Air occupies a certain amount of space, but it has no fixed shape or volume. When pressure is applied to air in a closed container, the volume of air is compressed, thereby increasing the internal pressure. When the external force is removed, the air returns to its original volume under the action of internal pressure. If there is a moving object in the container, when the air returns to its original volume, the object will be pushed outward by the air pressure in the container. This principle is widely used in production and life. For example: if compressed air is put into a balloon, the more it is inflated, the harder the balloon will be; if compressed air is put into a tire, the tire can support a certain weight. In large cars, compressed air is used to open and close doors and brakes; hydraulic presses use compressed air to pressurize water; In factories, compressed air is used to drivepneumatic hammers for striking iron in coal mines; pneumatic picks for drilling holes. Compressed air is also used in pipelines to transport liquids and granular objects.
Compressed air is the second largest source of energy after electricity, and it is also a source of process gas with multiple uses. Its application area covers petroleum, chemical industry, metallurgy, electric power, machinery, light industry and textiles. , automobile manufacturing, electronics, food, medicine, biochemistry, national defense, scientific research and other industries and departments. What is not ideal is that compressed air contains a considerable amount of impurities, mainly: solid particles - in a typical large city environment there are around 140 million particles per meter cube of atmosphere, of which about 80% are smaller. 2μm, the filtere suction of the air compressor cannot eliminate it. In addition, wear debris, rust residue and oil carbides will continue to be produced inside the air compressor system, which will accelerate the wear of gas equipment and lead to failure of the gas equipment. joints - relative humidity in the atmosphere usually reaches 65; % or more, which often After compression and condensation, it becomes saturated and humid air and results in a large number of liquid water droplets. They are the cause of corrosion of equipment, pipes and valves. Frost in winter will also block small holes. the pneumatic system. It should be noted that even if separated from pure saturated air, the condensed water will escape when the temperature decreases. Approximately every 10°C of drop, its saturated water content will decrease by 50%, or half of the water vapor. will be converted into liquid water droplets (see Table 1). By coTherefore, it is necessary to use multi-stage separation and filtration devices in the compressed air system or to pre-treat the compressed air into dry gas with a certain relative oil content - the use of lubricating oil for air compressors operating at high speed and; high temperature may play a role. It has lubricating, sealing and cooling functions, but it pollutes the compressed air. Although oil-free, semi-oil-free and fully oil-free motors developed from self-lubricating materials reduce the oil content of compressed air, they also result in reduced life of wearing parts, corrosion of parts internal damage to the machine and piping system, as well as air pollution. The press has side effects such as increased oil content during the break-in period, wear period and load reduction period. It isit undoubtedly poses a threat to automated production lines that seek high reliability. It should also be emphasized that the oil brought into the system by the air compressor is not beneficial in any way. Because after many times of high temperature oxidation, condensation and emulsification, the performance of the oil has been greatly reduced and it is acidic. Not only does it fail to lubricate subsequent equipment, it also destroys normal lubrication – in pharmaceuticals and bioengineering; , foodDuring the product manufacturing and packaging process, bacterial and phage contamination cannot be ignored.
How to store excess electricity from the national grid?
Electricity generation methods include: thermal power generation, power generation hydroelectric, nuclear power generation, wind energy production, geothermal energy production. , etc.
Power generation refers to the production process of using power generation devices to convert raw energy such as water energy, thermal energy from petrochemical fuels (coal, oil, natural gas), nuclear energy, etc. .in electrical energy.
Electricity generation is used to meet the needs of various departments of the national economy and people's lives.
Nowadays, fossil fuels are still used as the main form of electricity generation, but fossil fuel resources are not plentiful and are becoming increasingly depleted. Human beings gradually began to use solar energy, wind energy and geothermal energy. , ocean energy and other energy sources to generate electricity.
What does it mean that compressed air energy storage is a physical form of energy storage?
State Grid's methods of storing excess electricity are as follows:
1. Pumped hydroelectric storage: This is the most commonly used method today. Pumped storage power plants use excess electrical energy supplied by the electrical system to pump water from the lower reservoir to the upper reservoir when the electrical load is low or during flood periods, and store it as water. potential energy until power is reached. the system load is reaching its maximum or the water is dry. During the season, water from the upper tank is released and sent to the electrical system. However, this method is easily limited by geographical conditions and there will be considerable energy loss in the process ofwater pumping and electricity production.
2. Battery energy storage: Batteries can convert electrical energy into chemical energy and store it, such as lead-acid batteries, lithium-ion batteries, etc. Batteries can release stored energy when the electrical system needs it.
3. Compressed Air Energy Storage: When there is excess electricity, the excess electricity can be used to drive a compressor to compress air and store it in underground gas storage when electricity is needed ; compressed air can be released to drive a turbine. Generators produce electricity.
4. Flywheel Energy Storage: This is a method of mechanical energy storage that uses a motor (generator) to convert electrical energy into rotational kinetic energy of the flywheel.
5. Energy storage by superconducting coil: the storage of energyDC electricity in the form of a magnetic field in a superconducting spiral tube is an inductive energy storage.
6. Supercapacitor Energy Storage: Including electrical double-layer capacitors and Faraday quasicapacitors, which can enable rapid storage and release of electrical energy.
What is compressed air used for?
Compressed air energy storage is a physical form of energy storage, that is, the air only has temperature during the entire process.
Compressed air energy storage technology uses compressed air to store energy. Currently, compressed air energy storage technology is the second largest technology considered suitable for large-scale electrical energy storage at the GW level, after pumped hydroelectric energy storage. Its operating principle is that during periods of low consumptionelectric, electrical energy is used to compress air to high pressure and stored in caves or pressure vessels, so that the electrical energy is converted into the internal energy of the air and stored during peak periods ; of electricity consumption, high pressure air is exhausted from the air storage chamber. It is released and burned in the combustion chamber to use the fuel to heat and drive the turbine to produce electricity.
Detailed information:
From its principle, it can be known that compressed air stores a large part of energy, which is converted into heat energy during the compressed air process and is not used efficiently . This is an important reason for this. low efficiency of this technology. In order to improve the efficiency of the compressed air system, the heat generated during the compression process can be stored in a heat storage device. This part of the heat can be used to preheat the compressed air during the electricity generation process to achieve this goal. heat recovery. This technologyology improved, this system has not yet been implemented in real demonstration projects. The biggest challenge facing the system is how to ensure the constant heat storage of the heat storage device and how to achieve a more economical and reasonable system. design.
Baidu Encyclopedia - Compressed Air Energy Storage
Compressed air is the energy source for pneumatic tools and pneumatic instruments. The principle is to use kinetic energy generated by air compression, such as tire inflation, spray paint guns, steam nail guns, large car brakes, motorcycle brakes , pneumatic picks, pneumatic drills, pneumatic fire extinguishers, pneumatic components, pneumatic instruments, pneumatics. valves, pneumatic steam hammer,......