Proving Pump Efficiency With A Dynamic Torque Sensor
Background
Using helicopters has been found to be effective in a number of industries, including agriculture, forestry and firefighting in particular. Containing large fires, sometimes stirred by winds, is an extremely dangerous job, costing hundreds of lives of firefighters every year, not to mention the ones who get injured in the process.
As a result, when it comes to big fast-spreading fires, water bombers serve as an essential firefighting tool all around the world. Having an ability to deliver 10,000 litres of water in one drop on average and dump enough water to cover 6 double-width football fields, aerial firefighting is becoming an obvious choice for fast response fire-fighting services.
Although speed, mobility and capability of pump motors in the short run duration refill applications are beyond question, the water pump systems in are still complex, heavy and in many cases unreliable due to the absence of water sites nearby. The Kawak team worked on creating a new innovative jet pump series, able to improve the flexibility of the water bombers systems and therefore their performance.
Kawak Aviation Technologies has developed a new line of “Jet Pump” (or JP) series helicopter refill system, allowing to draw water from practically any accessible water resource, decrease refilling cycle times without a need for landing and use the motor as the driver of an air conditioning system. Unlike previous helicopter water pumps, the new Jet Pump line of products provides helicopter operators with a high-volume, lightweight powered fill option that can produce higher water fill rates between 1150 and 2500 gallons per minute, using shallow water resources as low as 40 cm. This new JP series solves current problems with mechanical issues, complexity and reliability of helicopter refill systems offering customers a better value and a competitive advantage to outperform competitors and win more contracts.
We had the challenge to demonstrate that the motor could meet the worst case drive requirements at temperatures over 50C. With the Datum M425 Torque Sensor, we were able to accurately measure the motor heat generation, do this quickly and be confident in the test data.
Solution
Following Datum’s M425 Torque Transducer Installation Guide, with a little bit of help from the Datum support team, the Kawak team positioned the M425 dynamic torque sensor on the new JP series pump motor and tests began. Measuring performance of the pump efficiency is enabled by accurate measurements of a power input to the pump (power in) that equal to the sum of pumping energy (water flow rate and pumping lift) and generated heat change (power out). Although the Kawak team wasn’t sure about test accuracy at the beginning, the inline rotary M425 Sensor was able to measure motor shaft power to an accuracy that confirmed the test results including the temperature changes across the pump.
Although we weren’t confident that we would be able to measure motor heat generation accurately (typically small errors in shaft output power measurement cause large uncertainty in heat generation estimates), we have been impressed with the accuracy of the Datum Dynamic Torque Sensor.
Impact
Accurate measurement of motor pump efficiency is essential for improving the pump efficiency as it can generate a big economic potential. The pump testing proved that heat generation is within a few percent difference between power in and power out. As a result, the Kawak team had enough information to create new uses for the motor, namely as the driver of an air conditioning system, where there is potential for much larger sales. Today, new JP series refill system a leap forward allowing Kawak to increase efficiency, sharpen reliability and improve the performance of the refill pump.