Combined cutoff device for large axial flow pump

Abstract

The invention discloses a combined cutoff device for a large axial flow pump. A straight water outlet flow passage of each water pump is uniformly partitioned into two parts by a concrete partition pier on the plane, the combined cutoff device formed by a rapid gate and a co-seat multi-leaf side-turning flap valve is arranged on each part of the water outlet flow passage of each water pump, and each rapid gate is arranged on one side, close to the corresponding water pump, of the corresponding side-turning flap valve. Each rapid gate is controlled by a hydraulic host, and closed gate shafts are adopted. By cooperation of the rapid gates and the side-turning flap valves, the requirement of valve-opening starting of the axial flow pump can be met, startup-shutdown procedures are simple, cutoff reliability is achieved, and safety of units and pump stations is guaranteed.

Description

technical field [0001] The invention relates to the technical field of water conservancy engineering, in particular to a large-scale axial-flow pump combined flow-cutting device. Background technique [0002] Axial flow pump is the main pump type suitable for low-lift and high-flow pumping stations. Its start-up and shutdown characteristics are as follows: (1) Limited by the characteristics of the water pump, the axial-flow pump needs to be started with the valve open to reduce the pump’s starting shaft power. Avoid causing the motor to stall during start-up. (2) After the water pump is shut down, it is necessary to reliably cut off the flow, so as to avoid the backflow of the water flow through the unit after the shutdown, causing the unit to reverse and cause flyaway, which will cause harm to the unit and the pump station building. [0003] According to the different forms of the outlet flow channel, the current shut-off methods for large axial flow pumps include the foll...

AI Technical Summary

Problems solved by technology

At present, there are generally the following methods for cutting off the straight pipe outlet flow channel: ①, single pump flow rate 8m 3 When / s and below, the overall free-style flap is used. At present, the energy-saving side-turn flap is basically used to cut off the flow; ②, the flow rate of a single pump is greater than 8m 3 / s, fast gates, double-section free integral flap gates or integral control flap gates are selected. Safety discharge facilities should be provided for these two cut-off methods. Due to the jacking up of the high water level on the outer river side, it is difficult to set up overflow facilities. If a small flap gate is installed on the fast gate as an overflow facility, the design and manufacture of the fast gate will be more demanding, and because the gate body The opening of a small flap gate increases the failure rate of the fast gate; if a controlled flap gate is used as the cut-off device, a set of hydraulic control device must be added. It is very difficult, and improper setting will bring a greater threat to the safety of the project and equipment; ③, the flow rate of a single pump is greater than 8m 3 The / s axial flow pump unit adopts a large side-turning flap door to cut off the flow. The page size will also increase, and the closing force of the flap door will also increase. The large closing force will bring potential hazards to the safe operation of the flap door; in addition, the increase in the size of the door page will cause the length of the sealing surface to increase, and consequently This will increase the amount of water leakage, especially when the water level on the outer river side is high, which will make it difficult for the maintenance and drainage of the unit, and even make it impossible to remove the accumulated water in the flow channel; if several units in the pumping station share one outlet box culvert, when When the side flip flap door leaf is damaged, the entire pump station will not be able to operate

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