Application of new technology of small water motor
After more than 40 years of development, China's small and medium-sized hydropower and rural power grids have formed a large industry, making great contributions to local economic and social development. At the same time, it has accumulated rich experience in practice and made great progress. It has not only achieved new achievements in engineering design, construction, equipment manufacturing, operation and maintenance, but also in the application of new technologies and the development of new equipment. A lot of results have been achieved. In order to improve the technology and operation level of medium and small hydropower and power grids in order to achieve maximum economic benefits, technological innovations in rural hydropower and equipment are very important. At present, the main new technologies in small hydroelectrics are:
- Pressure regulating valve. When the ∑LV/H of the long-pressure water diversion tunnel of a hydropower station is greater than 15-30, it is generally necessary to set up a surge tank, but the volume control well has a large amount of civil works, a long construction period, and an ideal terrain. The medium and small hydropower station uses a pressure regulating valve. Replacing the surge tank can save investment and shorten the construction period. The function of the pressure regulating valve is to open quickly when the load shedding guide vane is quickly closed. The flow through the unit is discharged from the pressure regulating valve. After the standby group is closed, the pressure regulating valve is slowly closed, so that the flow rate of the water diversion system is slowly changed, and the water pressure of the water diversion system is increased and the unit is flying.
- Guide vane control mechanism. For small and medium-sized hydropower units that bear the base load in the power grid, because they do not need to be frequency-modulated, the mechanical hydraulic governor with complicated structure, high price and high maintenance and operation cost can be eliminated, and the structure is simple and reliable, the price is low, and the maintenance operation cost is low. Replace the TC spring accumulator manual or hydraulic operator. When the unit operation power supply disappears, the spring energy storage can be used to automatically shut off the turbine, and the segmentation can be realized. When used together with the microcomputer water turbine speed control, the frequency modulation can also be performed.
- Automatic control system of the unit. The unit automatic control adjustment protection system is based on a single-chip microcomputer. The system can realize automatic shutdown, manual shutdown, and has the advantages of high operational reliability, small design, maintenance, installation workload and small floor space. It is an ideal equipment for small and medium-sized hydropower units to be unattended and few people on duty, and its main functions. There are single and parallel operation modes. The single-machine operation mode enables the unit to operate at a given frequency and a given voltage; the unit can perform automatic quasi-synchronous grid-connected or quasi-synchronous grid connection; it can operate according to the front pool water level; the unit has over-current, overload, over-voltage, Protection functions such as undervoltage, overspeed, low frequency, technical water supply interruption, bearing temperature too high, and air pressure drop.
- Heavy hammer butterfly valve. In the past, the inlet valves of small and medium-sized hydropower units mainly used electric manual butterfly valves, ball valves or gate valves. When the unit was in an accident, it was often unable to close automatically due to unreliable power consumption. In order to overcome this shortcoming, in recent years, heavy-duty butterfly valves and ball valves have been developed, relying on heavy hammers to implement automatic and reliable closing, and the closing time is adjustable, which can realize segmental closing, prevent the pressure of the water diversion system from being too high, and the unit can be quickly closed to prevent Flying.
