Rainpower Uses HBK Equipment to Develop a Unique Flight Recorder Tool for Accurate Dynamic Measurements on Water Turbines in Hydropower Plants

When it comes to water turbines, runner blades are a critical component. Often faced with tough conditions, such as high-water pressure and water speed, it is important to ensure specifications are consistent with the performance of the blade.  

To address this issue, Rainpower have developed a new measurement tool called a Flight Recorder to accurately measure the dynamic stress on runner blades during all modes of operation. HBK was invited to step in and specify a solution for the Data Acquisition System (DAQ) part of the unit.

The Flight Recorder is a battery-operated system, where all data is stored locally, negating the need for an underwater data transmission system. Used to measure strain on turbine blades, pressure distribution in the runner in different places, vibration on different locations, and temperature on the runner surface, such data is invaluable for calibration of data simulations and numerical analysis.

Meeting the Need

For this project, QuantumX units from HBK were used to collect data with a CX22 industrial computer/data recorder, with flash memory. The system, which runs with catman software, was mounted in a tailor-made framing system, and placed inside waterproof housing with waterproof subsea connectors.

The QuantumX data acquisition system (DAQ) is the perfect tool for reliable data acquisition of different physical quantities and sensor technologies. Flexible, reliable, and easy to use, the system is small and portable, meeting the design requirements specified. 

Before testing, HBM strain gauges are applied to runner blades on predefined spots, and the other transducers are mounted on their appropriate places. All transducers are then connected to the Flight Recorder with watertight cables, and the unit is then mounted onto the hub of the runner. Before filling the turbine with water, the recorder is switched on and the catman program starts collecting data. The recorder then collects data during filling up the turbine, through different modes of operation, after shutting down and when the dewatering of the turbine starts. When the system is empty, the runner can be inspected, and all data from the Flight Recorder can be transferred to a laptop, and a brief check of the collected data is done. Back in the office the measurement data can be conveniently analysed with advanced algorithms.

This is particularly important as it enables Rainpower to provide customers with accurate and valuable information on how parameters such as the number of starts, stops and operation in different power ranges can affect the lifetime of the runner.

“As a company dedicated to testing, we needed to choose the right equipment for this project. So, following a market review, we opted to use HBM components. HBM provided us with excellent service and knowledge in the strain gauge market, which was an especially important aspect to us”,

explains Kjell Sivertsen, Discipline Manager Lab Technology and Equipment, Rainpower AS, Turbine Laboratory, Trondheim.