A plate heat exchanger is a type of heat exchanger, which is also known as a heat transfer carrier. During its operation, heat exchange does not occur directly, but rather heat is transferred from one medium to another. The plate heat exchanger consists of corrugated plates that are assembled in a unique way, with gaps between the plates.

In these intermediate dimensions, two media circulate alternately: the heat absorption medium and the heat diffusion medium. The device is sealed both externally and underneath the media, which can be achieved in various ways. There are heat exchangers with screw plates, which are expandable and transfer flow differently.

There are various types of plate heat exchangers, with preferred types being those in which the different plates are welded together.