SU571622A1 - Power unit shutting-down method - Google Patents

Description

 ,, . - one

The expression refers to tetto & vrgvt, and can also be carried out at a siuiyatap in powerhouses, pars irator-tlrbida.

Known as the Oscillator water in the steam generator 1.

However, these methods do not provide sufficiently intense cooldown.

There is also known a method for shutting down a power unit with risking the turbine under load by lowering the temperature of 1 liter of steam before the turbine by acting on desuperheaters and adjusting the electrical load by varying the supply of fuel, air and water to the steam generator 1.21. Here, the electrical load is reduced as the steam temperature decreases.

The disadvantage of this spssoba - compare lvv. longer duration of the process

 ,, - .2 i,. .

Raskopazhvvvvv-oa work at reduced loads.

Chain voobrvRvnna - usksfek e npo tecca razvvepazv1 n8a.

In order to do this, at the same time, the load at all times is higher than the supply of fuel, air to water until the moment when the steam temperature is reached is at the same time as reducing the flow, supporting the maximum load allowed for 1 “head” of your own supply.

FIG. 1 shows the possibility of {a scheme of the reapvaadin method; in fig. 2 is a graph of the nepawetpoe kamenenn power unit nrn stop.

In tiOM T, the Zembni tts begin to stop envrgobpoi with the turbine discharge of the turbine. From now on, reduce the temperature of the steam in front of the turbine — temperature

the primary vapor i and the vapor vapor t - by the effect on vapor-cooling, From this moment they begin to increase the supply of fuel for the air (according to the burning conditions) and the supply of heated water. Improving this

the feeds are made in such a way that

electric load M remained at its original level. At the same time, regugiruk e turbine valves gradually open up.

The cooling down of the turbine in this way is carried out until time point 1, when, at some temperature, the temperature of the steam (feather, secondary) is equal to its minimum allowable value.

These values are determined from the conditions for ensuring reliable operation of the power unit components: turbine tacks and steam generator surfaces placed behind the desuperheater, and also when the desuperheater control range is exhausted. Starting from this point in time, the supply of air and feed water is reduced, maintaining the maximum permissible turbine load at current steam temperatures.

The automatic control circuit implementation of the ECU contains a switch-on unit 1, which is connected to the primary steam temperature regulation 2, the secondary steam temperature controller 43 and the load regulator 4. A high pressure cylinder (HPC) t) is equipped with a sensor 5 of temperature 1 metal (or relative shortening poTopia) connected to the box 6 formating the program for changing the temperature of the first steam to controller 2 and the latter is connected to sensor 7 of temperature first couple. Regulator 2 through block 8 is connected to a steam cooler valve 9, equipped with a steam temperature sensor U, 1% to 1% through block 11 compare temp 1m97ur connected by block 8. To bgk at 11. sensor 12, according to which Е «1 1 кШЮ1« «the test of the circuit of the näppävi. Jf Tyybf of the phase transfer of the first pair of the Mv yon-mv steam-generator. W nitna pe (spenve (csd) turbvs | oivn e) 13 in the temperature of 1 m (relative to щ гу у гу гу фа ф ф ф рот) associated with the infusion of the 14 forming program: second steam temperature with a regulator 3 which can be combined with the regulator | m gasapan 15 paroo; (secondary steam latch. Sensor 16 temperature 171 & 1 secondary jnapa connect with controller 3 and block 17, to which generator generator 18 load is connected. Sensor js is also connected to block 19 connected to dates h-icom 7 temperature (xy pair. BNK 17 and 19 are connected with block 2O compared. After dny associated with the regulation unit 8 and 4 torus load koto1Ya; 1st connected to the control valves 21 and CVP 22 L adjusters 23 feed water

and fuel accordingly. The air regulator 24 is connected to the latter.

In ms (the onset of cooldown, the switch-on unit 1 puts the circuit into operation. In accordance with the indications of sensors 5 and 13, blocks 6 and 14 set the program for changing steam temperatures by regulator 2 and 3 acting on control valves .9 and 15 desuperheaters. At the same time sensors 7 and 16 are received respectively in blocks 19 and 17, in which, depending on the load sensor 18 shown, the program of operation of controller 4 is formed: block 19 determines the maximum load value at the current temperature value primary (pair, block 17 is max. the stimulus load at a given temperature of secondary steam. The obtained values are compared with the comparison unit 2O, in which the lesser of the specified maximum values of the load occurs at given temperatures of primary and BTqpH4HCH4} steam. The selected load value is applied to the regulator 4, and the impact pressure on the control valves 21, controllers 22 and 23 provide the required load change.

In the initial period of cooling down, when the temperatures of primary and secondary steam are sufficiently low, regulator 4, in accordance with the conditions of blocks 17, 19 and 20, will be at the initial level. With yes 1 & 1 & 11 M. Decrease in temperature (they are measured by measuring sensors 5 and 13) 17; 19 and: 20 reduce the value of the load that is required (5) and (4) and 4 are controlled by icrtafiaffit 21 and do not need (22 and 23, which decrease according to feed water and Toontna respectively).

By reducing the load on the M1 (steam generator of the generator par01), the temperature of the steam behind the desuperheater measured by sensor 1O decreases. When this temperature drops to a value slightly above the saturation temperature | at the pressure in the steam generator path, which is compared to the readings of sensors 10 and 12 in block 11, block 11 acts on UIOK 8, which in this case interrupts the flow rate increase water to the desuperheater sent by controller 2 to the regulating valve 9. At the same time, unit 8 sends a correction signal to unit 2O of the comparison. Adjusted (skillfully) the value of a given load is applied to controller 4, which acts on controller 21, regulators 22 and 23. Reducing the supply of TOnAima leads to a decrease in steam, causing pre-excessive reduction of the temperature of steam behind the desuperheater to form a signal formed in block. Ke 11 enters the control valve 9, reducing the amount of water on the desuperheater. In g, the further cooling down period, unit 11 controls the flow of water to the desuperheater so that the temperature of the steam downstream of the desuperheater is slightly higher than the temperature at the drip point. The required speed of unloading is not reached by changing the fuel input and the degree of opening of the valve 21.

In the process of turbine cooling, two stages can be distinguished: in the first phase (until the temperature decreases), the pace of the steam is pa behind the steam cooler; spruce until the maximum permissible level is maintained: the ratio between the temperatures of the steam in front of the turbine and the load t) of the god of the turbine, optimal from the point of view of reliability, economy ("(accuracy and cooling rate. At the second stage (after the indicated moment), this ratio: may be violated, because the change in fuel supply, which previously affected the load ki becomes a means of temperature control.

The proposed method is tipomenexperienced / tested at the power unit I of the electrical interconnection unit providing substantial coiqpame-T 30

Claims (2)

1.Typov Instructions for the start-up and maintenance of the K-ZOO-4O KhTGZ steam turbine operating in a block with a double-housing koltlom, STSTI OGTRES, M., 1973, p. 5839. 2.Krol A Ya. Operation of block turb oodh installations of high power. Energy, ftWl.j 1965, p. 152. ter