Method for measuring temperatures of out-flowing water and discharged water of heater of turbine steam cooler

Abstract

The invention discloses a method for measuring the temperatures of the out-flowing water and the discharged water of a heater of a turbine steam cooler, which comprises the following steps: selecting a design condition or performance test condition of an assembling unit as reference conditions, and selecting the thermodynamic parameters of the j(th) heater under the reference conditions, wherein the thermodynamic parameters comprise a shell pressure, an extraction temperature, a shell extraction enthalpy, an out-flowing water temperature, a water inlet temperature and a power of the assembling unit; calculating the heat-transfer characteristic coefficient of a stream cooling section of the heater under the reference conditions; reading or calculating the actual shell pressure, extraction temperature, water inlet temperature of the j(th) heater and the actual power of the assembling unit from a supervisor information system (SIS) or decentralized control system (DCS) of a heat-engine plant; calculating and obtaining the heat-transfer characteristic coefficient of the heater according to the heat-transfer characteristic coefficient of the stream cooling section of the heater and the actual power of the assembling unit; and finally obtaining the out-flowing water temperature under the actual conditions by carrying out iterative computations, wherein the out-flowing water temperature is equal to the saturation temperature under the shell pressure.

Description

technical field [0001] The invention relates to a method for measuring and calculating heater parameters of a steam turbine with a steam cooler, in particular to a method for measuring and calculating the outlet water and drain temperature of a heater with a steam cooler for a steam turbine. Background technique [0002] With the continuous improvement of the parameters and capacity of thermal power units, improving the performance of the heat recovery system to improve the operating economy of the unit has attracted increasing attention. The measurement of the outlet water and drain temperature of the regenerative heater plays an important role in the calculation of the heat balance of the regenerative system and the monitoring and optimization of unit performance, so it is necessary to monitor it online. So far, there is no report on the calculation method of the outlet water and drain temperature of the heater with steam cooler in the heat recovery system. [0003] At pr...

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Problems solved by technology

[0003] At present, in the thermal power plant's plant-level monitoring information system SIS (Supervisory Information System) or system distributed control system DCS (Distribution Control System), for the regenerative heater with steam cooler, although there are water outlet and drain temperature measurement points , but due to poor operating conditions and poor maintenance, poor measurement reliability is common. In addition, the conventional measurement method of water side temperature of the heater has the following shortcomings: First, in the thermal measurement system of thermal power units, often A thermal resistance sensor is used to monitor the outlet water temperature of the regenerative heater, and the corresponding data acquisition system needs to use an active balance bridge to measure the resistance value of the sensor, and the measurement cost is high; When the change is large, the water temperature response shows a large thermal inertia, which affects the measurement accuracy; third, due to the complicated installation location on site, it is not easy to repair and maintain

The absence of any heater data will result in the inability to calculate the heat transfer coefficient, so the traditional heat transfer equation is suitable for design and verification calculations, and it is not convenient for the calculation and monitoring of outlet water and drain temperature during unit operation or test

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