Condition monitoring wind turbine gearboxes using on-line/in-line oil analysis techniques

Paper examining condition monitoring wind turbine gearboxes using on-line/in-line oil analysis techniques

Efficient use of energy

World energy demand is projected to grow by more than 50% by 2030.[21] Improving energy efficiency is one of the most economical and short to medium term ways Scotland can reduce its dependence on fossil fuels and reduce its emissions of greenhouse gases. Transportation and buildings, which account for two thirds of energy usage [16], consume far more than they need to, but even though there are many affordable energy efficient technologies that can save consumers money, current utilisation is small. To overcome this, the government must adopt policies that invest in research and development programs that target energy efficiency. Incentives schemes if properly implemented can stimulate and encourage energy efficiency which is one of Scotland's great hidden energy opportunities. This paper outlines the position of the Institution of Engineers and Shipbuilders in Scotland and makes recommendations for the Scottish Government by two separate means of improving energy efficiency; reducing wastage and providing the same end need using less energy

Comparison of 2nd generation LiDAR wind measurement technique with CFD numerical modelling

With the rapid increase in both on and offshore wind turbine deployment there is a requirement for a better understanding of the flow field in which such devices are deployed. Greater understanding of the flow field is necessary for optimisation of turbine control, turbine design, and machine interaction as well as maximise operation and performance. Advanced measurement tools can characterise the flow regime by either acoustic or laser pulses to measure the line of sight velocity of airborne particles. Such technology facilitates the acquisition of detailed and precise measurements of wind speed and direction remote from the device location; some solutions can even provide detail of the flow structure of the wind in the measurement field. In the current study an analysis of the methodology, relevance and potential of a 2nd generation LiDAR is presented along with results of a deployment at an onshore wind farm. The results demonstrate the potential of the LiDAR to capture details of wind farm flow and structures, along with the potential to corroborate numerical techniques with the measured data. Advances in Computational Fluid Dynamics (CFD) approaches coupled with the availability of significant computational resources makes it possible to conduct a valid comparative assessment. This paper presents the details of this comparative assessment and makes a judgement on the accuracy of the approach. The results show that remote sensing devices offer a useful and accurate capability for wind vector analysis and flow visualisation, along with the flexibility to organise bespoke measurement campaigns. The study also presents methodologies by which such devices can be used as validation tools for CFD

Development of a robust structural health monitoring system for wind turbine foundations

The construction of onshore wind turbines has rapidly been increasing as the UK attempts to meet its renewable energy targets. As the UK’s future energy depends more on wind farms, safety and security are critical to the success of this renewable energy source. Structural integrity is a critical element of this security of supply. With the stochastic nature of the load regime a bespoke low cost structural health monitoring system is required to monitor integrity. This paper presents an assessment of ‘embedded can’ style foundation failure modes in large onshore wind turbines and proposes a novel condition based monitoring solution to aid in early warning of failure

Design optimisation of a regenerative pump using numerical and experimental techniques

Regenerative pumps are the subject of increased interest in industry as these pumps are low cost, low specific speed, compact and able to deliver high heads with stable performance characteristics. The complex flow-field within the pump represents a considerable challenge to detailed mathematical modelling. This paper outlines the use of a commercial CFD code to simulate the flow-field within the regenerative pump and compare the CFD results with new experimental data. A novel rapid manufacturing process is used to consider the effect of impeller geometry changes on the pump efficiency. The CFD results demonstrate that it is possible to represent the helical flow field for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests. The ability to use CFD modelling in conjunction with rapid manufacturing techniques has meant that more complex impeller geometry configurations can now be assessed with better understanding of the flow-field and resulting efficiency

Rapid manufacturing technique used in the development of a regenerative pump impeller

This paper presents a method of rapid manufacture used in the development of a regenerative pump impeller. Rapid manufacturing technology was used to create complex impeller blade profiles for testing as part of a regenerative pump optimisation process. Regenerative pumps are the subject of increased interest in industry. Ten modified impeller blade profiles, from the standard radial configuration, were evaluated with the use of computational fluid dynamics and experimental testing. Prototype impellers were needed for experimental validation of the CFD results. The manufacture of the complex blade profiles using conventional milling techniques is a considerable challenge for skilled machinists. The complexity of the modified blade profiles would normally necessitate the use of expensive CNC machining with 5 axis capability. With an impeller less than 75 mm in diameter and a maximum blade thickness of 1.3mm, a rapid manufacturing technique enabled production of complex blade profiles that were dimensionally accurate and structurally robust enough for testing. As more advanced rapid prototyping machines become available in the study in the future, e.g. 3D photopolymer jetting machine, the quality of the parts particularly in terms of surface finish will improve and the amount of post processing operations will reduce. This technique offers the possibility to produce components of increased complexity whilst ensuring quality, strength, performance and speed of manufacture. The ability to manufacture complex blade profiles that are robust enough for testing, in a rapid and cost effective manner is proving essential in the overall design optimisation process for the pump

