A review of infrared thermography applications for ice detection and mitigation

Ice accretion on various onshore and offshore infrastructures imparts hazardous effects sometimes beyond repair, which may be life-threatening. Therefore, it has become necessary to look for ways to detect and mitigate ice. Some ice mitigation techniques have been tested or in use in aviation and railway sectors, however, their applicability to other sectors/systems is still in the research phase. To make such systems autonomous, ice protection systems need to be accompanied by reliable ice detection systems, which include electronic, mechatronics, mechanical, and optical techniques. Comparing the benefits and limitations of all available methodologies, Infrared Thermography (IRT) appears to be one of the useful, non-destructive, and emerging techniques as it offers wide area monitoring instead of just point-based ice monitoring. This paper reviews the applications of IRT in the field of icing on various subject areas to provide valuable insights into the existing development of an intelligent and autonomous ice mitigation system for general applications

Establishing a Comprehensive Wind Energy Program

This project was directed at establishing a comprehensive wind energy program in Indiana, including both educational and research components. A graduate/undergraduate course ME-514 - Fundamentals of Wind Energy has been established and offered and an interactive prediction of VAWT performance developed. Vertical axis wind turbines for education and research have been acquired, instrumented and installed on the roof top of a building on the Calumet campus and at West Lafayette (Kepner Lab). Computational Fluid Dynamics (CFD) calculations have been performed to simulate these urban wind environments. Also, modal dynamic testing of the West Lafayette VAWT has been performed and a novel horizontal axis design initiated. The 50-meter meteorological tower data obtained at the Purdue Beck Agricultural Research Center have been analyzed and the Purdue Reconfigurable Micro Wind Farm established and simulations directed at the investigation of wind farm configurations initiated. The virtual wind turbine and wind turbine farm simulation in the Visualization Lab has been initiated

Numerical simulations of ice accretion on wind turbine blades: are performance losses due to ice shape or surface roughness?

Ice accretion on wind turbine blades causes both a change in the shape of its sections and an increase in surface roughness. These lead to degraded aerodynamic performances and lower power output. Here, a high-fidelity multi-step method is presented and applied to simulate a 3 h rime icing event on the National Renewable Energy Laboratory 5 MW wind turbine blade. Five sections belonging to the outer half of the blade were considered. Independent time steps were applied to each blade section to obtain detailed ice shapes. The roughness effect on airfoil performance was included in computational fluid dynamics simulations using an equivalent sand-grain approach. The aerodynamic coefficients of the iced sections were computed considering two different roughness heights and extensions along the blade surface. The power curve before and after the icing event was computed according to the Design Load Case 1.1 of the International Electrotechnical Commission. In the icing event under analysis, the decrease in power output strongly depended on wind speed and, in fact, tip speed ratio. Regarding the different roughness heights and extensions along the blade, power losses were qualitatively similar but significantly different in magnitude despite the well-developed ice shapes. It was found that extended roughness regions in the chordwise direction of the blade can become as detrimental as the ice shape itself

Domain-invariant icing detection on wind turbine rotor blades with generative artificial intelligence for deep transfer learning

Wind energy’s ability to liberate the world from conventional sources of energy relies on lowering the significant costs associated with the maintenance of wind turbines. Since icing events on turbine rotor blades are a leading cause of operational failures, identifying icing in advance is critical. Some recent studies have utilized deep learning (DL) techniques to predict icing events with high accuracy by leveraging rotor blade images, but these studies only focus on specific wind parks and fail to generalize to unseen scenarios (e.g., new rotor blade designs). In this paper, we aim to facilitate ice prediction on the face of lack of ice images in new wind parks. We propose the utilization of synthetic data augmentation via a generative artificial intelligence technique—the neural style transfer algorithm to improve the generalization of existing ice prediction models. We also compare the proposed technique with the CycleGAN as a baseline. We show that training standalone DL models with augmented data that captures domain-invariant icing characteristics can help improve predictive performance across multiple wind parks. Through efficient identification of icing, this study can support preventive maintenance of wind energy sources by making them more reliable toward tackling climate change

