SU901729A1 - System for automatic control of water consumption in two-flow steam generator - Google Patents

Description

(54) SYSTEM OF AUTOMATIC REGULATION OF WATER CONSUMPTION IN A TWO-FLOW STEAM GENERATOR

one

The invention relates to a power system and can be used, for example, to regulate the power supply of a thermal power plant.

A system is known for automatically controlling the flow of water in a double-flow steam generator, which contains relay flow controllers for flows, to the inputs of which flow sensors for flows are connected, and to outputs more and less through the logic element with contacts — actuators of the regulator of nutrient performance pump and feed valves installed on the streams, an additional relay controller connected to the logic gate with its outputs “more and less and connected first with the meter limiting parameter 1.

A disadvantage of the known system is that with automatic connection of a fixed valve to maintain a predetermined pressure drop when the selected minimum load value is reached, as well as when returning to the original circuit with increasing load, the requirement of an unaccented switch-on is not satisfied.

as at the moment of switching, an unbalance may exist at the input of the connected controller.

The purpose of the invention is to provide a shock-free start.

5 The goal is achieved by the fact that the system additionally contains a relay with three windings with its contacts, while the first winding is connected to the output "more additional regulator"

d through the contact of the other windings, and the other two windings to the outputs “more flow controllers through the contacts of the first winding connected in series with the contacts of the logic element, and the contacts of the outputs with“ more and less than the auxiliary controller with the logic unit entered the first windings.

FIG. 1 shows a block diagram of an automatic control system for supplying water to a double-flow steam generator; FIG. 2 is a diagram of a logic element.

Claims (1)

20 The system contains relay controllers 1 and 2 of water flow by flow, to the inputs of which sensors 3 and 4 of water flow by flow and setting unit 5 are connected, and to outputs “more than 6 and 7 and“ less than 8 and 9 - through a logic element 10 s pins 11 and 12: 13 and 14, 15 and 16, 17 and 18 - actuators 19, 20 and 21, respectively, of the regulator of the performance of the feed pump and feed valves installed on the streams, connected to the logic element 10 with its outputs “greater than 22 and“ less than 23 additional relay controller 24 associated with The driver of the limiting parameter 25 and the setting device 26. The system also contains a relay 27, three windings 28, 29 and 30, each of which is equipped with its contacts 31, 32 and 33, and the first winding 28 with its contacts 31 fixes one state, and two the other 29 and 30 are different, while the first winding 28 is connected to the output "more than 22 additional regulator 24 through the contact 32 of the other windings, and the other two windings 29 and 30 to the outputs" are more than 7 and 6 flow regulators 1 and 2 through the contacts 31 of the first winding 28 connected in series with the contacts 33 and 3 4 of the logic element 10 and in the communication lines "more than 22 and" less than 23 of the additional controller 24 with the logic unit 10, the contacts 31 of the first winding 28 are entered. The actuators 19, 20 and 21 have the inputs "more than 35, 36 and 37 and" less 38, 39 and 40 respectively. Logic element 10 is made in the form of two relays, the control windings 41 and 42 of which are connected in series with the contacts 43 and 44 of the limit switches and are provided with contacts 45 and 46 of the actuators 20 and 21 and two other relays, the control windings of which 47 and 48 are connected in series with the contacts 45 and 46 and pins 32 and 33 of the windings 29 and 30 of the relay 27, which fix another state. As a limiting parameter meter, either a pump rotation speed sensor or a water pressure sensor behind the feed pump are used. The system works as follows. In the absence of limitation of the pump control range (the relay 28 is in the second state), the controllers 1 and 2, which regulate the flow of water in flows according to the signals from the sensors 3 and 4 and the setpoint 5, affect the actuators 20 and 21 of the control valves and the pump 19 according to the principle of minimum throttling, which is characterized by the fact that at the intermediate position of both valves, the outputs "less than 8 and 9 of the regulators 1 and 2 are connected to the input" less than 38 of the pump actuator 19, and the outputs "more than 6 and 7 - to the outputs more than 36 and 37 of the actuators 20 and 21 of its valves; when one of the valves opens, the flow controller 1 (2) switches its outputs “more than 6 and 7,“ less than 8 and 9 to control the inputs “more than 35 and“ less than 38 of the pump actuator 19, and the other flow controller 2 (1 ) connects outputs "greater than 6 and 7 and" less than 8 and 9 to inputs 36 and 39 (37 and 40) of the actuator of valve 20 (21) of this flow; when opening two valves, outputs "greater than 6 and 7 of regulators 1 and 2 are connected to the input “more than 35 of the actuator 19 of the pump, and the outputs“ less than 8 and 9 of the specified regulators to the inputs “less than 39 and 40 New mechanisms 20 and 21 valves. Switching the outputs more than 6 and 7 of the controllers 1 and 2 is produced by the logic element 10, which is triggered when the actuators 20 and 21 reach full open (the contacts 43 and 44 are closed, respectively). Switching the outputs "less than 8 and 9 of these controllers 1 and 2 is carried out by means of relays 47 and 48, and the necessary condition for the operation of any of them is to fix the second state by contacts 32 and 33. A sign of the presence of a limit is the operation of an additional controller 24 in the direction "more when the current value of the limiting parameter from the sensor 25 is lower than its minimum allowable value received from the setting device 26. To the output" more than 20 of the specified regulator 24 is connected through pin 32, closed at ph second state, the first control winding 28 of the relay 27. When voltage is applied to it, the first state of the specified relay is fixed and the outputs 23 and 22 of the controller 24 are connected by contacts 31 of the relay 27 to inputs 38 and 35 of the pump actuator 19, and outputs less than 8 and 9 regulators I and 2 are connected to the corresponding inlets 40 and 39 of the actuators 21 and 20 of the valves. This position is maintained until one of the regulators 1 (2), having received a command to increase the flow in its flow, switches on its actuator 21 (20). Then, when the output signal is greater than 6 (7) of the regulator 1 (2) and the closed state of contact 34 (33), the relay will energize control winding 30 (29), the second state of the relay 27 is fixed and the original scheme. Thus, in the presence of a limitation of the pump control range, the maintenance of the parameter for which the limitation has arisen is carried out by the pump, and an unaccented start occurs. Formula Invention A system for automatic control of water flow in a double-flow steam generator, containing relay flow controllers for flows, to the inputs of which flow meters for flow are connected, and for outputs “more and less” through a logic element with contacts — actuators of the regulating authority feed pump and feed valves installed on the streams, an additional relay controller connected to the logic element with its outputs is “more and less” e and coupled with the meter limiting parameter, characterized in that, with a view to providing shockless includant it additionally soderm m there is a relay with three windings with its contacts, while the first winding is connected to the output “more additional regulator through the contacts of the other windings, and the other two windings to the outputs” more flow regulators through the contacts of the first winding connected in series with the contacts of the logic element, and in the communication lines of the outputs “more and less” of an additional controller with a logic unit, the contacts of the first winding are entered. Information sources, taken into account in the examination 1 USSR Copyright Certificate No. 629405, cl. F 22 D 5/32, 1978.