Temperature control method for preheating type anti-freezing system of wet cooling tower

Abstract

The invention discloses a temperature control method for a preheating type anti-freezing system of a wet cooling tower. The temperature control method is used for controlling an air inlet shutter typeair door and a water inlet regulating valve of a preheater of the preheating type anti-freezing system and ensuring that the temperature of cooling water drained out of the tower is the lowest on thepremise of freezing prevention of the cooling tower. The control system comprises a shutter type adjusting air door, an air door executing mechanism, a water inlet adjusting valve, a valve executingmechanism, a PLC, an environment temperature sensor, a tower inlet and outlet water temperature sensor, a preheating air temperature sensor, an outlet water temperature sensor and an air preheater. The temperature control comprises combined control over the preheating air temperature, the preheater water outlet temperature and the cooling tower water outlet temperature, and the control process iscontinuous temperature control based on meteorological condition changes and unit load changes. According to the temperature control method, the operation states of the preheater and the cooling towercan be effectively monitored, and the closed-loop automatic control of the preheating air temperature and the tower outlet water temperature can be realized.

Description

technical field [0001] The invention relates to the technical field of antifreeze optimal operation control in cold seasons of natural ventilation wet cooling towers, in particular to a temperature control method for a preheating antifreeze system of a wet cooling tower. Background technique [0002] The natural ventilation wet cooling tower is an important equipment of the closed circulation cooling water system of the turbogenerator unit. Because of its small impact on the surrounding ecological environment during operation, low operating costs and failure rates, and easy maintenance, it is widely used and gradually replaced An open water supply method that draws water directly from rivers. In actual operation, its performance directly affects the exhaust pressure of the steam turbine, thus affecting the economical efficiency of the unit operation. In the cold season of winter and spring, the temperature in some areas drops to more than ten degrees below zero or even tens...

AI Technical Summary

Problems solved by technology

[0004] At present, most of the windshields of cooling towers are artificially suspended. Since the number of installed windshields is greatly affected by weather conditions, wind direction and force, labor intensity and maintenance costs, it cannot be achieved according to the ambient temperature and unit load. To adjust the coverage of the windshield in time, the cooling capacity of the cooling tower and the temperature of the outlet water also vary greatly, and in the actual operation process, excessive suspension of the windshield often occurs, so that the water temperature of the outlet tower is higher than the design value of winter operation

[0005] For the preheating antifreeze system, if only relying on separate control of the opening of the louvers on the air inlet side of the antifreeze system and the opening of the regulating valve on the water inlet side, deviations will easily occur, causing the preheating air temperature and the tower water temperature to deviate from the target optimal value

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