Challenges of wind power in cold climates:the impact and prevention of icing

Abstract. The global energy sector has begun a transition towards cleaner energy production due to comprehensive climate targets set by nations. Wind power is one of the low-emission and renewable forms of energy as its only fuel is the motion of air — the wind. The use of wind power is expected to increase significantly in the next decades, posing a strong demand for solutions addressing the challenges of wind power in non-conventional sites such as cold climates. Icing and cold environments can adversely affect wind power operation in multiple ways. This sets a requirement for research on the matter in order to assure safety and efficiency of wind power units in these areas. This thesis aims to present the impact of icing on wind power production. Both the effects of icing and solutions for preventing or reducing icing risks are examined. The operating principle of a wind turbine is studied to form an understanding of wind power technology. The current and future status of wind power in Finland and Scandinavian countries is also presented as their cold weathers, occurring particularly during wintertime, can impact local wind power production. These research questions are addressed through a literature review. In addition to icing issues, low temperature challenges and adaptations are assessed to provide an overview of wind power projects in cold climates. The main types of wind turbines, the concept of wind farms, and siting of wind power units are also introduced. The topic is approached by dividing wind power into onshore and offshore technologies. The conclusions of the thesis indicate that wind turbines and other site infrastructure can be notably affected by icing and low temperatures. Typical consequences are power losses, detrition of turbine structure, and safety risks caused by ice throw. Icing risks can be mitigated with commercially available ice protection systems and cold climate packages. The share of wind power in the electricity supply of Nordic countries is expected to increase notably towards 2030. In the discussion section of the thesis it is inferred that despite of possible additional costs of ice mitigation systems, these solutions can advance wind power production in cold climates and therefore bring environmental and financial benefits.Tuulivoiman haasteet kylmässä ilmastossa : jäätymisen vaikutukset ja ehkäisy. Tiivistelmä. Energia-ala on siirtymässä globaalisti puhtaampaan energiantuotantoon valtioiden asettamien kattavien ilmastotavoitteiden myötä. Tuulivoima on vähäpäästöinen ja uusiutuva energiamuoto, sillä sen ainoana polttoaineena toimii liikkuva ilmavirta eli tuuli. Tuulivoiman käytön odotetaan lisääntyvän merkittävästi lähivuosikymmeninä. Tämä kasvattaa haastaviin tuotantopaikkoihin, kuten kylmiin ilmastoihin, sopivan tuulivoimateknologian tarvetta. Jäätyminen ja kylmä ilma voi vaikeuttaa tuulivoiman tuotantoa monin tavoin. Aihetta on syytä tutkia, jotta tuulivoimaloiden turvallisuus ja tehokkuus kylmillä alueilla voidaan taata. Tämän kandidaatintyön tavoitteena on esitellä jäätymisen vaikutusta tuulivoiman tuotantoon. Työssä tarkastellaan sekä jäätymisen seurauksia että jäätymisen riskejä vähentäviä ja estäviä ratkaisuja. Tuuliturbiinin toimintaperiaatetta tutkitaan pohjakäsityksen muodostamiseksi tuulivoimateknologiasta. Tuulivoiman nykyinen ja ennustettu tilanne Suomessa ja skandinaavisissa maissa esitellään, sillä niissä erityisesti talviaikaan esiintyvät matalat lämpötilat ja lumisateet voivat vaikuttaa paikalliseen tuulivoimatuotantoon. Näitä tutkimuskysymyksiä käsitellään kirjallisuuskatsauksena. Jäätymisen vaikutusten lisäksi mataliin lämpötiloihin liittyviä haasteita ja ratkaisuja käydään läpi, jotta voidaan muodostaa yleiskuva tuulivoimaprojekteista kylmissä ilmastoissa. Työssä tutustutaan lisäksi tuuliturbiinien päätyyppeihin, tuulipuiston käsitteeseen ja tuulivoimaloiden sijoittamiseen. Aihetta käsitellään sekä maatuulivoiman että merituulivoiman kannalta. Työn johtopäätökset viittaavat, että jäätyminen ja matalat lämpötilat voivat vaikuttaa huomattavasti tuuliturbiinien toimintaan ja tuotantopaikkojen muuhun infrastruktuuriin. Tyypillisiä seurauksia ovat muun muassa tuotannonmenetykset, turbiinirakenteen kuluminen ja lavoilta putoavasta jäästä aiheutuvat turvallisuushaitat. Jäätymiseen liittyviä riskejä voidaan alentaa kaupallisesti saatavilla olevilla jäätymissuojausjärjestelmillä ja kylmään ilmastoon soveltuvilla varusteilla. Tuulivoiman osuuden pohjoismaisessa sähköntuotannossa odotetaan lisääntyvän merkittävästi vuoteen 2030 mennessä. Työn lopputuloksista pääteltiin, että jäätymissuojausmenetelmät voivat edistää tuulivoiman tuotantoa kylmissä ilmastoissa olennaisesti. Seurauksena voi olla niin ympäristöhyötyjä kuin taloudellisia etuja huolimatta menetelmistä mahdollisesti aiheutuvista lisäkustannuksista

Experimental investigations on wind turbine icing physics and anti-/de-icing technology

Wind turbine icing has been found to cause a variety of problems to the safe and efficient operations of wind turbines. Ice accretion on turbine blades would result in decreasing lift and increasing drag, thereby, leading to power reduction. The annual power loss due to icing was found to be 20 ~ 50% at harsh sites. Ice accretion and irregular ice shedding during wind turbine operation would lead to load imbalances and excessive turbine vibrations, which may cause structural failures, especially when coupled with strong wind loads. Icing issues can also directly impact personnel safety due to falling and projected large ice chunks. By leveraging the Icing Research Tunnel of Iowa State University (ISU-IRT), a series of experimental investigations were conducted to investigate the dynamic ice accretion process over the surfaces of typical wind turbine blade models and to explore the effective and robust anti-/de-icing strategies for wind turbines icing mitigation. More specifically, a comprehensive experimental study was conducted to quantify the transient surface water transport behavior over the ice accreting surface of typical wind turbine blade models by using a Digital Image Projection (DIP) technique. The aerodynamic performance degradation of the turbine blade models was characterized in the course of the ice accreting process by using two sets of high-sensitive multi-axis force/moment systems and a digital Particle Image Velocimetry (PIV) system. A novel hybrid anti-icing strategy that combines minimized electro-heating near the turbine blade leading edge and bio-inspired icephobic coatings to cover the blade surface was proposed. In comparison to conventional thermal-based anti-/de-icing methods to brutally heat the entire blade surface, the proposed hybrid strategy was demonstrated to be able to prevent the ice formation and accretion over the surfaces of the wind turbine blades effectively with only ~10% of the required power consumption. In addition to conducting wind tunnel experiments, a field campaign was also conducted in a mountainous wind farm to investigate the ice-induced performance degradation of multi-megawatt wind turbines by correlating the acquired images of ice accretion over the rotating wind turbine blades with an unmanned aerial vehicle (UAV) with the turbine operational data recorded by wind turbine supervisory control and data acquisition (SCADA) systems. The new findings derived from the present studies would lead to a better understanding of the underlying physics pertinent to the wind turbine icing phenomena, which could be used to improve current ice accretion models for more accurate prediction of ice accretion on wind turbine blades as well as to develop innovative anti-/de-icing strategies for safer and more efficient operation of wind turbines in cold weathers