Heat transfer from open tanks

[zaerdb]

Hello, this is my first post, so please forgive me if I am not doing this exactly right.

I am working on a problem in which I have an open top cylindrical tank that contains a fluid at a higher temperature than the ambient air temperature surrounding the tank. What I am trying to determine is the rate at which heat is transferred from the tank to the room. I believe this is a multi-faceted problem which requires looking at heat transfer from radiation, evaporation through the open top, conduction through the tank walls, and convection on all surfaces. I can do the conduction and radiation calculations, but I am unsure about how to do the calculations for evaporation and convection. Any help with this would be greatly appreciated!

 

[Achy47]

Hello and welcome to the forum! It sounds like you are working on a very interesting and complex problem. You are correct in identifying that there are multiple factors at play in determining the rate of heat transfer from the tank to the surrounding room. Let's break down each component and how it can be calculated.

1. Radiation: This is the transfer of heat through electromagnetic waves. The rate of radiative heat transfer can be calculated using the Stefan-Boltzmann law, which states that the rate of heat transfer is proportional to the fourth power of the temperature difference between the tank and the surroundings. This means that a small change in temperature can have a significant impact on the rate of heat transfer.

2. Evaporation: Evaporation is the process by which a liquid turns into a gas. In this case, the fluid in the tank is at a higher temperature than the surrounding air, so it will naturally tend to evaporate. The rate of evaporation can be calculated using the heat of vaporization of the fluid and the humidity and temperature of the surrounding air.

3. Conduction: This is the transfer of heat through a solid material, such as the walls of the tank. The rate of conduction can be calculated using Fourier's law, which takes into account the thermal conductivity of the material, the temperature difference between the two sides of the material, and the thickness of the material.

4. Convection: This is the transfer of heat through the movement of a fluid, such as air. In this case, the air surrounding the tank will be heated by the tank and then rise, creating a convection current. The rate of convection can be calculated using the convective heat transfer coefficient, which takes into account the properties of the fluid and the speed of the air flow.

It is important to note that all of these factors are interconnected and can affect each other. For example, evaporation can cool the fluid in the tank, which can then affect the rate of radiation and conduction. It may be helpful to use a combination of analytical calculations and numerical simulations to accurately model the heat transfer in your system.

I hope this information helps and good luck with your problem! If you have any further questions, please don't hesitate to ask.