scholarly journals A Study on a Floating Solar Energy System Applied in an Intertidal Zone

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7789
Author(s):  
Ray-Yeng Yang ◽  
Sheng-Hung Yu
Keyword(s):  
Energy System ◽  
Mooring Line ◽  
Solar Photovoltaic ◽  
Solar Panels ◽  
Floating Platform ◽  
Mooring Lines ◽  
Ansys Fluent ◽  
Wave Condition ◽  
Scale Ratio ◽  
Motion Characteristics

This study was aimed at investigating a floating solar photovoltaic (FPV) system by numerical and experimental simulations under wave and wind loads to analyze the motion characteristics of the platform, the tension of the mooring line, and the pressure and uplift coefficient of panels at 2.5 m/5 m water depth conditions. The floating platform was installed with four rows of solar panels, each row with five panels, attached with four catenary types of mooring lines at the corner of the platform. The numerical model was based on ANSYS AQWA and ANSYS FLUENT (ANSYS Inc., Canonsburg, PA, USA). The experiment model was a scaled FPV platform with four rows of panels scaled in the 1:4 scale ratio. The results obtained from the experiment and numerical simulation achieved a good agreement. The results show that under normal sea conditions, the FPV system may resonate in a high frequency of wave condition, and a larger lift force occurred at the windward surface. Under extreme sea conditions, the pitch motion of the floating platform changed about ±6° without overturning; however, the wind will cause a large drift of the floating platform and the vortex area formed, which will cause damage to the solar panel.

Dual Stiffness Approach for Polyester Mooring Line Analysis in Time Domain: Semisubmersible Case

2013 ◽  
Author(s):  
Arcandra Tahar ◽  
Djoni Sidarta
Keyword(s):  
Traditional Method ◽  
Dynamic Stiffness ◽  
Performance Comparison ◽  
Mooring Line ◽  
Analysis Tool ◽  
Floating Platform ◽  
Mooring Lines ◽  
Coupled Dynamic Analysis ◽  
Stiffness Method ◽  
Motion Characteristics

This paper is a continuation of a series of investigation for the dual stiffness approach for polyester mooring lines. Tahar et. al. (2012) has presented the global performance comparison between the dual stiffness method and the traditional method for the Spar platform. As shown in that study, there are appreciable differences between the former and the later methods especially in lateral motions, which, however, result in little difference in SCR strength response. Is it because the Spar has better motion characteristics than other wet tree floating platforms such as the semisubmersible and FPSO? This paper will investigate the effect of the dual stiffness method and the traditional method to SCR response for a Semisubmersible platform. The fully coupled dynamic analysis tool CHARM3D has been modified to incorporate the dual stiffness approach. Two axial stiffnesses (EA) of polyester line, post installation (static) stiffness and storm (dynamic) stiffness have been convoluted into a dual stiffness to represent the total response of the floating platform in a single run. In the traditional method, the analyses are done twice, one run for each stiffness. Then, the extremes from each run are used as governing values for design. The SCR will be modeled and analyzed using ABAQUS software.

scholarly journals Transient Responses Evaluation of FPSO with Different Failure Scenarios of Mooring Lines

2021 ◽  
Vol 9 (2) ◽  
pp. 103
Author(s):  
Dongsheng Qiao ◽  
Binbin Li ◽  
Jun Yan ◽  
Yu Qin ◽  
Haizhi Liang ◽  
...  
Keyword(s):  
Service Condition ◽  
Mooring Line ◽  
Mooring System ◽  
Transient Effects ◽  
Floating Platform ◽  
Transient Responses ◽  
Mooring Lines ◽  
Performance Deterioration ◽  
Steady State Responses ◽  
Influence Process

During the long-term service condition, the mooring line of the deep-water floating platform may fail due to various reasons, such as overloading caused by an accidental condition or performance deterioration. Therefore, the safety performance under the transient responses process should be evaluated in advance, during the design phase. A series of time-domain numerical simulations for evaluating the performance changes of a Floating Production Storage and Offloading (FPSO) with different broken modes of mooring lines was carried out. The broken conditions include the single mooring line or two mooring lines failure under ipsilateral, opposite, and adjacent sides. The resulting transient and following steady-state responses of the vessel and the mooring line tensions were analyzed, and the corresponding influence mechanism was investigated. The accidental failure of a single or two mooring lines changes the watch circle of the vessel and the tension redistribution of the remaining mooring lines. The results indicated that the failure of mooring lines mainly influences the responses of sway, surge, and yaw, and the change rule is closely related to the stiffness and symmetry of the mooring system. The simulation results could give a profound understanding of the transient-effects influence process of mooring line failure, and the suggestions are given to account for the transient effects in the design of the mooring system.

