The invention discloses a method and device for recycling
heat energy in reduction exhaust in a polysilicon production process. The method comprises the following steps: reduction exhaust and chlorsilane are subjected to primary heat exchange in a
tower bottom
reboiler; and after heat exchange, part of the chlorsilane is vaporized and delivered into a chlorsilane purification
tower to serve as a heat source for the chlorsilane purification
tower, the reduction exhaust subjected to heat exchange is delivered into a condenser, and the chlorsilane in the reduction exhaust is condensed into liquid to be delivered into the chlorsilane purification tower. The device for recycling the
heat energy in reduction exhaust in the polysilicon production process comprises a tower top condenser, a purification tower, a tower bottom
reboiler, an exhaust condenser, a chlorsilane
buffer tank and a chlorsilane delivery pump which are sequentially connected, wherein the outlet of the chlorsilane delivery pump is connected with the purification tower. By means of the technical improvement provided by the invention, the steam consumption of the reduction rectification
system can be reduced by 40%, the load of the refrigerator of a CDI (
capacitor discharge ignition)
system can be reduced by 7% simultaneously, and the circulating
water consumption is reduced by about 52.44%, thereby achieving the purposes of favorable
energy conservation and consumption reduction.