Plate heat exchanger (definition)

Plate heat exchanger — is a device designed to transfer heat between two working media (e.g. liquid-liquid or liquid-gas) through flat plates. It is a compact and efficient design where heat exchange is carried out through thin metal plates installed parallel to each other and separating the flows of media.

Design features:

1. Plates: Made from metals with high thermal conductivity, such as stainless steel, copper or titanium, the plates have a ribbed or waved surface to increase the contact area and improve flow turbulence, which increases heat transfer efficiency.
2. Sealing: The plates are hermetically connected using seals, which prevent mixing of the working media. The seals also allow easy disassembly and maintenance of the heat exchanger.
3. Modular design: Plate heat exchanger can be easily adapted to the requirements of a specific system by adding or removing plates, allowing the power and performance of the device to be changed.

Application:

1. Heating systems:
   • It is used to separate heating and hot water supply circuits, which avoids mixing of heat carriers and ensures high efficiency of the system.
   • It is used in cascade boiler houses where efficient heat exchange between several boilers is required.
   • The plate heat exchanger can be used to relieve flame stress in pellet boilers and as a primary ash filter to deposit ash particles as smoke moves.
2. Industrial processes:
   • In the food industry for pasteurization of liquids.
   • In the chemical industry for heating or cooling various reagents.
3. Cooling and air conditioning:
   • Used in central air conditioning systems to transfer heat between refrigerants or to transfer heat between systems with different temperature conditions.
   • In cooling systems to maintain temperature in technological processes.
4. Energy:
   • In thermal power plants for heat exchange between steam and water.
   • In renewable energy, such as solar and geothermal installations, to transfer heat from the energy source to the consumer.

Advantages:

• High efficiency: Due to the large surface area of the plates and improved flow turbulence, plate heat exchangers provide a higher heat transfer coefficient compared to tubular heat exchangers.
• Compactness: Due to their modular design and high heat transfer density, plate heat exchangers take up less space and weigh less compared to other types of heat exchangers, making them suitable for installation in limited spaces.
• Flexibility in operation: The ability to add or remove plates allows the heat exchanger capacity to be modified according to system needs, making it a versatile solution for a variety of applications.
• Ease of maintenance: The design allows the heat exchanger to be easily disassembled for cleaning or replacing plates, which reduces operating costs and increases the service life of the device.

Disadvantages:

• Sensitivity to pollution: The plate heat exchanger can become clogged when using dirty or highly contaminated media, which requires regular maintenance and filtration of the working media.
• Pressure and temperature limitations: Not all plate heat exchangers can operate at high pressures and temperatures, which limits their use in some industrial processes.