Microchannel Evaporators

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  • MICROCHANNEL EVAPORATORS

    Microchannel heat exchangers for efficient refrigerant evaporation

    Microchannel heat exchanger

HEAT EXCHANGERS ADOPTED FOR EVAPORATOR APPLICATIONS

Kaltra’s microchannel evaporators utilize advanced techniques to ensure uniform refrigerant distribution across microchannel tubes, effectively minimizing superheated regions. This results in optimal thermal performance across a wide range of operating conditions and loads, addressing key design challenges. With the capability of operating in reverse acting as condensers, our microchannel evaporators are ideally suited for air-source heat pumps.

By relying on our microchannel evaporators, customers enjoy the full spectrum of benefits offered by microchannel technology, including superior heat transfer rates, lower refrigerant charge, reduced fan power consumption, and a more compact, lightweight design—ensuring optimal efficiency across both full and part load conditions.

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Microchannel evaporator

EVAPORATOR DESIGN

The microchannel evaporator stands out from other coil types due to its unique construction, which is specifically engineered for optimum performance.

  1. Vertical tube arrangement for bottom-to-top refrigerant flow direction and gravity-assisted condensate drainage
  2. Inlet manifold with integrated refrigerant distribution devices
  3. Top outlet manifold
  4. Inlet/outlet refrigerant connections
  5. Reinforcement beams
  6. Fixtures

ADVANTAGES AND BENEFITS

Microchannel evaporators outperform traditional finned-tube coils by delivering superior heat transfer rates, ensuring stable efficiency on partial loads, enabling significant reductions in system refrigerant charge, and facilitating a more compact and lightweight system design. Additionally, their low airside resistances help minimize fan power draw.

HIGHER HEAT TRANSFER

MCHE
RTPF

REDUCED REFRIGERANT CHARGE

MCHE
RTPF

SMALLER HEAT TRANSFER AREA

MCHE
RTPF

Uniform Refrigerant Distribution

Uniform refrigerant distribution across microchannel tubes plays a crucial role in ensuring efficient evaporator operation. To achieve optimal two-phase flow distribution and prevent the formation of superheated regions, advanced techniques and specialized coil geometries are implemented, including:

  • In-built direct expansion (DX) refrigerant distributors
  • Optimized width-to-height ratios
  • Precisely quantified inlet-to-outlet manifold sectional areas
  • Hydraulic diameter optimization of ports
  • Flash gas separation and bypassing

Evaporator Coatings

In addition to advanced protective treatments against corrosion—such as electrophoretic epoxy coating, trivalent chromium coating, and nanoscale trichrome film—as well as UV protection, we offer performance-enhancing topcoats. These include hydrophilic and hydrophobic coatings that assist in condensation management, improving coil performance and efficiency, particularly under wet or freezing conditions.

With these topcoats applied, coil surfaces resist water adsorption and wetting, allowing water to flow effortlessly off the heat exchanger surface due to reduced surface tension. This results in enhanced heat transfer performance, especially in wet and frost conditions.

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DX distributor

Refrigerant Distributor

The primary function of the refrigerant distributor integrated into the inlet manifold of the evaporator coil is to ensure uniform refrigerant distribution across the microchannel tubes, optimizing performance across a wide range of operating conditions and equipment designs. The distributor achieves this by:

  1. Separating liquid and gas phases within the refrigerant mixture before distribution
  2. Injecting liquid refrigerant into distributor orifices, generating the necessary pressure drop to propel the refrigerant and achieve even distribution along the inlet manifold
  3. Delivering liquid refrigerant precisely into individual tube chambers
  4. Preventing refrigerant flow between tube chambers prior to entering the microchannel tube ports
MCHE selection software

SELECTION SOFTWARE

MCHE selection software offers a comprehensive solution for refrigeration professionals, covering condenser, evaporator, heat pump, and air-to-fluid coils. This all-in-one selection and calculation tool simplifies the design and optimization of microchannel heat exchangers for a wide range of applications.

With advanced capabilities, the software allows users to select and rate microchannel heat exchangers based on critical parameters such as application type, cooling capacity, refrigerant, evaporation and condensation temperatures, airflow, and air temperature. These detailed options ensure precise product selection and optimal system performance in refrigeration systems.

Software inquiry Performance simulation

PRODUCT SPECIFICATIONS

Min/Max width [mm]

FROM 50 TO 6000

Min/Max height [mm]

FROM 50 TO 2000

Design

HORIZONTAL/VERTICAL TUBE ARRANGEMENT • SINGLE-/MULTI-CIRCUIT

Tube width [mm]

12.0 • 16.0 • 20.0 • 25.4 • 28.0 • 32.0 • 36.0

Tube spacing [mm]

7.8 • 9.3 • 9.4 • 9.8 • 10.0

Manifold diameter [mm]

16 • 20 • 25 • 30 • 32 • 38 • 42 • 50

Fin type

LOUVERED

Fin pitch [FPI]

10.0 • 12.7 • 16.5 • 17.0 • 18.0 • 19.5 • 21.0 • 23.0 • 24.0 • BY REQUEST

Tube material(s)

AA3102 • HA9153A • AA3F03 • AA3F05 (TEMPER H112) ZINC ARC SPRAY

Fin material(s)

AA4343 • AA3003 • FA7971 (TEMPER H14)

Manifold material(s)

AA4343 • AA3003 OR AA4045 • AA3003/AA4045 • AA3005 (TEMPER H14)

Design pressure [bar]

32 • 45

Refrigerant

HFC • HFO • NATURAL

Protective coating

E-COATING • TCP-COATING • NANO-COATING • UV-PROTECTION

Special coating

HYDROPHILIC • HYDROPHOBIC • PAINT

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