The Dynamic Motion of the OC4 Floating Turbine with Different Incident Wave and Wind Directions in a Mooring System Failure Condition in Numerical Model

2020 ◽  
Author(s):  
Tzu-Ching Chuang ◽  
Wen-Hsuan Yang ◽  
Yi-Hong Chen ◽  
Ray-Yeng Yang
Keyword(s):  
Steady State ◽  
Line Tension ◽  
Time Domain Analysis ◽  
Mooring Line ◽  
Second Phase ◽  
Mooring System ◽  
System Failure ◽  
Floating Platform ◽  
Initial Tension ◽  
Wave Condition

<p><span>In this paper, the commercial software Orcaflex is used to simulate the motion behavior of the OC4 floating platform, and the floater stability and mooring line tension after the mooring system failure. In the time domain analysis, the discussion is divided into three phases—the first phase (before the tether failure), the second phase (before the tether failure, before reaching the new steady-state), and the third phase (after reaching the new steady-state). The motion characteristics and tension values at different stages were observed. In this study, only a 50-year return period wave condition is used as an input condition and simulating 11 different incident wind and wave directions. The numerical results are presented in the trajectory map and the table. About the tension of the mooring line, after the mooring system fails, it is notable that the mooring line tension will first decrease and then increase slightly above the initial tension value. In other words, the mooring system may survive after the failure of one mooring line and got a new balance of it. However, the tension amplitude will be higher than the first stage in the new balance and it will likely increase the risk of mooring line fatigue.</span></p>

Dual Stiffness Approach for Polyester Mooring Line Analysis in Time Domain

2012 ◽  
Author(s):  
Arcandra Tahar ◽  
Djoni Sidarta ◽  
Alex Ran
Keyword(s):  
Traditional Method ◽  
Dynamic Stiffness ◽  
Performance Comparison ◽  
Mooring Line ◽  
Axial Stiffness ◽  
Analysis Tool ◽  
Floating Platform ◽  
Mooring Lines ◽  
Nonlinear Stress ◽  
Offshore Industry

Polyester mooring lines have been used in the offshore industry since the late ’90s. With increasing oil exploration and production in deeper waters, using polyester lines provides greater benefit than using traditional steel wires and chains. Some advantages of using polyester include a reduction of mooring line weight, a reduction in vessel offset and a reduction in the dynamics of the line tensions. However, unlike steel, polyester lines exhibit axial stiffness characteristics that are nonlinear and vary with time and loading history. Tahar (2001) developed a comprehensive theory and numerical tool to capture this behavior. The formulas allow relatively large elongation and nonlinear stress-strain relationships, as typically observed in polyester fibers. The mooring line dynamics are based on a rod theory and finite element method (FEM), with the governing equations described in a generalized coordinate system. Since this theory is computationally intensive, the benefits outweigh the costs less than they do for the practical approach recommended by API. Therefore, the fully coupled dynamic analysis tool CHARM3D has been modified to incorporate the API-recommended approach. Two axial stiffnesses (EA), post installation (static) stiffness and storm (dynamic) stiffness, have been convoluted into a dual stiffness to represent the total response of the floating platform in a single run. In the traditional method, the analyses are done twice, one run for each stiffness. Then, the extremes from each run are used as governing values for design. This paper presents the global performance comparison between the dual stiffness method and the traditional method. The effect of motions on SCR strength is also investigated using ABAQUS software.

