SU1745984A1 - Method of extraction turbine regulation - Google Patents

Abstract

The invention relates to a power system and allows to automate the regulation of steam extraction of a cogeneration turbine plant. The steam valve installed on the steam supply pipe from the turbine take-off to the network water heater is controlled by the signals to turn down (turn down the power of the pre-selection compartment) and add (add the power of the pre-selection compartment). When the maximum permissible power of the pre-selection compartment is exceeded, by a signal to turn down the power regulator of the pre-selection compartment, the steam valve is closed and, when it is closed, the heat consumption valve installed at the outlet of the network water heater is opened. Due to the opening of the heat demand valve, i.e. reducing the heat consumption and power of the pre-selection compartment, on a signal to Add a power regulator open the steam valve until fully open, then switch the signal Add a power regulator to control the heat consumption valve. With low heat consumption, the power regulator is set to the stereo mode, the heat consumption valve is fully open, and the heat consumption is controlled by the steam valve. 1 hp ff, 1 ill. with C

Description

The invention relates to a power system and can be applied in the regulation of a cogeneration turbine plant.

There is a method of controlling a heat-generating turbine that heats steam of different pressure from turbine selections into the network water in water heaters by switching the latter along the network water to the heater for steam supply from selecting a higher pressure and switching on this heater to the network water in series with the other heaters. This method provides increased efficiency with increased heat load and no peak electrical load.

The disadvantage of this method is the complication of the thermal scheme of the turbine installation, which reduces the reliability of operation.

There is another method of regulating a heat-generating turbine unit with a pre-selection compartment, a network water heater, and a heat consumption control valve by varying the steam flow in the high and low pressure parts of the turbine by feeding control valve speed and pressure regulators to the servomotors of control valves.

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By adjusting the pressure regulator setpoint by a signal proportional to the deviation of the mains water temperature from the set one, and switching this signal to control the heat consumption control valve when it reaches (by the signal proportional to the pre-selection power, the limit value). the range of its changes.

The disadvantage of this method is the narrowing of the control range, since it prematurely switches to maintaining the set temperature of the supply water using the heat consumption control valve based on the signal generated by the position of the pressure regulator setting knob, with a known degree of accuracy determining the minimum pressure in the selection when the power of the pre-selection compartment reaches the limit value at the full electrical load of the turbine. Meanwhile, when the load of the turbine decreases, the pressure at which the power predotbornogo compartment reaches the limit value is lowered, which is not considered.

There is also known a method for controlling a heat-turbine installation by controlling the steam valve in the pipeline. Steam supply from the turbine take-off to the supply water heater by the signals Reduce and Add the power regulator of the pre-turbine compartment or control the heat demand valve on the take-off heater line using the heat demand control signals taking into account the position of the heat consumption valve and the power of the pre-selection compartment with the maximum allowable value. The electrical and heat loads of the turbine unit are controlled with fresh steam valves and low pressure parts of the turbine, and the heat demand valve is used for additional control.

This method provides full use of the operating range of the turbine and its pre-selection compartment, allowing you to select the maximum allowable amount of steam.

The disadvantage of this method is that in a certain part of the range of modes of turbines with adjustable steam pressure in the selection and in the whole range of modes of turbines with unregulated pressure of steam in the selection chamber, the heat load is controlled only by the heat consumption valve or (according to another variant of the method) steam valve installed on the steam supply pipe from the turbine take-off to the network water heater. If the valve regulates the heat consumption at the maximum permissible load of the pre-selection compartment and increases the electrical load, the pre-selection compartment is overloaded until then. until the pre-selection compartment power control signal opens the valve additionally, thereby reducing the thermal load of the turbine and the thermal overflow to the compartment, i.e. restoring the permissible power pre-selection compartment.

However, as a result of the substantial storage capacity of the network preheater, the duration of the transient, during which the pre-selection compartment remains overloaded, is significant, which reduces the reliability of the blade apparatus of the compartment and reduces its service life.

This is a disadvantage of this variation of the adjustment method.

The disadvantage of another option (when adjusting with a steam valve) is the need to throttle selected steam, and in a substantial part of the control range, the pressure drop across the valve is close to critical or exceeds it. In this connection, the flow rate of steam in the throttling valve sections is close to critical, which leads to erosive wear of parts, i.e.

reducing the reliability of the valve and reducing its resource, as well as a high level of noise, which affects the operating conditions of the staff.

The purpose of the invention is to increase reliability and improve operating conditions due to the short duration of operation at the maximum load of the pre-selection compartment and a slight pressure drop across the steam valve, which

increases its reliability and reduces noise, as well as expanding the range of regulation with low heat consumption.

