At the DLR (Deutsches Zentrum für Luft- und Raumfahrt) Propulsion Technology headquarters in Cologne, DLR provides test stands for gas turbine combustion chambers. Customers from both the aviation and power generation industries can conduct their tests under realistic pressure and temperature conditions, for combustion chambers with a thermal capacity up to 50MW.
“Our aim is to help turbine manufacturers increase efficiency and reduce noise and emissions from their turbines,” said Fleing. “To do this we need to replicate the operating environment as accurately as possible. This means the combustion chamber tests have to be conducted over a wide flow range of 100:1, at temperatures up to 300°C and pressures up to 200 bar.”
DLR originally installed orifice plates to measure gas flow, but these had limitations in their accuracy and turndown. Orifice flow meters are only accurate when measuring natural gas and the customer tests often require a mixture of gases.
DLR started working with Emerson to find a better solution to its measurement challenge and Emerson recommended its Micro Motion ELITE Coriolis flowmeter. The Micro Motion flowmeters were installed, allowing DLR to provide a new generation of combustion chamber testing. The new solution enables historic information to be accessed and diagnostics and calibration checks to be completed daily before the tests are started. Micro Motion flowmeters are able to accurately measure mixtures of gases, extending the scope of the tests. The Smart Meter Verification (SMV) feature on the Micro Motion flowmeters means that the calibration of the meter can be checked without removing it from the line, reducing energy use and maintenance costs.
Emerson’s Volker Kramer then explained the principles and benefits of SMV. For example, it takes just two minutes for the calibration of the meter to be checked against the original factory setting. During the combustion test, when conditions are stable, the calibration of the meter can be checked again. This reassures the customer of the accuracy of the measurements taken under actual test conditions.
“The Smart Meter Verification tool is initiated by the customer through the transmitter,” Kramer said. “The transmitter vibrates the sensor with different frequencies and the response is used to determine if the calibration of the sensor has changed. If the change exceeds the limits specified, the customer is notified.”
The sensor stiffness measurement can be used detect tube damage caused by erosion, cracking, pitting, etc. and determine whether the process measurement is being influenced.
“The proven accuracy and reliability of our tests has helped DLR win more customers,” continued Fleing. “Based on this success we are investing €47 Million in a new test facility to satisfy the demands of our customers for up to 30 years. This will be commissioned in June 2014 and will extend our test capacity up to 125 Mw thermal output.”