page_title: Plate heat exchanger
section_title: Flow distribution and heat transfer equation
hierarchical_section_title: Plate heat exchanger / Flow distribution and heat transfer equation
caption_attribution_description: English: Fig. 1. Manifold arrangement for flow distribution
context_page_description: A plate heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between two fluids. 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 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 flowrate of combination boilers. The small plate heat exchanger has made a great impact in domestic heating and hot-water. Larger commercial versions use gaskets between the plates, whereas smaller versions tend to be brazed.
  The concept behind a heat exchanger is the use of pipes or other containment vessels to heat or cool one fluid by transferring heat between it and another fluid. In most cases, the exchanger consists of a coiled pipe containing one fluid that passes through a chamber containing another fluid.
context_section_description: Design calculations of a plate heat exchanger include flow distribution and pressure drop and heat transfer. The former is an issue of Flow distribution in manifolds. A layout configuration of plate heat exchanger can
  be usually simplified into a manifold system with two manifold
  headers for dividing and combining fluids, which can be
  categorized into U-type and Z-type arrangement according to
  flow direction in the headers, as shown in manifold arrangement. Bassiouny and Martin developed the previous theory of design. In recent years Wang  unified all the main existing models and developed a most completed theory and design tool.
  The total rate of heat transfer between the hot and cold fluids passing through a plate heat exchanger may be expressed as:
  Q = UA∆Tm
  where U is the Overall heat transfer coefficient, A is the total plate area, and ∆Tm is the Log mean temperature difference. U is dependent upon the heat transfer coefficients in the hot and cold streams.
caption: Manifold arrangement for flow distribution
exif: {}