Marine icing sensor array for measuring ice thickness

Marine Icing is the process of ice accumulation on ships and other offshore structures in cold regions that can create serious working conditions besides the adverse effects to the offshore operations efficiency. Monitoring of icing conditions together with a number of de-icing strategies is therefore important in decreasing the safety hazards and increase the working effectiveness. Detection of the ice accretion rate on the offshore structures is a challenge due to the harsh environment and the multiphase property of the ice. This thesis is focused on developing a low cost array sensor for the ice accretion detection applicable to the harsh marine environments. We utilized a stray-capacitance technique that encodes a layered multiphase icing accretion uniquely. Capacitive sensors are popular in diverse industrial settings due to their relative simplicity, robustness and low cost. The sensor transducers are compatible with the printed circuit board technology which made this research time effective. The thesis is based on three distinct publications, two journal papers (IEEE, MDPI) and one peer-reviewed conference paper (IEEE), each in a separate chapter. All publications include a theoretical background, simulations, and experimental validation. The underlying novel approach that is more or less shared in all applications is the use of linearly independent sensor array for unique multiphase ice detection. The first two papers utilize a different inter-electrode spacing array but a different signal conditioning algorithm. The third paper then uses an array of constant spacing but different dielectric layer height. As stated above, the main objective of this work is to measure the multiphase icing accretion which consists of water above ice, the real situation which has not been addressed to date. A number of different techniques have been developed over the last two decades mainly as a response to the rapidly expanding offshore oil&gas in northern regions, offshore wind power generation, or shipping across or fishing in arctic waters. This thesis outlines three methods that can be directly applied to these industries

Marine icing sensor design using capacitive techniques

The Marine Icing project, in industrial collaboration with Statoil, explores and develops in-depth research on marine icing phenomena, and the appropriate sensor technology to detect ice accretion in marine and offshore environments. The overall project includes detailed analytical concepts, simulations, and experiments of on and off deck ice accretion activities in the form of wave breakup and droplet freeing phenomena. Part of the project is dedicated to developing appropriate low cost sensors for ice accretion detection in these harsh environments. Proposed sensors should be autonomous and easy to modify. After examining the available ice detecting systems, it was decided to explore capacitive techniques, a concept that have been used in other industrial applications like tilt sensing, liquid level sensing, and accelerometers. However, the capacitive sensing technique has not been explored for marine ice detection and therefore will be developed in this thesis. A capacitive based sensor is simulated, designed, tested, and documented in this thesis. The proposed sensor consists of a copper tracing on a PCB, capacitance to digital converter circuit and a microcontroller. The whole system runs on a simple battery system or powered by a programming cable, depending on the area of deployment. The microcontroller controls the capacitance to digital converter circuit as well as the temperature sensing circuit. Additionally, this research compares the change in capacitance observed with the change in ice thickness; proper sensor calibration is drawn from this result. The system is used to test ice accretion due to fresh and saline water, observation and conclusions are made based on the data obtained. This thesis focuses on developing a technical start up point for capacitive marine ice sensing

Icing Effects on Power Lines and Anti-icing and De-icing Methods

Icing on power lines may lead to compromise safety and reliability of electric supply network. Prolong icing can lead to power breakdown and collapse of towers. Since power transmission lines are mostly overhead and could face the direct impact of icing, and it is one of the main challenges faced by power distribution companies in cold regions. When the ice accretion crosses the safety limit then deicing action can be carried out. We can find number of deicing methods that are used in different parts of the world. However, all of these deicing techniques have their own advantages and disadvantages on implementation. It is one of the most difficult as well as dangerous process to perform deicing on power lines. If a fault is detected and that has been occurred due to icing or during routine maintenance, extra care must be taken in order to ensure safety of the personals when performing de-icing of lines. However, as technology evolved, new ways and techniques are adopted with the help of sensors that give quick feedback to control room in the national grid via wireless communication network for real time action. In the thesis we have discussed atmospheric icing impacts on power lines in the cold regions across the world. A literature review has been done for anti-icing and deicing methods that are currently adopted in the power distribution network. Methods that are used against ice buildups have also been analyzed. This work also shows the impacts of icing and deicing techniques presently adopted, and also throws light on their pros and cons during maintenance operations. It provides an overview of the evolving technology trends that are practiced to ensure the availability of existing power transmission system in cold climate regions

