Heat exchanger section: [Weekly topic] How are heat exchange devices classified? (2011.6.24-6.26)

Heat exchange equipment can be classified by purpose, heat exchange method, structure, and material. a. By purpose, they can be divided into: (1) Heaters. The fluid is heated to the required temperature, but no phase change occurs in the heated fluid. (2) Preheater. Preheat the fluid to provide standard process parameters for subsequent operations. (3) Superheater. Used to heat a fluid (process gas or steam) to a superheated state. (4) Evaporator. It is used to heat a fluid to a temperature above its boiling point, causing the liquid to evaporate, usually accompanied by a phase change. (5) Reboiler. Used to reheat the condensed liquid in the device so that it can evaporate. (6) Cryocooler. Used to cool a fluid to a low temperature below 0°C. (7) Cooler. Used to cool the fluid to the temperature required by the process. (8) Condenser. Used to cool condensable gases, causing them to condense and liquefy. (9) Full condenser. Condense all gaseous substances completely into a liquid. b. According to the heat transfer method, they can be classified as: (1) Partition-type heat exchangers. Two fluids at different temperatures are allowed to flow in a space separated by a wall, and heat exchange between them occurs through heat conduction through the wall and convection of the fluids at the wall surface. (2) Regenerative heat exchanger. By means of a heat storage material made of a solid, heat is transferred from the high-temperature fluid to the low-temperature fluid. The heat storage material comes into contact with the high-temperature fluid for a certain period of time, absorbing and storing a certain amount of heat, and then comes into contact with the low-temperature fluid for a certain period of time, releasing that heat to the low-temperature fluid. (3) Fluid-connected indirect heat exchanger. A heat exchanger that connects two surface heat exchangers via a heat carrier circulating between them. (4) Direct-contact heat exchangers. It is a device in which two fluids come into direct contact for heat exchange. c. Based on structure and materials, they can be classified as: (1) Shell-and-tube heat exchangers. Casing-type, shell-and-tube type, immersion type, spray type, finned type. (2) Plate heat exchanger. Jacketed, flat-plate, plate-type, spiral-plate, finned-plate, shell-and-plate. (3) Heat exchangers made of new materials. Heat exchangers made of graphite, polytetrafluoroethylene, fiberglass-reinforced plastic, titanium, and zirconium. (4) Heat pipe heat exchanger. Multi-chamber rotary type, centrifugal type, gravity heat pipe type, centrifugal heat pipe type.

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I. Classification by principle: 1. Direct contact heat exchangers. The main working principle of these heat exchangers is that heat is transferred between two media through direct contact, thereby enabling heat transfer. The contact area has a direct impact on the amount of heat transferred. In such heat exchangers, one of the media is usually a gas and the other is a liquid. They are primarily heat transfer devices that utilize towers as their core structure; however, mass transfer also plays a role in them, which makes it difficult to distinguish their relationship with towers. As a result, they are generally classified as tower-type devices. Cooling towers used in power plants are the most typical example of direct contact heat exchangers. 2. Regenerative heat exchangers (abbreviated as regenerators): These types of heat exchangers are used very rarely. Their principle is that a hot medium first passes through a solid substance to reach a certain temperature, after which a cold medium passes through the same solid substance to be heated, thereby achieving the purpose of heat transfer. 3. Partition-type heat exchangers: These types of heat exchangers are used in very large quantities, accounting for over 99% of the total. The principle behind them is that the hot medium transfers heat to the cold medium through metals or non-metals. Such heat exchangers are commonly referred to as shell-and-tube, plate, plate-fin, or shell-and-plate heat exchangers. II. Classification by type of heat transfer 1. Heat transfer without phase change is generally divided into heaters and coolers. 2. There is phase-change heat transfer, which is generally divided into condensers and reboilers. Reboilers are further divided into kettle reboilers, siphon reboilers, reboilers, evaporators, steam generators, and waste heat boilers. III. Classification by heat transfer elements
1. Tubular heat transfer elements
(1) Floating-head heat exchangers
(2) Fixed-tube-sheet heat exchangers
(3) Packing-box heat exchangers
(4) U-tube heat exchangers
(5) Coiled-tube heat exchangers
(6) Double-pass heat exchangers
(7) Single-sheath heat exchangers
(8) Multi-sheath heat exchangers
(9) External guide-tube heat exchangers
(10) Baffle-rod heat exchangers
(11) Heat-pipe heat exchangers
(12) Inserted-tube heat exchangers
(13) Sliding-tube-sheet heat exchangers

2. Plate-type heat transfer elements
(1) Spiral-plate heat exchangers
(2) Plate heat exchangers
(3) Plate-fin heat exchangers
(4) Plate-shell heat exchangers
(5) Plate evaporators
(6) Plate condensers
(7) Printed circuit board heat exchangers

IV. Classification of heat exchangers made of non-metallic materials
(1) Graphite heat exchangers
(2) Fluoroplastic heat exchangers
(3) Ceramic fiber composite material heat exchangers
(4) Fiberglass-reinforced plastic heat exchangers

