减阻剂在闭式循环水系统中应用的实验研究

在闭式循环水系统中添加减阻剂能有效减小循环冷却水泵的能耗,但现有研究关于减阻剂对换热的影响认识不足。分析了减阻剂CCTDRA在闭式循环水系统中应用时浓度、雷诺数及进口水温对其减阻率和换热减少率的影响。研究结果表明:在Re=11817、体积分数为0.30%时能取得较大的减阻率及相对较小的换热减少率,在25~55℃进口水温范围内,减阻率为46.37%~48.27%,换热减少率为9.72%~13.76%;但通过加大流速至水泵功耗最大值(82 W)时,换热减少率仍有8.89%~12.34%,表明该减阻剂在水泵不节能的情况下也不能完全弥补对换热设备的换热影响,此时该减阻剂在闭式循环水系统应用不可行。

Application research of drag reducing agents in closed circulating water systems

Adding drag reducing agents to closed circulating water system can effectively reduce the energy consumption of circulating cooling water pump,but the existing researches on the effect of drag reducing agents on heat transfer are not well understood.The effects of concentration,Reynolds number and inlet water temperature on the drag reduction(DR)and heat transfer reduction(HTR)of a drag reducing agent(CCTDRA)in the closed circulating water system are analysed.The results show that larger DR and relatively small HTR can be obtained when Re is 11817 and the volume fraction is 0.30%.In the inlet water temperature range of 25 to 55℃,the DR is 46.37% to 48.27%,and the HTR is 9.72% to 13.76%.However,by increasing the flow rate to the maximum power consumption of the pump(82 W),the HTR is still 8.89% to 12.34%,indicating that the drag reducing agent can not completely make up for the heat transfer effect on the heat exchanger even if the water pump is not energy-saving.At this time,it is not feasible for the drag reducing agent to be used in the closed circulating water system.