Shell and tube evaporator with anti-freezing function

The utility model relates to the technical field of evaporators, in particular to a shell and tube evaporator with an anti-freezing function, which comprises an evaporator, a temperature detection sensor, a heating component, a temperature controller, a relay and a power supply, when the shell and tube evaporator is used, high temperature and low temperature can be preset through the temperature controller, and when the water temperature of liquid in the evaporator is lower than 3 +/-1.5 DEG C, the heating component is started; when the water temperature reaches 8 +/-1.5 DEG C, the heating assembly is disconnected, a unit module does not need to be connected, a unit control point is not occupied, and compared with the connected unit, control feedback is fast, detection parameters are few, and control is easy; when the unit is shut down and does not work, the water temperature in the evaporator can still be automatically detected to switch on and switch off the heater, the evaporator is prevented from being fr