Cost-effective compressed air generation thanks to efficient heat recovery

AERZEN offers custom-fit solutions for optimum use of waste heat

01/07/2023

Especially in compressed air generation, measures to save energy really make sense - after all, expenditures for energy represent the largest part of the life cycle costs of blowers and compressors. By recovering the heat generated in the compression process, operators can save energy and significantly increase their competitiveness. AERZEN knows what matters and implements efficient heat recovery systems which pay for themselves within a very short time.

Due to thermodynamics, compressed air generation automatically involves a large amount of heat energy. It arises not only in the generated air flow, but also under the acoustic hood due to heat loss from the motor, silencer and compressor. In the past, it often remained unused. However, in view of the growing interest in ecological sustainability and business cost awareness, plant operators are looking at heat recovery with increasing attention. This development is accelerating, also due to attractive return on investment times, which are often less than two years. As manufacturer of high-performance compressors, AERZEN is well aware of the challenges and implements innovative solutions which make the most effective use of the thermal energy generated during the compression of gases.

Energy-saving process air generation

Basically, there are two options for heat recovery when operating blowers, rotary lobe and screw compressors or turbo blowers: the thermal energy from the pure exhaust air can be used most effectively for direct room heating of adjacent office areas or production areas. However, the greatest waste heat potential lies dormant in the discharge-side gas flow itself. Up to 85% of the electrical energy is bound there in the form of heat. Here, the use of pipe bundle heat exchangers opens up an energy source with significantly higher temperatures. This results in a multitude of possible applications in implementation. Typical applications are the support of heating systems, the preparation of hot water for showers and washrooms, and the heating of service water in industrial environments. In wastewater technology, the heat is also used to support the sludge drying process. When planning such systems, it is important to ensure that the heat exchanger is designed for the required heat quantity or temperature of the heat sink and that the pressure losses of the heat exchanger are kept as low as possible.

Customised systems for heat recovery

The basis for optimal waste heat utilisation is the determination of the available heat quantity. This depends on the usable temperature difference, the mass or volume flow, the time availability and the specific heat capacity of the heat transfer medium. AERZEN therefore tailors its smart heat recovery solutions precisely to the customer's individual application. In this way, the electrical energy used for compressed air generation can be recovered to a large extent, and the overall efficiency of compressed air generation can be increased.

Minimum investment costs, maximum resource efficiency

The investment costs for a heat recovery system are relatively low and quickly offset by the energy savings. Compressed air systems with long running times benefit the most. If the plant achieves a high utilisation rate, it is worthwhile even with low waste heat quantities. Older compressed air systems can be energetically optimised and retrofitted without much effort.