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Aluminium Tube SoluTionS
for Fin and Tube Heat exchangers
Drop-in solutions for copper replacement
increASed perFormAnceS wiTH Hygroove
Sapa asked the danish Technological institute to measure the heat transfer performances of three of its tubes for fin and tube heat exchangers. The heat transfer coefficient of 9.52mm precision drawn tube, Hygroove tube with straight grooves and Hygroove tube with helical grooves have been measured using a special test set-up1. based on the tube heat transfer coefficient values, Sapa calculated with a mathematical model the heat transfer coefficient of the overall heat exchanger. data show that both Hygroove tubes give higher performance results than smooth bore tubes. in particular, compared to precision drawn tube, Hygroove helical tube shows:1. up to 108% higher heat transfer coefficient of the tube, 2. up to 8% higher heat transfer performances of the overall heat exchanger.
Tube heat transfer performanceoverall heat exchanger heat transfer
performance
Tube heat transfer coefficient (HTc) at
massflux of 200 kg/m2s [w/m2s]
relative improvement
compared to pdT [%]
calculated overall heat exchanger heat transfer
coefficient [w/m2s]
relative improvement
compared to pdT [%]
preciSion drAwn TubeS
5000 - 576 -
Hygroove - Straight 6800 +36% 597 +4%
Hygroove - Helical 10400 +108% 618 +8%
1TeST cHArAcTeriSTicS
• Tubes: od x wT = 9,52 x 0,6 mm, 6m straight
test tube length with refrigerant inside
• Tube in tube (coaxial) test set up with counter
flow. water on outer side of test tube
• refrigerant r410A
• evaporating temperature at 10 ° c
• mass flux between 125 -250 kg/m2s
• inlet vapour quality of 0.1 and outlet vapour
quality of 0.9
• esther oil: oil circulation rate (ocr) approxi-
mately 1% of mass flow
Sapa is the world leader in aluminium solutions - a new company that has joined the aluminium extrusion businesses of Sapa and Hydro. Together, we are shaping a lighter future through a global reach and local presence within extrusions, building systems, and precision tubing. we have 23,000 employees in more than 40 countries, and our headquarters are located in oslo, norway.
AbouT SApA’S preciSion Tubing buSineSS AreA
Sapa precision Tubing is the clear market leader in the field of providing aluminium solutions for heat transfer applications. our company has 30 years of experience supplying the automotive and the HvAc&r (heating, ventilation, air-conditioning and refrigeration) industries.beside heat transfer applications, Sapa‘s precision Tubing business Area supplies aluminium extruded tubes and welded tubes for gas/fluid, structural and solar thermal applications. in addition, we also supply niche markets (railway, heavy vehicles, geothermal and other segments) where our technological competence and innovative products can serve our customers.
Sapa precision Tubing has about 2,000 employees at 17 plants and product and process development centers, serving local and global customers all around the world.
100
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
150 200 250
(3) Helical Hygroove
massflux g [kg/m2s]
Hea
t tra
nsfe
r coe
ffici
ent [
w/m
2 K]
(4) Straight Hygroove
(1) Aluminium Smooth
perFormAnce dATA
SAleS conTAcT:
europe
bjørn vestergaard
T +45 73 71 14 18
middle eAST
Adil Atiser
T +45 73 71 12 21
cHinA
Shen yang
T +86 512 6283 6368
JApAn And KoreA
Akira yamakawa
T +86 512 6283 5685
indiA
Sajith Jose
T +91 80988 60888
norTH AmericA
Anders Sorensen
T +1 321 638 1185
SouTH AmericA
rodolfo bocato
T +55 11 4025 6768
© Sapa 2013 version 1.1. december 2013www.sapatubing.com
For heat exchangers operating in aggressive environments, Sapa strongly recommends the addition of a zinc coating to the tubes. This additional layer will provide the tubes with increased corrosion protection and will improve lifetime compared to the equivalent bare tube. This zinc coating is available on smooth bore tubes, and straight inner grooved tubes.
THe STAndArd drop-in SoluTion For copper replAcemenT
precision drawn tubes are the light solution for standard heat exchangers manufactured with mechanically expanded round or oval tubes. The manufacturing process, which includes extrusion, drawing and annealing, guarantees narrow tolerance and a superior surface finish of the tubes. precision drawn tubes represent an economic alternative to copper.
improved HeAT TrAnSFer wiTH inner grooveS
Hygroove is an internally enhanced aluminium tube for high-fin density condensers and evaporators. The inner grooves improve heat transfer, offering higher efficiency by more compact design. Additional Zinc coating layers are available to further increase corrosion resistance, which makes this product a high performing tube. different grooves depth and geometry satisfy the specific regional requirements and refrigerants in use.
