The invention discloses a method and a
system for controlling secondary
water supply chlorination in a complex loop. The method comprises the steps of adding a
sodium hypochlorite solution as a
disinfectant to water in a water tank for disinfection, wherein the initial default adding coefficient is k1, the
disinfectant is proportionally added according to the
inflow rate Q1, and the adding amountQ2 is equal to k1Q1; after t1 time, adjusting the adding coefficient k according to the
residual chlorine concentration
signal of the
effluent fed back from the water outlet of the water tank, whereink is equal to k1-k2, the adjustment time is t2, and k2 is the adding coefficient that needs to be adjusted; and when the
residual chlorine concentration of the
effluent fed back from the water outletdoes not reach a set value, refilling the
disinfectant to the water tank, wherein the refilling amount V is equal to vk2, and v is the volume of water in the tank. The method and the
system achieve chlorination disinfection on the water in the secondary
water supply tank, and the equipment is intensive, efficient, simple and convenient; the whole equipment is
fully automatic, the adding amount ofthe
reagent is continuously analyzed and adjusted through the
residual chlorine concentration of the
effluent, thereby avoiding inaccurate adding amount caused by the concentration change of the
reagent, and prolonging the changing cycle.