Shell and tube heat exchanger

The invention relates to a shell and tube heat exchanger. The shell and tube heat exchanger has the advantages that the ratio of the shell side size to the heat exchanging area is small, the air or low-viscosity liquid can serve as a heat exchanging medium, the entire process is free of dead band, short circuit and turbulence, maximum temperature gradient coaxial and reverse heat exchange with a tube side refrigerant medium is performed, the heat exchanger can be oppositely opened and is convenient to open and close, physical descaling and cleaning are performed on a shell side and a tube side, and the air or low-viscosity liquid medium can be automatically switched and exchanges heat with a tube side refrigerant. 本发明涉及种壳管式热交换器，具有壳程体积与热交换面积比值小、可以空气或低粘度液体为热交换介质、全流程无死角、无短路、无紊流与管程冷媒介质进行最大温度梯度同轴逆向的热交换，热交换器可对开分合方便对壳程和管程进行物理除垢清洗，是可以用于空气或低粘度液体介质自动切换与管程冷媒进行热交换的热交换器。