Tube bundle heat exchangers utilize waste heat

Utilizing thermal energy from gas compression

Compressed air generation is automatically associated with a lot of heat energy. It is created both in the generated air flow and under the acoustic hood by the waste heat from the motor, silencer and compressor. In the past, it often remained unused. In view of the growing interest in ecological sustainability and economic cost awareness, system operators are increasingly looking at heat recovery.

This development is gathering pace - also due to attractive return-on-investment times, which are often less than two years. As a manufacturer of high-performance compressors, Aerzen knows the challenges and implements solutions that use the thermal energy generated during the compression of gases as effectively as possible.

Energy-saving process air generation

There are basically 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 space heating of adjacent office areas or production areas. However, the greatest waste heat potential lies dormant in the pressure-side gas flow itself. Up to 85 percent of the electrical energy is tied up there in the form of heat.

Here, the use of shell and tube heat exchangers opens up an energy source with significantly higher temperatures. This opens up many possible applications. Typical applications include supporting heating systems, heating water for showers and washrooms and heating service water in industrial environments. In wastewater technology, the heat is also used to support sewage sludge drying. 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.

Customized systems for heat recovery

The basis for optimal waste heat utilization is the determination of the available heat quantity. It 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 tailors its heat recovery solutions precisely to the customer-specific application. This means that a large proportion of the electrical energy used to generate compressed air can be recovered and the overall efficiency of compressed air generation can be increased.

Low investment, high resource efficiency

The investment costs for a heat recovery system are relatively low and are quickly offset by the energy savings. Compressed air systems with long running times benefit in particular. If the system achieves high capacity utilization, it is worthwhile even with low waste heat quantities. Older compressed air systems can be energy-optimized and retrofitted without great effort.