Main categories of compact heat exchangers

Main categories of compact heat exchangers

^{A compact heat exchanger (CHE) is a highly efficient heat transfer device characterized by a large heat transfer surface area per unit volume, significantly exceeding that of conventional shell-and-tube heat exchangers.}

^{Key Features:}

^{1. High Thermal Efficiency: Enhanced heat transfer through compact designs (e.g., thin plates, microchannels, fins) to minimize thermal resistance.}

^{2. Small Size & Lightweight: Ideal for space-constrained applications in aerospace, automotive, chemical processing, etc.}

^{3. Diverse Configurations: Includes plate-type, plate-fin, spiral plate, printed circuit (PCHE), and other advanced designs.}

^{Main categories:}

^{1. Plate Heat Exchanger (PHE)}

^{- Structure: composed of corrugated metal plates stacked, the formation of fluid channels between the plates.}

^{- Characteristics: high heat transfer coefficient, easy to disassemble and clean, but lower pressure resistance.}

^{- Application: HVAC, food processing, chemical liquid heat transfer.}

^{2. Plate-Fin Heat Exchanger (PFHE)}

^{- Structure: Sandwich fins (such as serrated, porous) between parallel plates to form a multi-layer flow path.}

^{- Characteristics: Ultra-compact (surface area densities up to 5000 m²/m³), suitable for gases or low Reynolds number fluids.}

^{- Applications: air separation equipment, aerospace (e.g. aircraft engine oil coolers), LNG liquefaction.}

^{3.Spiral Plate Heat Exchanger}

^{- Structure: two metal plates rolled into a spiral, forming a coaxial spiral channel.}

^{- Characteristics: self-cleaning ability, can handle particles or high viscosity fluids, low pressure drop.}

^{- Application: paper, waste water treatment, viscous liquids heat transfer.}

^{4. Printed Circuit Plate Heat Exchanger (PCHE)}

^{- Structure: through chemical etching on the metal plate to form micro-channels, stacked and diffusion welding.}

^{- Characteristics: Resistant to high temperatures and pressures (up to 1000°C, 600 bar), extremely compact (micron-sized flow channels).}

^{- Applications: supercritical CO₂ cycles, nuclear reactors, hydrogen energy systems.}

^{5.Compact Shell-and-Tube Heat Exchanger}

^{- Structure: Small diameter tubes (e.g., microtubes), high-density arrangement, or reinforced tubes (threaded tubes, low-finned tubes).}

^{- Features: 30%-50% volume reduction compared to traditional shell and tube, suitable for high pressure conditions.}

^{- Application: high pressure heat exchange in petrochemical and electric power industries.}

^{6.Plate and Shell Heat Exchanger}

^{- Structure: Plate bundle (similar to plate) encapsulated in a cylindrical shell, combining the advantages of plate and shell and tube.}

^{- Characteristics: High pressure resistance, thermal stress resistance, higher heat transfer efficiency than traditional shell and tube.}

^{- Application: high temperature and high pressure working condition in oil refining and chemical industry. 7.}

^{7. Tube-Fin Heat Exchanger}

^{- Structure: Install fins (aluminium fins are common) outside the tube to enhance heat transfer on the gas side.}

^{- Characteristics: lightweight, low cost, but easy to accumulate dust need regular maintenance.}

^{- Applications: automotive radiator, air conditioning condenser, data centre cooling.}

^{8.Microchannel Heat Exchanger}

^{- Structure: flow channel size of micron-level (0.1-1 mm), using aluminium or copper.}

^{- Features: ultra-high heat transfer efficiency, low refrigerant charge, but easy to clog.}

^{- Applications: Thermal management of electric vehicles, home air conditioning, heat dissipation of electronic devices.}

^{Selection basis:}

^{- Working pressure/temperature: PCHE or plate and shell type for high pressure, spiral plate type or PCHE for high temperature.}

^{- Fluid nature: spiral plate type for particles, plate-fin type or tube-fin type for gases.}

^{- Space constraints: Microchannel or plate-and-fin for very small spaces.}

^{- Maintenance requirements: Plates are easy to dismantle, microchannels require an anti-clogging design.}

^{Compact heat exchangers achieve high heat transfer efficiency through structural innovation, but need to weigh the pressure drop, the risk of clogging and manufacturing costs. The actual selection needs to be combined with specific conditions and fluid characteristics.}