Selection criteria for irrigation pumps
The selection criteria for irrigation pumps is a comprehensive consideration process, mainly based on the specific needs and conditions of farmland irrigation. The following are some key selection criteria:
1. Flow requirements
Definition: The flow rate of a water pump refers to the amount of water pumped per unit time, usually in cubic meters per hour (m³/h) or liters per second (L/s).
Determination method: The flow rate required for farmland irrigation should be determined based on factors such as irrigation area, irrigation water depth, irrigation cycle, and channel loss. Generally speaking, flow rate = (total farmland water demand + channel water loss) / pump working time. Among them, the total farmland water demand is equal to the product of the farmland area and the irrigation depth, and the channel water loss is estimated based on actual conditions, usually between 5%-25% of the farmland water demand.
2. Head requirements
Definition: The head of a water pump refers to the energy of a unit weight of water inside the water pump, usually in meters (m). It determines the maximum height to which the pump can deliver water.
Determination method: The determination of the head requires field measurement, that is, the vertical height from the water surface of the water source to the water surface of the irrigation area. For water sources such as rivers, lakes, etc., the low water level during drought resistance should be used as the standard. At the same time, the installation height of the water pump and the water suction loss head should also be considered to ensure that the water pump can work normally.
3. Power requirements
Definition: The power of the water pump refers to the power required for the water pump drive equipment, usually in kilowatts (kW).
Determination method: The power of the water pump needs to be determined according to the scale and irrigation area of the irrigation system to ensure the stable operation of the system. At the same time, factors such as the conveying distance and the resistance of the water pipeline should also be considered to ensure that the water pump can stably convey water to the destination.
4. Selection of water pump type
Common agricultural water pump types include centrifugal pumps, axial flow pumps and mixed flow pumps.
Centrifugal pumps: small flow rate, high head, suitable for farmland irrigation with an actual head of more than 10 meters.
Axial flow pumps: large flow rate, low head, suitable for farmland irrigation with an actual head of less than 4 meters.
Mixed flow pump: between centrifugal pump and axial flow pump, suitable for farmland irrigation with a head of 5-10 meters.
5. Economic and practical considerations
When choosing a water pump, in addition to meeting the above technical requirements, its economy and practicality must also be considered. For example, the supporting power of the water pump should be appropriately selected to ensure that the water pump starts quickly and is safe to use. At the same time, the model and specifications of the water pump should be easy to operate and maintain to reduce management costs.
6. Other precautions
Purchase of water pumps: should be purchased at sales outlets approved by the agricultural machinery department, and the manufacturer and product quality certificate should be clearly identified. Avoid purchasing "three-no" products (i.e. no manufacturer, no production date, no production license).
Installation and commissioning of water pumps: installation and commissioning should be carried out in accordance with the product manual to ensure that the water pump can work normally. At the same time, attention should also be paid to the maintenance of the water pump to extend its service life.
The selection criteria for irrigation water pumps is a process that comprehensively considers flow, head, power, water pump type, economy and practicality. Only by making scientific and reasonable selection based on the specific needs and conditions of farmland irrigation can we ensure that the farmland is fully irrigated and efficiently utilized.
