SU866335A1 - Device for automatically regulating water feed into multichannel straight-through steam generator - Google Patents

Description

The invention relates to devices for ... automatic control of technological processes of steam generators at thermal power plants.

Known devices for automatically controlling the power of direct-flow steam generators in which the change in the performance of the feed pumps is carried out by a mismatch signal coming from the pump capacity regulator, and the change in the degree of opening of the control distribution valves installed in each channel at the input of the steam generator is made by the mismatch signals coming from the outputs of the distribution controllers of each channel fl J.

The disadvantage of these devices is the high degree of throttling in the channels, i.e. large pressure drop of the supply water to the distribution regulator valve.

Closest to the invention, the technical solution is a device for automatic control, water supply to a multi-channel direct-flow steam generator, with

^{5 a} holding pump with a water flow rate controller, an adder whose output is connected to the input of the specified controller, and one of the inputs is to a constant signal source ¹⁰ , water flow sensors in each channel, connection to water flow controllers, the outputs of which are connected to respective control valves ¹⁵ through Execu tional mechanisms £ 2].

The disadvantage of this device is the low reliability due to the large number of contact elements ·.

The purpose of the invention is to increase the reliability of the device for automatically controlling the water supply in multichannel direct-flow steam generators.

This goal is achieved by the fact that in a device for automatically controlling the flow of water into a multi-unit. a direct-flow steam generator containing a pump with a regulator of water supply performance, an adder whose output is connected to the input of the specified controller, and one of the inputs is to a constant signal source, water flow sensors in each channel connected to water flow controllers, the outputs of which are connected to the corresponding distribution valves through actuators, the outputs of the water flow regulators are connected to the inputs of the adder.

The drawing shows a diagram of a device for automatically controlling the flow of water into a multi-channel direct-flow steam generator.

A device for automatically controlling the flow of water into a multi-channel direct-flow steam generator contains a controller 1 of the capacity of the feed pump 2, channels 3 and 4 of the water supply, sensors 5 and 6 of the water flow in channels 3 and 4, flow controllers 7 and 8 in the channels 3 and 4, controllers 9 and 10 of the initial water flow rate, actuators I 1 and 12 of the flow rate controllers and control valves 13, 14, adder 15, pressure switch 16 of the minimum pressure in the main channel 17, actuator 18 of the feed pump 2. Water supply channels 3 and 4 are connected to a steam generator 19.

The device operates as follows.

The flow rate controllers 7 and 8 receive signals from sensors 5 and 6 of the water flow rate and signals for setting the initial water flow rate in the channels from the control units 9 and 10.

At the input of the controller 1 of the capacity of the feed pump, a total signal is supplied from the outputs of the flow controllers 7 and 8 and the minimum pressure setpoint 16. The controller 1 of the capacity of the feed pump is unbalanced to receive the feed water from the minimum pressure setter, and the imbalance is introduced in such a way that when the balance (zero) at the inlet, the capacity controller works towards Less. The flow controllers 7 and 8 maintain the set flow rates of the feed water in accordance with action with the signals arriving at the inputs of the regulator. After the controller 1 of the capacity of the feed pump is switched to automatic control, by shifting its zero point, the feed pump 2 will reduce the pressure in the main channel 17, which will lead to a decrease in the flow rate of feed water through channels 3 and 4.

Regulators 7 and 8 of the flow rate, restoring the specified flow rate of feed water, will begin to open the control valves 13 and 14 until one of the valves opens 100%, after which an error signal from the output of the flow rate controller in the channel, where the valve is open on 100% increases and compensates for the signal from the setpoint 16 of the minimum pressure and the feed pump 2 will stop reducing the pressure in the main channel 17.

The invention, with its simplicity and high reliability, ensures the minimum possible losses on throttling of feed water at control distribution valves and reduces the energy consumption spent for steam generation in steam generators at thermal power plants.

