循环水泵节能改造与应用

Water Circulating Pump Energy Saving Upgrade and Application

水泵流量、扬程和功率分别与其转速的一次方、二次方和三次方成正比。对于流量经常变化的场合,采用变频调速技术,控制电机转速,改变泵的流量和扬程,可节约电能50%,显著降低节流损耗,且生产工艺稳定,具有调速性能好、节能效果显著、运行工艺安全可靠等优点。根据运行参数,输送同等流量的水,减少压头损失40m,电流降低约40A,节约用电14kW.h,按目前工业电价0.67元/kW.h计,每年产生直接经济效益8万余元。叶轮切割也是常用的节能技术之一,其技术实施要满足三个条件:水泵实际循环流量满足系统需求,水泵铭牌扬程高于实际扬程5m以上;水泵在装置内所有循环系统主支路调节阀全开时,循环水泵的运行电流超过额定电流;能够降低装置循环系统的阻力。应用叶轮切割技术后,单台水泵工作电流由32A降至30A,一年节电68590kW.h。

A water pump′s flow rate,lifting capacity and power are respectively in direct proportion to the first,second and third power of its rotating speed.Where the flow rate changes frequently,using variable frequency speed regulating technology to control the rotating speed of the motor to change the flow rate and lifting capacity of the pump can save up to 50% of electricity used.This method can significantly reduce throttling loss and has many other benefits such as stable production process,good speed regulating properties,good energy saving effect and safe and reliable operating procedures.Operational data show that when water is transmitted at the same flow rate,head loss dropped by 40m,the current dropped about 40A and 14kW·h of electricity was saved.At the current electricity price for industrial users（0.67 yuan/kw·h）,up to more than 80,000 yuan could be saved annually.Impeller cutting is one of commonly used energy saving techniques.To use this method,three conditions must be met：the actual circulating flow of the water pump meets the system′s requirements and the nameplate lifting capacity of the water pump is at least 5m higher than the actual lifting capacity;when all main and branch line regulating valves of the circulating system of the pump in the unit are fully turned on,the operating current of the water circulating pump exceeds its rated current;the resistance of the circulating system of the unit can be reduced.If the impeller cutting technique was used,the working current of a single water pump could drop to 30A from 32A and 68,590kW·h of electricity could be saved annually.