Radeberg GmbH: Energy-saving plan successfully implemented, mandatory energy-saving program
Given the federal government’s ambitious goal of reducing CO2 emissions by 40% by 2020 compared to 1990 levels, energy-intensive businesses in particular may soon face a mandatory energy-saving program! Energy management and energy audits have already become driving forces behind a comprehensive energy-saving policy in a large number of companies. Currently, the obligation to establish an energy management system and continuously implement energy-saving measures applies only to companies that wish to take advantage of the so-called peak compensation under Section 55 of the Energy Tax Act and Section 10 of the Electricity Tax Act. In the future, this requirement may become mandatory for all companies. In any case, all non-SMEs are required to conduct an energy audit in accordance with DIN EN 6247 within their company by December 5, 2015. One thing is certain: through these initiatives, companies will for the first time receive comprehensive and detailed information on their energy situation—comparable to a company-specific energy inventory—within their own organization. This transparency naturally also creates opportunities to address problem areas in a highly targeted manner.
One step ahead
The example of Gießerei Radeberg GmbH impressively demonstrates how to successfully implement an energy-saving plan! With a strong partner at their side, they have been able to significantly reduce both energy costs and environmental impact at the same time.
For example, energy paid for once is used as efficiently as possible! Innovative and successful in its core business, the company recognized global development trends early on and, in addition to its core business, optimized all areas of the company with a forward-looking approach and entrepreneurial foresight.
Specifically, the previously operated cooling system, which was supplied with cooling energy via an open cooling tower, was replaced by a new cooling system equipped with a closed, glycol-free air cooler as a recooler.
This change immediately yields a number of benefits for the plant operator.
Constant operating conditions
In a production facility such as the Radeberg foundry, consistent and reliable operating conditions are crucial. With the cooling system previously in use—which featured an open cooling tower—the facility had to adapt to temperature fluctuations caused by seasonal changes. In addition, the costs of water treatment and the chemicals added to the cooling circuit water had risen steadily over the years. Another issue arises from the newly formulated requirements regarding the hygienic safety of such systems, which are summarized in VDI 2047 Part 2, “Recooling Plants; Ensuring Hygienic Operation of Evaporative Cooling Systems (VDI Cooling Tower Rules).”
The ideal solution to this problem was the conversion from an open to a closed cooling water system. In place of the cooling tower system, a glycol-free, self-draining open-loop cooling system was installed as a recooling unit. In the new system, the circulating water no longer comes into contact with the atmosphere, requires a significantly reduced amount of water treatment chemicals, and ensures constant temperature conditions in the cooling circuit. Furthermore, the closed system opens up the possibility of further utilizing waste heat for heating purposes.
Even though primary energy prices have fallen slightly in the meantime, energy costs have become a significant factor in companies’ cost structures. In this regard, we all certainly want the ability to use the energy we consume efficiently and as fully as possible. Gießerei Radeberg GmbH demonstrates how this can be impressively achieved in practical operation. The ability to use energy efficiently is made possible by the use of an ONI heat recovery system. Specifically, cooling water is required for the peripherals of the melting facilities at Gießerei Radeberg. At full capacity of the melting facilities, approximately 650 kW of cooling capacity must be provided by the recooling system. On the other hand, as in other foundries, there is a need to supply fresh air to the melting furnace area to ensure the necessary air exchange. While this is not a problem during the summer months, heating the fresh air is absolutely necessary during the transitional and winter months. In many cases, this fresh air is then heated using expensive primary energy sources such as heating oil or natural gas. In Radeberg, this problem is solved through the use of a clever concept.
The waste heat from the process cooling system, which would normally be discharged into the environment via the recooling units, is used as free heating energy at the Radeberg foundry. To achieve this, the cooling water—after being heated in process components—is not sent to the recooling units, but is first directed to the heating coils of a ventilation system.
Instead of releasing this energy unused into the environment, the waste heat is used to heat fresh air, which is blown into the production hall via a newly installed ventilation system. In this way, free waste heat is converted into valuable heating energy that replaces heating oil or natural gas. The use of waste heat for heating purposes results in additional savings. The energy previously required for recooling is eliminated, at least to a large extent, during the transitional and winter months.
Of course, implementing such energy-saving concepts does not come for free. However, the investments required for these measures pay off in a relatively short time. With the energy concept currently being implemented, the management of Gießerei Radeberg GmbH demonstrates how a successful and innovative company with customers throughout Europe can also set an example in energy efficiency while making a significant contribution to environmental protection. As a result, both the economy and the environment at Gießerei Radeberg GmbH in Radeberg benefit ideally from innovative and sustainable energy-saving technology from ONI.
