The company EVC oper­ates a highly exclu­sive gas power plant in Dresden. Its only customer is the neigh­boring microchip factory of Glob­al­foundries, the semi­con­ductor industry giant. The power plant supplies elec­tricity with an extremely stable voltage and frequency across the way, guar­an­teeing the chip foundry a worry-free energy package. On site, every day Zeppelin Power Systems makes sure that the systems in the gas plant func­tion perfectly.

Senior Service Tech­nology Engi­neer Andreas Büttner runs a tight ship there. “We are constantly on the lookout for poten­tial means of getting more with less energy. We take envi­ron­mental and climate protec­tion very seri­ously,” said Büttner. “In 2015 and 2016, we updated and equipped the hori­zontal condenser on the roof for the cooling water with 216 EC fans.” The result was an almost 87 percent savings on energy. “That spurred us on to search for more poten­tial and we found it in the air intake system.”

Three medium-pres­sure EC axial fans now supply the gas engines with combus­tion air. Their biggest plus in this context: they are easy to main­tain. (Photo | ebm-papst)

Less pres­sure works too

The air intake system supplies the new gas engines with combus­tion air and cools the space in which they roar and bellow – which happens to be as large as a two-car garage. An air duct leads from each of the new rooms. Today, three EC medium pres­sure axial fans are mounted on each ceiling and trans­port air inside. “Until a short time ago, it was one AC centrifugal fan. Unfor­tu­nately we didn’t have enough space back then and they were posi­tioned so poorly that half of the fan cross-section was blocked. And the air intake system had ducts that were too narrow. We simply decided to convert every­thing.”

The advan­tages are obvious: with three fans we have redun­dancy. If one fails, the engine can still be oper­ated.

Andreas Büttner, Zeppelin Power Systems

Büttner commis­sioned an engi­neering office to completely revise the air intake system. The goal was to signif­i­cantly reduce the required air pres­sure at the same air volume. “We enlarged the pipe cross-section, modi­fied the air grid and opti­mized the shut­ters – the entire system from begin­ning to end.” This reduced the required pres­sure from 560 Pascal to 307. And instead of one large centrifugal fan, Büttner was able to install three medium pres­sure axial fans to distribute the air. “The advan­tages were obvious: with three fans we have redun­dancy. If one fails, the engine can still be oper­ated,” explained Büttner.

“But in my opinion, the biggest plus was that the axial fans now hang from the ceiling. They were easy to install, and main­te­nance and repair will be much easier too. When we used to have to replace a defec­tive centrifugal fan, it was a big deal: we even needed a crane. Now if worse comes to worse, we just need a three-tech­ni­cian team.”

95 percent energy savings

After running the new system for nine months, Büttner measured the amount of energy that was saved. “It now takes an amazing 95 percent less energy to run the air intake system than before. With the new engines, the system now saves us 1.4 million kilo­watt-hours – around 792 tons of carbon per year!”