U-shaped tubular heat exchanger has only one tube plate and the two ends of the pipe are fixed on the same tube plate. The advantages of this heat exchanger are :the pipe bundle an expand and contract flexibly and will not produce thermal stress due to the temperature difference between the pipe shell, with good thermal compensation performance; the tube pass is double tube pass, with long flow path ,high rate and good heat conducting performance ;strong loading capacity; the pipe bundle is easy to be taken out from the shell, convenient for overhaul and washing; and it is simple in structure with low fabrication cost.