Plate Heat Exchangers were first produced in the 1920s and have since been widely used in a great number of sectors.This type of heat exchanger that uses metal plates to transfer heat between two fluids.A plate exchanger consists of a series of parallel plates that are placed one above the other so as to allow the formation of a series of channels for fluids to flow between them.The space between two adjacent plates forms the channel in which the fluid flows.
This has a major advantage over a conventional heat exchanger in that the fluids are exposed to a much larger surface area because the fluids are spread out over the plates. This facilitates the transfer of heat, and greatly increases the speed of the temperature change. Plate Type heat exchangers are now common and very small brazed versions are used in the hot-water sections of millions of combination boilers. The high heat transfer efficiency for such a small physical size has increased the domestic hot water (DHW) flowrate of combination boilers. The small plate heat exchanger has made a great impact in domestic heating and hot-water.
Optimization of Plate Heat Exchangers
To achieve improvement in Plate Heat Exchangers, two important factors namely amount of heat transfer and pressure drop have to be considered such that amount of heat transfer needs to be increased and pressure drops need to be decreased. In plate heat exchangers due to presence of corrugated plate, there is a significant resistance to flow with high friction loss. Thus to design plate heat exchangers, one should consider both factors. For various range of Reynolds numbers, many correlations and chevron angles for plate heat exchangers exist.The shape of plate heat exchanger is very important for industrial applications that are affected by pressure drop.
The plate geometry is one of the most important factor in heat transfer and pressure drop in plate heat exchangers, however such a feature is not accurately prescribed. In the corrugated plate heat exchangers, because of narrow path between the plates, there is a large pressure capacity and the flow becomes turbulent along the path.Therefore, it requires more pumping power than the other types of heat exchangers.Therefore, higher heat transfer and less pressure drop are targeted. An important aspect to take into account when evaluating a heat exchanger are the forms of corrugation within the heat exchanger.