Kota Mizuno

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The suppressive effect of triazole-based passivators such as 1,2,3-benzotriazole (BTA) and Irgamet 39 and duration of the suppressive effect on copper sulfide deposition are investigated by changing the time when passivators are added to oil. All corrosive sulfur tests were performed by the method stipulated by IEC 62535. In order to simulate the timing for(More)
Copper sulfide deposition on Kraft paper in oil-immersed transformers is found to be accelerated by di-tert-butyl p-cresol (DBPC), which is widely used as an antioxidant, and paraffinic hydrocarbons in their oils, which is verified in laboratory experiments. DBPC can prolong the lifetime of precursors of the copper sulfide deposition by reacting(More)
Copper sulfide deposition on cellulosic insulating materials in oil-immersed transformers is evaluated by heating tests stipulated by IEC 62535. Although this method is suitable for evaluation of the corrosivity of unused insulating oil, the subject remains in diagnosis of the insulating oil used. It is because dibenzyl disulfide (DBDS), which is the prime(More)
Copper sulfide deposition on cellulosic insulating materials in oil-immersed transformers was investigated by heating tests stipulated by IEC 62535 with controlled atmospheres to which mineral insulating oils were exposed. Both oxygen in the atmosphere and 2,6-di-tert-butyl-p-cresol (DBPC) in the oil were found to accelerate the copper sulfide deposition on(More)
Hydrofluoroolefin (HFO) and hydrocarbon (HC) refrigerants have been considered for use in air-conditioning systems and refrigerators as low global warming potential (GWP) refrigerants. These refrigerants are determined the lubrication performance of the sliding parts in compressor. To clarify lubrication performance of unsaturated and saturated refrigerants(More)
Generation of hydrogen from oils with the addition of passivators such as 1, 2, 3-benzotriazole (BTA) and Irgamet® 39 for suppressing copper sulfide deposition was investigated by heating tests. Large amounts of hydrogen were generated from the oils with the addition of Irgamet® 39 compared to the oils with the addition of BTA. BTA is suitable(More)
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