Heat Exchangers - Overall Heat Transfer Coefficients
Overall heat transfer coefficients in common heat exchanger designs - tubular, plate or spiral.
Overall heat transfer coefficients in some common heat exchanger designs and applications:
| Type | Application | Overall Heat Transfer Coefficient - U - | |
|---|---|---|---|
| W/(m2K) | Btu/(ft2 oF h) | ||
| Tubular, heating or cooling | Gases at atmospheric pressure inside and outside tubes | 5 - 35 | 1 - 6 |
| Gases at high pressure inside and outside tubes | 150 - 500 | 25 - 90 | |
| Liquid outside (inside) and gas at atmospheric pressure inside (outside) tubes | 15 - 70 | 3 - 15 | |
| Gas at high pressure inside and liquid outside tubes | 200 - 400 | 35 - 70 | |
| Liquids inside and outside tubes | 150 - 1200 | 25 - 200 | |
| Steam outside and liquid inside tubes | 300 - 1200 | 50 - 200 | |
| Tubular, condensation | Steam outside and cooling water inside tubes | 1500 - 4000 | 250 - 700 |
| Organic vapors or ammonia outside and cooling water inside tubes | 300 - 1200 | 50 - 200 | |
| Tubular, evaporation | steam outside and high-viscous liquid inside tubes, natural circulation | 300 - 900 | 50 - 150 |
| steam outside and low-viscous liquid inside tubes, natural circulation | 600 - 1700 | 100 - 300 | |
| steam outside and liquid inside tubes, forced circulation | 900 - 3000 | 150 - 500 | |
| Air-cooled heat exchangers | Cooling of water | 600 - 750 | 100 - 130 |
| Cooling of liquid light hydrocarbons | 400 - 550 | 70 - 95 | |
| Cooling of tar | 30 - 60 | 5 - 10 | |
| Cooling of air or flue gas | 60 - 180 | 10 - 30 | |
| Cooling of hydrocarbon gas | 200 - 450 | 35 - 80 | |
| Condensation of low pressure steam | 700 - 850 | 125 - 150 | |
| Condensation of organic vapors | 350 - 500 | 65 - 90 | |
| Plate heat exchanger | liquid to liquid | 1000 - 4000 | 150 - 700 |
| Spiral heat exchanger | liquid to liquid | 700 - 2500 | 125 - 500 |
| condensing vapor to liquid | 900 - 3500 | 150 - 700 | |
