The system of irrigation systems is usually divided into continuous irrigation and rotation irrigation. Continuous irrigation is the simultaneous water supply for all pipelines within the system, i.e. the whole irrigation system as a round irrigation area. Its advantages are irrigation timely, short run time, easy to other management operation arrangements; The disadvantage is that the dry tube flow is large, the project investment is high, the equipment utilization is low, the control area is small. Therefore, the continuation of the irrigation method is only used for a single and small area.
For the vast majority of irrigation systems, to reduce engineering investment, improve equipment utilization, expand irrigation area, generally adopt a rotary irrigation work system, the branch pipe is divided into several groups, each group includes one or more valves, irrigation through the dry tube to the groups in turn water supply.
1. The principle of dividing the wheel irrigation group
The number of 1.1 rounds of irrigation groups should meet the requirements of water, while keeping the irrigation area and the water supply to be coordinated;
1.2 for manual, water pump and the first non-pressure device system, the total flow of each round irrigation group as consistent or similar, to make the pump run stably, improve the efficiency of the machine and pump, reduce energy consumption;
1.3 The same round irrigation group, choose a type or performance similar nozzle, simultaneously planting varieties consistent or the demand for irrigation similar;
1.4 For ease of operation and management, usually a rounds of the irrigation group controlled by the best of the scope of the strip. However, the automatic irrigation control system is not subject to this restriction, and the valves in the same round irrigation group are scattered and arranged to maximize the flow of the dry tubes, reduce the diameter and reduce the cost.
2. Determination of the number of wheel irrigation groups
The number of wheel-irrigation groups depends on the daily allowable operation time, the irrigation cycle and the duration of the irrigation. For fixed-type irrigation systems, the number of round irrigation groups can be determined according to the following:
n ≤ cT/t
N-the system allows the maximum number of rounds to be divided, taking integers.
C-One days of the hours running, generally not more than 20 hours.
T-irrigation cycles, i.e. intervals between two irrigation times
3. Valve selection and installation location of the wheel irrigation group