Xi'an Zhengqinghe Environmental Technology Co., Ltd. has been engaged in the technical research and development of generator internal cooling water treatment systems for a long time. The developed nuclear grade internal cooling water resin has a high transformation rate and large work exchange capacity. , long operating cycle and excellent operating indicators Stability and other advantages. Nuclear-grade internal cooling water resin has applied for an invention patent, titled: "A development process of nuclear-grade internal cooling water resin", patent number: 201910932995.8. The nuclear grade internal cooling water resin model is: ZQH-NGWR. Nuclear grade internal cooling water resin is an imported resin with better performance than domestic resin. The resin is regenerated in depth thanks toe to a special process and filled according to a special formula. The resin has undergone strict pretreatment and deep regeneration, which significantly reduces the content of weak and organic leachable polymers and improves the processing rate. The hydrogen type rate of nuclear grade internal cooling water resin cation resin can reach more than 99%, and the hydrogen-oxygen type rate of anion resin can reach more than 95%, which greatly improves labor exchange capacity and lifespan. For 500-600L ion exchangers, the duty cycle can reach two and a half to four years, which is longer than the ordinary internal cooling water resin on the market. After the nuclear grade internal cooling water resin is put into operation, for the stator cooling water system using the alkaline ion exchange method, the pH value of theThe stator cooling water after stable operation is 8.0-9.0, the conductivity is 0.4-1.0? s/cm, Cu2+≤10? The system indicators are better than the internal cooling water quality requirements stipulated in the national standard DL/T801-2010 “Internal Cooling Water Quality and System Technical Requirements for Large Generators”.
How high does the temperature difference between the generator stator coil outlet water and the generator stator coil reach an alarm level and trigger a trip?
Mechanical rotation generates heat. The buildup of this heat will damage the equipment. There is lubricating oil in the friction area, and this oil will become hotter and hotter if the temperature does not decrease, the bearing temperature will increase and the bearing will be damaged.
The circulation of cooling water in the condensateseur is even more necessary, otherwise the steam cannot condense quickly and cannot be transformed into water for recycling.
The generator stator also needs cooling water, because the stator's insulation is likely to break down when it heats up. Cooling water is therefore necessary to ensure that it does not overheat.
If not cooled, the exhaust gases from the steam turbine - the steam that has finished the job will gradually fill the steam turbine cylinder, and there will be no pressure difference. , the steam turbine will not be able to produce electricity.
The pressure difference between intake and exhaust must therefore be maintained. That is, the cylinder should not be filled with low-temperature steam that has finished the job, but should be able to condense into water. The condensation of gas into water is an exothermic process, so the water is cooledmust be used to cool the spent gas. steam (the steam that finished the job) so that it turns into water. This way, even if the back of the turbine is close to vacuum, more and more exhaust gas will fill the cylinder. Once the cooling water is interrupted, the vacuum will not be maintained and may even reach positive pressure. This time is very short, so protection against vacuum reduction is usually activated. Likewise, as the vacuum decreases, the efficiency of the steam turbine decreases. Due to the reduction in efficiency, the temperature of the steam discharged at the rear is naturally higher than before. Once it gets too high, the blades at the back of the steam turbine shrink. the turbine will be deformed by the high temperature and damage the turbine.
When will the generator stator cooling water system be put into operation?
The range ofGenerator coil cooling water temperature is 40-50°C. An automatic adjustment device is provided to adjust the inlet water temperature, and the cooling water temperature fluctuation range is not more than 2°C. The water temperature at the battery outlet must not be higher than 85°C. This is a requirement for 660 MW units. As for alarms and trips, each manufacturer's regulations stipulate this.
Under what circumstances can the generator stator cooling water pressure be higher than the gas pressure in the generator
After the test, it's normal. The generator stator cooling water system can be put into operation after testing everything is normal. Start a water pump, slowly inject water into the stator cooling water system and release the air after the air release is completed, openthe stator output gate completely. Cooling water pump to confirm the vibration of the water pump and bearings. Parameters such as motor temperature and current are normal.
The main process flow of the generator stator cooling water system is:
Stator cooling water tank --- stator cooling water pump --- cooling heat exchanger --- mechanical filter --- magnetic filter ---Generator stator winding---Stator cooling water tankThere are also two special subsystems, a nitrogen purge system and an ion purification system: the nitrogen purge system is installed on the upper part of the stator cooling water tank, with There are two pipelines for supply and nitrogen blowing; ion purification system is a branch of s cooling water systemtator. It mainly circulates part of the water after the mechanical filter through the ion purification system to remove impurities from the front ions. return to the stator cooling water tank.