Operation Analysis And Numerical Simulation Of Air-cooled Condenser Dust Accumulation And Antifreeze In220MW Unit

The operation of direct air-cooled system is critical to the safety and economy of air-cooled unit. While air-cooled condenser as an important part of cold end system, it is necessary to analyze and do the research on it. Taking220MW unit of one power plant as an example, the temperature field distribution of air cooled island can be obtained and be shown accurately and vividly by principal computer by monitoring the outlet temperature of condenser. While the principal computer displays that the temperature is abnormal or even below the environment temperature in some area of condenser during the cold weather, it indicates that freeze may exist. Relevant measures must be taken in order to avoid the unrelenting frosty accident of finned tube. This paper proposes a new concept, which is named air-cooled steam condenser cleanliness. This concept is under the consideration of outlet temperature, environment temperature, and fan speed, which can be regarded as an evaluation index of condenser performance. Then, the relation between the outlet temperature and the heat transfer coefficient, the thickness of dust accumulation, the quantity of condensed steam and cleanliness can be obtained, with analyzing and calculating the monitored temperature. And the relation curve of them can be got. The value of each parameter can be easily achieved through the outlet temperature data displayed by principal computer. Especially, when the thickness of dust accumulation reaches a certain extent which endanger the safety and economy of the unit, it immediately guide operation personnel to wash finned tube with high pressure water and remove dust. Then, this paper makes a numerical simulation for condenser, which provides reasonable and effective basis for air-cooled unit with the theoretical calculation, in order to achieve the purpose of energy-saving effectively.