Tubular Heat Exchangers
Tubular waste heat recovery heat exchangers are a common structural type, mainly composed of tube bundles, tube sheets, and shells. The tube bundle is the core component, consisting of numerous metal tubes. The hot medium flows inside the tubes, while the cold medium flows outside the shell. Heat is conducted through the tube walls, achieving heat exchange.
The tube sheet fixes the tube bundle and separates it from the shell, ensuring that the two media flow along predetermined paths. The shell encloses and protects the internal tube bundle, while also guiding the cold medium to flow around the tube bundle efficiently, creating a favorable thermal convection environment. Depending on the application, tubular heat exchangers can be further subdivided into fixed tube sheet type, floating head type, and U-tube type, each with its own characteristics in terms of handling thermal expansion and contraction, ease of cleaning, and maintenance.
Plate Heat Exchangers
Plate waste heat recovery heat exchangers consist of a series of corrugated metal plates stacked together. The plates are sealed with gaskets, forming numerous narrow channels. The hot and cold media flow in opposite directions in adjacent channels, with heat transferred through thin metal plates.
This structure makes plate heat exchangers extremely efficient because the corrugated shape of the plates increases the surface area, and the heat exchange distance between the two media is very short. Simultaneously, its compact structure and small footprint make it easy to install and disassemble, suitable for applications with limited space but high heat exchange efficiency requirements. However, it has high sealing requirements; if the gaskets malfunction, media leakage can easily occur, affecting the normal operation of the heat exchanger.
Heat Pipe Heat Exchangers
The core component of a heat pipe heat exchanger is the heat pipe, which typically contains a working medium (such as ammonia or water). It is an element with high thermal conductivity. A heat pipe consists of three parts: an evaporation section, a condensation section, and an adiabatic section. In waste heat recovery applications, the high-temperature waste heat medium causes the working medium in the evaporation section of the heat pipe to absorb heat and evaporate. The vapor flows along the inside of the heat pipe to the condensation section, where it releases heat to the cold medium and re-condenses into a liquid. The liquid then returns to the evaporation section through capillary action and other processes. This cycle repeats, achieving efficient heat transfer from the high-temperature side to the low-temperature side.