Equation for heat transfer rate

In summary, the speaker is seeking advice on how to calculate thermal conductivity for a woody pellet using peltier effect. They have identified the fundamental equation and are considering using voltage and current to calculate resistance, but are unsure if this is the correct method. They are still waiting for input from their supervisor.
  • #1
icecool8
6
0
Hi,

I am trying to create an apparatus to measure the thermal conductivity of woody pellet based on peltier effect. the fundamental equation for thermal conductivity is Q"=kA(Δt/Δl), where k is thermal conductivity. A is the area of pellet, Δt is measured by using thermocouple and peltier plate and length of the pellet is known. However, I am not too sure how to calculate the Q" based on the information that I have, Could anyone give me some tips to find the Q" by using other parameters? The one I was think of is using voltage & current from the power supply to calculate the resistance (R) through the pellet , and Q" =ΔT/R, Can I use this equation? Thanks
 
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  • #2
I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?
 
  • #3
Greg Bernhardt said:
I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?

I am still awaiting for the reply from my supervisor from uni to verify my assumption, but at this stage, I don't have answer...
 

What is the equation for heat transfer rate?

The equation for heat transfer rate, also known as the heat transfer equation, is Q = mcΔT, where Q represents the heat transfer rate in Joules per second (J/s), m is the mass of the object in kilograms (kg), c is the specific heat capacity in Joules per kilogram Kelvin (J/kgK), and ΔT is the change in temperature in Kelvin (K).

What factors affect the heat transfer rate?

The heat transfer rate is affected by several factors, including the surface area of the object, the temperature difference between the object and its surroundings, the thermal conductivity of the material, and the type of heat transfer (conduction, convection, or radiation).

How is the heat transfer rate calculated for different types of heat transfer?

The heat transfer rate can be calculated using different equations depending on the type of heat transfer. For conduction, the equation Q = kAΔT/l is used, where k is the thermal conductivity, A is the cross-sectional area, ΔT is the temperature difference, and l is the length of the object. For convection, the equation Q = hAΔT is used, where h is the heat transfer coefficient. For radiation, the equation Q = εσA(T_h^4 - T_c^4) is used, where ε is the emissivity, σ is the Stefan-Boltzmann constant, T_h is the temperature of the hot object, and T_c is the temperature of the cold object.

How does the equation for heat transfer rate relate to the laws of thermodynamics?

The equation for heat transfer rate is derived from the first law of thermodynamics, which states that energy cannot be created or destroyed, only transferred or converted. In this case, the heat transfer rate represents the transfer of thermal energy from one object to another. It also follows the second law of thermodynamics, as heat always flows from a higher temperature to a lower temperature.

What are some real-world applications of the equation for heat transfer rate?

The equation for heat transfer rate has many practical applications in everyday life, such as determining the rate at which food cooks in an oven, calculating the required size of a heater for a room, designing efficient cooling systems for electronic devices, and understanding the behavior of materials in extreme temperatures. It is also used in various industries, including engineering, manufacturing, and energy production.

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