Extrusion International 2-2020

47 Extrusion International 2/2020 able to offer an unrivalled, short delivery time. They could not provide the new refrigeration system at the start-up phase of our new production lines, but they supplied a rental system which allowed up to set up and test the new plastic processing lines. The situation was turbu- lent, requirements changed at short notice, but the team adapted without any problems. We felt well advised right from the start, also by Mirko Jurke from Reisner’s sales partner Jurke Engineering GmbH – and we felt excellently accompanied during the whole planning phase”. Adding to the performance while saving energy The most important factor, however, was the unique en- ergy saving concept developed by Reisner managing di- rector Thomas Imenkämper and his staff. It is based on the fact that the new DRS production requires a lot of cooling capacity, but it does not always need to be supplied at full load. The tailor-made cooling system therefore consists of three separate cooling machines. Each machine has a maximum cooling capacity of 400 kW, so that a total of 1,200 kW is available. The individually programmed Reis- ner control system regulates which machine contributes which amount of cooling performance at any given time. This demand-oriented supply goes even further, as each individual unit can be regulated again and thus reduced a partial load of up to 25 percent. Consequently, energy consumption is always kept as low as possible in any giv- en production situation. As an attractive side-effect, the self-sufficient operation of the individual cooling units also boosts operational safety. Reisner has even enhanced the energy saving effect by adding further technologies that also reduce the con- sumption. An important feature is the Reisner Vario technology. It allows the cooling machines to adjust their condensation temperature to the low average outside temperatures that are common in Germany. The lower the condensation temperature, the more efficient the refrigeration system. Thanks to precise control, DRS also save energy operating their condensers. They are equipped with EC fans which adjust their output precisely to the respective operating point, reducing not only en- ergy consumption but also noise emissions. Finally, two dry coolers, also equipped with EC fans, supplement the cooling system. Each of these dry coolers provides up to 600 kW cooling capacity. Together, they gradually relieve the refrigeration systems when outside temperatures de- cline, and during wintertime they can even completely supply the production, reducing the chillers’ compressor energy by 100 percent. Extreme effects From all these measurements, Reisner have assembled a complete package that effectively keeps energy con- sumption as low as possible under given circumstances. The figures speak for themselves: without energy-saving technologies the DRS refrigeration system would con- sume 1,366,743 kWh per year. The Vario technology alone reduces energy consumption by 550,687 kWh, while the winter relief system saves a further 636,784 kWh per year. This reduces electricity consumption to just 178,272 kWh per year - drastic savings of around 87%! Costs are re- duced accordingly. While with a conventional system DRS would have to spend 205,011 Euro per year on cooling energy, using the Reisner system they get away with no more than 26,891 Euro. Our environment benefits from the fact that much less CO 2 is emitted to provide the necessary electricity. Annu- ally, based on the local power mix, the Reisner concept saves the atmosphere around 630 tons of carbon dioxide. In addition, the system is designed for the future as it is operated with the state-of-the-art refrigerant R513a. This substance is much less harmful to our climate than com- parable refrigerants. Its so-called Global Warming Poten- tial (GWP) is only 631, while the reference value of CO 2 is DRS’ managing director Andreas Seibel and Reisner’s Thomas Imenkämper (left to right) read off the well-structured touch panel how the system adapts to each operation situation Three cooling units with a capacity of 400 kWeach plus the respective control cabinets are installed inside the container – neatly and with a lot of space for service and maintenance works