Condenser dirt degree online monitoring method

Abstract

The invention belongs to the technical field of condenser monitoring, and particularly discloses a condenser dirt degree online monitoring method. The method includes the steps that a steam turbine off-design performance model is built, condenser steam parameters are obtained according to the steam turbine off-design performance model, and the overall heat exchange thermal resistance of a condenser is obtained through calculation according to the steam parameters of the condenser; the cooling pipe water side convection heat transfer thermal resistance of the condenser, the heat conduction thermal resistance of the wall of a cooling pipe and the steam side condensation heat transfer coefficient of the condenser are calculated, the steam side condensation heat transfer coefficient is modified, and the steam side condensation heat transfer thermal resistance is obtained; the dirt thermal resistance of the condenser is solved according to the overall heat transfer thermal resistance of thecondenser, the cooling pipe water side convection heat transfer thermal resistance, the heat conduction thermal resistance of the wall of the cooling pipe and the steam side condensation heat transfer thermal resistance, the dirt thermal resistance represents the water side cleanliness of the condenser, and then dirt degree online monitoring of the condenser is achieved. By means of the method, dirt degree real-time online monitoring of the condenser can be achieved, and the method has the advantages of being stable, accurate and tolerant to faults.

Description

technical field [0001] The invention belongs to the technical field of condenser monitoring, and in particular relates to an online monitoring method for condenser fouling, in particular to an online monitoring method for condenser fouling based on soft measurement technology. The invention can be applied to the on-line monitoring of the fouling degree of a thermal power plant or a nuclear power plant with a condenser system and the prediction and analysis of the thermal performance of the condenser system. Background technique [0002] Condenser is an important equipment for heat exchange in power plants, and its cleanliness directly affects the economics of power plant operation. At present, most of the SIS systems (Supervisory Information System in plant level) of thermal power plants have integrated An on-line monitoring device for condenser tube corrosion was developed. This condenser fouling monitoring method is based on flow measurement, that is, the main condensate ...

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Problems solved by technology

However, the actual operating conditions of the unit often deviate from the calibration conditions, especially when the unit output changes, that is, when the unit changes load, the actual working conditions will deviate further from the experimental calibration conditions. This deviation between the actual working conditions and the experimental calibration is caused One of the main causes of inaccurate field flow measurement

Moreover, the flow orifice plate is prone to bending and deformation with the operation of the unit, and the inlet edge is worn or corroded to cause a gap, which will further aggravate the deviation between the flow measurement value and the true value

[0004] In addition, some scholars have proposed to install the sensor on the measurement branch outside the condenser for monitoring. The advantage of this sensor is that it is easy to find and deal with the problem of the sensor, and it can simulate the heat load of the condenser, measure the biofouling rate and Fouling rate, the disadvantage is that the flow state of the inner surface of the sensor is different from that of the actual copper pipe, and the measured corrosion state cannot accurately represent the corrosion state of the actual copper pipe

In addition, the cleanliness of the condenser can also be judged by shutdown inspection, which is the most accurate detection method, but this method does not conform to the actual production situation of the power plant to a large extent

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