Large chillers, which are commonly used in industrial and commercial cooling applications, typically utilize highly efficient water-cooled condensers to transfer heat effectively. The three primary types of water-cooled condensers used in large chillers are shell-and-tube, coaxial tube-in-tube, and brazed plate condensers, each with its unique features and benefits.
Shell-and-Tube Condenser
Shell-and-tube condensers are a popular choice for large chillers due to their high efficiency and robust design. These condensers feature straight water tubes enclosed within a cylindrical shell, with the water tubes positioned to create a vapor-tight fit. The cooling process begins when the hot refrigerant, released from the compressor, enters the top of the cylindrical shell. As the refrigerant makes contact with the water tubes, the vapor-to-liquid conversion process commences.
Key Features and Specifications:
- Cylindrical shell design with straight water tubes
- Vapor-tight fit of water tubes to ensure efficient heat transfer
- Typical shell diameter range: 24 to 72 inches (610 to 1,830 mm)
- Typical tube length range: 4 to 40 feet (1.2 to 12.2 meters)
- Tube material: Copper, stainless steel, or titanium
- Shell material: Carbon steel or stainless steel
- Cooling capacity range: 100 to 3,000 tons (350 to 10,500 kW)
- Pressure rating: Up to 300 psi (20.7 bar)
The final cooling phase of packaged water-cooled chillers with shell-and-tube condensers occurs when the newly condensed liquid refrigerant is collected at the bottom of the shell, ready for the next stage of the cooling cycle.
Coaxial Tube-in-Tube Condenser
Coaxial tube-in-tube condensers are highly effective and compact heat exchangers, known for their superior anti-fouling characteristics. These condensers utilize two nested tubes, with the water passing through the inner tube while the refrigerant flows through the outer tube. The coaxial design ensures that the coldest water makes contact with the coldest refrigerant, maximizing heat transfer efficiency.
Key Features and Specifications:
- Nested tube design with water flowing through the inner tube
- Refrigerant flowing through the outer tube
- Compact and space-saving design
- Excellent anti-fouling properties due to the smooth inner tube surface
- Typical tube diameter range: 0.75 to 2 inches (19 to 51 mm)
- Tube material: Copper, stainless steel, or titanium
- Cooling capacity range: 50 to 500 tons (175 to 1,750 kW)
- Pressure rating: Up to 300 psi (20.7 bar)
The coaxial tube-in-tube water-cooled condenser design ensures that the coldest water makes contact with the coldest refrigerant, maximizing heat transfer and improving the overall efficiency of the chiller system.
Brazed Plate Condenser
Brazed plate condensers are a popular choice for large chillers due to their corrosion resistance, cleanability, and enhanced heat transfer capabilities. These condensers are constructed of a series of metal plates held together with a copper-based brazing material, resulting in a non-ferrous construction that eliminates rusting and corrosion. The embossed pattern of the plates creates a channel for fluids to flow, allowing for highly efficient heat transfer between the refrigerant and the water.
Key Features and Specifications:
- Corrosion-resistant, non-ferrous construction
- Brazed plate design with embossed flow channels
- Compact and space-saving footprint
- Easily cleanable and maintainable
- Typical plate material: Stainless steel or titanium
- Typical plate size range: 11.8 to 47.2 inches (300 to 1,200 mm)
- Cooling capacity range: 50 to 1,000 tons (175 to 3,500 kW)
- Pressure rating: Up to 450 psi (31 bar)
Brazed plate condensers are used in a wide range of single and dual packaged water-cooled chillers, including fractional hermetic, scroll, digital scroll, semi-hermetic, screw, and tandem scroll models.
In summary, large chillers primarily utilize shell-and-tube, coaxial tube-in-tube, and brazed plate water-cooled condensers, each with its unique design, features, and performance characteristics. These condensers are engineered for high efficiency, anti-fouling, and corrosion resistance, ensuring optimal performance and longevity in industrial process cooling applications.
Reference:
- Drake Chillers Blog: What Types of Packaged Water-Cooled Condensers Are Used in Chillers?
- Cold Shot Chillers: How Water-Cooled Condensers Work
- KKT Chillers USA: The Chiller Condenser Explained