Intelligent cooling meets sustainable heating

qtec Kunststofftechnik boosts efficiency with a central technotrans cooling system through coupled heat and cold generation

Growth demands infrastructure that keeps pace. At qtec Kunststofftechnik GmbH, the existing process cooling system had reached its performance limits. technotrans SE developed a bespoke thermal management concept: a central container-based cooling system with integrated heat recovery and chemical-free cooling water treatment – serving 30 injection moulding machines in three-shift operation.

380 kW

Cooling capacity

30

Injection moulding machines

5,000 Liter

Buffer tank

65°C

Target temperature for heat recovery

50 %

guaranteed performance in the event of a refrigeration circuit failure

qtec Kunststofftechnik GmbH

qtec Kunststofftechnik GmbH, headquartered in Quedlinburg in the Harz region, is a specialist in the manufacture of high-precision, demanding plastic components. The family business's broad portfolio includes components for the automotive and medical technology sectors, as well as for the household and electrical industries.

With around 100 employees and 30 injection moulding machines, qtec operates in three-shift production – an environment in which process stability and plant reliability are of the utmost importance.

Infrastructure at its limits// Over the years, the machinery pool and the cooling infrastructure at the site grew steadily. Most recently, two separate legacy systems were supplying the production facility with cooling water. "Our cooling infrastructure was no longer fit for purpose and required a high level of maintenance. One of the main units had already failed, which was increasingly compromising overall process stability," explains Christopher Hamann, Head of Production and Technology at qtec. Water quality presented an additional challenge. Contaminants were clogging the fine cooling channels in the injection moulding tools and impairing heat dissipation – directly affecting cycle time consistency and component quality. The new system needed to guarantee maximum operational reliability, energy efficiency, a sustainable overall concept, and a significant improvement in water quality.

Holistic concept as the deciding factor

When searching for a suitable solution provider, the choice fell on technotrans. The thermal management specialist stood out from the competition with a well-thought-out overall package that went far beyond simply providing the required cooling capacity. Two central requirements shaped the project planning: the new system should not only cool, but also support building heating through heat recovery – with the long-term goal of replacing the existing gas heating systems. In addition, qtec wanted a fully chemical-free cooling water treatment solution. On this basis, technotrans developed the overall technical concept and integrated a specialised system from partner Bauer WT Systems GmbH for the demanding water treatment requirements.

»For us, it was crucial to find an established partner who could deliver the technological expertise for such a complex project from a single source whilst also ensuring a high standard of service.«

Christopher Hamann
Head of Production and Technology,
qtec Kunststofftechnik GmbH

Energy-efficient and operationally reliable at all times

Technical solution// The centrepiece of the new solution is a central cooling system in a container design, installed in a space-saving manner outside the production hall. It delivers a cooling capacity of 380 kilowatts and is precisely tailored to qtec's process parameters – with a flow temperature of 20°C and a return temperature of 25°C.

The intelligent control system 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: large heat exchangers cool the process water directly using ambient air – without the need for the refrigeration machine's compressors to run. This significantly reduces electricity consumption for large parts of the year.

To ensure maximum availability, the system incorporates a multi-level safety concept: key pumps are installed redundantly, and the refrigeration machine has two independent refrigeration circuits. Should one circuit fail, the second still secures 50 per cent of total capacity – preventing a complete production shutdown.

»With this approach, we use the waste heat as the primary heat source and cover the base load for large parts of the year. This significantly reduces the load on the existing gas heating systems and lowers the CO₂ footprint.«

Maxim Retich
Sales Manager Cooling Solutions, technotrans solutions GmbH

Chemical-free water quality

Physically effective – without any chemicals

To address the specific problem of water contamination without the use of chemicals, technotrans integrated a treatment system from partner Bauer WT Systems GmbH. It operates using a purely physical process: high-frequency magnetic fields generate nano air bubbles in the water which – similar to carbonation bubbles in sparkling water – adhere to surfaces and form an effective barrier layer, preventing deposits of limescale, rust, and biofilm.

Sustainability

Heat recovery converts waste heat into heating energy

A further key component of the concept is heat recovery. It transforms the process cooling system from a pure energy consumer into a valuable energy source for the site. This is achieved technically by 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 the energy highly efficiently to the building's heating circuit. When heating is required in the building, the system activates this refrigeration circuit and heats the 5,000-litre buffer tank to up to 65°C. Once the target temperature is reached, the system shuts down the compressor and maximises free cooling performance. For the few production-free days over the Christmas shutdown, a supplementary electric heating solution is also planned.

»The consistently clean process water not only protects the tooling, but also allows us to operate the temperature control units without interruption and without the need for hard fresh water.«

Christopher Hamann
Head of Production and Technology, qtec Kunststofftechnik GmbH

Using waste heat.
Shaping the Future.

Results

Seamless implementation during ongoing production

qtec and technotrans successfully managed the transition to the new central cooling system whilst production continued – a particular challenge in three-shift operation. In advance of the switchover, technotrans provided extensive support in adapting the pipework network. Since commissioning in spring 2024, the system has been running consistently and without interruption.

The new cooling solution also prepares qtec for future growth, as technotrans factored in capacity reserves for a potential site expansion when designing the system.

The centrepiece of the technotrans solution is a central container-based cooling system supplying 30 injection moulding machines whilst simultaneously heating the building via integrated heat recovery.

To ensure maximum availability, technotrans designed the system with a multi-level safety concept. Key pumps are installed redundantly, and the refrigeration machine itself has two independent refrigeration circuits.

Numerous well-known customers rely on the quality of qtec's injection-moulded products.