Experimental Study On Water Evaporation And Water-Saving Of PVC Floating Plate And Floating Ball In The Plain Reservoir Of Arid Area

Aiming at the solving the problem of low evaporation capacity and effective utilization of reservoir in the of Northwest China, this paper adopts the method of physical coverage as the main research direction of restraining water surface evaporation.On the basis of the previous research on the related experiment, PVC foam floating plate, PVC soft ball, PVC foam floating ball and PE hard ball are used as the main cover material for the test.The form of the covering material is arranged as a test plan,having observed and recorded the working conditions of the free float in the test area,the calculated evaporation of different covering materials during the test period, the inhibition rate and all kinds of test were analyzed.The main results of this paper are as follows:(1)The calculation model of water surface evaporation in the area is established,and the floating plate with different area is used as the test cover material,the wetting rate of floating plate affected by floating plate area and wind speed is used as variable quantity,the rate has been counted.A regression analysis method was used to establish the model of different coverage area and evaporation inhibition rate,based on the calculation, the maximum floating plate area suitable for the reservoir is calculated.It is proved that the feasibility of reducing water evaporation and increasing the utilization rate of reservoir is greatly reduced.(2)The PVC foam floating plate with different thickness was laid on the surface of the reservoir with the same upper surface area and different thickness of the three groups,the wetting rate of floating plate with different thickness was statistically different under different meteorological conditions.The evaporation inhibition rate of PVC foam floating plate with different thickness under different wind speed is obtained.The results show that the evaporation inhibition rate of the floating plate is not only related to the wind speed or the area of the single plate during the test period but also its thickness.(3)Through laboratory test observation and analysis of motion without counterweight float under different wind speed, the causes of irregular rotation and rolling motion of floating ball has been explored.Based on the principle of “Tumbler”. the contrast of different weights of floating ball under different meteorological conditions of wet rate and inhibiting effect on the evaporation during the experimental period was evaluated. The results show that the load weight ratio of the floating ball float without the weight of anti evaporation water saving effect is more significant.