Plate heat exchanger is a heat exchange device designed to transfer heat from a working fluid with a higher temperature to a working fluid with a lower temperature.
Heat exchangers are divided into recuperative and regenerative types based on the method of heat transfer. In recuperative heat exchangers, the working fluids are separated by a heat-conducting wall, usually made of steel, while in regenerative heat exchangers, they alternately come into contact with the same heat-accumulating surface.
Recuperative heat exchangers are divided into high-speed and storage types. In high-speed heat exchangers, heat transfer occurs only when the working fluids separated by a heat-conducting wall are moving, while in the storage type, it is enough for one working fluid to move through a heat-conducting coil located in a heat-accumulating container.
Shell-and-tube heat exchangers and plate heat exchangers belong to high-speed heat exchangers, while storage-type heat exchangers include storage water heaters.
This section presents high-speed recuperative heat exchangers of the water/water type.
In residential and administrative buildings, heat exchangers are used in boiler rooms and heat substations of buildings to connect heating systems on an independent circuit, as well as to heat water used in hot water supply systems.
In heating systems, heat exchangers are used in cases when the hydraulic regime of the heat source (heat network) does not correspond to the hydraulic regime of the building, for example, the pressure in the heat network is too low to supply water to the upper floor of the building, or so high that it can damage elements of the heating system that are not designed for such pressure.
In hot water supply systems, heat exchangers are used to heat circulating water in the heat network, which is technically unsuitable for domestic water supply, to suitable tap water and supply it to the hot water supply system.
In industry, heat exchange devices are used for heating and cooling liquid and gaseous media.