The evaporator is a key component in the refrigeration cycle of industrial heat pumps used for generating process heat. In this component, a refrigerant in a liquid state at low pressure is transformed into a gaseous state by absorbing ambient or waste heat—essentially evaporating. This phase change enables efficient heat extraction even at relatively small temperature differences. Additionally, evaporation allows for the transfer of significant amounts of heat over small heat exchanger surfaces, making the evaporator compact in design. The evaporator is specifically adapted to different heat source temperatures, whether low, such as waste heat from chillers, or high, such as waste heat from production processes.

Design and operating principle

An evaporator typically consists of tube bundles or plates through which the refrigerant flows—this is the cold side that absorbs heat. On the warm side (referred to as the heat source), water or a water-glycol mixture circulates around the tubes or through the plates, cooling down in the process. The refrigerant uses the extracted energy to evaporate. A precise balance of pressure, temperature, and flow rates is essential to ensure stable and efficient operation. The design details of the evaporator significantly influence the overall performance of the heat pump, which is particularly crucial in industrial applications requiring consistent and high levels of process heat.

Importance in process heat generation

In industrial environments, the efficient use of available heat sources is becoming increasingly important. The integration of an optimally designed evaporator plays a crucial role in improving the cost-effectiveness and sustainability of industrial heating processes. High-temperature industrial heat pumps typically do not use environmental heat but instead recover waste heat from production processes, converting it into usable process heat with high efficiency. This results in a significant increase in energy efficiency and reduces the reliance on fossil fuels, along with the associated CO₂ emissions.

Conclusion

In summary, the evaporator is an essential component of industrial heat pumps. By converting the refrigerant from a liquid to a gaseous state, it forms the foundation for efficient heat generation. The technically optimized design and precise control of operating parameters are key to the successful utilization of process heat in modern industrial applications, driving both the ecological and economic decarbonization of industrial processes.