The main performance parameters of water pumps include flow rate, head, power, efficiency and speed.
Flow rate: The volume of fluid delivered by a water pump per unit time is called flow rate, which is represented by the symbol Q. Common units are m³/s, m³/h or L/s. The flow rate on the nameplate of the water pump is the design flow rate of the water pump, also known as the rated flow rate. The efficiency is highest when running at this flow rate.
Head: The head of a water pump refers to the total energy increase obtained after a unit weight of fluid passes through the water pump. It is represented by the symbol H. The common unit is meter water column (m). The head on the nameplate of the water pump is the design head of the water pump, which corresponds to the head at the design flow rate.
Power: The power of a water pump includes shaft power and effective power. Shaft power refers to the power transmitted to the shaft of the water pump by the power machine, also known as input power; effective power refers to the power output by the water pump, also known as output power. The power on the nameplate of the water pump refers to the power corresponding to the design flow rate, called rated power.
Efficiency: The efficiency of a water pump refers to the ratio of its effective power to shaft power, indicating the degree of effective energy utilization of the water pump, and is represented by the symbol η. The higher the efficiency of the water pump, the smaller its energy loss during operation.
Speed: The speed refers to the number of revolutions per minute of the water pump impeller, represented by the symbol n, and the commonly used unit is revolutions per minute (r/min). The speed on the water pump nameplate is the design speed of the pump.