Flooded Evaporator Tubes | TE/LE/LF Enhanced Boiling Tubes

Flooded evaporator tubes are the core heat transfer components in large central air conditioning chillers and industrial water chiller flooded evaporators. In a flooded evaporator, the tubes are fully submerged in liquid refrigerant or secondary coolant, with boiling occurring on the outside of the tubes.

Kenergy's flooded evaporator tubes feature specially engineered external surfaces — including porous coatings, rolled fins, and dimpled structures — that increase nucleation site density and dramatically enhance outside boiling heat transfer coefficients. 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 surfaces for refrigerants) and the LF series (rolled-fin tubes for ammonia, water, and glycol solutions), providing optimal solutions for different operating conditions.

Core Advantages

50%+ Improvement in Boiling HTC

Porous/finned/dimpled surface structures significantly increase nucleation site density, reducing boiling superheat and dramatically improving 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 & Glycol

Rolled-fin tubes designed for pool boiling of ammonia, water, and glycol solutions in industrial refrigeration and process cooling applications.

High-Pressure Design

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

Technical Parameters

Available outer diameters, wall thicknesses, and surface structure types. Custom specifications available upon request.

Outer Diameter (mm)	Wall Thickness (mm)	Surface Structure	Boiling HTC (W/m²·K)	Working Fluid	Max W.P. (MPa)	Material
19.05	0.80–1.20	Porous / Rolled-Fin / Dimpled	4,000–8,000	R134a / R22 / R1233zd / NH₃	2.5	TP2, T2
25.40	0.90&ndash>1.35	Porous / Rolled-Fin / Dimpled	4,500–9,000	R134a / R22 / R1233zd / NH₃	2.5	TP2, T2, CuNi10Fe1Mn
31.80	1.00–1.50	Porous / Rolled-Fin / Dimpled	5,000–10,000	R134a / R22 / NH₃ / Water / Glycol	3.0	TP2, T2, CuNi10Fe1Mn

Typical Applications

Centrifugal & Screw Chiller Flooded Evaporators

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

Industrial Large-Capacity Water Chillers

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

Heat Pump Flooded Evaporators

Large heat pump systems utilizing flooded evaporator configurations for high-efficiency heating and hot water production.

Ammonia Refrigeration System Evaporators

LF series rolled-fin tubes for ammonia (R717) flooded evaporators in food processing, cold storage, and industrial refrigeration.

Frequently Asked Questions

Q: What is the difference between TE/LE and LF series tubes? How do 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 a rolled-fin (machined fin) surface designed for fluids with different wetting characteristics such as ammonia (R717), water, and glycol solutions. For refrigerant flooded evaporators in HVAC chillers, choose TE/LE series. For ammonia industrial refrigeration or water/glycol evaporators, choose LF series. Contact our engineering team for detailed selection guidance.

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

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

Q: Can the porous coating detach 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 strength. Under normal operating conditions with clean fluids, the porous layer will not detach or clog. The service life typically exceeds 15-20 years, matching the design life of the chiller itself. In systems with excessive fouling or particulate contamination, 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 for 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.

Flooded Evaporator Tubes — TE/LE/LF Series Enhanced Boiling Tubes