Three of its production lines were supported by electrical equipment that was protected by a 25kW climate control system. This was configured as one chiller feeding three heat exchangers (HEX) in order to maintain temperature levels at 27°C.
However, the chiller was struggling to maintain this level, particularly on days when ambient temperature was higher. Operators at the plant used an 18°C coolant but this was still not delivering an acceptable performance. Not only was the chiller was constantly running, temperatures were regularly creeping above a critical threshold of 28°C. The business was in danger of losing all production if the (overworked) chiller broke down. And while the chiller should have had spare cooling capacity, it was constantly struggling to meet the demands of supporting three heat exchangers.
Initial discussions with the business centred around replacing the chiller with a similar unit, albeit one with an IoT interface to integrate chiller data into the DCS for better process control. However, Rittal sales engineer Paul McGarry suggested an alternative solution. This involved splitting the heat exchanger circuit into three independent circuits (one per production line) so that each one could be controlled independently. This would have been particularly helpful as one line was always running hotter. The main advantage was that it introduced redundancy into the system; the current configuration meant that a chiller failure stopped all production across every line. The alternative system ensured two lines would still be in operation should one chiller fail.
In order that the correct product was chosen, coolant flow rates needed to be accurately measured and all external parameters had to be accurately recorded. McGarry’s recommendations were backed by Rittal’s international network of climate control experts (Stephen Ruch and Bjoern Burger in Germany) who calculated the flowrate at 15 l/m with a total cooling output requirement of 15kW - an energy saving over the existing system (25kW cooling output).
Once the three new 3334400 chillers were specified, together with their IOT interfaces, they were installed in late August 2019.
The company’s production manager has expressed his approval with the installation, the communications between the new IoT interfaces with the DCS system and that the system feedback and production control has improved. In addition, the newly-configured system with three chillers is now said to be more dynamic and stable than the previous one.