SU1235579A1 - Method and apparatus for control of accelerated cooling of a strip - Google Patents

Abstract

1. A method for controlling accelerated cooling of a strip, including changing the coolant flow rate by varying the length of the accelerated cooling zone depending on the magnitude of the speed, temperature and thickness of the strip to provide the desired coiling temperature, determining the accelerated cooling time required and then increasing the length of the accelerated cooling zone after the acceleration of the strip begins characterized in that, in order to increase the quality of the strip by increasing the control accuracy of the coiling temperature, after root band is increased during acceleration cooling it by shortening the vozdun - a cooling and further increase the length of the zone of accelerated cooling strip. Ш Ш Ш X to оо сд с со с

Description

2. A control unit for accelerated cooling of the strip containing gauges of thickness thickness, rolling end temperature and strip coiling temperature, first and second setters, a correction unit, an adder, the inputs of which are connected to a strip coiling temperature meter and the first setting unit, and the output to the input of the correction unit , the dividing unit, the first and second multiplying units and the distributing device, characterized in that, in order to improve the quality of the strip by increasing the control accuracy of the winding temperature, in addition to Four set points, acceleration start sensor, tracking unit, comparator, three adders, band presence sensor, driver, two air-cooled speed sensors, a switch, two time sensors, a length sensor and a distributor, and a speed meter connected to the input of the tracking unit and with the first input of the switch, the thickness meter with the first inputs of the air cooling rate sensors, the temperature meter of the end of rolling with the second inputs of the first air speed cooling sensor and the second adder, the first The unit is connected to the second input of the second cooling rate sensor and the first input of the second adder, the second setpoint is connected to the third inputs of the air cooling rate sensors, the third setpoint is connected to the first input of the comparator, the fourth setpoint is connected to the first input of the third adder, the fifth setpoint is with the first inputs of the second time sensor and the length sensor, the sixth

The invention relates to rolling production and can be used in systems for regulating the temperature of strip coiling in hot rolling mills.

The purpose of the invention is to improve the quality of the strip by increasing the accuracy of adjusting the temperature of the coiling.

FIG. 1 shows a block diagram of the device that implements the proposed method; in fig. 2 is a block diagram of an air cooling rate sensor; in fig. 3 is a block diagram of a time sensor; in fig. 4 --- block diagram of the length sensor; in fig. 5 --- curves of the process of cooling the strip on the outgoing roller table.

The control unit for accelerated cooling of the strip (Fig. I) contains a strip speed meter 1, a strip thickness meter 2, a meter 3 and 4 temper sensor with the first input of the fourth adder, an acceleration start sensor with fourth inputs, a second O time sensor and a length sensor, a sensor the presence of a band — with the first input of the first time sensor; the output of the tracking unit is connected to the second inputs of the comparator and the third adder, the output of which is connected to the second input of the switchboard). the driver input is connected to the comparator output, and the output to the second input of the first

the time sensor and the control input of the switch, the first output of which is connected to the second inputs of the second time sensor, and the length sensor, and the second output to the third input of the second time sensor, the output of which is connected to the first input of the first multiplication unit, the output of the first time sensor with the first input of the second inflating unit, the second input of which is connected to the output of the first air-cooled speed sensor, and the output to the third input of the second adder, the fourth input of which is connected to the output of the first block scabbard. the output of the second air velocity sensor; xo; ijazi is connected to the second inputs of the first multiplication unit and the fourth summatf; the first and second inputs of the divider are connected to the outputs of the second I fourth and 4 adders, and the pykhod is connected to the third input of the length sensor, the output of which is connected to The second input of the correction unit, the input of the distributor - with the output of the correction unit, and B1.1 approach - with the installation of a shower.

Circulation of rolling and reeling end, setting knobs 5 --- 10, acceleration start sensor 11, tracking unit 12, comparator 13, adders 14-17, presence sensor 18, driver 19, air curtain heat sensor 20 and 21, switch 22, sensors 23 and 24 of time, blocks 25 and 26 by clenning, block 27 of dividing, sensor 28 of length, block 29 of correction, distributor 30, ducting device 31. The figure also shows the last clean stand 32, with an operating roller, to which is connected measure,: | 1 speed strip, and winder 33 for winding strip 34.

