Flooded evaporator tubes are the core heat transfer components of flooded evaporators in large central air conditioning chillers and industrial water chillers. In a flooded evaporator, the tubes are completely submerged in liquid refrigerant or secondary coolant, and boiling occurs on the outer surface of the tubes.

Kaineng's flooded evaporator tubes feature specially designed external surfaces—including porous coatings, finned coils, and dimple structures—which increase nucleation site density and significantly enhance the external boiling heat transfer coefficient. Compared to smooth tubes, enhanced flooded evaporator tubes improve boiling heat transfer by 50-100%. We offer the TE/LE series (high-efficiency enhanced boiling for refrigerants) and the LF series (finned coil tubes for ammonia, water, and glycol solutions), providing optimal solutions for different operating conditions.

Heat exchange tubes for flooded evaporators

Core Advantages

Boiling HTC increased by over 50%

Porous/finned/textured surface structures significantly increase nucleation site density, reduce boiling superheat, and greatly enhance heat transfer efficiency.

TE/LE series for refrigerant boiling

High-performance enhanced boiling surfaces, optimized for R134a, R22, R1233zd, and other refrigerants, used in large chiller flooded evaporators.

LF series for ammonia and glycol

Rolled fin tube design for pool boiling of ammonia, water, and glycol solutions in industrial refrigeration and process cooling applications.

High-pressure design

Reinforced wall thickness, capable of withstanding shell-side pressures up to 3.0 MPa, suitable for high-pressure flooded evaporator applications.

Technical Parameters

Outer Diameter (mm)	Bottom Wall (mm)	Tooth Height (mm)	Number of Teeth	Helix Angle (°)	Weight (g/m)	Heat Transfer Area (m²/m)	Material
7.00	0.25-0.32	0.12-0.18	45-55	15-25	42-50	0.021-0.024	TP2, T2
9.52	0.30-0.40	0.14-0.20	50-65	18-28	52-62	0.025-0.028	TP2, T2
7.94	0.27–0.35	0.12–0.18	45-60	18>28	63–75	0.028–0.032	TP2, T2

Typical Applications

Centrifugal and Screw Chiller Flooded Evaporator

Large-capacity flooded evaporators for centrifugal and screw compressor chillers in commercial and industrial HVAC systems.

Industrial Large-Capacity Chiller

Flooded evaporators for process cooling, plant temperature control, and heavy industrial refrigeration systems.

Heat Pump Flooded Evaporator

Large heat pump systems utilizing flooded evaporator configurations for efficient heating and hot water production.

Ammonia Refrigeration System Evaporator

LF series finned tube coils for ammonia (R717) flooded evaporators used in food processing, cold storage, and industrial refrigeration.

Frequently Asked Questions

Q: What is the difference between TE/LE and LF series tubes? How should I choose?

TE/LE series tubes feature highly enhanced boiling surfaces (porous or structured surfaces) optimized for refrigerant-side pool boiling—ideal for R134a, R22, R1233zd, and similar refrigerants in chiller flooded evaporators. LF series tubes use rolled fin (machined fin) surfaces, designed for fluids with different wetting characteristics such as ammonia (R717), water, and glycol solutions. For refrigerant flooded evaporators in HVAC chillers, choose the TE/LE series. For ammonia industrial refrigeration or water/glycol evaporators, choose the LF series. Please contact our engineering team for detailed selection guidance.

Q: How do enhanced boiling tubes prevent oil film contamination from affecting heat transfer?

Oil accumulation on boiling surfaces can significantly reduce heat transfer performance. Our enhanced surface structures are designed with optimized pore/fin geometries to promote bubble nucleation and fluid agitation, which helps continuously disrupt and displace the oil film. For systems with high oil circulation rates, we recommend regular maintenance and can provide surface treatment options to improve oil resistance. Additionally, proper system oil management and separator design are important complements to tube surface design.

Q: Can the porous coating separate or clog over time? What is the service life?

Our TE/LE series porous structures are metallurgically bonded to the base tube through a high-temperature sintering process, ensuring excellent adhesion. Under normal operating conditions with clean fluids, the porous layer will not separate or clog. The service life typically exceeds 15-20 years, matching the design life of the chiller itself. In systems with excessive contamination or particulate fouling, periodic chemical cleaning can restore performance without damaging the enhanced surface. We recommend following standard water treatment and maintenance practices.

Q: Can you provide tube layout and selection design recommendations?

Yes, Kenergy's engineering team offers comprehensive technical support, including tube bundle layout design, heat transfer area calculation, and performance prediction for flooded evaporator applications. We can provide recommendations on tube pitch, bundle geometry, and surface structure selection based on your specific operating conditions, refrigerant type, and capacity requirements. Please share your design specifications with our team, and we will provide a detailed selection report and performance estimate.

Heat exchange tubes for flooded evaporators