The goal is achieved by the fact that in the well-known method of controlling a cogeneration turbine installation by controlling the steam valve on the steam supply pipe from the turbine take-off to the network water heater by the signals Reduce and Add the power regulator of the pre-selection turbine section and control the heat consumption valve on the bypass line of the heater heat consumption torus, taking into account the position of the heat consumption valve and

when the pre-selection compartment power reaches the maximum permissible value, when the pre-selection compartment power exceeds the maximum permissible value and the steam valve starts to close, the full opening of the steam valve under the influence of the Add signal is restored, after which the pre-select compartment power decreases below the maximum permissible signal consumption.

In order to achieve an extension of the control range at low heat consumption, after the full opening of the heat consumption valve is achieved, the heat consumption regulator is switched to the control of the steam valve.

The drawing shows a schematic diagram of the implementation of this method.

The steam turbine unit consists of a high pressure part 1 with a pre-selection compartment 2 low pressure parts 3 and a network water preheater 4, which receives steam from a turbine intake. The fresh steam admission is regulated by valves 5, thermal consumption by valve 6 installed on line 7, bypass heater 4, with drive 8, valve 10 with drive 11 is installed on line 9 of the steam extraction.

The three-position regulator 12 of the power of the pre-selection compartment 2 is connected at the output 13 Decrease with the actuator 11, and at the output 14 Add through the switching contacts 15 of the limit switch 16 of the valve 10c with the actuator 8 or the actuator 11.

A heat demand controller 17, for example, a network water temperature controller, is connected to the output through the switching contact 18 of the limit switch 19 of valve 6 with the actuator 8 or the actuator 11.

The method is as follows (as follows.

When the power of the pre-selection volume is equal to the limit, the signal at the outputs of the controller 12 is absent. With an increase in the power of the compartment above the limit controller 12 has a signal at output 13 Turn off, and at output 14 Add a signal that is not present. When the power of the compartment is below the limit controller, 12 has a signal at output 14 Add, and at output 13 a subtract there is no signal.

The contacts 15 of the limit switch 16 are shown in the position corresponding to the power of the pre-selection compartment equal to or lower than the limit, the contacts 18 of the limit switch 19 are in the position corresponding to the partially open or closed valve 6.

When increasing the power of the pre-selection compartment above the limit regulator 12 5 with a signal, the steam valve 10 closes. After the contacts of the limit switch 16 are opened, the signal for opening the valve 6 comes, and the circuit of the Regulator 12 is added by contacts 15 is disconnected from

0 of the actuator 8 and is connected to the control of the actuator 11 of the valve 10. As the valve 6 is opened, the heat-generating load decreases and the power of the pre-selection compartment 2 becomes lower than the limit, after

5, the regulator 12 with a signal to Add adds the valve 10. The process continues until the valve 10 is completely opened, after which the contacts of the switch 16 open the circuit influencing the actuator 8 and opening the valve

0 b is stopped, at the same time the circuit Add regulator 12 by switching contacts 15 is connected to the actuator 8.

When reducing the power of the pre-selection compartment below the limit controller 12

5 signal Add closes valve 6, restoring the maximum capacity of the compartment and the maximum possible heating load.

If the load of the heat consumer

0 is below the maximum permissible condition of the pre-selection compartment, the regulator 12 is switched to the steering mode: the circuit of the actuation of the limit switch 16 on the valve actuator 8 and the circuit Add the regulator are disconnected, the sub-circuit remains in operation.

The controller 17 maintains a given heat load, controlled valve 6, after full opening of which

Claims (1)

0 by the switching contact 18, the regulator is connected to the control valve 10. Claim 1. The method of regulating a heat-generating turbine installation by controlling the steam valve on the steam supply pipe from the turbine take-off to the network water heater by the signals to turn off and add the power control of the turbine compartment and valve control 0 heat consumption on the bypass line of the preheater by signals of the heat consumption regulator taking into account the position of the heat consumption valve and reaching the pre-selection compartment with the power of the maximum permissible value, characterized in that, in order to increase reliability and improve operating conditions, the maximum pre-selection compartment power the allowable value and the beginning of the closing of the steam valve restore the full opening of the steam valve under the influence of the signal to Add, then when To reduce the power of the pre-selection compartment below the maximum allowable, they switch the signal Add to control the heat consumption valve. 2, a method according to claim 1, characterized in that, in order to expand the control range at low heat consumption, after reaching the full heat consumption valve, the heat demand regulator is switched to the steam valve control.