A real-time measurement method of flue gas temperature field at the furnace outlet and horizontal flue of a power station boiler

Abstract

The invention discloses a real-time measuring method for smoke temperature fields of a hearth outlet and a horizontal flue of a power station boiler. The real-time measuring method comprises the steps of constructing a multi-point three-dimensional measuring system, arranging a plurality of columns of smoke temperature measuring points on the horizontal flue of the boiler, and enabling the distance between each column of smoke temperature measuring points and a front / rear heated surface of each column of smoke temperature measuring points to be equal; and then, correcting the temperature acquired at each smoke temperature measuring point to be the smoke temperature of the hearth outlet of the boiler, and calculating the smoke temperature distribution of an inlet of each heated surface along the width direction according to the relation between a convection superheater in the horizontal flue and inlet smoke temperature distribution as well as outlet steam temperature distribution of each heated surface of the preheater. The online real-time measured value of the smoke temperature can be seen on a DCS picture of a centralized control center, and the online real-time measured value of the smoke temperature and the corrected smoke temperature value can be seen in the production process of an SIS page; and the distribution condition of the smoke temperature in the horizontal flue along the width and depth directions are approximately represented by smoke temperature fields on the sections of a fourth-stage superheater inlet, a second-stage reheater inlet and a vertical first-stage reheater inlet, so that the operation of the boiler can be conveniently monitored in real time, and furthermore the operation safety is ensured.

Description

technical field [0001] The invention belongs to the technical field of power station boiler monitoring, and relates to a method for real-time measurement of flue gas temperature fields at the furnace outlet of the power station boiler and the flue gas temperature field of the horizontal flue. Background technique [0002] Furnace flue gas temperature, especially the flue gas temperature in the furnace outlet area, is a very critical parameter that needs to be monitored during the operation of power plant boilers. Realizing real-time and accurate temperature measurement of furnace flue gas is crucial to ensuring the safe operation of thermal power plants, improving unit economy and optimizing boilers. Design matters. [0003] In the design of traditional thermal power plants, the smoke temperature probes (one set on the left and one on the left) are specified with the boiler as a means of measuring the smoke temperature at the furnace outlet. figure 1 shown. The smoke tempe...

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Problems solved by technology

However, the temperature probe can only work within 1 hour of starting powder feeding and when the smoke temperature is <530°C, and the 8m-9m long smoke temperature probe is easily damaged when entering and leaving the high-temperature furnace (most boiler smoke temperature probes are damaged), so it cannot meet the needs of monitoring the whole process of boiler operation, which is not conducive to the optimization of boiler combustion

In particular, the power plants of various power generation groups are currently carrying out coal type adaptability test research and operation monitoring management due to the changeable coal types. It is particularly important to realize the measurement of the furnace outlet smoke temperature within the full load range. Obviously, the traditional The smoke temperature probe temperature measurement system cannot meet the smoke temperature measurement requirements of the furnace outlet of the thermal power plant

At the same time, it should be noted that the traditional smoke temperature probe measurement method only simply compensates the ambient temperature, and does not correct the low measurement temperature caused by the low-temperature heating surface around the thermocouple. It can only characterize the change trend and rate of the smoke temperature, not It can well represent the real temperature of flue gas

Moreover, the traditional flue temperature probe flue temperature measurement system has only one temperature probe on the left and right sides, which can only measure the flue gas temperature along the width direction of the fixed position of the horizontal flue of the boiler, which cannot satisfy some unit operating conditions and conditions based on the temperature field of the entire furnace outlet. Equipment Condition Analysis Requirements

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