Study of a regenerative pump using numerical and experimental techniques

Regenerative pumps are the subject of increased interest in industry as these pumps are low cost, low specific speed, compact and able to deliver high heads with stable performance characteristics. The complex flow-field within the pump represents a considerable challenge to detailed mathematical modelling as there is significant flow separation in the impeller blading. This paper presents the use of a commercial CFD code to simulate the flow within the regenerative pump and compare the CFD results with new experimental data. The CFD results demonstrate that it is possible to represent the helical flowfield for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests. The CFD models are currently being used to optimise key geometric features to increase pump efficiency

Analysis of offshore wind turbine operation & maintenance using a novel time domain meteo-ocean modeling approach

This paper presents a novel approach to repair modeling using a time domain Auto-Regressive model to represent meteo-ocean site conditions. The short term hourly correlations, medium term access windows of periods up to days and the annual distibution of site data are captured. In addition, seasonality is included. Correlation observed between wind and wave site can be incorporated if simultaneous data exists. Using this approach a time series for both significant wave height and mean wind speed is described. This allows MTTR to be implemented within the reliability simulation as a variable process, dependent on significant wave height. This approach automatically captures site characteristics including seasonality and allows for complex analysis using time dependent constaints such as working patterns to be implemented. A simple cost model for lost revenues determined by the concurrent simulated wind speed is also presented. A preliminary investigation of the influence of component reliability and access thresholds at various existing sites on availability is presented demonstrating the abiltiy of the modeling approach to offer new insights into offshore wind turbine operation and maintenance

Development of a regenerative pump impeller using rapid manufacturing techniques

This paper presents a method of rapid manufacture used in the development of a regenerative pump impeller. Rapid manufacturing technology was used to create complex impeller blade profiles for testing as part of a regenerative pump optimisation process. Regenerative pumps are the subject of increased interest in industry. Ten modified impeller blade profiles, relative to the standard radial configuration, were evaluated with the use of computational fluid dynamics and experimental testing. Prototype impellers were needed for experimental validation of the CFD results. The manufacture of the complex blade profiles, using conventional milling techniques, is a considerable challenge for skilled machinists. The complexity of the modified blade profiles would normally necessitate the use of expensive CNC machining with 5 asis capability. With an impeller less than 75mm in diameter and a maximum blade thickness of 1.3mm, a rapid manufacturing technique enabled production of complex blade profiles that were dimensionally accurate and structurally robust enough for testing. As more advanced rapid prototyping machines become available in the study in the future, e.g. 3D photopolymer jetting machine, the quality of the parts, particularly in terms of surface finish, will improve and the amount of post processing operations will reduce. This technique offers the possibility to produce components of increased complexity whilst ensuring quality, strength, performance and speed of manufacture. The ability to manufacture complex blade profiles that are robust enough for testing, in a rapid and cost effective manner is proving essential in the overall design optimisation process for the pump

Design study of a regenerative pump using one-dimensional and three-dimensional numerical techniques

Regenerative pumps are low cost, compact, able to deliver high heads at low flow rates. Furthermore with stable performance characteristics they can operate with very small NPSH. The complexity of the flow field is a serious challenge for any kind of mathematical modelling. This paper compares an analytical and numerical technique of resolving the performance for a new regenerative pump design. The performance characteristics computed by a CFD approach and a new one-dimensional model are compared and matched to experimental test results. The approaches of both modelling techniques are assessed as potential design tools. The approaches are shown to not only successfully resolve the complex flow field within the pump; the CFD is also capable of resolving local flow properties to conduct further refinements. The flow field is represented by the CFD as it has never been before. A new design process is suggested. The new regenerative pump design is considered with a comparable duty centrifugal pump, proving that for many high head low flow rate applications the regenerative pump is a better choice