InvenSor cooling container produces sustainable energy for an international plastic enterprise

December 6, 2018

With over 130 years of history, Busch-Jaeger has come to be the market leader in the field of electrical installation technology. At the same time, the company places great value on sustainability: it has firmly integrated quality, environmental, work, health and energy management into its business strategy. Within the fields of energy and the environment, Busch-Jaeger has - among other things - concentrated on optimising the cooling system for its own 100 injection moulding tools and made the decision to invest in a new, innovative energy system. This has led to a reduction in CO² emissions of 381 tonnes per year, as well as a considerable reduction in energy costs.

This has all been thanks to a system which generates power, heat and cooling (a trigeneration system); which is made up of seven aDsorption chillers from the clean tech company InvenSor and a combined heat and power unit (CHP unit). Based on this configuration, power, heat and cooling is now generated by Busch-Jaeger Elektro (BJE) at its Bad Berleburg location. The CHP unit serves as a heat source, providing the aDsorption chillers with the waste heat they require to generate cooling.

Creating the new energy system

Before the new energy system was introduced, BJE used a compression chiller with a cooling capacity of 211 kW to cool their injection moulding tools. Emergency cooling was carried out with water from the municipal mains system. If the chiller would break down, 500 m³ of fresh water would be required per day for cooling. As this amount of water could only be made available by the local energy provider for a maximum of three days, this meant that production losses were a real possibility. The company did not want to take this risk any longer. Furthermore, as the existing chiller was dated anyway, the decision to make it over to be as energy efficient as possible was the logical conclusion.

The CHP supplies BJE with heat and power

Lucas Bergmann, Energy Manager at Busch-Jaeger Elektro GmbH, had investigated the potential of trigeneration systems as part of his Master’s degree thesis. These systems then made the shortlist thanks to the economic advantages which they present, such as reduced power and maintenance costs. As the use of thermally-driven chillers is being subsidised by the Federal Office for Economic Affairs and Export Control and, as water is used as the refrigerant—completely excluding any risk to the environment—the decision was ultimately made to use aDsorption technology. “We no longer considered simply exchanging the traditional cooling system for a new one, above all because, although the investment costs for an absorption chiller are almost identical, the maintenance and operating costs would have been considerably higher,” said Lucas Bergmann. A sophisticated energy concept was developed in cooperation with Edin Gracic from planning office Gertec GmbH. The base cooling load was 160 kW, with a peak load of 211 kW. A heat output of 230 kW was required for the aDsorption chillers; an output which the “agenitor 306” CHP unit from 2G, which had already been installed and which boasts a thermal output of 290 kW and an electrical output of 250 kW, covered as the heat source. The estimated runtime of the CHP unit amounts to approx. 7000 hours a year. Now, all they had to do was find a suitable cooling systems manufacturer.

Requirements implemented efficiently

InvenSor cooling container with the aDsorption chillers

It was during the planning phase of this project that contact arose between Busch-Jaeger and InvenSor. As part of a reference visit, Hendrik Gillert, Account Manager for the north-west region of Germany at InvenSor, presented Mr Bergmann and Mr Gracic with the cooling system, along with seven InvenSor aDsorption chillers and a CHP unit, in more detail. The technical advantages of such an energy system were quickly recognised. BJE decided upon four InvenSor LTC 30 e plus units and three InvenSor HTC 18 plus units, each with an integrated free-cooling function. The chillers deliver a flow temperature of 9°C and a return temperature of 14°C. It is imperative that the free-cooling function is used, so that additional, substantial energy savings can be made. This function allows for chilling directly above the ambient air, meaning that the waste heat is available, e.g. for heating purposes in winter.

A dry recooling unit, which is to be simultaneously used as a free cooler, was selected for recooling. The heat emission is achieved through convective heat transfer to a forced air flow. The dry recooler is a self-contained system without water and no hygiene controls are needed. It works quietly and is simple to operate.

From cogeneration to trigeneration

As the heating room in Bad Berleburg was too small for a cogeneration solution, Busch-Jaeger specified the delivery of a turn-key container solution. Based on this, InvenSor developed a tailor-made container under the leadership of Product Manager Oliver Tamm. The seven aDsorption chillers were installed inside the container, while the recooler, with a weight of 3400 kg, was placed on the roof, along with a maintenance platform. “This project is very unique for us because the container had to fit perfectly between two buildings, meaning that we were dealing with a special construction,” explained Mr Tamm. The container unit is 8.60 m long and 3.0 m wide. Furthermore, it contains all the components which are important for the smooth operation of the cooling system.

The planned operating time of this system is approx. 20 years. It saves a total of 381 tonnes of CO² per year. After 20 years, that makes a phenomenal 7620 tonnes. A concept with high ecological value. “We achieved our goal; the chillers are working perfectly. What makes the trigeneration solution special is the fact that it can be easily projected onto other locations and industrial companies,” added Mr Bergmann.

About Busch-Jaeger Elektro GmbH

In 1879, the brothers Hans-Curt Jaeger and Georg Jaeger founded a metal goods factory in Lüdenscheid, Germany. In the beginning, they only manufactured simple electronic installation material. In the meantime, the company now successfully produces, sells and exports around 5,500 articles to more than 60 countries around the world from its two locations in Germany. In doing so, their array of products ranges from complete electronic installation programmes all the way to high-end electronic products for facility management. The company stands out as a high-powered manufacturer based on its outstanding quality and its many years of experience.

Technical details of the system

Cooling system 7 InvenSor aDsorption chillers with a nominal cooling capacity of 174 kW
Driving heat CHP „agenitor 306“ 2G Energy AG with outputs of 290 kW th.  / 250 kW el.
Operating since 2016