光伏压块配重

1、l.Determine the Design Wind LoadUsing the Analytical Method - ASCE 7 - 05The procedure to determine Design Wind Load is specified by the American Society of Civil Engineers (ASCE) and referenced in the International Building Code (IBC) 2006oF purposes of this document, the values, equations, and pro

2、cedures used in this document reference ASCE 7-05, Minimum Design Loads for Buildings and Other Structures. Please refer to ASCE- 05 if you have any questions about the definitions or procedures presented in this manualThe wind force analysis is based on ASCE -05, Chapter 6. Upon review of the diffe

3、rent methods available for calculating wind loading, it has been determined that Method 2 (Analytical Procedure) is most appropriate. Specifically Section 6.5.13 (Design Wind Loads on Open Buildings with Mono sloped, pithed, or Troughed Roofs), was seleced as the method most closely approaching the

4、application of Solar Matrix racking system. The pressures are dertmined following Section (Main WindForce Resisting System) according o the following formula:p = qh x G x Cn Equation 1Wherep = design wind pressure (+ denotes down towards the roof) qh = velocity pressure evaluated at mean ro

5、of heightG = gust effect factor as deermined in ASCE 7 - 05Section 6.5.8Cn = net pressure coefficient determined from ASCE 7 05 Fig.6 - 18A, p.66.Determine the Velocity Pressure according 6.5.10qz = qh = 0.00256 x Kz x Kzt x Kd x V2 x I=17.63( lb晦sf)Wind Speed, V =100 mph(45m/s)Importance Factor I =

6、 1 (Table 6-1)Direct. Factor, Kd = 0.85 (Table 6-4)Topo. Factor, Kzt = 1.00 (Sect.6.5.7)Topographic Factor, Kz= 0.81 (Table 6-3)Determine the Gust Effect Factor, GThe gust factor, G , is defermined to equal 0.85, according to Equation 1, then goingot ASCE 7-05 Section , and using the structur

7、e definition from ASCE -05, Section 62.Determine the Net Pressure Coefficient, CnThe net pressure coefficient, Cn, can be determined from ASCE -05 Fig. 6-18A, p.66.Cn=-0.9Cn=-1.3Calculate the Design Wind Load, p (psf)The max uplift Velocity Pressure = qh x G x Cn = -13.49psfThe max down Velocity Pre

8、ssure =qh x G xCn = -19.48psf2.Load Forces on Solar Matrix Mounting SystemThe solar panels size is 5.18x2.65 x0.15The weight is 18 Kg.So the module area = 5.18x2.65=13.73 sq ftThe Dead load (not include the ballast) R=59 lbfThe total occupation area for the simplify systm is A about 19.67 sq ftOVER

9、VIEW FOR THE SOLAR MATRIX STRUCTUREFor a large Solar Matix system, the danger is o be turnover by the uplift wind force. We can check the panels on the last row to ensure the systems safety.The force on the panels on the last row must keep equal. rF)m the figure, we know:Bwx1.42+D1.2= Wlu x 1.325Wlu= max upli 代 Velocity Pressure x the module area =19.4813.73 = 267.5 lbfSo,Bw=( Wlu x 1.325-D1x 1.2) /1.42 =(267.81.325 -59*1.2 ) /1.42=199.7lbfThe safety factor is 1.5,So,Bw=1.5 x 199.7=299.6 lbf (It means each ballast weight is 135 kg)From th