高压管道浇灌工程计划设计示例(国外英文资料).docVIP

低压管道灌溉工程规划设计示例(国外英文资料)Example of the design of irrigation project of 4.4 low pressure pipeline4.4.1 basicallyA certain area are mainly composed of food production, rich groundwater, over the years built a centrifugal pump as the main water equipment, earth canal water conveyance system of irrigation works, for the irrigation area of grain production provides a reliable guarantee. Due to the continuous drought in recent years, groundwater irrigation area is generally fall, for the development of water-saving irrigation, improve irrigation water use coefficient, submersible pump instead of centrifugal pump for water, the change of earth canal water for low pressure pipeline.The area of the area is flat, field, forest and road layout (see figure 4-27). The area of single well is 12.7 hm. Below ground, the 1_megabyte layer of earth is the middle loess, the average weight is 14.8 kN/m. In the field, the water rate was 24 percent.The project is located in the middle of the irrigation area. According to the analysis of the water quality test, the water quality of the well is in accordance with the water quality standards of farmland irrigation, which can be used as the irrigation water source of the project, and the water source is 380V 3 power source. According to many years of pumping test, the well water yield of 55 m3 / h, borehole diameter is 220 mm, the steel plate drum of the management, the depth of 20 m, static water depth 7 m, dynamic water level 9 m depth, wellhead elevation is flush with the ground.4.4.2 design parameters of the irrigation system in the well irrigation area(1) the irrigation design guarantee rate: 75%.(2) the utilization rate of water in piping system: 95%.(3) coefficient of irrigation water utilization: 0.85.Design crop water intensity: 5mm/d.(5) design moistening layer depth: 0.55 m.4.4.3 system and working systemThe net irrigation quota is calculatedThe formulaType: = 0.55 m, = 14.8 kN/m3, = 0.24 x 0.95 = 0.228, = 0.24 x 0.65 = 0.1560, and s