Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Ryoden Kasei Co., Ltd.

Satoru Toyama

Tsuyoshi Amimoto

Kota Mizuno

Eiichi Nagao

Fukutaro Kato

Junji Tanimura

Shinobu Ogasawara

Yoshihiro Sumida

Susumu Kawaguchi

Noboru Masuda

Hiroshige Konishi

Noboru Hosokawa

Hitoshi Maruyama

Ryota Kuriyama

Tatsuaki Shimizu

Ryuichi Nishiura

Kentaro Taninouchi

Kozo Tachibana

Kenji Kojima

Junji Kobayashi

Hiroshi Kurokawa

Shigeyuki Yamamoto

Hirotaka Muto

Takuho Hirahara

Yoshinori Shirafuji

Hisakatsu Kawarai

Takanori Sone

Sou Suzuki

Noriaki Matsunaga

Eiji Hara

Yasushi Akahori

Yukio Hidaka

Toshifumi Kanri

Shiki Hayamizu

Katsuyuki Kawasaki

Yutaka Hirakawa

Jiro Naka

Noriko Hirano

Akemi Ueyama

Kengo Hiratsuka

Manami Nakamura

Nobuyuki Kamegawa

Takeharu Kageyama

Yoshio Kimura

A refrigeration cycle apparatus including a refrigeration circuit, the refrigeration circuit including a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an expansion valve, wherein a refrigerant is sealed within the refrigeration circuit, the refrigerant contains trifluoroiodomethane, the compressor is filled with a refrigerator oil, and the refrigerator oil contains at least one of a first compound represented by the following chemical formula 1 and a second compound represented by the following chemical formula 2:

Refrigeration cycle apparatus

A temperature estimation method estimating a temperature of a heat generating site in an oil-immersed electric appliance immersed in insulating oil, the insulating oil being silicone oil or ester oil. The temperature estimation method includes measuring concentrations of two types of thermal decomposition products in the insulating oil and calculating a temperature of the heat generating site in the oil-immersed electric appliance based on a concentration ratio between the two types of thermal decomposition products and a relational expression between the temperature of the heat generating site and the concentration ratio prepared in advance. When the silicone oil is adopted as the insulating oil, at least one of the two types of thermal decomposition products is straight-chain siloxane, alcohol containing silicon, or benzene. When the ester oil is adopted as the insulating oil, the two types of thermal decomposition products are fatty acids.

Temperature estimation method

The present invention is a diagnosis method for internal fault of an oil-immersed electric apparatus using a silicone oil as an insulating oil. The method diagnoses an internal fault of the oil-immersed electric apparatus based on a first concentration ratio that is a concentration ratio between two gases selected from an analysis gas group consisting of hydrogen gas, methane gas, ethane gas, and ethylene gas contained in the, silicone oil, and a second concentration ratio that is a concentration ratio between the other two gases selected from the analysis gas group. A combination of the two gases and a combination of the other two gases are a combination of ethylene gas and hydrogen gas, a combination of ethane gas and hydrogen gas, a combination of ethylene gas and methane gas, or a combination of methane gas and ethane gas.

Diagnosis method for internal fault of oil-immersed electric apparatus

The method for diagnosing the oil-filled electrical apparatus in the present invention is a method for diagnosing whether or not discharge has occurred inside the oil-filled electrical apparatus. The diagnosing method includes: an in-oil gases analyzing step of analyzing hydrogen gas and a gas selected from the group consisting of methane, ethane, ethylene, acetylene, hydrocarbon having a carbon number of 3 or 4, carbon monoxide, carbon dioxide, oxygen, and nitrogen, contained in an insulating oil used inside the oil-filled electrical apparatus; a step of analyzing a causative substance serving as a cause of generation of hydrogen in the insulating oil irrespective of whether or not the discharge has occurred; and a step of diagnosing whether or not the discharge has occurred based on an analysis result of the in-oil gases analyzing step and an analysis result of the step of analyzing the causative substance.

Method for diagnosing oil-filled electrical apparatus

An insulating material that tends not to hydrolyze is used to thereby provide a heat pump apparatus having long-term reliability. An electric motor of a compressor is fixed to a sealed container and includes a stator around which a winding wire is wound through intermediation of an insulating material, and a rotor surrounded by the stator. The insulating material is a wholly aromatic liquid crystal polyester (LCP) having a molecular main chain constituted by a monomer including p-hydroxybenzoic acid (PHB) as an essential monomer and a monomer solely including benzene-ring as another monomer via an ester bond. The refrigerating machine oil has a saturated water content of 2% or less at 40 degrees C., a relative humidity of 80%, for 24 Hr. To suppress the explosive decomposition reaction of ethylene-based fluorohydrocarbon, a flame retardant is used to generate chemical species that complement active radicals that cause the decomposition reaction.

Heat pump compressor including liquid crystal polymer insulating material

The present invention is a method for preventing copper sulfide generation in oil-filled electrical equipment having an inhibitor of copper sulfide generation in insulating oil, and the method is characterized in monitoring characteristics of the insulating oil and performing re-addition of the inhibitor at an appropriate moment in accordance with a result of the monitoring.

Method for suppressing copper sulfide generation in oil-filled electrical equipment

The present invention relates to an electric insulating oil inspection method for determining whether or not an inhibitor-consuming substance is present in an electric insulating oil. The inhibitor-consuming substance is such a substance that causes to decrease over time a concentration of an inhibitor which is added to the electric insulating oil to inhibit copper sulfide from being generated on an insulating paper immersed in the electric insulating oil. The electric insulting oil inspection method includes steps of: preserving the electric insulating oil at a predetermined condition, measuring a concentration of the inhibitor, and determining that the inhibitor-consuming substance is present upon condition that a decrement of the concentration of the inhibitor relative to an initial concentration of the inhibitor becomes not less than a specified amount within a predetermined period.

