Having trouble with heat loss to environment problem

In summary, the individual is seeking help with calculating the heat transfer in an air system with non-insulated pipes. They have the necessary information about pipe size, materials, and temperatures, but are unsure of which equation to use due to the temperature variations inside the pipe. They mention the use of Fourier's law, but are unsure if it applies in this situation. They also mention the need to consider convection and conduction, as well as flow characteristics and assumptions about flow development. They ask for any input or equations that could help with their situation.
  • #1
sixateseven
1
0
Hi guys, I kept trying different searches in Google and it kept bringing me to threads on this forum, so I thought it was time to join.

I'm trying to calcuate the heat transferred into the environment from an air system and am having a bit of trouble... I really don't have very much experience with this at all and I feel like its a pretty common issue, but I don't know where to start.

The situation:

I have a system of non-insulated pipes, it starts at one location with warm air flowing through it, at one point the pipe splits and runs to two different air to air coolers. I know the size of the pipes, the materials, the k values, the lenghts of pipe, and the temps at all three end points... but I feel like just using the standard form of Fourier's law that I've found doesn't really work, the temperature inside the pipe isn't constant (it cools from points A-B and A-C) and I feel like there would be a curve made by the heat transfer.. Starting off with a greater value at the beginning, and decreasing as a curve as the air in the tube cooled.

Does anyone have any input on what I should be looking for as an equation? I'm seeing a situation where if you had a steam system, for example, and knew the lenght, pipe size, starting temp and environmental temp you could calculate the final temp... but like I said, I knew to this type of situation.

Any help would be awesome. Thank you in advance!
 
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  • #2
Conservation of energy.
 
  • #3
shushu97 is correct.

[tex] \frac{dE_{sys}}{dt} = \dot{E_{In}}-\dot{E_{Out}} [/tex]

You will have to look at convection and conduction.
Also, you will have to know flow characteristics of the air through
the pipes(velocites, density). This will allow you to calculate your
convection coefficient. You will have to make assumptions about
flow development.

Do you have access to a heat transfer text?
 

1. How does heat loss to the environment affect the overall temperature of a system?

Heat loss to the environment can significantly decrease the overall temperature of a system. This is because when heat is lost to the surrounding environment, the system has less thermal energy available to maintain its temperature. This is especially noticeable in closed systems with poor insulation.

2. What factors contribute to heat loss to the environment?

There are several factors that can contribute to heat loss to the environment, including the temperature difference between the system and its surroundings, the surface area of the system, the type of material used for insulation, and the presence of air currents or drafts.

3. How can heat loss to the environment be minimized?

To minimize heat loss to the environment, it is important to improve insulation and reduce air currents or drafts. This can be achieved by using materials with low thermal conductivity, sealing any gaps or cracks in the system, and using proper ventilation techniques to control air flow.

4. What are some consequences of excessive heat loss to the environment?

Excessive heat loss to the environment can lead to a decrease in energy efficiency and an increase in energy costs. It can also result in discomfort for individuals in the environment, as well as potential damage to equipment or materials that are sensitive to temperature changes.

5. How can heat loss to the environment be measured and monitored?

Heat loss to the environment can be measured and monitored using various instruments such as infrared cameras, thermometers, and heat flow meters. These tools can provide accurate readings of temperature changes and help identify areas where heat loss is occurring.

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