A plate heat exchanger is a key component in industrial thermal engineering that transfers heat between two media—typically liquids or gases—without direct contact. This is achieved through a series of thin metal plates arranged in parallel, with the media flowing in separate channels between them.

Heat exchanger or heat transfer device?

In everyday language, the term “heat exchanger” is commonly used to refer to a device that transfers heat between different media. Technically, however, the correct term is “heat transfer device”.

Structure and operating principle

The plates are typically made of corrosion-resistant stainless steel and feature special embossing patterns that enhance the turbulence of the flowing media. This improves heat transfer efficiency. The media flow in opposite directions (counterflow principle), which further optimizes heat exchange.

Application in high-temperature heat pumps

In industrial applications, particularly in high-temperature heat pumps, plate heat exchangers play a crucial role. High-temperature heat pumps can recover unused waste heat from production processes and convert it into process heat in the form of steam and hot water at temperatures up to 200°C. These industrial heat pumps improve energy efficiency and reduce CO₂ emissions. In these systems, plate heat exchangers function as both evaporators and condensers:

• Evaporator: Here, the refrigerant of the heat pump absorbs heat from an external source (e.g. waste heat) and evaporates. The plate heat exchanger enables effective heat absorption due to its large surface area and induced turbulence.
• Condenser: The now gaseous refrigerant is compressed, increasing its temperature. In the condenser, it releases the absorbed heat to the target medium and condenses back into a liquid. Again, the plate heat exchanger ensures efficient heat dissipation.

Advantages of plate heat exchangers

• High efficiency: The large heat transfer surface and turbulence allow for maximum heat exchange.
• Compact design: Plate heat exchangers require less space than other heat exchanger types with similar capacity.
• Flexibility: The number of plates can be easily adjusted to meet required performance needs.
• Easy maintenance: Plates can be easily removed for cleaning or replacement, simplifying maintenance.

Thanks to these properties, plate heat exchangers are particularly well-suited for high-temperature heat pumps used in industrial process heat generation. They help optimize energy use and reduce operating costs.