Cold smoke recirculating unit heat conduction oil recovery bypass smoke heat system and control method

The invention discloses a cold smoke recirculating unit heat conduction oil recovery bypass smoke heat system. The cold smoke recirculating unit heat conduction oil recovery bypass smoke heat system comprises a bypass smoke cooling device, a recirculating cold smoke heating device, a closed circulating oil pump, a heat conduction oil replenishing system, an adjusting baffle door, an air preheaterand a boiler body. A first inlet of the bypass smoke cooling device communicates with a smoke exhaust port through the adjusting baffle door, and a first outlet of the bypass smoke cooling device communicates with a smoke outlet of the air preheater. The bypass smoke cooling device communicates with the recirculating cold smoke heating device in a circulating manner. The recirculating cold smoke heating device communicates with a cold smoke recirculating draught fan and a hearth dry bottom hopper of the boiler body. The input end of the closed circulating oil pump communicates with a second outlet of the recirculating