In previous articles we have been seeing what the Kinetic energy and the mechanical energy. In these articles we mentioned thermal energy as part of the energy that influences and possesses the body in question. Thermal energy It is the energy that all the particles that make up a body have. When the temperature fluctuates, the activity of the particles increases. This internal energy increases as the temperature increases and decreases when it is lower.
Now we are going to take a closer look at this type of energy to further complete our knowledge of the different types of energy that exist. Do you want to know more about it? Keep reading.
Characteristics of thermal energy
Thermal energy is the energy that is transferred between systems that are at different temperatures. It manifests itself as the heat we feel when, for example, we touch a surface that is warmer than another. This transfer of energy always goes from a warmer body to a colder one. In this process, thermal energy is distributed until both bodies reach thermal equilibrium, that is, when they are both at the same temperature.
An important characteristic of thermal energy is that it depends on the number of particles in a substance and the speed at which they move. The faster the particles move, the greater the thermal energy.
This energy is also related to changes in the state of matter. For example, by increasing the thermal energy of a solid body, it can reach a point where it changes to a liquid state, and if it continues to gain energy, the liquid becomes a gas.
Examples of thermal energy
Some examples of obtaining thermal energy are the following:
- Nature and the SunThe Sun is the largest source of thermal energy that we know of. Bodies that are exposed to sunlight, such as a rock or water, absorb this energy and their temperature increases.
- Boil waterWhen we apply heat to water, its molecules begin to move faster, until they reach the boiling point. At that moment, the water changes state, going from liquid to gas.
- chimneysFireplaces burn wood and other fuels to generate heat, which increases the thermal energy of the environment.
- exothermic reactionsLike the burning of fuels or the combustion of gasoline in a car engine, these reactions release heat.
- FrictionWhen two surfaces rub together, the friction generates thermal energy. An example would be when our hands get warm when we rub them together.
How is thermal energy produced?
Thermal energy is generated by the movement of particles within bodies. These particles, called atoms or molecules, are in constant motion, and the faster they move, the greater the amount of thermal energy they possess.
An important concept in thermal energy production is that this It is neither created nor destroyed, it is only transformed. We can generate thermal energy through various processes, such as the combustion of fossil fuels, nuclear energy, chemical reactions or simply by contact between bodies of different temperatures.
How is thermal energy used?
Today, thermal energy has many important uses. We can transform it into other forms of energy, such as electrical energy, or use it directly to generate heat. Here are some examples of how it is used:
- In heatingIt is produced using boilers or generators that burn some fuel to heat water, which transports the heat to different areas of the home or building.
- In internal combustion enginesSuch is the case of car engines, where the combustion of fuel generates thermal energy that is converted into mechanical energy to move the vehicle.
- In power plantsThermal power plants use thermal energy generated by burning fuel to heat water; the resulting steam moves turbines that generate electricity.
Measurement of thermal energy
Thermal energy is measured in Joules (J) according to the International System of Units, although it can also be expressed in calories. A calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. Therefore, One calorie is equal to 4,184 joules..
In addition to Joules or calories, other units such as metric tonnes are also used in some contexts. British Thermal Unit (BTU), which is approximately equivalent to 1.055 joules and is used in heating or cooling systems.
Examples of thermal energy in everyday life
Thermal energy is present in many common phenomena and devices. Here are some examples:
- In humans and warm-blooded animals. We maintain our body temperature constant, which implies a continuous expenditure of thermal energy that we produce when breaking down food.
- On metals exposed to the sunOn a hot day, the metal of a car or other metal surface heats up by absorbing heat energy from the sun.
- In household appliancesFurnaces, radiators and heaters use thermal energy to operate.
- In the combustion of wood or coalWhen we light a campfire or barbecue, the thermal energy produced heats the environment and cooks the food.
Common confusions with terms such as heat and temperature
It is common to confuse thermal energy with calorific energy or heat. Although these terms are related, they do not mean exactly the same thing:
- Thermal energy It is the total energy contained in a system due to the motion of its particles.
- Heat It is the transfer of thermal energy from a body with a higher temperature to one with a lower temperature.
- Temperature It is the measure of the average thermal energy of the particles of a body.
It is important to note that although heat and thermal energy are related, heat is not an intrinsic property of a body, but a transfer process, while thermal energy is a property of matter.
Other energies related to thermal energy
Thermal energy is linked to other forms of energy, allowing it to be transformed into various applications. Here are some of these relationships:
Solar thermal
Solar thermal energy is a type of renewable energy that transforms the sun's energy into heat. This type of energy is commonly used for heat the water in homes or to generate electricity through solar thermal plants.
Geothermal Energy
This form of energy comes from the heat stored inside the Earth. Geothermal energy uses this natural heat to produce electricity or heating in a cleaner and more sustainable way.
Electric power
Thermal energy can be converted into electrical energy in thermal power plants, where the heat is used to generate steam and drive turbines that generate electricity, a common process in fossil fuel or nuclear power plants.
The study of thermal energy is essential to understanding how energy is generated and used in our daily lives. From the heat of the sun to the energy we use for cooking, thermal energy has a significant impact on our environment and the way we live.