. Flow speed, water height, kinetic energy. Objects of a certain mass moving at a certain speed have kinetic energy, and water is no exception. Kinetic energy can be converted into potential energy, that is, the kinetic energy of. Flowing water can be converted into a certain height of water. The kinetic energy of the flow velocity is consistent with the kinetic energy formula: 1 /2 mv^2 2. Hydroelectric head fall energy The essence of hydroelectric generation is to convert the potential energy of water highlands. in electrical energy. For the same quantity of water, the greater the water fall, the greater the energy. The falling energy is proportional to the product of the volume of water and the falling, i.e.: mgh 3. Loss links and loss rates of flow velocity and kinetic energy of head in hydropower (like water inlet, water outlet(water, turbine vortex, pipe vortex, etc.) There is friction in the water flow channel. The force will cause the water to lose kinetic energy, thereby affecting the efficiency of energy conversion. Friction and eddy currents exist at the inlet (i.e. water inlet), pipe and outlet (water outlet). , usually called draft pipe in terminology) of the flow channel, thereby consuming the kinetic energy of the water for electricity generation. When the water flow turns or bypasses obstacles, it will produce a spilling phenomenon. The spill part will generally produce vortices which are locally turbulent water flows, which consume a lot of water flow energy. towers and obstacles. When the operating conditions of the turbine deviate from the design range, vortices will be generated in the blades and suction tube, resulting in lossof energy. 4. The term “non-pressure pipeline power generation” or “pressure pipeline power generation” is not very precise. Hydroelectric power plants typically use pipelines and canals to divert water to produce electricity. Pipeline methods are divided into non-pressure and pressure methods. , the water is filled with water diversion pipes, the water flow has a certain pressure, this is called pressure. No pressure: that is, the water does not fill the pipe. Although the water flows through the pipe or tunnel, it is physically equivalent to flowing through the canal. 6. In hydropower production, the utilization rate of conversion of flow, height, kinetic energy - high, low and general final (excluding intermediate loss links and loss rates) of electrical energy is not very clear. and conversion utilization rateis not very high. In principle, the flow rate if it is too high, it will definitely be more affected by the friction of the pipe walls, but there are principles in the design of hydropower plants. the higher the design throughput. 7. I did not understand the calculation formula corresponding to the conversion rate of hydraulic energy and electrical energy. The formula of the hydraulic turbine is: P=9.8gQH P is the output power, the unit is 9.8 kilowatts, that is; the acceleration of gravity; g is the efficiency (originally this symbol is not, cannot be printed, temporarily replaced), which is determined by the efficiency of the turbine, pipeline and other efficiency losses. Generally, a power plant can just take 0.8 to 0.9; is the flow rate, unit: cubic meter/second; H is the water height, that is to say the water level upstream and downstream of the power plant. The difference, also called drop, can bebe calculated using the altitude difference, unit: meter < /p>
The relationship between the head of the hydroelectric plant and the electricity production
First calculate: the work done by the water on the generator each day
p>Work = flow (volume of water flowing in a day) * pressure of the water on the blades (according to calculation: 490000Pa) * time (one day)
In addition, the generator can convert this work How much is used (the amount of electricity produced today):
Generator work = work of water * generator efficiency
In theory, this is the case, but the actual production of hydroelectricity is notFormula: N=9.81QHη, where N is the power of the hydroelectric power station (kW); Q is the reference flow (m3/s) H is the net water height (m) (see water height of the hydroelectric power station); ; eta is the total efficiency of hydroelectric generator set, its value is 0.70~0.90. From the above formula, it can be seen that the output of a hydropower plant is also related to the efficiency of the unit, and H is the net drop, that is, the loss of load is removed. The two examples you mentioned have not been removed. the load loss, therefore the electricity production capacity is different.