
Yang, H., Nurdiawati, A., Gond, R., Chen, S., Wang, u., Tang, B., . . . Han, T. (2024). Carbon-negative valorization of biomass waste into affordable green hydrogen and battery anodes. International journal of hydrogen energy, 49, 459-471
Open this publication in new window or tab >>Carbon-negative valorization of biomass waste into affordable green hydrogen and battery anodes
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2024 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 49, p. 459-471Article in journal (Other academic) Published
Abstract [en]

The global Sustainable Development Goals highlight the necessity for affordable and clean energy, designated as SDG7. A sustainable and feasible biorefinery concept is proposed for the carbon-negative utilization of biomass waste for affordable H2 and battery anode material production. Specifically, an innovative tandem biocarbon + NiAlO + biocarbon catalyst strategy is constructed to realize a complete reforming of biomass pyro-vapors into H2+CO (as a mixture). The solid residues from pyrolysis are upgraded into high-quality hard carbon (HCs), demonstrating potential as sodium ion battery (SIBs) anodes. The product, HC-1600-6h, exhibited great electrochemical performance when employed as (SIBs) anodes (full cell: 263 Wh/kg with ICE of 89%). Ultimately, a comprehensive process is designed, simulated, and evaluated. The process yields 75 kg H2, 169 kg HCs, and 891 kg captured CO2 per ton of biomass achieving approx. 100% carbon and hydrogen utilization efficiencies. A life cycle assessment estimates a biomass valorization process with negative-emissions (−0.81 kg CO2/kg-biomass, reliant on Sweden wind electricity). A techno-economic assessment forecasts a notably profitable process capable of co-producing affordable H2 and hard carbon battery anodes. The payback period of the process is projected to fall within two years, assuming reference prices of 13.7 €/kg for HCs and 5 €/kg for H2. The process contributes to a novel business paradigm for sustainable and commercially viable biorefinery process, achieving carbon-negative valorization of biomass waste into affordable energy and materials.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Biomass, Pyrolysis, Catalytic reforming, Biochar, Syngas, Auger
National Category
Energy Engineering Materials Chemistry
Research subject
Energy Technology; Chemical Engineering; Materials Science and Engineering
Identifiers
urn:nbn:se:kth:diva-339172 (URN)10.1016/j.ijhydene.2023.09.096 (DOI)001132794800001 ()2-s2.0-85172247785 (Scopus ID)
Funder
Vinnova, 2021-03735
Note

QC 20231106

Available from: 2023-11-03 Created: 2023-11-03 Last updated: 2025-02-25Bibliographically approved
Choque Campero, L. A., Wang, W., Cardozo, E. & Martin, A. R. (2024). Decentralized biomass-based Brayton-Stirling power cycle with an air gap membrane distiller for supplying electricity, heat and clean water in rural areas. Applied Thermal Engineering, 254, Article ID 123889.
Open this publication in new window or tab >>Decentralized biomass-based Brayton-Stirling power cycle with an air gap membrane distiller for supplying electricity, heat and clean water in rural areas
2024 (English)In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 254, article id 123889Article in journal (Refereed) Published
Abstract [en]

Ensuring access to essential services, such as clean water and electricity, is a key challenge for achieving sustainable development goals in rural areas. This study proposes a novel Brayton-Stirling combined cycle-based cogeneration system for utilizing locally available biomass waste to generate both electricity and clean water. The system employs an externally fired gas turbine, a Stirling engine, and an air–gap membrane distiller. Four operation modes—parallel-powered, fully-fired, straightforward, and by-pass—were modeled for their efficiency and output. Four operation modes can be switched by two three-way valves. Sunflower husk, identified as the most effective biomass source, enabled the system to achieve up to 160 kW of electricity and 0.7 m3/h of freshwater. The electrical and exergy efficiencies of the system peaked in the parallel-power mode, offering a practical solution for enhancing rural sustainability. Moreover, the by-pass mode maximized water production, highlighting its effectiveness in addressing water scarcity along with energy generation. Through a case study, the cogeneration system has demonstrated its capability in satisfying both rural electricity and water demands throughout the day by controlling the combination of different operation modes and parameters. Therefore, it provides a promising solution for advancing rural electrification and water purification in rural areas.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Biomass pellets, Brayton-Stirling cycle, Cogeneration, Externally fired microturbine, Rural electrification, Water desalination
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-350689 (URN)10.1016/j.applthermaleng.2024.123889 (DOI)001267223300001 ()2-s2.0-85197783149 (Scopus ID)
Note

QC 20240719

Available from: 2024-07-17 Created: 2024-07-17 Last updated: 2024-08-20Bibliographically approved
Ruan, T., Topel, M., Padovani, F., Wang, W. & Laumert, B. (2024). Pv-load matching based on combination of different consumers: A case study in Swedish contexts. Solar Energy, 281, Article ID 112885.
Open this publication in new window or tab >>Pv-load matching based on combination of different consumers: A case study in Swedish contexts
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2024 (English)In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 281, article id 112885Article in journal (Refereed) Published
Abstract [en]

The transition towards sustainability necessitates robust growth of renewable energy, especially solar power. However, increasing the shares of solar power may lead to mismatch of electricity supply and demand, thus worse solar power performance could be received due to lower self-consumption and self-sufficiency. This issue has attracted more attention recently as it also requires additional costs for controlling and battery integration. This study combines several load profiles from consumers having different behaviors with different proportions to find out the optimal shares with higher level of PV penetration and self-sufficiency. A visualizing matching layout is proposed to present the PV-load matching level of all the possibilities at different seasons based on a Swedish context. It is found an 8% improvement of self-sufficiency reaching 70% in summer without additional equipment and scarification of self-consumption. The results could assist in the design and planning of the future power sector. Regarding specific targets, various optimal solutions could be found based on the layout.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Load profile combination, Matching heatmap, Performance improvement, PV loading matching, Urban areas
National Category
Energy Engineering Energy Systems
Identifiers
urn:nbn:se:kth:diva-353483 (URN)10.1016/j.solener.2024.112885 (DOI)001310501900001 ()2-s2.0-85202337103 (Scopus ID)
Note

QC 20240919

Available from: 2024-09-19 Created: 2024-09-19 Last updated: 2024-09-27Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4134-3520

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