Comprehensive Comparison For Entirely Tubular Pumping Installation And Semi-tubular Pumping Installation

The pumping installation of large and middle scale pump station consists of pump, inlet conduit, outlet conduit, motor and driving device generally, it is the main working body in the pumping station. Tubular pumping installation is divided into two types, one is entirely tubular pumping installation, the other is semi-tubular pumping installation, semi-tubular pumping installation also can be divided into three types further:bulb tubular pumping installation, shaft tubular pumping installation and submerged tubular pumping installation.Entirely tubular pumping installation and semi-tubular pumping installation have each different characters, there are lots of study and application at present, but because of some reasons, lots of people still have the previous understanding for the entirely tubular pumping installation, which is the low efficiency of motor and not high efficiency of pumping installation,it is not much highly known and accepted; With the continuous improvement and development of science and technology level,industrial manufacturing level and the technology of pumping station engineering during the past years, three are much improvement in manufacturing material and process of wet stator coils for entirely tubular motor, the performance of entirely tubular pumping installation has a great improvement and some applications have happened in some area. To know the tubular pumping installation more comprehensively and make all kinds of the tubular pumping installation be applied much better, 3-D tubular flow numerical simulation of the entirely tubular pumping installation and the study of optimum hydraulic design for inlet and outlet conduits have been made in this paper, and according to some relative information, the comprehensive comparisons have been done among these 4 kinds of tubular pumping installations (entirely tubular and rear-positioned bulb tubular, front-positioned shaft tubular, rear-positioned submerged tubular), which included hydraulic performance, unit structure, installation and service, project investment, etc.The main research conclusions are as follows:(1) The hydraulic performance of entirely tubular pumping installation which passed by optimized hydraulic design is excellent; The analysis and comparison show that the hydraulic performance of these 4 kinds of tubular pumping installations are all excellent, Among them, because of the entirely tubular pump eliminates the gap cavitation, its cavitation performance is much better.(2) Semi-tubular pumping installation adopts the normal dry-type motor and normal pump, its pump shaft loads complex force, the gear decelerate transmission applied generally, the number of the bearing are many; Entirely tubular pumping installation’s motor adopts the structure of wet stator, the motor is arranged pump’s outer margin; the pump is normal too, but the motor rotor and pump impeller’s outer margin are welded the whole, vane angel is fixed and not adjustable, the pump shaft loads simple force, no driving device and a few bearings.(3) The pump unit’s structure of entirely tubular pumping installation and rear-positioned submerged tubular pumping installation is integrative, convenient installation; But if the failure, minor repair or major repair is occurred, they need to be served and maintained which carried back to factory; Because of the limited space of the rear-positioned bulb tubular pumping installation’s bulb, the workers enter and exit only through the manhole, and lift the components into and out, installation and maintenance are difficult; The installation and maintenance of front-positioned shaft tubular pumping are medium.(4) Pump unit of entirely tubular pumping installation has characters of compact structure, small axial size and less investment; For this moment rear-positioned bulb tubular pumping installation which adopted the gear transmission still needs international bidding, large equipment investment; Pump unit of rear-positioned submerged tubular pumping installation has characters of compact structure and less civil construction investment, but the equipment investment is much more; Front-positioned shaft tubular pumping installation has moderate investment.(5) With the continuous improvement and development of science and technology level and industrial manufacturing level, the entirely tubular pumping installation has very broad application prospect in engineering, which depended on the unique advantages of simple structure and high reliability.