Characters of head of low head pump station and the pump shaft power areanalyzed. Influence of each single factor on pump shaft power is expressed as change of specificshaft power. (non-dimensional) and the probabilit...Characters of head of low head pump station and the pump shaft power areanalyzed. Influence of each single factor on pump shaft power is expressed as change of specificshaft power. (non-dimensional) and the probability density function is determined. Influences ofmultiple factors on pump shaft power are analyzed. Method of calculating none over-loadedprobability of motor by integration by successive reductions is put forward and then relationbetween power spare coefficient and none over-loaded reliability of electric motor is established.Influences of all factors on pump shaft power being considered completely; power spare coefficientsof motor are calculated in three kinds of heads (changing and unchanging), two kinds of dirty-outconditions. Electrical motor power spare coefficients should be chosen as 1.20 approx 1.44, 1.11approx 1.19, 1.09 approx.14 respectively when pump heads are 4, 7, 9.5 m. The results mean much toreasonable choose of electrical motors in large pump stations, increasing reliability of pump unitsand saving equipment investment.展开更多
The largest RE consumer in China isthe foundry industry.Statistics showthat 46.3% of the total RE consumptionwas used as cast iron additions in 1988.The amount of RE applied in casting inall the steel plants increased...The largest RE consumer in China isthe foundry industry.Statistics showthat 46.3% of the total RE consumptionwas used as cast iron additions in 1988.The amount of RE applied in casting inall the steel plants increased twice inthe past ten years.Many spare parts for metallurgical ma-chinery including wearing piates,grin-ding balls,sludge pumps,carriers of sin-tering machine,ingot molds,rolls,draw-ing heads,guides,pipes,cylinder casings,gears,etc.,are made out of RE-treatednodular-,vermicular-,and gray cast iron,展开更多
文摘Characters of head of low head pump station and the pump shaft power areanalyzed. Influence of each single factor on pump shaft power is expressed as change of specificshaft power. (non-dimensional) and the probability density function is determined. Influences ofmultiple factors on pump shaft power are analyzed. Method of calculating none over-loadedprobability of motor by integration by successive reductions is put forward and then relationbetween power spare coefficient and none over-loaded reliability of electric motor is established.Influences of all factors on pump shaft power being considered completely; power spare coefficientsof motor are calculated in three kinds of heads (changing and unchanging), two kinds of dirty-outconditions. Electrical motor power spare coefficients should be chosen as 1.20 approx 1.44, 1.11approx 1.19, 1.09 approx.14 respectively when pump heads are 4, 7, 9.5 m. The results mean much toreasonable choose of electrical motors in large pump stations, increasing reliability of pump unitsand saving equipment investment.
文摘The largest RE consumer in China isthe foundry industry.Statistics showthat 46.3% of the total RE consumptionwas used as cast iron additions in 1988.The amount of RE applied in casting inall the steel plants increased twice inthe past ten years.Many spare parts for metallurgical ma-chinery including wearing piates,grin-ding balls,sludge pumps,carriers of sin-tering machine,ingot molds,rolls,draw-ing heads,guides,pipes,cylinder casings,gears,etc.,are made out of RE-treatednodular-,vermicular-,and gray cast iron,
