Time : 2021-11-15 Browse : 14
In industrial production, efficiency improvement means getting greater benefits at a lower cost, and optimizing the production process is the key. In the field of thermal power generation, fluid couplings have become an important choice for most power plants to improve equipment efficiency. They can improve efficiency by 30% and play a significant role in improving efficiency, as follows:
In modern thermal power plants, as the boiler pressure continues to increase, in order to overcome the resistance to steam-water flow, the pressure required by the feedwater pump is also getting higher and higher, and the power demand for driving high-speed feedwater pumps increases accordingly. In order to achieve economic operation, it is an effective way to adapt to changes in operating conditions through speed regulation, and hydraulic couplings perform well in this process.
In the past, the feedwater pump was driven by a small steam turbine with direct speed change. Although speed regulation can be achieved, a spare steam source is required when the unit is ignited and started, and the mechanism is complex. In contrast, the use of hydraulic fluid couplings to change the speed of the feedwater pump to adapt to the starting conditions of the unit has obvious advantages: It can greatly reduce the motor configuration margin of the electric feedwater pump, so that the feedwater pump can be started at a smaller speed ratio, reducing the ineffective energy consumption of the motor.
It avoids the situation that the fixed-speed electric pump needs to throttle and reduce pressure to adapt to the working conditions when the unit is started, improves the unit's economy, and prevents the high-pressure valve from being scrapped in a short time due to throttling and wear, reducing the cost of equipment replacement.
At present, most power plants adopt an economic configuration plan: the feedwater pump turbine drives the feedwater pump to supply water during normal operation, and a starter/standby feedwater pump driven by a hydraulic coupling is configured for unit start-up. During operation, the working oil flowing in from the gap between the impeller and the turbine (or the oil inlet hole on the turbine) rotates with the rotating housing and the turbine, and forms an oil ring under the action of centrifugal force. The working oil obtains energy in the impeller and releases energy in the turbine to complete the energy transfer, ensuring the stability and efficiency of the starting process.
In summary, the hydrodynamic coupling effectively improves the unit's economy and operating efficiency in thermal power generation by optimizing the operation mode of equipment such as the feedwater pump, and reduces cost losses.
