地下水中铁锰离子对地下水地源热泵回灌影响的试验研究

摘要

针对地下水地源热泵工程回灌过程中存在铁、锰化学堵塞问题，研究了不同含量及配比的铁、锰离子在间歇回灌条件下对化学堵塞的影响。以沈阳城区为例，配制了含有不同铁、锰离子浓度的水样进行室内模拟回灌试验，对回灌前后多孔介质表面进行了 SEM 扫描电镜图对比。结果表明，Fe2＋是影响堵塞程度的主要因素之一，其浓度越高堵塞发生时间越早且程度越严重；只存在 Mn2＋的试样回灌后并没有明显堵塞发生，其必须在 Fe2＋的协同作用下才会造成堵塞；间歇回灌会带入大量氧气使铁、锰氧化沉淀反应加快，导致堵塞加剧。回灌过程中应严格并优先控制 Fe2＋含量，选址时应避免高铁离子浓度的地区及铁、锰离子浓度均较高的地区，并且减少与氧气的接触，以增加回灌效率，减少洗井次数。%For the chemical clogging problem by ferrous and manganese ions in recharge of groundwater source heat pump system,studies the influence of different ferrous and manganese ion contents and ratios on the chemical clogging in intermittent recharge conditions.Taking the urban area of Shenyang as an example,conducts the laboratory test of simulative recharge process with different recharge water samples,and contrasts the SEM pictures of porous medium surface before and after recharge.The results show that Fe2+ is one of the important factors of influencing clogging degree.The higher the concentration of Fe2+ is,the earlier the clogging occurs and the more severe the degree of clogging is. There is not obvious impact on clogging with the sample that only has Mn2+ in it.Mn2+ has not obvious impact on clogging except in the synergy of Fe2+ .Intermittent recharge can bring in a lot of oxygen.That accelerates the precipitation of ferrous and manganese oxidation reaction and leads to aggravated clogging phenomena.Therefore,Fe2+ content must be controlled preferentially and strictly in the recharge process. The area with high ferrous content or high concentration of ferrous and manganese ions should be avoided during the consideration of site construction.In addition,the possibility to contact with oxygen during the process must be reduced,which can increase the recharge efficiency and reduce the times of washing wells.