Design And Experimental Study Of Recharge Well With Filter Layer For Pump And Recharge

In the analysis of the recharge process of dual-purpose self-infiltration and reverse filtration recharge wells,the factors affecting the recharge quantity and efficiency of single well in dual-purpose self-infiltration and reverse filtration recharge wells are analyzed and summarized.Combined with pumping and recirculation,the recirculation quantity is mutual.The circular and square self-infiltration and reverse-filtration recharge wells were redesigned.The single well recharge volume of new pumping and recharging wells and recharge efficiency were observed.A test device of self-infiltration and recharge for indoor pumping and irrigation was developed,through indoor recharge test,it is verified that the newly designed dual-purpose self-infiltration and reverse filtration recharge well has the characteristics of high recharge efficiency and siltation prevention.At the same time,the theoretical calculation formulas of single well recharge volume of diversion aquifer pumping and irrigation dual-purpose self-infiltration and reverse filtration recharge well and single well pumping volume of diversion aquifer pumping and irrigation dual-purpose self-infiltration and reverse filtration recharge well are deduced.In order to explore the influence of wellhead loss on the flow through the wellhead during the process of water flow recirculation through the wellhead,a laboratory test device was developed,and the indoor wellhead loss test was carried out,and the characteristics and rules of wellhead loss were summarized.It has theoretical value and practical guiding significance to analyze wellhead loss of pumping-irrigation dual-purpose self-infiltration and reverse filtration recharge wells and to calculate single well recharge volume of pumping-irrigation dual-purpose wells.The main conclusions are as follows.(1)Compared with the existing recharge wells and dual-purpose pumping wells,the new dual-purpose self-infiltration and reverse filtration recharge wells have the following characteristics.Compared with pumping and irrigating dual-purpose wells,thermal energy can realize self-seepage and filtration of rainwater and flood,and has a large amount of recharge,and can recharge rainwater and flood in a short time.(2)The main influencing factors on the recharge rate of single well in pumping-irrigation dual-purpose wells are the wellhead part of pumping-irrigation dual-purpose wells,and thewater inflow capacity of pumping-irrigation dual-purpose wellhead directly affects the single well recharge volume.The main factors affecting the water intake capacity of the dual-purpose well head are the cross-section area of the well head,the shape of the well head,the permeability coefficient of the filter layer,and the silting condition of the dual-purpose well head.(3)This paper analyzes the flow pattern of the new irrigation and drainage dual purpose self permeation and recharge well,and according to the single well recharge theory calculation formula of the common recharge well in the confined aquifer,the theoretical calculation formula of the single well recharge quantity of the dual-purpose well in the phreatic aquifer and the single well of the dual-purpose well in the phreatic aquifer are derived.Theoretical calculation formula of well pumping volume.(4)An indoor device for recharge test of pumping and irrigating dual-purpose wells has been developed.The single well recharge volume and the recharge flow curve of the dual-purpose well are obtained from the indoor experiment.From the state of flow curve,it can be concluded that the design of test device is reasonable,and it can well simulate the process of water recharge through pumping and irrigation dual-purpose wellhead and common recharge wells.An indoor device for well loss of pumping and irrigation dual-purpose self-infiltration and reverse filtration recharge wells is developed.The variation law and characteristics of well loss at wellhead are analyzed under the conditions of different wellhead types,different perforation rates and different water supply heights.