Most manufacturers supply heat exchangers with L, M or H herringbone patterns, or in a combination of L + M or M + H. Smaller board thickness increases efficiency but reduces The next factor determining the efficiency of the exchanger is the thermal conductivity. Which encapsulates both circuits, thus having 4 connections in total. This approach only makes sense for small flow rates, as Pressure losses can be reduced by increasing the numberĪnother improvement in efficiency can be achieved by placing two exchangers in a However, more efficient heat exchangers have Temperatures of primary-secondary circuits). The longer the heat exchanger, the greater the efficiency (approaching the If the number of plates and the flow rates double, then the transmitted capacity also With increasing number of plates, it is necessary to increase the flow rates. Initially, the performance increases, further addition of plates The graph illustrates: Heat exchanger plates countīy increasing the plates count, the performance can undoubtedly be EachĪdditional increase in heat exchanger efficiency is more and more expensive, as In many applications, it is not worth aiming towards extremeĮfficiency, as unused heat is not waste, but returns to the source. When designing the heat exchanger, the optimum between price and efficiency Opened and cleaned, and it is also possible to additionally increase their For gasketed heatĮxchangers, a rubber seal is used instead of solder. Solder also participates in heat exchange. Solder (copper, nickel) is usually used to seal the individual chambers between plates. The media are separated by plates and cannot get mixed. The hot or cold medium flows alternately in every other layer and Plates are arranged in the exchanger so that the two independent flows are As a result, the plate heat exchanger has a self-cleaning ability. Such design also brings turbulence in theįlow. To increase the heat exchange area, the plates are ribbed and the media flow Stainless steel, mostly AISI 316 with a thickness of 0.5 mm. Layers: a circuit of hot and cold medium alternates. Inside the heat exchanger, the plates are stacked in many To achieve high heat exchanger efficiency, it is necessary to provide a large If the two media were mixed in a container. Practice, this means that the cold side is heated to a higher temperature than
Typically, efficiencies greater than 90% are achieved. However, a plate heat exchanger is the most efficient A real heat exchanger does notĪchieve such efficiency. The ideal exchanger has an efficiency of 100%. A great approximation of primary-inlet and secondary-outlet temperatures can be achieved. Heat exchanger efficiency when connected as countercurrent and cocurrent: the efficiency of the exchanger is much higher when connected in countercurrent. Pressure losses can be reduced byĪdding the number of plates: doubling the number of plates will reduce the Long exchanger also puts up more resistance and a more powerful pump will be
Thanks to the countercurrent connection, primary-inlet and the secondary-outlet temperatures can almost be met. If the plates are long, then the heat is transferred over a long length and, Such a connection, it is much more efficient than with a cocurrent connection. The heat exchanger is usually connected in countercurrent.
It is necessary to assess a specific application. Performance depends on a number of parameters and Specified for a given heat exchanger type: one heat exchanger can carry 20 orġ00 kW depending on the temperatures and media used. Performance is what most users are most interested in. it changes from the gas phase to the liquid phase). condenser (the refrigerant in the exchanger condenses, i.e.it passes from the liquid to the gaseous phase), or evaporator (the refrigerant evaporates in the exchanger, i.e.Sometimes the phase changes in the exchanger:.Without a phase change: typically water/water for heating or as oil/water cooler.Plate thickness and channel patterns (H, M or L)Ĭustomers usually request heat exchangers for equipment.Principle and capacity of heat exchangers