In the condensing power plant, most of them will use the rotary vane vacuum pump as the extraction equipment of the condenser. This paper introduces the application of the rotary vane vacuum pump in the condensing power plant.
rotary vane vacuum pump structure:
Rotary vane pump is mainly composed of pump body, rotor, rotary vane, end cover, spring, etc. A rotor is installed eccentrically in the cavity of the vane pump, the outer circle of the rotor is tangent to the surface of the pump cavity (there is a very small gap between the two), and two discs with springs are installed in the rotor groove. During rotation, the centrifugal force and spring tension keep the top of the rotary vane in contact with the inner wall of the pump chamber, and the rotation of the rotor drives the rotary vane to slide along the inner wall of the pump chamber. Rotary vane vacuum pump is one of the most basic vacuum equipment in vacuum technology. Rotary vane pumps are mostly small and medium-sized pumps. There are two types of rotary vane vacuum pump: single stage and double stage. The so-called two-stage is to connect two single-stage pumps in series in the structure. Generally, it is made of two-stage to obtain a higher vacuum. The rotary vane vacuum pump can pump out the dry gas in the sealed container. If it is equipped with a gas ballast device, it can also pump out a certain amount of condensable gas. However, it is not suitable for pumping gases with high oxygen content, corrosive to metals, chemical reaction to pump oil and dust particles.
The rotary vane vacuum pump is a two-stage direct connection structure. Its working performance is composed of high-pressure stage and low-pressure stage. Its suction port is connected with the vacuum equipment. During operation, a large amount of gas in the container will be inhaled and discharged. When the equipment obtains vacuum, the high-pressure stage exhaust valve will be closed, and the gas inhaled in the high-pressure stage will be transferred to the second stage, and then inhaled and discharged through the second stage. In this way, the vacuum equipment A certain amount of vacuum can be obtained. The technical parameters of the pump are 6 × 10-2. The pump is connected with the motor, with high speed, small appearance, compact structure and convenient liquidity.
The gas from the condenser is divided into condensable gas and non condensable gas. One part of the condensable gas condenses when it meets the injected sealing water at the inlet of the rotary vane vacuum pump, another part of the condensable gas condenses when it meets the sealing water in the pump, and another part of the condensable gas and all the non condensable gas are discharged out of the pump together. The seal water is only related to the output of vacuum pump.
When the rotary vane vacuum pump is used in the condensing power plant, the temperature of the mechanical seal water can be kept within 30 ℃ in summer, which ensures the output and improves the vacuum of the condenser.
Advantages of rotary vane vacuum pump in condensing power plant:
1. The advantage of rotary vane vacuum pump is that the vacuum degree of the new pump is relatively high.
2. The gas compression in the rotary vane vacuum pump is isothermal. Because there is no exhaust valve and friction surface, the mixture of dusty gas, condensable gas and gas water can be removed.
3. Simple structure, low demand for manufacturing accuracy, simple processing and compact structure.
4. It is equipped with pump stop and oil return prevention device, which is convenient to start again.
5. It is equipped with an air valve to pump out a small amount of water vapor.
6. The exhaust port is equipped with an oil mist catcher to avoid environmental pollution.
7. It can maintain high pumping speed under low pressure and strong.