Mooring- and Riser-Induced Damping in Fatigue Seastates

2002 ◽  
Author(s):  
D. L. Garrett ◽  
R. B. Gordon ◽  
J. F. Chappell
Keyword(s):  
Coupled Model ◽  
Rational Approach ◽  
Coupled Analysis ◽  
Mooring Line ◽  
Floating Platform ◽  
Mooring Lines ◽  
Equivalent Linear ◽  
Floating System ◽  
Linear Damping ◽  
Stiffness And Damping

Viscous damping due to drag on mooring lines and risers is seastate dependent and significantly affects the motion of a floating platform in deep water, particularly in everyday seastates. This in turn impacts design of the risers, which are typically controlled by fatigue. The dynamic interaction between the platform, mooring and risers cannot be evaluated using conventional uncoupled analysis tools, where each is analyzed separately. Rather, coupled analysis is required to provide a consistent way to model the drag-induced damping from mooring lines and risers. We describe a coupled, frequency domain approach (RAMS – Rational Approach to Marine Systems) for calculating the dynamic response of vessel, mooring and risers. In coupled analysis, the risers and mooring lines are included in the model along with the floater. In this way, damping of the floater motion due to drag on the mooring lines and risers is incorporated directly. It is also valuable to estimate the linear damping factors from the full, coupled analysis results. These damping factors may then, for example, be used in an equivalent linear model of the floating system in which the stiffness and damping effects of the mooring and risers are represented as additions to the floater stiffness and damping matrices. Such a model could be used to efficiently design a subsystem (e.g.; an export riser). We describe a technique to determine the equivalent linear damping factors from the coupled analysis results. This paper also illustrates the use of these methods for a West Africa FPSO. The need for coupled analysis is shown by comparing results from the fully coupled model with those obtained using an uncoupled method in which the mooring line damping is approximated.

scholarly journals Alternative Mooring Systems for a Very Large Offshore Wind Turbine Supported by a Semisubmersible Floating Platform

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Jinsong Liu ◽  
Lance Manuel
Keyword(s):  
Wind Turbine ◽  
Integrated System ◽  
Offshore Wind ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
System Response ◽  
Mooring System ◽  
Floating Platform ◽  
Mooring Lines ◽  
Wind Speeds

As offshore wind turbines supported on floating platforms extend to deep waters, the various effects involved in the dynamics, especially those resulting from the influence of moorings, become significant when predicting the overall integrated system response. The combined influence of waves and wind affect motions of the structure and induce tensile forces in mooring lines. The investigation of the system response under misaligned wind-wave conditions and the selection of appropriate mooring systems to minimize the turbine, tower, and mooring system loads is the subject of this study. We estimate the 50-year return response of a semisubmersible platform supporting a 13.2 MW wind turbine as well as mooring line forces when the system is exposed to four different wave headings with various environmental conditions (wind speeds and wave heights). Three different mooring system patterns are presented that include 3 or 6 mooring lines with different interline angles. Performance comparisons of the integrated systems may be used to define an optimal system for the selected large wind turbine.

scholarly journals HELIANTHUS - SMART SOLAR PANEL

2013 ◽  
pp. 19-22
Author(s):  
Prof. Shashank Pujari ◽  
Prangyadarshini Behera ◽  
Devendrakumar Yadav
Keyword(s):  
Power Generation ◽  
Embedded System ◽  
Tracking System ◽  
Energy System ◽  
Solar Panel ◽  
Solar Photovoltaic ◽  
Solar Panels ◽  
Fixed Position ◽  
Photovoltaic Power ◽  
Solar Tracking

The paper outlines an application of smart solar “photovoltaic” power generation. Solar panels are typically in fixed position. They're limited in their energy-generating ability because they cannot consistently take full advantage of maximum sunlight. For more effective solar energy system, the solar panel should be able to align with sunlight as it changes during a given day. The present paper examines the design advantages of creating an intelligent solar tracking system like a helianthus flower using microcontroller based embedded system.

scholarly journals Effect of Water Depths on the Hydrodynamic Responses of an FPSO Platform

2018 ◽  
Vol 203 ◽  
pp. 01022
Author(s):  
Matthew Guan ◽  
Montasir Osman Ahmed Ali ◽  
Cheng Yee Ng
Keyword(s):  
Oil And Gas ◽  
Response Spectrum ◽  
Low Frequency ◽  
Mooring Line ◽  
Random Wave ◽  
Statistical Parameters ◽  
Mooring Lines ◽  
Line System ◽  
Wave Condition ◽  
Water Depths