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

Overview on lightweight multifunctional materials

Lightweight multifunctional materials represent an increasing field in materials science and engineering based on their technological applications in a wide variety of areas ranging from sensors and actuators, materials for structural and environmental applications, energy generation and storage, or biomedicine, among others. This chapter presents an overview on the main types, preparation techniques and applications of the most relevant lightweight multifunctional materials, as well as on relevant materials to be applied and/or implemented in lightweight structures.FCT (Fundação para a Ciência e Tecnologia) for financial support under the framework of Strategic Funding grants UID/CTM/50025/2019, UID/FIS/04650/2019; and supported by FEDER funds through the COMPETE 2020 Programme under the project number PTDC/FIS-MAC/28157/2017 and POCI-01-0145- FEDER-007688. The authors also thank the FCT for financial support under grants SFRH/BPD/112547/2015 (C.M.C.) and SFRH/BPD/110914/2015 (P. C.). Financial support from the Basque Government under the ELKARTEK, HAZITEK and PIBA (PIBA-2018-06

An integrated method for detection and mitigation of ice accretion on wind turbine blades

Ice formation on structures, particularly on the leading edges of curved surfaces such as cylinders and airfoils, can be dangerous, and it is necessary to use an ice sensor combined with an ice mitigation system to prevent ice from forming on these surfaces. Wind turbine blades, which are commonly used in cold climate regions, are particularly susceptible to ice accumulation due to their sensitivity to changes in aerodynamic performance. To address this issue, it is necessary to have an integrated system for detecting and mitigating ice formation on wind turbine blades. Various ice detection and mitigation techniques for wind turbine blades in cold regions are reviewed and categorized based on key parameters. The conceptual design of integrating ice sensing and mitigation systems is also investigated, along with the advantages and disadvantages of these systems. A new technique for estimating the volume of frozen water droplets on a cold solid surface based on the contact angle and thermal images is presented. This technique takes into consideration factors such as temperature, surface roughness, and droplet size. An integrated ice tracking and mitigation technique using thermal imaging and heat elements along the stagnation line of a cylindrical surface is developed. This technique, which employs IR camera to monitor ice buildup, de-icing, and relaxation, is validated using an optical camera. The average uncertainty of ice thickness determined from thermal and optical images is about 0.16 mm during ice buildup and about 0.1 mm during ice mitigation, making it suitable for many cold environment applications. Finally, the relationship between ice thickness at the stagnation line and ice thickness at the heater edge is investigated in order to control ice accumulation mass and limit the heat energy required for de-icing. It is shown through de-icing experiments that the heat energy needed to remove the ice accumulation on the surface of a cylinder can be reduced by controlling the ice thickness at the heater's edge

Sputter deposited metal layers embedded in composites : from fundamentals to applications

Due to the low heat flux towards the substrate, magnetron sputter deposition offers the possibility to deposit thin films on heat sensitive materials such as fiber-reinforced polymers, also known as composite materials. Passive thermal probe measurements during the sputter deposition of metal layers show indeed that the temperature increase remains well below 25 degrees C for film thicknesses up to 600 nm. The latter thickness threshold is based on the influence of embedded metal films on the adhesion of the composite plies. Films thicker than this threshold deteriorate the mechanical integrity of the composite. The introduction of the uncured composite in the vacuum chamber strongly affects the base pressure by outgassing of impurities from the composite. The impurities affect the film properties as illustrated by their impact on the Seebeck coefficient of sputter deposited thermocouples. The restrictions to embed thin films in composites, as illustrated by both the heat flux measurements, and the study on the influence of impurities, are however not insurmountable. The possibility to use embedded thin films will be briefly demonstrated in different applications such as digital volume image correlation, thermocouples, and de-icing