The detachable plate heat exchanger is made up of a plurality of heat exchange plates (metal sheets stamped with corrugated grooves),which is sealed at intervals by a sealing gasket, and pressed by clamping studs. There are holes in the corners constitute continuous passage, the medium enters the passage from the inlet and is distributed into the flow passage between the heat exchange plates. Each plate has a gasket, and the position between the plates is alternately placed..Hot and cold fluids entering the respective channels, separated by plates. Under normal circumstances, the two media flow in countercurrent flow in the channel, the heat medium transfers heat energy to the plates, and the plates transfer heat energy to the cold medium on the other side to reach the heat medium. The hot side temperature is reduced and the cold side temperature is raised to obtain the purpose of heating.