ENGINE & TURBINE TECHNOLOGY
company had already demonstrated its capabilities in the same area back in 2014, and its experts also developed and supplied the exhaust gas stack and silencer for the larger test rig known as HBK 5. However, this latest order came with some special challenges. Firstly, the timeframe for the project was extremely tight. Work had to be completed by the end of the year, which meant taking care of everything in the space of five and a half months. Secondly, the new silencer was not to reach any higher than the mouth of the old model and the existing foundations had to be left as they were.
NEW CONCEPT DEVELOPED WITH CFD SIMULATION
“Te fundamental technical challenge for the new exhaust system concept was how to deal with the exceptionally inhomogeneous exhaust gas flow and convert it to a flow profile that would be compatible with the silencer,” recalls Paul Karle, the project manager at G+H. Te concept was ironed out in close coordination with the customer and using computational fluid dynamics (CFD). DLR had made a number of stipulations for the design. Among these was a requirement that the exhaust system and silencer of HBK 2 must be designed for core exhaust streams at flow rates of up to 1,000m/s and temperatures in excess of 1,300°C at the outlet of the combustion chamber choke. Demanding acoustic requirements also had to be met.
A NEW APPROACH One of the key problems when working with such a compact test rig was how to redirect the exhaust flow 90° from the horizontal duct into the stack. “From the outset, we knew we would have to develop an alternative concept for redirecting the flow 90° if we were to ensure an even flow against the silencer panels in the stack,” says Karle. G+H therefore worked with DLR to develop a prototype exhaust routing system tailored specifically to the test rig that was able to achieve an exceptionally homogeneous flow profile after redirection. Karle explains: “Te flow rate, the flow distribution and the temperatures generated in the combustion chamber place exceptional demands on the materials used. Te knowledge we have acquired by manufacturing this prototype will be a valuable asset for the development of future bespoke solutions for our customers.”
The HBK 2 rig (without cladding)
OUTPERFORMING THE NOISE EMISSION REUIREMENTS Ultimately, Karle’s team overcame all the challenges. Besides satisfying the construction-based requirements of the order, the team also completed the project on time. In fact, the new plant even outperforms the operational parameters that were stipulated in the order, keeping noise emissions at the stack opening well below the maximum permissible limit. Karle is particularly pleased his company has been able to play its part in the future of gas turbine technology. After all, DLR uses HBK 2 as a research platform for developing combustion chamber technologies to be used in next- generation gas turbines. Karle comments: “Lots of people have said that the days of gas turbines are over, but that’s just not true.” His reasoning is rooted in the
“future fuels” that are coming online, such as hydrogen and synthetic fuels, which could be used to considerably reduce environm entally harmful emissions from gas turbines. “Tanks to low-emission and even entirely emission-free usage, and against the backdrop of renewable energy sources, the powerhouse that is the gas turbine is taking on a new meaning in power plant technology,” points out Karle. With renovations potentially having to be made to thousands of gas turbines in power plants around the world, he can see a whole new field of activity opening up for his noise control team.
Jörg Meyer is with G+H Noise Control.
www.guh-group.com
www.engineerlive.com 33
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