Measuring device of 1 speed to the reservoir with block entrance

tracking and with the first entrance

switch 22, thickness gauge 2 with the first inputs of the airflow cooling sensors 20 and 21 (VO), measuring device 3 for the rolling end temperature - with the second inputs of the sensor 20 and the adder 15, the setting device 9 is connected to the second input of the speed sensor 21 VO and the first inputs of adders 15 and 17, the second input and output of which are connected to the coil temperature meter 4 and the first input of correction unit 29, respectively, setting device 8 - with third inputs of speed sensors 20 and 21, VO, setting device 5 - with first input of comparator 13, setting device 6 - with the first input adder 14, dial 7 - with the first inputs of sensors 24 and 28, dial 10 - with the first input of the adder 16, acceleration start sensor 11 with the fourth inputs of sensors 24 and 28, presence sensor 18 with the first input of time sensor 23, output of the tracking unit 12 connected to the second inputs of the comparator 13 and the adder 14, the output of which is connected to the second input of the switch 22, the input of the driver 19 is connected to the output of the comparator 13, and the output to the second input of the time sensor 23 and the control input of the switch 22, the first output of which is connected to the second inputs of sensors 24 and 28, and the second Swarm input - with the third input of sensor 24, the output of which is connected to the first input of multiplication unit 26, output of sensor 23 is connected to the first input of multiplication unit 25, the second input of which is connected to the output of speed sensor 20, VO, and output to the third input of adder 15, whose fourth input is connected to the output of multiplication unit 26, the output of speed sensor 21 21 is connected to the second inputs of multiplication unit 26 and adder 16, the first and second inputs of division block 27 are connected to outputs of adders 15 and 16, and the output to third input of length sensor 28 whose output is soy Inonii a second input correction unit 29, the input distributor 30 is connected to the output correction unit 29, and output - with dushiruyuschey installation 31.

Each of the sensors 20 and 21 of the speed VO (Fig. 2) contains a power raising unit 35, a multiplication unit 36 and a division unit 37. The first sensor input is connected to the first input of the division block 37, the second input is connected to the input of the exponentiation unit 35, the third input is connected to the first input of the multiplication unit 36, and the output is connected to the output of the division block 37, the second output of which is connected to the output unit of the multiplication unit 36 , the second input of which is connected to the output of the exponentiation unit 35.

The time sensor 24 (FIG. 3) contains blocks 38 and 39 divisions, blocks 40 and 41 of the exponentiation, block 42 of multiplication, adders 43 and 44 and switch 45. The second time sensor input is connected to the input of the booster 40 and the first the inputs of the division unit 38 and the adder 44, the third input with the second inputs of the unit 38

division and multiplication unit 42, the first input with the first inputs of multiplication unit 42 and division unit 39, the fourth input with the control input of the switch 45, and the output with the output of the switch 45. The adder 43 with the first and second inputs is connected to the outputs of the blocks 40 and 42, respectively, and the output is connected to the input of the raising unit 41, the output of which is connected to the second input of the adder 44. The second input of the block

0 39 divisions are connected to the output of the adder 44, and the output is connected to the first input of the switch 45, the second input of which is connected to the output of the division unit 38.

The length sensor 28 (FIG. 4) contains a power exponent 46, blocks 47 and 48

5 multiplication, the adder 49 and the switch 50. The first input of the length sensor through the switch 50 is connected to the first input of the multiplication unit 48, the second input to the first input of the multiplication unit 47, the third input

d with the input of the block 46 and with the second input of the multiplication unit 47, the fourth input with the control input of the switch 50, and the output with the output of the adder 49, the first input of which is connected to the output of the multiplication unit 47, and the second input with the output of the unit 48

5 multiply, the second input of which is connected to the output of block 46.

The method is carried out as follows.

When rolling at a charge rate, depending on the thickness of the strip, the speed of its movement and the temperature of the end of the rolling, such amount of coolant is fed to the strip in order to provide the specified temperature of the coil. At the same time, the length of the accelerated cooling zone (VF) is established depending on the flow rate of the refrigerant.

5 In FIG. 5 curve А B С D depicts the process of cooling the strip on the outgoing roller table, with point A corresponding to the temperature of the end of rolling, point B to the temperature of the beginning of the CC, point C to the temperature of the end

0 PP, point D at a given coiling temperature, i.e. segment OB | corresponds to the time TI VO to U O, the segment BiCi - the time then EO, the segment CiDi - the time ts VO after U O, the segment ODi - the total time of cooling the strip on the outgoing roller table.

5 During acceleration, due to an increase in the speed of the strip, the overall cooling time of the strip on the discharge roller table and, consequently, its cooling time in the VO zones, shortens the coiling temperature. Let for the given cross-section of the strip the total cooling time corresponds to the segment OEi, i.e. the total cooling time is reduced by., and the cooling time in the first VO zone is reduced by FiBi, i.e. the cooling in the first VO zone corresponds to the segment OF ,.

Consider how the QE process is controlled to compensate for the increase in temperature.

T2

W2- Ws

(one)

winding coils corresponding to this Dt according to the proposed method.

This section of the band after the start of acceleration in the first zone of the VO from point A is cooled along the line AF, in the zone of the SV by line FG in the second zone of the BO along the line GF. The position of point G, which corresponds to the completion of the SV, is determined by the intersection of the straight line, the passage of the line through the point F, and the parallel BC line, and the straight line passing through the point E and the parallel CD line. Point E is the intersection point of the perpendicular, constructed from the end of the segment OEi, with the set coiling line. The cooling lines FG and GE are practically parallel to the corresponding lines BC and CD due to the slight temperature difference between them.