THe HigHeST perFormAnce in HeAT TrAnSFer
The inner grooves are following a helical pattern and have been optimized to improve heat transfer. The improvement in heat transfer coefficient of the tube is two times what can be achieved with traditional smooth bore tubes3. This increased efficiency can help achieve a more compact design of the heat exchangers and a reduction in refrigerant load. different grooves depth and geometry satisfy the specific regional requirements and refrigerants in use.
3 refer to the performance data on the backside of this brochure
Zinc coATing And clAd lAyerS For round TubeS
when converting from copper to aluminium or expanding the use of aluminium for additional applications, there are several technical challenges that have to be overcome.
Sapa has 30 years of experience supplying the automotive and the HvAc&r industries with solutions and our Applications & development engineers will support you in every step of the project. From selecting the right dimensions and alloys for your application to providing in-depth knowledge of metallurgy, joining methods and brazing, Sapa has the experience and capability to be your partner.
choosing aluminium solutions from Sapa is more than choosing the price tag. Sapa provides more than the metal: processability in the customers process and performance in the field are also part of what you get with Sapa as your supplier.
Additionally Sapa‘s research and development department ensures you will remain at the forefront of technology and continue having the most cost efficient and effective solutions in the market.
wHy
preciSion drAwn TubeS Hygroove STrAigHT inner grooved TubeS
wHy All-Aluminium Fin And Tube HeAT excHAngerS?
The heating, ventilation, air conditioning and refrigeration HvAc&r industry has been using mechanically assembled copper tubes and aluminium fin solutions for years. replacing the copper tubes with aluminium tubes provides tangible benefits:
Hygroove
1. price per meTer
The price of aluminium raw material is one-fourth the price of copper1. This will definitely impact your bottom line.
3. corroSion reSiSTAnce
corrosion can manifest itself in two ways. First, it can lead to reduced performance of the system, due to galvanic corrosion between tube and fin. in all-aluminium heat exchangers, due to a closer galvanic balance between fin and tube, this will occur far later than in a mixed metal - copper tubes and aluminium fins - unit. of course, care has to be taken in aluminium alloy selection, so that the tube will be more noble than the fin material. Second, corrosion can lead to tube leakages. with proper alloy selection, tube failures will not occur. However for all-aluminium heat exchangers in outside units, Sapa recommends zinc coating of the tubes as extra protection against the possible effects of aggressive environments.
2. weigHT per meTer
Aluminium tubes are 35% lighter than copper, for equivalent burst pressure.2 This improves system weight significantly.
4. perFormAnce
in an all-aluminium fin and tube heat exchanger, the tubes have the same thermal expansion coefficient as aluminium fin stock. The bond between tube and fin will be constant regardless of temperature, thus ensuring better heat transfer. in addition, aluminium has less spring-back effect than copper, meaning a better bond between the tube and fin during expansion.
5. recyclAbiliTy
Aluminium recycling is important for resource preservation. There is no need to separate different materials in an all-aluminium heat exchanger, thus making recycling easier.
HelicAl inner grooved TubeS
producT deScripTion Key FeATureS AvAilAbiliTy AlloyS
ouTer diAmeTer [mm]
wAll THicKneSS
[mm]
burST preS-Sure 4
[bars]
burST preS-Sure 4
[pSi]grooveS
depTH [mm]number oF grooveS
grooveS Angle [°] coATingS
precision drawn tube
precision drawn tube with smooth inner surface
• Easy to form and bend• Low cost and weight
• Level wound coils• Cut to length
HA3003, HA9158,
HA9134m
Standard range: 5 to 22
other od upon request
Standard range: 0.35 to 2
other wT upon request
- - - - - Zinc coating
Hygroove - straight grooves
precision drawn tube with inner grooved surface
• High heat transfer efficiency• Easy to form and bend• Low cost and weight
• Level wound coils• Cut to length
HA9158, HA9134m
77.17
9.529.52
0.470.500.500.700.50
130145147152106
19002000210021501500
0.280.250.300.300.30
4540385050
- Zinc coating
Hygroove - helical grooves
precision drawn tube with inner grooved surface
• Very high heat transferefficiency
• Easy to form and bend• Low cost and weight
• Level wound coils• Cut to length
HA9158, HA9134m
777
9.529.525
10
0.470.500.450.680.500.70
130147131147106144
190021001900210015002000
0.160.160.230.300.180.25
485548404040
182520201820
nA
our Tube rAnge AT A glAnce
1 Based on avergae LME price from January 1 to November 29, 2013. Primary aluminium, 3-months buyer 1.854 $/kg. Copper grade A, 3-months buyer 7.332 $/kg. Ratio copper/aluminium price=3.96.
2 For outside diameter of 9.52mm and burst pressure of 123 bar, aluminum tube weight is 46g/m (tube WT=0.6mm, density=2.73g cm3). Copper tube weight is 72g/m (tube WT=0.28mm, density= 8.9g/cm3).
4 Calculated values for alloy HA9158. Temper O
