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# Cooling loss

## Cooling loss

(OP)
I have a 16 inches (outside diameter)chilled water pipeline (carbon steel) that is 20 feet long. Water is flowing through it with an initial temp of 1 degC. The line is exposed to an air temperature of 40 DegC and I would like to know the temperature at the end of the pipeline. The flow rate is 2000L/Hr.
I'm trying to generate some kind of pipeline heat gain table using the exposed pipe.
Can anybody helps

### RE: Cooling loss

2 m3/ HOUR??

In a 16" pipe? Why. Far too big

Can you check your units and flow?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

### RE: Cooling loss

(OP)
Sorry I was busy.
This statement is a scenario. You can change flow, dis of pipe. I just want to calculate cool in loss

### RE: Cooling loss

(OP)
I want to calculate the temperature at other ends of the pipe. e.g if pipe length is 10m, water enters at 1 degC and 20000 L/hr.

### RE: Cooling loss

Arslanash,

Use your engineering degree. Internal resistance to flow will be the standard convective heat transfer coefficient calculation based on Re and liquid properties. The pipe will, too, will be standard with the metal thickness and material properties.

It's the outside air that presents something not found standard in engineering textbooks. If this pipe is outside, there are usually too many factors to get an accurate number because the conditions change so wildly. If you want to approach this analytically, there is a method for calculating the Reynold's number of a gas flowing on the outsideof a pipe based on wind speed. You would treat this as convective heat transfer, with your thermal boundary layer thickness being dependent on the Re number. Then, you can do your usual Q = U*A*dT, with U being the inverse of the sum of the thermal resistances.

If it rains or if your pipe temperature is below the dewpoint, be prepared for all of the above calculations to wildly underestimate the heat loss.

### RE: Cooling loss

(OP)
How to calculate temperature at other end of pipe. For example if length of pipe is 10ft and entrance temperature is 2 def C

### RE: Cooling loss

#### Quote (Arslanash)

How to calculate temperature at other end of pipe. For example if length of pipe is 10ft and entrance temperature is 2 def C
Use a pipeline software. I was doing this in Inplant/Pipephase and bet Pipenet, Flowmaster and similar are able to do this also.

### RE: Cooling loss

Also whilst there are many variables - wind speed being the main one, you're probably at about 10 to 20 W/m2K. Do the maths.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

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