Invensor backs tri-generation benefits

GERMANY: Adsorption chillers from German company InvenSor have been employed in a tri-generation project at an electroplating company in Dresden.

Medium-sized German manufacturers and processors with a demand for vast quantities of process heat and cooling are said to be increasingly turning to solutions involving CHP units in conjunction with thermally-driven cooling systems.

Power and heat can be produced efficiently and at low costs through the use of CHP cogeneration systems. With an adsorption chiller, the benefits can also be extended to the otherwise energy-intensive cooling processes in production. In May, Oberflächentechnik Döbeln, an electroplating company based near Dresden, implemented a tri-generation system for power, heating and cooling by combining two CHP units and two InvenSor adsorption chillers.

“These tri-generation systems are not only on the rise in server rooms and sales rooms throughout Germany, but are also gaining popularity in industrial usage,” says Invensor

In addition to the two CHP units, installed in 2008, a photovoltaics system on the roof of the premises based in Saxony also ensures that the company produces a significant portion of its energy requirements.

The decision was made for two InvenSor LTC 10 plus FC low temperature chillers with 20kW nominal power. The two adsorption chillers were installed in May 2014 and, since then, have been cooling the electrical rectifiers.

The trigeneration system has many benefits for operators. Waste heat from CHP units is now mainly used to produce cold water cost-efficiently and in an environmentally friendly manner, thus increasing the annual time of operation of CHP units. “We want to obtain around 5,000 operating hours from our adsorption chillers every year, as the company needs the cold water virtually 24 hours a day, since we follow three-shift operations here,” explained Holger Radisch, whose company designed the system.

In the case of low ambient temperatures, the InvenSor system can work with free cooling, so the heat from the CHP unit is then directly available as before. The cooled water is directed to the rectifiers via computer at a temperature of 15-17°C, while the return temperature is 23-25°C depending on the type of operation.