Geothermal energy is a long-term source of energy worldwide. With the geothermal energy stored in the top three kilometers of the Earth's crust, theoretically, the current energy demand could be covered for more than 100,000 years. However, only a small part of this energy is technically usable and the effects on the earth's crust during extensive heat dissipation are not yet clear.
When geothermal energy is used, a distinction is made between direct use, that is, the use of heat in itself, and indirect use, the use for conversion into electricity in a geothermal power plant. With the…
Geothermal energy is a type of renewable energy on a human scale that is obtained from the heat of the interior of the Earth. Equestrian thermal energy can be obtained without the combustion of any material, it is therefore a form of clean energy without carbon dioxide emissions.
The temperature in the inner layers of the Earth remains constant during the different seasons of the year. Generally the inner layers are hotter than the surface in winter and cooler in summer. This is because the surface layers are heated and cooled more easily according to the laws of thermodynamics.…
A solar thermal collector is a component of a solar thermal installation. A solar collector is a type of solar panel responsible for capturing solar energy and transforming it into heat. It is also called the solar thermal collector.
The solar collector is the basic element of this renewable energy source.
From solar collectors there are many types. The solar collector used will depend on the use that is going to be given. For example, if we want to heat a pool to a temperature of 25-28ºC, in the spring, we need a simple sensor, since the ambient temperature will easily be…
A solar concentrator is a concentration system of solar energy that is used to convert solar energy into thermal energy. Its operation is based on the exploitation of the reflection of the solar rays obtained through reflective surfaces (substantially of mirrors), in order to concentrate on a receiver of contained size. Similar to a magnifying glass focusing its light on a point, the concentrators reflect sunlight by means of an arrangement of mirrors aligned towards a lens capable of capturing that energy for its use.
In general, heat is converted into mechanical energy by means of…
In physics, in particular in thermodynamics, heat is defined as the contribution of transformed energy as a result of a chemical or nuclear reaction and transferred between two systems or between two parts of the same system. This energy is not attributable to a job or a conversion between two different types of energy. Heat is, therefore, a form of transferred energy and not a form of energy contained as internal energy.
As the energy is exchanged, the heat is measured in the International System in joules. In practice, however, it is often still used as the unit of measurement of calories,…
Thermodynamics is the branch of classical physics that studies and describes the thermodynamic transformations induced by heat and work in a thermodynamic system, as a result of processes that involve changes in the temperature and energy state variables.
Classical thermodynamics is based on the concept of macroscopic system, that is, a portion of physical mass or conceptually separated from the external environment, which is often assumed for convenience that is not disturbed by the exchange of energy with the system. The state of a macroscopic system that is in equilibrium conditions…
One of the applications of solar thermal energy is the obtaining of sanitary hot water (ACS). Solar collectors capture the energy of solar radiation to increase the temperature of a fluid.
Domestic hot water (DHW) is water intended for human consumption (potable) that has been heated. It is used for sanitary uses (bathrooms, showers, etc.) and for other cleaning uses (washing dishes, washing machine, dishwasher, floor scrubbing). In terms of energy, the ACS is an important component to take into account, since it represents between 25 and 40% of the energy consumption of homes.
We refer to hight-temperature solar thermal to those collectors who work at temperatures above 500 ° C. They are used for power generation.
The technologies used in hight-temperature solar thermal energy are:
Parabolic trough solar collectors…
- Parabolic trough solar collectors
- Central tower
- Parabolic dishes or parabolic reflector
- Linear Fresnel concentrators
Low-temperature solar thermal energy is used in applications that require temperatures between 100ºC and 250ºC. From 80ºC the flat collectors practically no longer have any performance and it is necessary to resort to other capture systems.
Low-temperature thermal energy systems are used mainly for applications that demand thermal energy, that is, heat between 125º C and 400º C. To reach higher temperatures it is necessary to concentrate the solar radiation.
For this type of solar thermal energy, two types of solar collectors are used:
These equipments have a natural circulation based on convection currents formed in the fluid at different temperatures.
If we heat a water tank at the bottom when the bottom water warms, it becomes less dense and rises to the surface where it cools. Then returns to the bottom of the container and thus a natural circulation flow is generated.
This is the operating principle of a thermosiphon team, which will be essential that:
- The solar collector (heat sources) is always located below the level of the accumulator.
- The primary circuit is as short as possible…
Low thermal solar installations are considered those installations that provide useful heat at temperatures below 65ºC through solar energy.
A low-temperature solar thermal installation consists of solar collectors, two water circuits (primary and secondary), heat exchanger, accumulator, expansion vessel and pipes.
Circulation of the water inside the circuits can be obtained by thermosiphon, taking advantage of the density difference of the water at different temperatures or by means of a circulation pump, although in this case an external contribution of electrical energy…
The solar thermal energy consists of the use of energy from the Sun to transfer it to a medium that carries heat, usually water or air.
Among the different applications of solar thermal energy there is the possibility of generating electric power. The current technology allows to heat water with solar radiation to produce steam and subsequently obtain electrical energy.
Although the principle of operation is very similar there are two main applications of solar thermal energy:
- Thermal single energy for use in homes and small installations
- Large thermal solar…
The geothermal heat pump is an air conditioning system for buildings that exploits the heat exchange with the superficial subsoil, by means of a heat pump. Since the heat in the subsoil comes largely from the interior of the Earth, geothermal energy of low enthalpy is classified as a source of renewable energy, although the heat pump itself consumes electricity, generally produced from other sources of energy (for example, fossil fuels).
The heat pump allows the exchange of heat between a "source" at a lower temperature than the "well", or the point where the heat is introduced. In a…
A solar collector of vacuum tubes is a type of solar panel that takes advantage of solar thermal energy. This type of solar panel is formed by linear collectors housed in vacuum glass tubes.
The solar collector of vacuum tubes consists of a set of cylindrical tubes. The tubes are formed by a selective absorber, located on a reflector settlement and surrounded by a transparent glass cylinder.
Between the transparent outer tube and the inner absorber, the vacuum has been made. With this, conduction and convection losses from the absorbent surface are avoided and this fact allows…