Electric insulating oil inspection method, electric insulating oil treatment method, and oil-filled electric device maintenance method

To obtain water-dispersible varnish used in an alternative refrigerant/refrigerating machine oil refrigerant system or a natural refrigerant/refrigerating machine oil refrigerant system, the water-dispersible varnish being capable of solving two problems, namely, reducing the volatile components and the like during thermal curing and resistance of the cured varnish to the refrigerant system, wherein the water-dispersible varnish has a specific thermosetting resin as base polymer, a specific vinyl monomer as reactive diluent, organic peroxide as reaction initiator, and water mixed therein.

Water-dispersible varnish

An object of the invention is to provide a diagnostic method for an oil-filled electrical device that considers a temperature distribution in the oil-filled electrical device and enables accurate diagnosis to be conducted even when the method is applied to diagnosis of an actually operating device, and further provide a method with which such diagnosis of an oil-filled electrical device can be conducted from a component analysis value of an insulating oil in the oil-filled electrical device. The invention is a diagnostic method for an oil-filled electrical device including in an insulating oil a metal part wrapped with insulating paper, and determines that a time when a surface resistivity of a maximum precipitation site where metal sulfide is most precipitated on the insulating paper reaches a preset surface resistivity management value is a time of occurrence of an abnormality.

Diagnostic method for oil-filled electrical device, diagnostic device for implementing the diagnostic method, and oil-filled electrical device provided with the diagnostic device

A method for analyzing a minute quantity of a material included in a different material is performed in short extraction treatment without taking a long time and the minute content is rapidly analyzed. The method of analyzing a minute content includes mounting on a sample table a sample piece of a material having a minute content of a different material to be analyzed; dropping onto the sample table a solvent for extracting the minute content from the sample piece, so that the solvent is disposed between the sample table and the sample piece; maintaining at room temperature the solvent between the sample table and the sample piece, and, with the solvent maintained between the sample table and the sample piece, extracting the material of the minute content from the sample piece; and analyzing the content extracted from the sample piece.

Method of determining minute amounts of additives in polymers

The present invention provides a method for inhibiting production of copper sulfide in an electrical insulating oil inside an oil-filled electrical apparatus, including adding a benzotriazole compound not having a long-chain alkyl group when the oil-filled electrical apparatus is an open-type oil-filled electrical apparatus, or adding a benzotriazole compound having a long-chain alkyl group when the oil-filled electrical apparatus is a closed-type oil-filled electrical apparatus.

Method for inhibiting generation of copper sulfide

An initial concentration of the residual concentration of a causative substance contained in an insulating oil is compared with a reference value. The causative substance reacts with a conductor forming a winding of an oil-filled electrical device to generate an electrically conductive compound. The reference value is defined as a value for determining whether a main determinant that determines the lifetime of the oil-filled electrical device is generation of the electrically conductive compound or degradation of insulating paper. Based on the initial concentration of the causative substance and the reference value, the lifetime of the oil-filled electrical device is assessed.

Lifetime assessment apparatus and method for oil-filled electrical device, and degradation suppression apparatus and method for oil-filled electrical device

An oil immersed electrical apparatus such as an oil immersed transformer that can detect copper sulfide precipitated on coil insulating paper is provided. In the oil immersed transformer in which a coil with its surface covered by insulating paper is arranged in a container filled with insulating oil, a detection member is prepared by providing two electrodes on a surface of a plate-like pressboard formed of cellulose, which is a same material as that of the insulating paper, this detection member is arranged in contact with the insulating oil, and generation of copper sulfide is detected from reduction in a surface resistance between the electrodes. The temperature of the detection member is set higher than the temperature of the coil so that copper sulfide is generated thereon prior to generation of copper sulfide on a coil unit.

Oil immersed electrical apparatus

A method allowing an accurate diagnosis of a failure of an oil-filled electrical apparatus resulting from production of copper sulfide even with a small amount of an insulating oil is implemented. A diagnostic method for an oil-filled electrical apparatus for diagnosing a failure of the oil-filled electrical apparatus having a copper part disposed in an insulating oil is implemented by detecting at least one compound of bibenzyl and dibenzyl sulfide in the oil of the oil-filled electrical apparatus, to diagnose a failure of the oil-filled electrical apparatus in accordance with the detected amount of the compound. It is configured such that a failure of the oil-filled electrical apparatus resulting from production of copper sulfide can be diagnosed by detecting a specified substance, which allows an accurate diagnosis of a failure even with a small amount of the insulating oil.

Diagnostic method for oil-filled electrical apparatus

A refrigerant circulating system that uses a highly polar refrigerant, as typified by a hydrofluorocarbon-based one, and a refrigerating oil that has slight solubility with a liquid refrigerant on the condensation side. Also, a refrigerant circulating cycle that uses a highly polar refrigerant, as typified by a hydrofluorocarbon-based one, and a refrigerating oil that has a slight solubility with a liquid refrigerant and which has a greater specific gravity than the liquid refrigerant. Thereby, it provides a high electrical insulation and moisture resistance, good oil return to the compressor, and high reliability.

Refrigerant circulating system

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Chiyoda-ku, Japan

Satoru Toyama