Francis turbine runner with ultra-low specific rotating speed specially used for driving cooling tower fan

Abstract

The invention relates to a Francis turbine runner with ultra-low specific rotating speed specially used for a driving cooling tower fan, which effectively solves the problems of the matching of the water turbine runner and the water flow system of the cooling tower and the fan parameters and the reduction of noise and vibration; the structure of the Francis turbine runner is characterized in that vanes are uniformly distributed between an upper coronal and a lower ring; the diameter ratio of a runner inlet and a runner outlet is 1.5-2.5; the ratio of the height of the runner inlet edge and the diameter of the runner outlet is 0.07-0.1; the specific rotating speed of the runner is 60-70m.kW; the unit rotating speed is 40-500r / min; therefore, characteristics of ultra-low rotating speed and ultra-low unit rotating speed are formed; and the space between the vane inlet and the vane outlet is a bent shape and the bending degree is decided by the difference of the vane inlet installation angle and the vane outlet installation angle and the amount of the vanes is 10-19. The Francis turbine runner has unique structure, ultra-low specific rotating speed and ultra-low unit rotating speed, sufficiently utilizes water flow energy, carries out conversion effectively and has excellent stability and huge economical and social benefits.

Description

1. Technical field [0001] The invention relates to a water turbine, in particular to a special-purpose ultra-low specific speed mixed-flow water turbine runner for driving a cooling tower fan. Without using a reducer, the speed of the water turbine can be matched with the cooling tower fan to realize the high efficiency of the hydrodynamic fan driving device. , cheap and low noise. 2. Background technology [0002] At present, there is no water turbine runner suitable for industrial cooling tower fans in my country. Existing impact turbine runners are designed for hydroelectric power generation, the specific speed is generally between 100-1000m.kW, and the unit speed is between 60-150r / min. The specific speed of the water turbine in the cooling tower needs to be between 50 and 70, and the unit speed needs to be between 35 and 45. It can be seen that the runner of the water turbine for power generation is not suitable for directly driving the fan of the cooling tower. [0...

AI Technical Summary

Problems solved by technology

[0005] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a cooling tower fan-driven special ultra-low specific speed Francis water turbine runner, which can effectively solve the problem of the water flow system between the existing water turbine runner and the cooling tower. The parameters of the fan are matched, and it can be directly connected to the fan without a reducer, so that the structure of the water turbine device is simplified, efficient, and the manufacturing cost is low. It can also reduce the problems of noise and vibration. The technical solution is to include the above The crown, blades and lower ring, the blades are evenly distributed between the upper crown and the lower ring, the runner has a large ratio of inlet and outlet diameters, the ratio of the runner inlet diameter to the runner outlet diameter is 1.5 to 2.5, the runner inlet side The ratio of the height to the inlet diameter of the runner is between 0.07 and 0.1, the specific speed of the runner is 60-70m.kW, and the unit speed is 40-50r / min, which constitutes the characteristics of ultra-low specific speed and ultra-low unit speed. The blade inlet and outlet are curved, and the curvature is determined by the difference between the blade inlet placement angle and the blade outlet placement angle. The difference between the blade inlet placement angle and the blade outlet placement angle is 100°-125°, and the number of blades is 10. ~19 pieces, the present invention is simple in structure, novel and unique, with ultra-low specific speed and ultra-low unit speed, the runner has innovative flow path parameters, the runner flow path has a large ratio of inlet and outlet diameters, and the blades have large curvature It effectively ensures the good matching between the turbine speed and the cooling tower fan, and can make the turbine and the fan directly connected, and at the same time make the water flow energy fully utilized in the runner to realize the efficient conversion of water flow energy in the runner, which has a good performance stability, huge economic and social benefits

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