Heat exchange system for fresh air system

The invention provides a heat exchange system for a fresh air system, and belongs to the technical field of fresh air. According to the technical scheme, the heat exchange system for the fresh air system comprises a pipeline, a wind direction changing assembly and an end connecting assembly; the pipeline comprises a plurality of heat exchange pipeline sections which are arranged in a straight line and are sequentially connected end to end in a clamped mode; each heat exchange pipeline section comprises an outer pipe used for ventilation of cold air all the time, an inner pipe located in the outer pipe and used for ventilation of warm air all the time, and a fixing assembly arranged between the inner wall of the outer pipe and the inner pipe; the wind direction changing assembly is arranged between the pipeline and a fresh air machine in a communicating mode; and the end connecting assembly is located between the wind direction changing assembly and the pipeline and used for communicating the pipeline with the