Low-temperature smoke recirculation system

A low-temperature smoke recirculation system is mounted on a pulverized coal boiler, wherein cold smoke access points are arranged in the positions at the bottom and at the back of a separation screen of the pulverized coal boiler; the cold smoke access points are communicated with a recirculation fan through an outlet flue of a circulation fan; the recirculation fan is communicated with a cold smoke extraction point of a deduster through an inlet flue of the recirculation fan; and a control damper is arranged on the inlet flue of the recirculation fan. The low-temperature smoke recirculation system transmits the cold smoke to the bottom or the back of the separation screen of the pulverized coal boiler and rapidly cools high-temperature smoke in the field, so as to reduce the contamination activity of higher-sodium coal, and enables the higher-sodium coal to be attached to fly ash particles, thereby avoiding or mitigating the problems of contamination, wear, corrosion and the like of a tail convection heatin