Search results
Results from the WOW.Com Content Network
A shell-and-tube heat exchanger is a class of heat exchanger designs. [1] [2] It is the most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes ...
The number of transfer units (NTU) method is used to calculate the rate of heat transfer in heat exchangers (especially parallel flow, counter current, and cross-flow exchangers) when there is insufficient information to calculate the log mean temperature difference (LMTD). Alternatively, this method is useful for determining the expected heat ...
The Tubular Exchanger Manufacturers Association (also known as TEMA) is an association of fabricators of shell and tube type heat exchangers. [1] TEMA has established and maintains a set of construction standards for heat exchangers, known as the TEMA Standard. [ 2 ]
Typical approaches to achieve this consist of corrugating the tubes or plates or extending their surface with fins. However, these geometry conformation technologies, the calculation of optimum mass flows and other turbulence related factors become diminished when fouling appears, obliging designers to fit significantly larger heat transfer areas.
Tubular heat exchanger Partial view into inlet plenum of shell and tube heat exchanger of a refrigerant based chiller for providing air-conditioning to a building. A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. [1]
For the Pohlhausen solution for laminar flow on a heated flat plate, [10] it is found that thermal boundary layer thickness defined as = + where = /, tracks the 99% thickness very well. [ 11 ] For laminar flow, the three different moment cases all give similar values for the thermal boundary layer thickness.
Concentric Tube (or Pipe) Heat Exchangers are used in a variety of industries for purposes such as material processing, food preparation, and air-conditioning. [1] They create a temperature driving force by passing fluid streams of different temperatures parallel to each other, separated by a physical boundary in the form of a pipe.
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. [2]