SU920317A1 - Straight flow boiler feeding automatic control system - Google Patents

Description

(S) METHOD FOR AUTOMATIC REGULATION OF SUPPLY OF THE DIRECT-FLOW BOILER

The invention relates to heat-and-heat engineering and, in particular, to the automatic regulation of the power supply of a flow boiler of supercritical pressure. A known method of automatically regulating the supply of a flow boiler by varying the feedwater flow rate by load signals, feedwater flow rate and a correction signal and determining the phase transition coordinate of the medium in the water-vapor path 1P. The aim of the invention is to extend the control range to supercritical pressure boilers. This goal is achieved by measuring the temperature and pressure of the medium along the entire vapor-vapor path and using the signal on the medium temperature at the superheat point closest to the phase transition coordinate as a correction signal. The drawing shows a diagram of the control system that implements the proposed method. The steam boiler 1 is equipped with a fuel supply device 2 to the furnace and a feed water supply device 3, which are controlled respectively by the fuel regulator C and the feed regulator 5. The structure of the regulator of the fuel torus is performed according to one of the known variants. A sensor 6 of a given load, a sensor 7 of water flow into the boiler are connected to the controller 5, and through a switching device 8 controlled by a computing device 9, for example, a microcomputer, temperature switches 10. All sensors 10 are connected to device 9

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temperature, as well as pressure sensors 11. ,

The operation of the method is based on a comparison of the parameters of the state of the working medium, for example, temperatures and pressures at several points of the water-steam path, in which temperature and pressure are monitored. Under conditions of changing the operation mode of the boiler 1, the device 2 under the influence of the regulator C increases or decreases the fuel supply, and the controller 5 according to signals from sensors 6 and 7 and the temperature sensor 1 connected to it sets the water flow to the boiler . Computing device 9, based on signals from temperature sensors 10 and pressure sensors 11, determines the position of the phase transition point a and superheated steam. If the coordinate change has not occurred, the switching device 8 is not activated and the same temperature sensor 10 closest to the phase transition point remains connected to the controller 5.

 If the transition to the new mode caused the phase transition point to move, device 9 will give control to the device 8, and the latter will connect a temperature sensor, also closest to the phase transition point, to controller 5.

Installing an appropriate number of temperature sensors 10 and pressure sensors 11 along the entire water-steam path of the boiler ensures tracking of the computing device 9 as it moves the phase transition point in all modes of operation of the boiler, including supercritical pressure boilers.

invention formula

A method of automatically regulating the supply of a flow boiler by changing the feed water flow rate by load signals, flow water flow and a correction signal and determining the phase transition coordinate of the medium in the water vapor path, characterized in that, in order to extend the control range to the supercritical pressure boilers, the temperature and the pressure of the medium along the entire water-vapor tract and as a corrective signal use a signal on the temperature of the medium at the point of overheating closest Nate phase transition.

Sources of information taken into account in the examination

1. USSR author's certificate N 210870, kg. F 22 B 35/10, 1966.

Claims (1)

Claim A method for automatically controlling the supply of a once-through boiler by changing the feed water flow according to the load signals, the flow rate of the readout water and the correcting signal and determining the coordinate of the phase transition of the medium in the water-vapor path, distinguishing with the fact that, in order to expand the control range for supercritical pressure boilers, measure temperature and pressure of the medium along the entire water vapor path and use the signal for the temperature of the medium at the superheat point closest to the coordinate as the correction signal inate phase transition.