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Dissolved Gas Analysis
Dissolved gas analysis (DGA) is an examination of electrical transformer oil contaminants. Insulating materials within electrical equipment liberate gases as they slowly break down over time. The composition and distribution of these dissolved gases are indicators of the effects of deterioration, such as pyrolysis or partial discharge, and the rate of gas generation indicates the severity. DGA is beneficial to a preventive maintenance program. The collection and analysis of gases in an oil-insulated transformer was discussed as early as 1928. , many years of empirical and theoretical study have gone into the analysis of transformer fault gases. DGA usually consists of sampling the oil and sending the sample to a laboratory for analysis. Mobile DGA units can be transported and used on site as well; some units can be directly connected to a transformer. Online monitoring of electrical equipment is an integral part of the smart grid. Oil Large power transformers are filled with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Transformer Oil
Transformer oil or insulating oil is an oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled wet transformers, some types of high-voltage capacitors, fluorescent lamp ballasts, and some types of high-voltage switches and circuit breakers. It functions to insulate, suppress corona discharge and arcing, and serves as a coolant. Most often, transformer oil is based on mineral oil, but alternative formulations - with different engineering or environmental properties - are growing in popularity. Function and properties Transformer oil's primary functions are to insulate and cool a transformer. It must therefore have high dielectric strength, thermal conductivity, and chemical stability, and must keep these properties when held at high temperatures for extended periods. Typically, they have a flash point greater than , pour point less than , and a dielectric breakdown at greater than 28 kVRMS. To improve cooling of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Vacuum
A vacuum (: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective (neuter ) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a ''perfect'' vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term ''in vacuo'' is used to describe an object that is surrounded by a vacuum. The ''quality'' of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the chemical formula, formula , called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas (dihydrogen) and in molecular forms, such as in water and organic compounds. The most common isotope of hydrogen (H) consists of one proton, one electron, and no neutrons. Hydrogen gas was first produced artificially in the 17th century by the reaction of acids with metals. Henry Cavendish, in 1766–1781, identified hydrogen gas as a distinct substance and discovere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Ethane
Ethane ( , ) is a naturally occurring Organic compound, organic chemical compound with chemical formula . At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is List of purification methods in chemistry, isolated on an industrial scale from natural gas and as a petrochemical by-product of oil refinery, petroleum refining. Its chief use is as feedstock for ethylene production. The ethyl group is formally, although rarely practically, derived from ethane. History Ethane was first synthesised in 1834 by Michael Faraday, applying electrolysis of a potassium acetate solution. He mistook the hydrocarbon product of this reaction for methane and did not investigate it further. The process is now called Kolbe electrolysis: : acetate, CH3COO− → CH3• + carbon dioxide, CO2 + electron, e− : CH3• + •CH3 → C2H6 During the period 1847–1849, in an effort to vindicate the radical theory of organic chemistry, Hermann Kolbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it is difficult because it is a gas at standard temperature and pressure. In the Earth's atmosphere methane is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Methane is an Organic chemistry, organic Organic compound, compound, and among the simplest of organic compounds. Methane is also a hydrocarbon. Naturally occurring methane is found both below ground and under the seafloor and is formed by both geological and biological processes. The largest reservoir of methane is under the seafloor in the form of methane clathrates. When methane reaches the surface and the Atmosphere of Earth, atmosphere, it is known as atmospheric methane. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Ethylene
Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon bond, carbon–carbon double bonds). Ethylene is widely used in the chemical industry, and its worldwide production (over 150 million tonnes in 2016) exceeds that of any other organic compound. Much of this production goes toward creating polyethylene, which is a widely used plastic containing polymer chains of ethylene units in various chain lengths. Production greenhouse gas emissions, emits greenhouse gases, including methane from feedstock production and carbon dioxide from any non-sustainable energy used. Ethylene is also an important natural plant hormone and is used in agriculture to induce ripening of fruits. The hydrate of ethylene is ethanol. Structure and properties This hydrocarbon has four hydrogen atoms bound to a pair of carbon atoms that are con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Acetylene
Acetylene (Chemical nomenclature, systematic name: ethyne) is a chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure form and thus is usually handled as a solution. Pure acetylene is odorless, but commercial grades usually have a marked odor due to impurities such as divinyl sulfide and phosphine.Compressed Gas Association (1995Material Safety and Data Sheet – Acetylene As an alkyne, acetylene is Saturated and unsaturated compounds, unsaturated because its two carbon atoms are Chemical bond, bonded together in a triple bond. The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of 180°. The triple bond in acetylene results in a high energy content that is released when acetylene is burned. Discovery Acetylene was discovered in 1836 by Edmund Davy, who identified it as a "new carburet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Carbon Dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at normally-encountered concentrations it is odorless. As the source of carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared, infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. It is a trace gas Carbon dioxide in Earth's atmosphere, in Earth's atmosphere at 421 parts per million (ppm), or about 0.042% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.028%. Burning fossil fuels is the main cause of these increased concentrations, which are the primary cause of climate change.IPCC (2022Summary for pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Carbon Monoxide
Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simplest oxocarbon, carbon oxide. In coordination complexes, the carbon monoxide ligand is called ''metal carbonyl, carbonyl''. It is a key ingredient in many processes in industrial chemistry. The most common source of carbon monoxide is the partial combustion of carbon-containing compounds. Numerous environmental and biological sources generate carbon monoxide. In industry, carbon monoxide is important in the production of many compounds, including drugs, fragrances, and fuels. Indoors CO is one of the most acutely toxic contaminants affecting indoor air quality. CO may be emitted from tobacco smoke and generated from malfunctioning fuel-burning stoves (wood, kerosene, natural gas, propane) and fuel-burning heating systems (wood, oil, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. It is a common element in the universe, estimated at Abundance of the chemical elements, seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element chemical bond, bond to form N2, a colourless and odourless diatomic molecule, diatomic gas. N2 forms about 78% of Atmosphere of Earth, Earth's atmosphere, making it the most abundant chemical species in air. Because of the volatility of nitrogen compounds, nitrogen is relatively rare in the solid parts of the Earth. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772 and independently by Carl Wilhelm Scheele and Henry Cavendish at about the same time. The name was suggested by French chemist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Gas Chromatograph
Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture. In preparative chromatography, GC can be used to prepare pure compounds from a mixture. Gas chromatography is also sometimes known as vapor-phase chromatography (VPC), or gas–liquid partition chromatography (GLPC). These alternative names, as well as their respective abbreviations, are frequently used in scientific literature. Gas chromatography is the process of separating compounds in a mixture by injecting a gaseous or liquid sample into a mobile phase, typically called the carrier gas, and passing the gas through a stationary phase. The mobile phase is usually an inert gas or an unreactive gas such as helium, argon, nitrogen or hydrogen. The stationary phase can be solid or li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |