Design And Research Of Jet Dust Weather Simulation System For High Altitude Areas

UHV Transmission has broad development prospects due to its advantages such as strong transmission capacity and small energy consumption on the route.However,the high altitude and dust environment in northwest China will affect the corona characteristics of UHV transmission lines,and then affect the safe and orderly operation of power grids.Therefore,the design and research of high altitude dust weather simulation system can lay a material foundation for the experimental study of Corona characteristics of UHV transmission lines in northwest China.In view of the demand of the experimental study on the corona characteristics of UHV transmission line under the northwest Dust weather,combined with the corona cage and natural environment conditions of Xining base in Qinghai,the economy and mobility of the test system are fully considered,and two sets of sand blasting schemes based on free submerged jet are developed.The feasibility of the hybrid injection scheme of gas-solid ejector is verified by sand blasting experiment.On this basis,mainly carried out the key component design,drawing drawing,equipment selection and system layout work,completed the Product trial production.In order to reduce the manpower consumption of field experiments,a numerical simulation study of the Designed Dust weather simulation system was carried out before mass production and field test,and the conditions for the dust weather simulation system to be met at different altitudes were put forward,and the diffusion effect of the dust weather simulation system and the concentration distribution under different sediment levels were obtained.To guide the field test and commissioning.The results show that: 1)The gas-solid ejector injection mixed scheme is easier to realize the precise adjustment of dust concentration compared with the positive pressure pneumatic conveying scheme,and the cost is lower,and 2)the sediment quantity of small screw conveyor is basically linear with the frequency of frequency converter.3)in the vicinity of the ejector and near the outlet of the ejector there are obvious shock boundary layer interference phenomenon,the air flow in the interference zone is not fixed constancy enhancement,4)The ejector must meet the geometric conditions of first shrinkage and then expansion,in the filling stomata,the pressure in the tube must be lower than the external back pressure,the greater the pressure difference 5)in order to extend the dust weather simulation system to different altitude areas,the total inlet pressure of the ejector can be calculated by the equal pressure ratio method.6)In Xining area of Corona Test,the air pressure in the gas storage tank should be maintained at 0.55 MPa.Under this condition,the gas consumption of the single ejector is about 4m3/min,and the outlet of the central wire is about 7.3m from the ejector.If fine particles are used for experiments,the test section needs to be arranged in parallel with 8 devices at intervals of 3m,and if coarse particles are used for experiments,10 devices need to be laid out in the test section at intervals of 2.4m.At the same time,the space position of the ejector should be about 0.5m higher than that of the "Central wire".7)Dust weather simulation system can simulate the maximum dust concentration of about 700mg/m3,to meet the corona test needs of the concentration requirements and adjustment needs.