Product Details
I. Definition
Heat exchangers, also known as heat exchange devices, 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 Exchanger A shell-and-tube heat exchanger involves two fluids of different temperatures flowing in separate spaces separated by the wall. Heat transfer occurs between the fluids through conduction through the wall and convection at the wall surface.
2. Heat Storage Heat Exchanger: The heat storage heat exchanger utilizes a heat storage medium composed of solid substances to transfer heat from a high-temperature fluid to a low-temperature fluid. The heat medium first heats the solid substance to a certain temperature, and then the cold medium is heated through the solid substance to achieve the purpose of heat transfer.
3. Indirect Fluid Connection Heat Exchangers - These are heat exchangers that connect two surface heat exchangers via a circulating heat carrier. The heat carrier 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 double-effect heat exchanger that combines both surface-type indirect heat exchange between steam and water and direct mixed flow heat exchange between water. Compared to the surface-type indirect heat exchange between steam and water, it boasts higher heat exchange efficiency; compared to direct mixed heat exchange between steam and water, it offers greater stability and lower unit noise.
Section 3: Categorized by Application
1. A heater is a device used to heat fluids to the necessary temperature without causing a phase change in the fluid.
2. The preheater preheats the fluid, providing standard process parameters for the operation.
3. Superheater - Used to superheat fluids (process gas or steam) to a superheated state.
4. Evaporator - An evaporator is used to heat a fluid to temperatures above its boiling point, causing it to evaporate, usually involving a phase change.
Section 4: Categorized by Structure
They can be categorized into: floating head heat exchangers, fixed tube sheet heat exchangers, U-tube heat exchangers, plate heat exchangers, etc.
