Autarkic power generation by high-precision fuel metering
In the northern reaches of Chile's Atacama Desert, 66 huge, high-precision antennas stand at 5,000 m above sea level, taking advantage of the clear, thin air at this altitude to obtain very sharp, high-contrast images of space. The system is part of the Atacama Large Millimeter Array Observatory (ALMA). Since there are no power lines running to this remote part of the world, an operations support unit was installed with three 3.5-megawatt multi-fuel gas turbines for autonomous power generation.
Any interruption in the supply of power would be a disaster for ALMA. Without power, the water treatment plant cannot work, there would be no heating, no light, and communications to the outside world would be silenced. Even a short interruption could lead to a loss of calibration in the antennas and thus, the destruction of hours of valuable work.
To ensure a stable and reliable supply, the energy has therefore been generated locally since the installation of three gas turbines that run on diesel or LPG in May 2013. A robust design of the pumps is indispensable in the face of the harsh environmental conditions in the desert: not only the human organism, but also the working of pumps is greatly influenced by the temperatures in the desert, since the viscosity of the medium changes and it can even heat up to the point that cavitation occurs in the pipeline. Engine powers also vary in the thin, high air. At 2,900 m – the altitude of the observatory's operations unit – it is about 15 to 20 percent below the value the same engine can achieve at altitudes below 1,000 meters above sea level.
For the supply with the required amount of fuel, LEWA triplex diaphragm metering pumps are used, which have been designed taking into account the local conditions. To keep the entire system in balance and to be better able to plan service work, switching between multiple pumps is possible: One pump is in operation, the second serves as a replacement. If one pump should fail, the second would be started. The switchover works entirely automatically and is controlled by the turbine controller. The LEWA solution ensures uninterrupted fuel supply, which also avoids overloading and overvoltage by highly precise control of the fuel feed. Despite the remote location, LEWA provides a personal on-site service if irregularities or emergencies occur.
Producer: LEWA GmbH
|Pump||LEWA triplex diaphragm metering pump|