SU1672124A1 - Method for controlling the flow rate of waste gases from chimney in automatic manner - Google Patents

Abstract

The invention relates to a power system and can be used in automatic systems for controlling the rate of exhaust gas outflow from the mouth of a single-stem chimney of a thermal power plant. The aim of the invention is to improve the quality of regulation when using several thermal power plants. To achieve this goal, the pressure drop is measured at the chimney section, from which the exhaust gas flow rate is determined, the exhaust gas temperature is measured, the opening degree of the regulator is measured, the time-differentiated total steam flow rate from all heat and power plants is measured, and the area change The outflows are made depending on the measured parameters. 1 il.

Description

The invention relates to a power system and can be used in automatic systems for regulating the speed of exhaust gas outflow from the mouth of a single-stem chimney of a thermal power plant with several boilers connected to this pipe.

The purpose of the invention is to improve the quality of regulation when using several heat and power plants.

The drawing shows a scheme that implements a method for automatically controlling the speed of the exhaust gas outflow from the stack of a thermal power plant.

The scheme includes a chimney 1, inside which a regulator 2 is installed, connected to the actuator 3, which is connected to the position sensor of the actuator 4. Inside the pipe 1 at various points in height there are nozzles 5 and 6 for the extraction of pulses for the static pressure of the exhaust gases connected to a differential pressure gauge-flow meter 7 (for example, a differential pressure gauge of the DMER type) connected to an automatic regulator 8, which is also connected to the setpoint sender 9 Botan gas sensor 10, the exhaust gas temperature, an actuator position sensor 3 and the actuator 4. The adder boiler steam load 11 via a differentiator 12 connected to the automatic regulator 8.

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The method is carried out as follows.

At steady state operation of a thermal power plant, the pulse according to the position of the regulator 2 is balanced by pulses in terms of exhaust gas flow, exhaust gas temperature and signals from unit 9 of the velocity of gases emerging from the mouth of the pipe. The signal from differentiator 12 in steady state is zero. The velocity of the exhaust gases exiting the mouth of the pipe is within a predetermined interval. When increasing (decreasing) the total load or steam capacity of a group of boilers connected to the pipe, a positive (negative) impulse goes to the input of controller 8 from differentiator 12, including actuator 3 for additional opening (closing) of the gap at the mouth of the pipe by moving the regulator 2 The pressure drop between the pipes 5 and 6, after a certain lag time, increases (decreases) due to an increase (decrease) in the exhaust gas flow rate, which will also create a positive (negative ) a pulse at the output of the differential pressure gauge - flow meter 7, from where this signal goes to the input of the regulator 8, and, as a result, an additional opening (closing) of the gap in the wellhead by the regulating device 2 opens the (close) gap in the wellhead and is accompanied by a negative flow (positive) pulse from the position sensor of the actuator 4 to the input of the regulator 8.

As a result of this interaction of pulses after setting the total load of the boilers at a new, higher (low) steady-state level, the pulse from differentiator 12 will decrease to zero, and the increased (reduced) positive signal (in terms of gas flow) from differential pressure gauge 7 will again be balanced by an increased (reduced ) a negative signal from the sensor position of the regulator 2. In this case, the gas flow rate through the pipe will be higher (lower) and higher

the stump opening the mouth of the pipe will be more (less), which will allow to keep the rate of gas outflow from the pipe at the same level.

In the event of an increase in the temperature of the gases

With the same pressure drop between nozzles 5 and 6, in the absence of a temperature sensor, the rate of outflow of gases from the pipe may increase. To eliminate this on

the regulator input a pulse is introduced by the temperature of the gases in the pipe from the temperature sensor 10. When the temperature of the gases in the pipe increases (decreases), the regulator 9 additionally opens (closes) the gap in

the mouth of the pipe, thereby maintaining the constancy of the rate of gas outflow from the mouth of the pipe into the environment, since in this case an increase (decrease) in the positive pulse from the sensor 10 of temperature

will be compensated by an increase (decrease) in the negative pulse from the position sensor of the actuator 4.

The use of the invention allows

to ensure the maintenance of exhaust flow rate from the chimney, to which several boilers of the thermal power plant are connected, within the specified limits, which contributes to the improvement

uniform dispersion of exhaust gases into the environment.

Claims (1)

The invention The method of automatic control of the flow rate of exhaust gases from the chimney, including the change in the flow area at its outlet by the change in steam consumption, from the fact that, in order to improve the quality of regulation using several heat and power plants, the pressure drop across the chimney along its height is measured and the change in the exhaust gas flow rate, the exhaust gas temperature is measured, the degree of opening of the regulator, the time-dependent total steam consumption of all thermal power plants, which rrektiruyut lapse change in the area. tttt From boilers k ////////////////// //////////////