Product Details
I. Definition
Heat exchangers, also known as heat exchanges, are devices that transfer a portion of heat from a hot fluid to a cold fluid. They play a crucial role in chemical, petrochemical, power, food, and many other industrial production processes. In chemical production, heat exchangers can serve as heaters, coolers, condensers, evaporators, and reboilers, with wide applications.
II. Classified by Heat Transfer Principle
1. Shell-and-tube heat exchangers operate by allowing two fluids of different temperatures to flow in separate spaces separated by a wall. Heat transfer occurs between the fluids through the wall's conduction and convection at the wall surface.
2. Regenerative Heat Exchangers - These heat exchangers utilize a regenerative body made of solid material to transfer heat from a high-temperature fluid to a low-temperature fluid. The heat medium first heats the solid material to a certain temperature, and then the cold medium is heated through the solid material to achieve the heat transfer goal.
3. Indirect Fluid Connection Heat Exchangers - These are heat exchangers that connect two surface-type heat exchangers through a circulating heat medium. The heat medium circulates between the high-temperature fluid heat exchanger and the low-temperature fluid, absorbing heat from the high-temperature fluid and releasing it to the low-temperature fluid.
4. Direct-contact heat exchangers, also known as mixed-flow heat exchangers, are devices where two fluids come into direct contact and mix for heat exchange. Examples include cooling towers and gas condensers.
5. A dual heat exchanger that combines both surface-to-surface indirect heat exchange and direct water-to-water mixing heat exchange methods. Compared to the surface-to-surface indirect heat exchange, it offers higher heat exchange efficiency; compared to direct water-to-water mixing heat exchange, it has higher stability and lower unit noise.
Section 3: Categorized by Application
1. A heater is used to heat a fluid to the required temperature without causing a phase change in the heated fluid.
2. The preheater preheats the fluid, providing standard process parameters for the operation.
3. Superheater - Used to superheat fluids (process gas or steam).
4. Evaporator - Used for heating fluids to temperatures above their boiling point, causing the fluid to evaporate, typically involving a phase change.
IV. Categorized by Structure
They can be categorized into: floating head heat exchangers, fixed tube sheet heat exchangers, U-tube plate heat exchangers, plate heat exchangers, etc.
