The variety of thermal energy results in various examples of heat transfer , which are produced by a temperature gradient .
In turn, the transfer of heat or thermal energy is mediated by thermodynamics , a branch of science that is responsible for investigating the interaction of a thermal gradient and heat transfer.
Examples of heat transfer with their characteristics
1. By bathing in a cold tub
Generally, our body produces internal heat and when we bathe with cold water, a heat transfer occurs through the convection process.
Therefore, the body releases a flux of variable density and avoiding the breakdown of the balance between internal heat and convection towards a cold temperature liquid .
For its part, when bathing in a cold tub, the body adapts due to thermal transfer and the temperature gradient changes, modifying the internal environment.
2. Hot air balloons
One of the examples of heat transfer by means of convection, a process of thermodynamics, is hot air balloons when they are in flight.
This function is due to the production of heat in the air , which makes the balloon remain suspended.
However, when there is a cooling or thermal change in the air, the balloon begins to descend until it touches the surface or ground.
3. The ice when it melts
The direct action of fire towards a body of cold or warm temperature complies with the properties of thermodynamics .
On the other hand, if we put a cup of hot water and add ice, it melts through the drastic change of the thermal gradient in the physical environment.
Consequently, when ice comes into contact with direct heat, it transforms from a solid body to a liquid thanks to the temperature gradient.
4. The microwave oven
An example of radiation with the direct action of heat transfer is the microwave and the propagation of electromagnetic waves .
According to this example, a different thermal gradient target is brought into contact with microwave electromagnetic waves; so that it interacts with the temperature.
In this sense, electromagnetic waves and kinetic force cause heat energy that is directly proportional to the time that determines the action.
For example, a liquid in a porcelain container enters the microwave, if we adjust the time, the action will depend on the time interval.
5. Hot water
When boiling water, various thermal or heat transfer processes occur, such as condensation, boiling, and evaporation.
Subsequently, the water container in the metal case can come into contact with the fire (thermal mediator) and change the physical properties of the liquid.
When exposed to high temperatures, evaporation occurs, which transforms the liquid body into a gas.
Consequently, there is a change in temperature over time through the conduction of a thermal element to a given body or matter.
6. The sun
The climate on our planet is mediated by the action of the sun and the emission of ultraviolet rays.
This is another radiation process, which determines the earth’s temperature gradient.
On the other hand, the conditions of a temperature vary with other physical factors and direct interaction with the sun.
With regard to solar radiation, it is in charge of establishing the time zone in the countries, thermal changes and the seasons.
7. Water vapor
The convection process is a physical action in the migratory movement of the particles or molecules of a gaseous and liquid substance.
Next, the heat emanating from the interaction of a liquid or gas transforms the molecules in question through the condensation process .
Therefore, the liquid can go to the gaseous state and this thermal process is known as evaporation , which expands thanks to the temperature gradient.
For example, steam can mist the glass if there is hot water in the shower, this is due to the temperature gradient in the liquid.
8. The dryer
One of the examples of heat transfer is that produced by this household appliance. The dryer produces heat through forced convection, generating a thermal gradient in the form of direct gas.
One of the thermodynamic processes in question and where the electrical component participates is the light emitted to a light bulb.
Therefore, if we light an electric light bulb, it will produce a heat transfer through the effect of electricity.
This process is known as radiation, which causes the electric field to have a higher temperature than the object (light bulb).
Therefore, without electricity, the object would remain at a normal temperature and thermodynamics would not come into play.
10. Ionizing radiation
Finally, the propagation of gamma rays and, in turn, ionizing radiation produces heat through this process, generating changes in temperature gradients.
For example, a nuclear power plant has a core and through it, chemical and physical radiation propagates, causing heat and thermal energy.
In conclusion, heat transfer is determined by three fundamental elements: conduction, convection and radiation.