The customer

The GARDENA Manufacturing GmbH in Gerstetten near Ulm is the production facility for injection molding of components being part of the Gardena group. Gardena again is a subsidiary of the Husqvarna Group and a global leader in gardening technology. GARDENA is characterized by innovative strength, high brand quality and high user benefit. It is a worldwide recognized manufacturer of intelligent products and systems for garden irrigation and maintenance. At the site in Gerstetten, components are mass-produced for over 60 years.

Project and implementation

The task of the project was to ensure the cooling of an extruder for the production of garden watering tubings, which are to be produced with high quality at low cost. Due to different product recipes and resulting changes in heat load and temperature control, this extruder should not be connected to the central cooling water supply.
What was needed was a chiller for chilled water production in the temperature range between 16 °C and 20 °C with a capacity of 30 kW. Further criteria were the installation as close as possible to the extruder, integrated free cooling to reduce energy costs and the use of an environmentally friendly and sustainable refrigerant. The eChiller was able to meet all of these requirements and in July 2017 commissioning took place.

Result

Since the commissioning, the eChiller has been in continuous operation at Gardena Manufacturing GmbH. The operator on site confirms the ease of use when changing the product and thus changing flow temperatures between 16 °C and 18 °C, depending on the dimension. After one year of operation, an annual work count (SEER) of over 16 was recorded by the eChiller Monitoring.

The eChiller is also convincing in its long-term operation by fulfilling all project requirements as well as ecological and economical goals.
The proximity to the extruder allows the direct interaction of the operator according to the production needs. The short piping reduces the pump size and thus the pump energy consumption. The adjusted setpoint temperature increases the operating hours in the Free cooling mode and the Free cooling+ of the eChiller. Unlike with other natural refrigerants, using the safety refrigerant water (R718), the site of installation can be chosen freely without noise, vibration, personal or environmental risks.
Semi-central cooling has been implemented with product and production-related cooling, which minimizes standby energy consumption. Temperatures and cooling energy are produced on a production-related basis. This is also supported by an integrated, stepless control system, which ensures the ideal switching between the operating modes. Read more about the smart control of the eChiller model range in the article of our PLC supplier.

Since the production of the extruder is already working to capacity, extensions of the premises are considered.

Technical facts
Cooling capacity (kW)approx. 25 to 30 kW. Depending on the piping dimension
Set temperatureChilled water supply 18 °C
RefrigerantR718 (Wasser)
Coolant inlet40 °C
Sound power68.6 dB (A), pressure level in 5 meters: 42 dB (A)
CoolingAir-cooled dry cooler