The temperature control system of heat exchanger is composed of a proportional integral TC temperature controller, water temperature sensor TE -1 -1 and TV -1 integrated electric control valve. Effect of TC controller-1 is to TE -1 the detected temperature sensor with temperature controller set comparison, and according to the result of the comparison through the proportion, integral calculation, making the electric valve TV -1, so that theheat exchanger outlet temperature is maintained at the temperature range required.

Electric control valve and hot water circulating pump linkage, when the pump power is cut off, and the electric control valve TV -1.

Temperature control is applied to a typical domestic hot water and heating water system