| The large bulb tubular pump system is suitable for the low head pump station, because of its straight flow, high efficiency and low investment. But the motor of bulb tubular pump unit, embedded in the enclosed bulb, has bad operation environment and requires better cooling facilities. The investigate ventilation cooling of the large bulb tubular pump unit was studied under the financial of Project Supported by National Science and Technology Major Project of China in the Eleventh Five-year Plan, Project Supported by Author Special Foundation of National Excellent Doctoral Dissertation of China and so on. The main research works and results are as follows:(1) Influences of the pump unit structure on choosing cooling methods were summed up. Water cooling effect outside of the bulb shell on motor was analyzed, and motor average temperature rise was calculated. The motor average temperature rise of Huai’an third pumping station is37.25K, and that of Huaiyin third station is31.53K.(2)Influences of motor operation power, non-uniform air-gap, manufacture errors, air temperature&humidity and eletricity voltage wave on motor temperature rise were researched. The results indicate that the highest temperature of the motor in the hot air export is at the smallest gap when a motor has non-uniform air-gap. The motor temperature rise of Huaiyin third station is11.20～24.62℃. The correctness of the theoretical results are validated by the motor temperature testing data.(3) The cooling way characteristics were analyzed. The typical motor cooling mode cooling effects and energy consumption were researched. The methods of choosing ventilation cooling ways and improving system performances were put forward. Under the premise of cooling effects, the influences of dust scaling of ventilation on the overhaul periodic and expenses were considered. Different ventilation modes were compared in economy. Two new cooling modes, which are air-inlet filtering dedusting mode for an open cooling mode and close ectotheca air duct mode using stainless steel bulb shell without lacquer, were put forward. The results indicate that open forced air-cooling and outer water-cooling system has the best installation, maintainability and reliability. Closed forced circular air-cooling system is complicated. The new ventilation cooling modes could realize clean ventilation, prolonging overhaul periodic, saving overhaul expenses and also having advantages in economy.(4) The environmental temperature time distribution was analyzed. Relation of motor temperature to environmental temperature and ventilation volume was established. The constant volume fun operation cost was calculated. The constant speed fun operation quantity and the frequency conversion fan ventilation volume were identified. The operation cost of different fan system was compared. The results indicate that7.24～7.44and17.91～22.66thousand Yuan could be saved respectively by the constant speed and the frequency conversion system per year. The energy-saving rate is more than28.9%. Frequency conversion add equipment cost would be recovered in1-1.3years. The conclusions are useful for improving the cooling system operation economy.Main creative points in the diddertation are as follows:(1) Typical bulb tubular pump unit motor cooling modes were analyzed and compared. Two new cooling modes were put forward, and they have advantages in economy.(2) Influences of motor motor operation power, non-uniform air-gap, manufacture errors, air temperature&humidity and eletricity voltage wave on motor temperature rise were researched. Ventilation volume was identified reasonably.(3) The fun number of constant speed ventilation system was confirmed. The frequency conversion ventilation was put forward to optimize fans operation cost. The results indicate energy saving effect of the frequency conversion ventilation is obvious. |
PDF Full Text Request