Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Pipes Submerged in Water - Heat Emission

Heat emision from steam or water heating pipes submerged in water - assisted (forced) or natural circulation.

Steam heating coils in oil tanks

Heat emission from steam or water pipes or tubes submerged in water:

Pipes Submerged in Water - Heat Emission
Temperature Difference between the Steam/Water in the Pipe and the Surrounding WaterHeat Transfer Rate to the Surrounding Water
(oF)(oC)(Btu/(ft2 h oF))(W/(m2 oC))
50 28 100 - 225 570 - 1280
100 56 175 - 300 1000 - 1700
200 111 225 - 475 1300 - 2700

Note that with a higher temperature difference there is a more vigorous movement on the water side and the heat transfer rate goes up. Forced or assisted circulation on the water side also results in higher heat transfer rates as indicated below.

For practical applications - the heat transfer rates can roughly be set to:

Pipes Submerged in Water - Heat Transfer
Type of ApplicationHeat Transfer Rate to the Surrounding Water
(Btu/(ft2 h oF))(W/(m2 oC))
Tank coils with low pressure steam, natural circulation in the tank 100 570
Tank coils with high pressure steam, natural circulation in the tank 200 1100
Tank coils with low pressure steam, forced circulation in the tank 200 1100
Tank coils with high pressure steam, forced circulation in the tank 300 1700

Example - Steam Coil in Water

A DN25 (1") Std steam coil of one meter is submerged in water with temperature 20 oC. The steam pressure is aprox. 1 bar with a steam temperature aprox. 120 oC.

The area of the submerged coil can be calculated as:

A = (1 m) 2 π (0.0334 m) / 2

   = 0.10 m2

With low pressure steam and non-assisted circulation we presume from the table above that the heat transfer rate is 570 W/m2oC.

Heat transfer from steam to water can then be calculated:

Q = (570 W/(m2oC)) (0.10 m2) (120 oC - 20 oC)

   = 5700 W

   = 5.7 kW

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter


















































6.20.11

.