SU885703A1 - System for controlling steam temperature after heat generating unit undustrial superheater - Google Patents

Description

(54) STEAM TEMPERATURE MANAGEMENT SYSTEM FOR THE PROMPER HEATER OF THE HEAT UNIT

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The invention relates to a power system, in particular to the automation of heat units with combined-cycle plants equipped with reheaters.

The steam temperature control systems behind the reheat unit of the heating unit are known, which contain a main controller, a temperature controller, a flue gas bypass valve, a cooling water supply valve to the desuperheater, an air exhauster valve and two temperature sensors before and after the heat exchanger P.

However, the known system does not allow achieving the required quality of temperature control in heat units with combined-cycle plants.

The purpose of the invention is to improve the quality of temperature control in heat units with steam-gas installations.

The goal is achieved by the fact that the device additionally contains a logic unit, an adder, a differentiator, and the temperature controller is made with an unstressed switching unit and a setpoint corrector, the logic unit being installed between the controller

temperature and valves and is connected to the main regulator and the corrector settings, and the controller input is connected to the adder with the first temperature sensor, a differentiator and a second temperature sensor.

The drawing shows a diagram of the device.

Claims (1)

The steam temperature control system of the steam and gas unit contains an injection type desuperheater 1, a reheater 2, a cooling water supply valve 3 with limit switches 4, a valve 5 on a recirculation exhaust fan guide 6, a flue gas bypass valve 7 from a gas turbine unit with limit switches 8 associated with the output of the temperature controller 9. Thermoelectric transducers 10 and 11 are connected to the input of the latter through a differentiator 12. The controller of the tel-device has a device 13 of unstressed switching, a corrector, i.e. a device 14 for changing dynamic parameter settings and a logic control unit 15 introduced between temperature controller 9 and valves 3, 5 and 7. Logical control unit 15 is connected to limit switches 4, 6 and 8 of all valves, as well as change device 14 dynamic settings of the controller 9 and the main controller 16. The logical control unit is implemented using AND, OR, and NOT logic elements. The device operates as follows. When the steam temperature deviates downstream of the superheater 2, which is measured by thermoelectric converter 10, or when the temperature deviation speed signal arrives at the input of temperature regulator 9, the steam behind the desuperheater 1. (the signal is formed by a thermoelectric thermoconverter 11 and a differentiator 12) the controller 9 processes the command on the controller through the block 15 logical control. From the main regulator 16, depending on the operating mode of the combined-cycle plant (combined-cycle or steam-powered), the control command from the regulator 9 is supplied to the flue gas bypass valve 7 from the unit's gas turbine or to the valve 5 of the recirculation exhaust fan guide. The regulator 9 is connected to the device 13 unstressed on chesh. From the main regulator 16, the block 15 of the logic controller receives information on the type of mode (steam-gas or steam-power), on the load of the plant and through the device 14 to change the innummatical parameters of the dynamic adjustment affects the regulator 9. When the flue gas properties of the valve 7 are exhausted, the bypass flue gases or the valve 5 of the recirculation guide of the D1z1mosos directional device, it is necessary to reduce the temperature of the superheated steam, i.e. when the switch-limit switch 8 or 6 is operated, the logic control unit 15 from the controller 9 commands the opening of the control valve 3 and supplies cooling water to the desuperheater 1. When the end switches of switch 4 are activated, this information is entered into the logic control unit 15, which corrects the dynamic parameters the settings of the regulator 9 through the device 14 change the parameters and namichesky settings, taking into account the operating mode of the combined-cycle plant and the load. At elimination of the reasons leading to an increase in the steam temperature behind the reheater, the temperature regulator 9 through the logic control unit 13 closes the cooling water supply valve 3, after which the end switches 4 are actuated. Information is entered into the logic control unit 15 and, taking into account mode view, the output of the temperature controller 9 is connected to the bypass valve 7 of the diesel gas or to the valve 5 of the smoke guide. coca recycle. Taking into account the type of mode and the load, the logic control unit J5 acts on the controller 9 through the device 14 to change the dynamic tuning parameters. Thus, in the proposed system, the emergency injection controller is excluded, which adjusts to a higher temperature than the superheated steam temperature controller behind the superheater, and controlled by the injection of cooling water is subordinated to the temperature controller through the logic control unit, which prevents the temperature from rising to higher than emergency level and increases the adjustment range. The invention The control system of steam temperature behind the reheater of the heating unit, comprising a main controller, a temperature controller, bypass valves for flue gases, a cooling water supply valve to the desuperheater, an air exhauster valve and two temperature sensors before and after the heat exchanger, which has The fact that, in order to increase the quality of temperature control in heat units with combined-cycle plants, the device additionally contains a logic block, an adder, a differentiator, and a temperature controller, nen with block unstressed and incorporating a corrector setting, wherein the logic unit is installed between the temperature controller and valves and connected to the main regulator and the corrector setting, and the input of regulator is connected to a first adder temperature sensor, the differentiator and the second temperature sensor. Sources of information taken into account in the examination, 1. Report 092703 / 0-9353. NPO CKTI, 1978,;. 32,