V. Classification of air-cooled heat exchangers
(1) Dry air coolers
(2) Wet air coolers
(3) Combined dry-wet air coolers
(4) Power plant air coolers
(5) Surface-evaporation type air coolers
(6) Plate air coolers
(7) Energy-recycling air coolers
(8) Natural-convection air coolers
(9) High-pressure air coolers
(10) Perforated plate heat exchangers

VI. Classification by heat transfer enhancement elements
(1) Threaded-tube heat exchangers
(2) Corrugated-tube heat exchangers
(3) Special-shaped tube heat exchangers
(4) Surface-porous tube heat exchangers
(5) Spiral flat-tube heat exchangers
(6) Spiral-groove tube-sheet heat exchangers
(7) Ring-groove tube heat exchangers
(8) Longitudinal-groove tube heat exchangers
(9) Helically wound tube heat exchangers
(11) T-fin tube heat exchangers
(12) New-structure high-efficiency heat exchangers
(13) Inserted-element heat exchangers
(14) Serrated-tube heat exchangers

Reply to 1# w9970165 by purpose and heat exchange method

I. Classification by structure 1. Shell-and-tube heat exchanger； 2. Plate heat exchanger ； 3. Extended surface heat exchangers (tube-fin, plate-fin type), etc. II. Classification by heat transfer process: 1. Indirect heat transfer heat exchangers; 2. Direct heat transfer heat exchangers. III. Classification by fluid flow pattern 1. Co-current heat transfer exchangers ； 2. Fluid counterflow heat exchanger ； 3. Fluid cross-flow heat exchanger ； IV. Classification by number of passes: 1 Single-shell and single-pass heat exchanger ； 2. Single-pass multi-tube heat exchanger ； 3 double-shell and multi-pass heat exchangers ； ---- V. Classification by fluid phase state 1. Liquid-liquid heat exchangers ； 2. Gas-liquid heat exchanger ； 3. Gas-to-gas heat exchanger. VI. Classification based on heat transfer mechanisms 1. Condensers ； 2. Evaporator ； 3. Heater ； 4. Coolers, etc. Wait.

Let’s learn this first; everyone, please discuss it among yourselves

Reply to 2# ray1513: I. By purpose – Heaters are used to heat a fluid to the required temperature, but no phase change occurs in the fluid during this process； Preheater – Preheats the fluid to provide standard process parameters for subsequent operations ； Superheater – used to heat a fluid (process gas or steam) to a superheated state ； Evaporator – used to heat a fluid to a temperature above its boiling point, causing the fluid to evaporate; generally involves a phase change ； Reboiler – used to reheat the liquid that has condensed in the device, causing it to evaporate ； Cryocooler – used to cool a fluid to temperatures below 0ºC ； Cooler – used to cool a fluid to the temperature required by the process ； Condenser – used to cool condensable gases, causing them to condense and turn into a liquid state ； Total condenser – converts all gaseous substances that can be condensed into liquid form. II. By heat exchange method: Shell-and-tube heat exchangers – Two fluids with different temperatures flow in spaces separated by wall surfaces; heat exchange between these fluids occurs through heat conduction through the walls and convection of the fluids at the wall surfaces ； Regenerative heat exchanger – Utilizes a solid-based heat storage material to transfer heat from a high-temperature fluid to a low-temperature fluid. The heat storage material comes into contact with the high-temperature fluid for a certain period of time, absorbing and storing heat, and then comes into contact with the low-temperature fluid for a certain period of time, releasing that heat to it ； Fluid-connected indirect heat exchanger – a heat exchanger that connects two surface heat exchangers through a heat carrier that circulates within them ； Direct contact heat exchangers – are devices in which two fluids come into direct contact to exchange heat. III. By Structure and Material: Shell-and-tube heat exchangers – double-pipe type, shell-and-tube type, submerged type, spray type, finned type ； Plate heat exchangers – jacketed, flat-plate, plate type, spiral plate, finned plate, shell-and-plate ； Heat exchangers made of new materials — heat exchangers made of graphite, PTFE, fiberglass-reinforced plastic, titanium, and zirconium ； Heat pipe heat exchangers – multi-chamber rotary, centrifugal, gravity heat pipe, and centrifugal heat pipe types. This article is from: Machinery Repair Network (www.imqd.com). For the detailed source, see: http://www.imqd.com/article/huagong/201011/9079.html

1. Classification by purpose: The various heat exchange devices used in chemical production can be divided into the following categories based on their functions and purposes. (1) Cooler. (2) Condenser. (3) Heater. (4) Heat exchanger. (5) Reboiler. (6) Steam generator. (7) Waste heat (or excess heat) boiler. 2. Classified by heat exchange method, they can be divided into three categories: shell-and-tube type, direct contact type, and regenerative type.

Replies to 1# w9970165: There are three types: 1. Direct mixing heat exchangers: Common equipment includes cooling towers, spray-type cooling towers, and mixing condensers. 2. Indirect heat exchangers: Common types include jacketed, shell-and-tube, coiled-tube, plate-fin, and double-pipe heat exchangers. 3. Thermal storage type: Primarily used for utilizing waste heat and cold energy from gases