Ship-shaped Floating Production Storage Offloading platforms (FPSO) are commonly used in the production of oil and gas in offshore deepwater regions. The vessel is held in place by mooring lines anchored to the seabed during operation, either in spread or turret mooring arrangement. When designing such systems, water depth is a main factor that needs to be considered. At greater depths, the hydrodynamic properties of mooring lines become important and may not be accurately predicted through traditional experiments or numerical quasi-static models. Numerical simulation using coupled dynamic analysis is thus recommended, as the hull-mooring behaviour is analysed simultaneously, and the damping and added mass properties of the entire mooring line system is taken into account. This paper investigates the motions and mooring line tensions of a turret-moored FPSO at various water depths ranging from 1000 m to 2000 m. The analysis focuses on numerical simulations in the fully coupled dynamic time domain. The study utilizes the commercial software AQWA, with the FPSO model subjected to a unidirectional random wave condition. The hull hydrodynamics is first solved using the 3D radiation/diffraction panel method, and the hull response equation is then coupled with the mooring line equation. The dynamic motions and mooring line tensions results are presented in terms of statistical parameters as well as response spectrum. The results highlight the significance of greater water depths on low frequency responses in surge motions and mooring line tensions, and provides insight on the increasing and decreasing trend of these responses.

Numerical Analysis of Submersible Mussel Raft for Exposed Marine Environment

2017 ◽  
Author(s):  
Xinxin Wang ◽  
Fenfang Zhao ◽  
Yanli Tang ◽  
Liuyi Huang ◽  
Rong Wan ◽  
...  
Keyword(s):  
Finite Element ◽  
Marine Environment ◽  
Line Tension ◽  
Hydrodynamic Characteristics ◽  
Mooring Line ◽  
Mooring Lines ◽  
Finite Element Program ◽  
Wave Condition ◽  
Waves And Currents ◽  
Submergence Depth

To study the hydrodynamic characteristics of the submersible mussel raft in waves and currents, the numerical model of the submersible raft was established based on the finite element method and kinematics theory. The finite element program Aqua-FE™ was applied to simulate the impacts of waves and currents on the hydrodynamic responses of the surface and submerged rafts, respectively. Morison Equation was applied to compute the tension of the mooring lines. Apart from the wave condition, the flow has a significant effect on the mooring line tension of the submersible raft. The submerged raft is useful for reducing the mooring loads. The submergence depth of the mussel raft can be adjusted depending on the marine environment. The results show that the submerged raft wave response was found to be reduced relative to the surface raft. The vertical motion of mussel rope connection points was significantly reduced by submergence, resulting in reduced potential for mussel drop-off. Compared the performance of the submerged raft in the same condition, the motion amplitude of the framework of the raft decreased significantly while increasing the submergence depth. At the same period, the trend of the decrease followed by levelling off with an increasing wave height. However, the submergence depth had no significant effect on the mooring line tension.

scholarly journals Monitoring and Controlling Solar Photovoltaic (PV) Performance with Active Cooling System using IoT

2021 ◽  
Vol 2107 (1) ◽  
pp. 012001
Author(s):  
M F A Razak ◽  
M Z Hasan ◽  
J A M Jobran ◽  
S A S Jamalli
Keyword(s):  
Cooling System ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Solar Panel ◽  
The Internet ◽  
Air Cooling ◽  
Solar Photovoltaic ◽  
Solar Panels ◽  
Air Cooling System ◽  
Cooling Air

Abstract Solar photovoltaic technologies are worldwide renewable energy sources. However, the elevated temperature in solar panels is one explanation for reducing the performance of solar systems. An active air cooling system can be mounted on the back of the solar panel to avoid this phenomenon. In order to ensure that the solar system runs smoothly, monitoring needs to be done at each place where this solar energy system is located. The Internet of Things (IoT) is a network of linked, internet-accessible physical objects. It is the technology of the next generation that will soon be extended to society. The IoT refers to the system or ecosystem in which devices are connected to the Internet in real-time. Based on IoT, a smartphone can track the temperature of the solar panel anytime and anywhere. To overcome this problem, a Blynk IoT system monitors solar power status and controls the cooling air system. NodeMCU was the main microcontroller used in IoT systems. The IoT framework can be implemented easily and efficiently using NodeMCU. The experimental results of this project will monitor the performance of the solar panel and monitor it.

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