The temperature of the cooling medium, the velocity of the water side of the heat exchanger, the water temperature at the water outlet, the heat flow density, the annual thermal resistance of the fouling the annual corrosion rate of the heat exchanger are closely related to the water treatment. The general provisions are as follows:

(1) Flow rate of cooling water side of heat exchanger: the tube side should be less than 0. 9 m / S; the shell side shall be less than 0. 3 m/s。

(2) Water outlet temperature: higher than 50 ℃ (the situation is subject to this limit).

(3) Heat flow density of heat exchanger: more than 58. 2 kW/m2。

(4) Fouling thermal resistance value: according to the nature of the enterprise, production characteristics requirements of heat exchange equipment.

(5) Annual corrosion rate of heat exchanger: ① ordinary carbon steel should be less than 0. 125mm/a。 ② Steel, copper alloy stainless steel should be less than 0. 005mm/a。

(6) Total number of heterotrophic bacteria: it should be less than 5 × 10 5 times / ml.

(7) Sludge sticking amount of heat exchanger: it should be less than 4 ml / m3 water by 180 mesh biological filter method.

(8) Leakage of process medium of heat exchanger: the process medium of heat exchanger often leaks. If the leakage contains ammonia, carbon dioxide, oil other substances, the water quality will deteriorate bacteria algae will grow.