Spherical shape diaphragm of heat exchanger tube channel is a new structure of green and environment protection as its no leakage under high temperature and high pressure. Part structures and whole structures were designed for baffle plate of small diameter tube-channel

because spherical shape diaphragm new structure can not sealing with baffle plate by force. Strength design of baffle plate was calculated which of four kind boundary conditions

including four sides simple support

symmetric sides simple support and half-ellipse side fixed support or four sides fixed support. Formulas were introduced that used to check the strength of baffle plate fixed support sides. Combined baffle by parts were designed for baffle plate of large diameter tube-channel.