Claims (2)

(54) DEVICE FOR AUTOMATIC REGULATION OF WATER SUPPLY INTO MULTICHANNEL DIRECTLY The invention relates to devices for automatic control of technological processes of steam generators at thermal electric power stations. Known devices for automatic regulation of the power supply of the steam generators, in which the flow capacity of the feed pumps are driven by the error signal coming from the pump performance regulator, and the change in the degree of opening of the control valves installed in each channel at the steam generator input is done by the signals of the error valve coming from the outputs of the distribution controllers of each channel 1. The disadvantage of these devices is the high degree of channelization, i.e. high differential pressure of water in the distribution regulator valve. STEAM GENERATOR The closest technical solution to the invention is a device for automatic control of water supply to a multichannel direct-flow steam generator, which contains a pump with a water supply capacity controller, an adder whose output is connected to the input of the specified controller, and one of the inputs to source of constant signal, water flow sensors in each channel, connected to water flow regulators, the outlets of which are connected to the corresponding distribution valves through actuators nexaniz ad G. The disadvantage of this device is the low reliability due to the large number of contact elements. The purpose of the invention is to increase the reliability of the device for automatic control of water supply in multichannel recirculating steam generators. This goal is achieved by the fact that in the device for automatic regulation of the water supply in a multistream. a direct flow steam generator containing a pump with a water supply capacity controller, an adder, the output of which is connected to the input of the specified controller, and one of the inputs to a constant signal source, water flow sensors in each channel, connected to water flow regulators , the outlets of which are connected to the corresponding distribution valves through the actuators, the outlets of the water flow controllers are connected to the inlets of the adder. The drawing shows a schematic of a device for automatically regulating the supply of water to a multichannel direct-flow steam generator. A device for automatic control of water supply to a multichannel direct-flow steam generator contains regulator 1 of feed pump 2, channels 3 and 4 of water supply, sensors 5 and 6 of water flow in channels 3 and 4, controller 7 and 8 of flow rates in channels 3 and 4, setting devices 9 and 10 of the initial water flow rate, actuators I1 and 12 flow rate controllers and distribution valves 13, 14, adder 15, setting unit 16 for minimum pressure in the main channel 17, actuator 18 for changing the performance of the nutrient pump 2. The water supply channels 3 and 4 are connected to the steam generator 19. The device operates as follows: m. The flow controllers 7 and B receive signals from the water flow sensors 5 and 6 and the initial water flow reference signals from the set points 9 and 10. The input of the regulator 1 of the capacity of the feed pump is supplied to the sum signal from the outputs of the regulators 7 and B of the flow rate and the setpoint 16 of the minimum pressure. The regulator 1 for the performance of the feed pump is unbalanced to get the feed water from the minimum pressure unit, and the imbalance is introduced so that when the balance (zero) is at the inlet, the capacity regulator works in the Smaller direction. Flow regulators 7 and 8 support the specified feed water flow rates in accordance with the signals supplied to the controller inputs. After transferring the feed pump regulator 1 to automatic control, at the expense of shifting its zero point, the feed pump 2 will reduce the pressure in the main channel 17, which will reduce the flow of feed water through the canal; 3 and 4. Regulators 7 and B flow rates, restoring the desired feedwater flow, will start to open control valves 13 and 14 until one of the valves opens 100%, after which the error signal from the output of the flow control in the channel where the valve is open 100 The% increases and compensates for the signal from the setpoint pressure generator 1b and the feed pump 2 stops reducing the pressure in the main channel 1-7. The invention, with its simplicity and high reliability, ensures the minimum possible losses for throttling feedwater on control valve distribution and reduces the energy consumption required for steam generation in steam generators at thermal power plants. The invention The device for automatic control of water supply to a multichannel continuous steam generator, comprising a pump with a water supply capacity regulator, an adder, the output of which is connected to the input of the specified regulator, and one of the inputs to a constant signal source, sensors of water flow in Rear canapes connected to water flow regulators, the outlets of which are connected to the corresponding distribution valves through actuators, characterized in that, in order to increase ezhnosti operation device outputs flow regulators are connected to the cy e atopa inputs. Sources of information taken into account in the examination I. N. N. N. Davidovd and A. S. Rubashkin. Automatic Regulatory Schemes fuel and power domestic boilers, M., Energie, 4972, p. 172. 2. Automation: thermal power plants. Ed. Shelman, M.P.M., Energii, 197D, p. 97-99. f5