DH
The Alfa Laval DH is a two-pass dry expansion evaporator for commercial and industrial refrigeration cooling applications with evaporation temperatures ranging from 0°C to +10°C. DH can be used with HCFC and HFC refrigerants at medium and high pressures (30 - 45 barg). Capacity range 18 - 1500 kW. PED/CE, ASME, EAC, SELO, DNV and other major marine approvals are available. The Alfa Laval DH replaces the Alfa Laval Dryplus-3 product line for positive evaporation temperature applications (>0°C).
Commercial and industrial refrigeration applications
The Alfa Laval DH dry-expansion evaporator has been developed for commercial and industrial refrigeration cooling applications, such as air conditioning or industrial process cooling. These applications typically require an evaporation temperature in the range of 0°C to +10°C, depending on the system efficiency.
The DH dry-expansion evaporator will replace the Dryplus-3 evaporator.
Innovative dry-expansion evaporator
The innovative Alfa Laval DH dry-expansion evaporator has a unique patented refrigerant distribution system, which has been optimized for R407F/C and R410A refrigerants. It can also be used with R134a as well as other HFC/HFO refrigerants. The new plastic baffle design improves the shell-side heat transfer performance. Thanks to these innovations, the new Alfa Laval DH evaporator offers the same capacity as the Alfa Laval Dryplus-3 model but is up to 30% shorter in length.
Easy cooling and refrigeration
- Easy to upgrade to the new Alfa Laval DH dry-expansion evaporator from the Alfa Laval Dryplus-3
- Easy to select thanks to the Alfa Laval smarTube software, a calculation tool for thermal sizing
- Easy to buy at any time thanks to easy access through the Alfa Laval e-business portal: contact Alfa Laval local sales organization to get the login
- Easy to receive prompt service thanks to a high level of support
- Easy to handle and stock thanks to its compact design (Length is up to 30% shorter than the Alfa Laval Dryplus-3)
- Easy to install and decommission thanks to the low refrigerant charge
- Easy to reduce the environmental impact with CO2 emission levels that are 25% lower than the Alfa Laval Dryplus-3
High performance cooling and refrigeration
The Alfa Laval DH dry-expansion evaporator is a perfect mix of high performance and high quality at a competitive price.
High performance
- Innovative plastic baffles to improve the shell-side heat transfer performance
- One unit handles various refrigerants: R407F, R407C, HFC/HFO, R134a and R410A
- Unique patented refrigerant distribution system optimized for R407F/C and R410A
High quality
- Corrosion reduction thanks to innovative plastic baffles
- High level of technical support and qualified expertise from quotation through to after-sales support and service
Options
- ASME, EAC, SELO, DNV and other major marine approvals available upon request
- Mounting feet (recommended)
- Flanges and victaulic flanges
- Removable tube bundle
- Insulation
- Tubes in CuNi 90/10, AISI 316L and carbon steel
- Shell in AISI 316L
- High pressure version for R410A (45 bar)
How it works
Operating principle
The Alfa Laval DH dry-expansion evaporator is basically a heat exchanger that uses the shell-and-tube principle to achieve the desired effect. It consists of a pressure vessel (the shell) with a bundle of tubes inside it. The primary fluid (the refrigerant) flows through these tubes, while the secondary fluid (usually water or anti-freeze brine) flows over the tubes (through the shell) in order to bring about heat transfer from one fluid to the other. The standard tube bundle consists of copper inner-finned tubes.
The Alfa Laval DH dry-expansion evaporator is designed for use as one component in cooling systems that consist of a compressor, a condenser, an evaporator and an expansion valve. The two-phase refrigerant arrives at the evaporator from the expansion valve. It then flows inside the tubes and evaporates as it absorbs heat from the surrounding secondary fluid, which is cooled as a result of the heat loss.
The final part of the tube run is used to superheat the refrigerant in order to transform the refrigerant fluid into vapour form before it arrives at the compressor in order to ensure the most efficient cooling possible. Specially designed baffles are used on the shell side in order to boost heat transfer efficiency further.