qtec Kunststofftechnik GmbH Quedlinburg improves efficiency and sustainability with a central technotrans cooling system featuring integrated heat recovery
Growth requires an infrastructure that can keep pace. At qtec Kunststofftechnik GmbH Quedlinburg, the existing process cooling system had reached its performance limits and was becoming increasingly unreliable. The company therefore opted for a comprehensive modernisation and invested in a new system solution for its demanding production processes. technotrans solutions GmbH was awarded the contract and implemented a tailored thermal management concept. At the heart of the solution is a central containerised cooling plant supplying 30 injection moulding machines while simultaneously heating the building through integrated heat recovery. In addition, the holistic concept incorporates an innovative chemical-free cooling water treatment system.
qtec Kunststofftechnik GmbH Quedlinburg, based in the Harz region of Germany, specialises in the production of highly precise and sophisticated plastic components. The family-owned company’s broad portfolio includes components for the automotive, electrical and household appliance industries as well as for medical and heating technology applications. Numerous well-known customers rely on the quality of products manufactured using injection moulding technology. With around 100 employees and 30 injection moulding machines, qtec operates a three-shift production environment where process stability and system reliability are of paramount importance.
Over the years, the machine fleet – and with it the cooling infrastructure at the site – continued to grow steadily. Most recently, two separate legacy systems supplied the production with cooling water. “Our cooling infrastructure was no longer up to date and required extensive maintenance. One of the main systems had already failed, which increasingly affected overall process stability,” explains Christopher Hamann, Head of Production and Technology at qtec. Cooling water quality also posed a challenge. “Impurities clogged the fine cooling channels in the injection moulding tools and impaired heat dissipation. This had a direct impact on the consistency of cycle times and component quality,” says Hamann. The new system therefore needed to ensure maximum operational reliability, operate energy-efficiently, follow a sustainable overall concept and significantly improve water quality..
Holistic concept as the decisive factor
In its search for a suitable solution provider, qtec selected technotrans. The thermal management specialist impressed compared with competitors by offering a comprehensive overall package that went far beyond simply providing the required cooling capacity. “For us, it was crucial to find an established partner capable of delivering the technological expertise for such a complex project from a single source while also ensuring a high level of service quality,” emphasises Hamann.
Two central requirements shaped the project planning. First, the new system was not only intended to provide cooling but also to support the building’s heating system through heat recovery – with the long-term objective of replacing the existing gas heating systems. Second, qtec wanted a completely chemical-free cooling water treatment process. Based on these requirements, technotrans developed the overall technical concept. For the demanding water treatment process, the company integrated a specialised system from its partner Bauer WT Systems GmbH.
Energy-efficient and reliable at all times
The heart of the new solution is a central containerised cooling system installed outside the production hall to save space. It provides a cooling capacity of 380 kilowatts and is precisely designed for qtec’s process parameters with a supply temperature of 20 degrees Celsius and a return temperature of 25 degrees Celsius. From the outset, the system was designed for resource-efficient and energy-efficient operation, explains Maxim Retich, Sales Manager Cooling Solutions at technotrans: “The system’s intelligent control continuously monitors the outside temperature and automatically selects the most energy-efficient operating mode. Whenever outdoor temperatures permit, the system switches to integrated free cooling. In this mode, large heat exchangers cool the process water directly using ambient air, without the compressors of the refrigeration unit running.” This significantly reduces electricity consumption for large parts of the year. Only when free cooling is no longer sufficient does the system seamlessly switch to active refrigeration.
To ensure maximum availability, technotrans designed the system with a multi-stage safety concept. Critical pumps are configured redundantly so that if one fails, a reserve pump automatically takes over. The refrigeration unit itself features two independent cooling circuits. If one circuit fails, the second can still deliver 50 per cent of the total capacity, preventing a complete production shutdown. To solve the specific problem of water contamination without chemicals, technotrans integrated a treatment system from partner Bauer WT Systems GmbH. The system operates using a purely physical process in which high-frequency magnetic fields generate nano air bubbles in the water. These bubbles attach themselves to surfaces – similar to carbon dioxide bubbles in mineral water – and form an effective separating layer that prevents deposits such as limescale, rust and biofilms. “The consistently clean process water not only protects our tools but also enables us to operate the temperature control units without disruption and without using limescale-rich fresh water,” confirms Hamann.
Heat recovery converts waste heat into heating energy
Another key element of the concept is heat recovery. It transforms process cooling from a pure energy consumer into a valuable energy source for the site. Technically, this is realised via an additional heating condenser integrated directly into one of the machine’s refrigeration circuits. Instead of releasing the heat generated during refrigerant condensation unused into the environment, the heat exchanger transfers this energy highly efficiently to the building’s heating circuit.
The system control operates dynamically. When there is a heating demand in the building – indicated by a low temperature in the 5,000-litre buffer storage tank – the system specifically activates the refrigeration circuit with the heating condenser. At the same time, it reduces the output of the free cooler in order to optimise overall energy consumption. As soon as the buffer storage tank reaches the target temperature of 65 degrees Celsius, the system switches off the compressor again and maximises free cooling performance. “With this method, we use waste heat as the primary heat source and cover the base heating demand for large parts of the year. This significantly reduces the load on the existing gas heating systems and lowers the CO₂ footprint,” explains Retich. For the few production-free days each year during the Christmas shutdown, an additional electric heating solution is planned to ensure independence from fossil energy sources during this period as well.
Smooth implementation during ongoing operations
qtec and technotrans successfully completed the transition to the new central cooling system during ongoing production – a particular challenge in a three-shift environment. In advance, technotrans provided intensive support in adapting the existing pipe network. “Working with technotrans was consistently constructive. The team understood exactly what matters in our production environment and implemented the project very professionally,” Hamann recalls. Since commissioning in spring 2024, the system has been running consistently and without disruptions. “We are very satisfied with the overall package consisting of the technical solution, the collaborative consulting approach and the achieved results,” Hamann concludes. The new cooling solution also prepares qtec for future growth, as technotrans already incorporated capacity reserves into the system design for a potential site expansion.
Further information under: www.technotrans.com