Market users reported that the failure of the complete set of vacuum pump units they purchased accounted for the largest proportion, resulting in limited output of vacuum pump and affecting the improvement of condenser vacuum. It has a great impact on the unit economy. In low temperature season, the vacuum pump ejector of unit 6 could not be put into operation, and the output of vacuum pump was limited, resulting in poor condenser vacuum. Now, the fault of "ejector can not be put into operation" of vacuum pump is eliminated, the output of complete set of equipment is increased, and the vacuum of condenser in low temperature season is increased by 0.8kpa.

1、 The reason analysis of vacuum pump ejector can not be put into operation

1. Internal leakage of injector bypass valve

2. Increased mechanical wear

3. Increased mechanical wear

4. Maintenance is not in place

5. Maintenance is not in place

6. Improper formulation of maintenance standards

7. Cooling water temperature is high in low temperature season

8. Excessive water content in ejector air source

9. Improper adjustment of injector flow

During the inspection, it was found that there was no internal leakage in the bypass valve of the injector, and the surface temperature of the injector was stable, not lower than 0 ℃. Check that the temperature difference before and after the injector bypass valve reaches 8 ℃ ~ 15 ℃, indicating that the valve internal leakage is serious, which directly affects the output of the complete vacuum pump device. When the injector is put into operation, the pipe wall temperature changes dramatically from normal temperature to - 15 ℃. The vacuum of condenser fluctuates greatly. Check that the inlet pipe of injector contains a lot of water.

2、 Solution:

1. The air source of injector is changed to atmosphere with relatively low humidity. The air source of the injector is connected to the atmosphere and installed with manual isolation valve and filter screen.

2. In order to eliminate the internal leakage of the valve and repair the modified valve, the reasonable transformation of the replica check valve was carried out, and the pneumatic rubber lined butterfly valve with high reliability was used to eliminate the internal leakage.

After the implementation, the effect comparison shows that: after the transformation of vacuum pump D, the injector is put into normal operation. Under the load of 558mw, the vacuum of the condenser at side B is increased by 0.88 kPa, and the exhaust temperature is decreased by 2.77 ℃. However, the cost of transformation is 100000 yuan, the coal consumption is reduced by 1.8g/kwh, 5184 tons of coal are saved every year, the power generation cost is saved by 2.3 million yuan, and the emission of CO2 and SO2 is reduced.