Calculating of heat transmission loss (convection) in a thick glass plate

In summary, the rate at which a heated tempered glass plate loses heat energy depends on factors such as thermal conductivity and thickness, and can be calculated using the Fourier heat equation or measured using a thermal imaging camera.
  • #1
Iknowalittle
1
0
Hi.

Do anybody here know how much and how quick a 50-100mm thick tempered glass plate of size 500mm * 500mm fully heated up within its bulk mass to a temperature of 60 degrees celcius looses it heat energy/temperature over time when surrounded by standing ambient air (20 degrees celcius)?

What I want to know, is the temperature profile "out-of-plane" inside the 50-100mm thick glass and related to time, especially within the first 10 minutes.

I know there are several programs out there, who could answer this question, such as COMSOL 3.5, ANSYS Multiphysics, etc. But unfortunately I don't have access to any of these fancy software packages.

Did anyone here made already/are able to do some calculations related to the above?


Thanks in advance
 
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  • #2


Hi there,

I can definitely help answer your question about the temperature profile of a heated tempered glass plate. The rate at which the glass loses heat energy will depend on various factors such as the thermal conductivity of the glass, the thickness of the glass, and the surrounding ambient temperature.

To calculate the temperature profile "out-of-plane" inside the glass, we can use the Fourier heat equation, which describes how heat is transferred through a material. The equation is as follows:

q = -k∇T

Where q is the heat flux (energy per unit time per unit area), k is the thermal conductivity of the material, and ∇T is the temperature gradient.

Since we know the initial temperature of the glass (60 degrees Celsius) and the surrounding ambient temperature (20 degrees Celsius), we can calculate the temperature gradient and therefore the heat flux.

To get a more accurate calculation, we would need to know the specific thermal conductivity of the tempered glass you are using. This information can usually be found from the manufacturer or by conducting experiments.

Alternatively, if you have access to a thermal imaging camera, you can directly measure the temperature profile of the glass over time. This would give you a more accurate and visual representation of the heat loss.

I hope this helps answer your question. Let me know if you have any further inquiries.
 
  • #3
for any help or tips on how to calculate this.

Hello!

Calculating heat transmission loss (convection) in a thick glass plate requires understanding of various factors such as the material properties of the glass, the surrounding environment, and the heat transfer mechanisms involved.

To calculate this, you can use the Fourier's law of heat conduction which states that the heat flux (rate of heat transfer per unit area) is proportional to the temperature gradient and the thermal conductivity of the material. In this case, the thermal conductivity of tempered glass can be found in engineering handbooks or online resources.

Next, you can use the Newton's law of cooling which describes the convective heat transfer between a solid surface and a fluid (in this case, the ambient air). This law states that the heat transfer rate is proportional to the temperature difference between the solid surface and the fluid, and the heat transfer coefficient of the fluid. The heat transfer coefficient can be found in engineering handbooks or can be estimated based on the properties of the fluid and the flow conditions.

Using these equations, you can calculate the heat transfer rate and the temperature profile within the glass plate over time. However, this calculation may become complicated due to the non-uniform temperature distribution within the glass plate and the transient nature of the heat transfer process. This is where the use of simulation software such as COMSOL or ANSYS Multiphysics can be helpful as they can provide more accurate and detailed results.

If you do not have access to these software packages, you can try using simpler numerical methods such as finite difference or finite element methods to approximate the temperature profile within the glass plate. However, these methods may require some expertise in numerical analysis and programming.

I hope this helps and provides some guidance on how to approach the calculation of heat transmission loss in a thick glass plate. Best of luck with your calculations!
 

1. How is heat transmission loss calculated in a thick glass plate?

The heat transmission loss in a thick glass plate can be calculated using the formula Q = hA(T1 - T2), where Q is the heat loss, h is the convective heat transfer coefficient, A is the surface area of the glass plate, and T1 and T2 are the temperatures on either side of the glass plate.

2. What factors affect the convective heat transfer coefficient in a glass plate?

The convective heat transfer coefficient in a glass plate is affected by factors such as the temperature difference between the two sides of the plate, the properties of the fluid surrounding the plate, the shape and orientation of the plate, and the surface roughness of the plate.

3. How does the thickness of a glass plate impact heat transmission loss through convection?

The thickness of a glass plate can impact heat transmission loss through convection as it affects the surface area of the plate and the temperature gradient between the two sides. Thicker plates have a larger surface area and can allow for a greater temperature difference, resulting in higher heat loss.

4. Is the heat transfer coefficient constant for all types of glass plates?

No, the heat transfer coefficient is not constant for all types of glass plates. It can vary depending on the type of glass, its thickness, and the surrounding environment. For example, a plate with low thermal conductivity may have a lower heat transfer coefficient compared to a plate with high thermal conductivity.

5. How can convection heat transfer in a glass plate be improved?

Convection heat transfer in a glass plate can be improved by increasing the surface area of the plate, increasing the temperature difference between the two sides, and using materials with higher thermal conductivity. Additionally, using fins or other heat transfer enhancement techniques can also improve the overall heat transfer in a glass plate.

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