Question

What is the formula for specific heat dissipation due to convection of oil?

(a) specific heat dissipation = 40.3*(temperature difference of the surface relative to oil/height of the dissipating surface)^1/4  W per m^2 – °C

(b) specific heat dissipation = 40.3 / (temperature difference of the surface relative to oil/height of the dissipating surface)^1/4  W per m^2 – °C

(c) specific heat dissipation = 40.3*(temperature difference of the surface relative to oil * height of the dissipating surface)^1/4  W per m^2 – °C

(d) specific heat dissipation = 40.3*(temperature difference of the surface relative to oil + height of the dissipating surface)^1/4  W per m^2 – °C

I had been asked this question in examination.

I need to ask this question from Temperature Rise in Transformers topic in portion Design of Transformers of Design of Electrical Machines

Answer 1

The correct answer is (a) specific heat dissipation = 40.3*(temperature difference of the surface relative to oil/height of the dissipating surface)^1/4  W per m^2 – °C

To explain I would say: First the temperature difference of the surface relative to oil is calculated, then the height of the dissipating surface is also calculated. Substituting in the above formula provides the specific heat dissipation due to convection of oil.