Thus, the strip is subjected to accelerated cooling for a longer time than by a known method. For this, the length of the area of the CCR is additionally increased due to the inclusion of additional sections of the routing unit (RC). Moreover, the length of time for additional cooling corresponds to the value of Al2 FiBi - CiG |. This makes it possible to compensate for the deviation of the coiling temperature DT Е2E, which is not eliminated by a known method. The magnitude of this deviation can be determined as follows. On the abscissa from the point FI, lay the segment Fini, the equal BiCi and the corresponding time of the EI by a known method, restore the perpendicular p from the point HI to the intersection with the FG line and find the point H of the end of the EO by a known method, from which draw the HE2 line parallel to Soo Thus, the AFHE2 curve is a cooling line for this section of the strip by a known method, and the E2E section is the deviation of the coiling temperature in this case.

The device operates as follows. The time required for accelerated ohl cooling, ensuring the desired coiling temperature, can be determined from the expression

TkiTsmsz- W | T | W3T23

where T2 is the time of the SV;

Tkp - end rolling temperature; TcM.i - set coiling temperature; А 1, W3- speed IN in the first and

the second zones IN;

T | - cooling time in the first VO zone; T23 - total cooling time in the zone

MA and in the second zone of HE; W2-speed UO.

After the start of the acceleration, the band of magnitude T | and T23 are reduced in comparison with their values when rolling at a filling speed, therefore, the time of the SV

five

, O

0 5 0

o

five

five

after the start of acceleration, as can be seen from expression (1), it should increase accordingly. According to the lime value of the time of the CR, the length U of the zone of the CC is determined in accordance with the expressions:

1.2 V 12 (at a constant speed); 12 V T2 + 0.5 and T2 (after the start of acceleration;,

where V is the speed of the strip; and - acceleration. When a strip appears in the outgoing roller table, the meters 1-3 measure the speed V, the thickness h and the temperature Tcp of the end of the strip rolling, the strip presence sensor 18 starts the time sensor 23, which starts counting time, and the speed tracking unit 12 determines the location of the strip on the discharge roller table, i.e. for each strip section, determines the distance 1 traveled along the outgoing roller ang. According to the coefficient K, which characterizes the steel grade and is set in setpoint 8, thickness h and temperature Tkki of the end of rolling, a signal is formed in sensor 20, W, --К1 -1 corresponding to the first cooling rate of the strip in the first zone VO. At the same time, in the sensor 20, the signal corresponding to Tcp is raised to the fourth power in block 35, multiplied by the coefficient K in block 36. And in block 37, the product K TKPI is divided by h, forming a signal W |. When this cross-section of the strip comes to the end of the first VO zone, i.e. at 1 1 |, where 1 | - the length of the first zone VO, given in the unit 5, the comparator 13 is triggered; on its output signal, the former 19 generates a pulse. According to this pulse, the time sensor 23 determines the time T | finding the cross-section of the strip in the first zone VO. In multiplication unit 25, the product WI-TI is formed and output to the adder 15. Along the length I of the withdrawing roller table specified in the setter 6, and the distance I in the adder 14, the current difference L- is determined, corresponding to the distance from the beginning of the zone to the winder . When the comparator 13 is triggered and the driver 19 outputs to the control input of the switch 22 a signal that translates it into a conducting state, the signals corresponding to the speed v and the distance I ..-- I go to the second and third inputs of the sensor 24 , the first input of which from the setting device 7 receives a signal corresponding to the acceleration a. At the charge rate, the signal at the fourth time input 24 of the accelerator start sensor 11 is zero, i.e. the signal at the control input of the switch 45 is zero. The output of the switch 45 is closed at its second input, and the sensor output 24 a signal is determined on the output of the division 38, corresponding to the time T2 of the cooling of the strip from the beginning of the transducer to the coiler: m; z is pi This signal in block 26 is multiplied by the signal and;

velocities in the second zone of the VO, formed in the sensor 21 U of the K coefficient, thickness h and the set temperature To.:, coiling nOvTocbi. In the adder 15, the difference Tcp-Ton-wiTi-W3T2: i is formed, which in block 27 is divided by the difference W2-ws formed in the adder 16 by the speed w accelerated cooling coming from the setpoint 10, and by the speed W ;; air cooling in the second VO zone.

Thus, in block 27 division, in accordance with the expression (1), a signal is generated that corresponds to the required time TQ EO. At the fourth input of the length sensor 28 and, therefore, to the control input of the switch 50 before the acceleration begins, the signal is zero and the switch 50 is open. Therefore, the acceleration signal a from the first input of the sensor 28 and the first input of the multiplication unit 48 is not received, and the output signal of the block 48 is zero, i.e. the output signal of the adder 49 and the sensor 28 is determined only by the output signal of the multiplication unit 47: 12 V-TJ . This signal, corresponding to the required length L of the area of the CCR, passes through the correction block 29 to the distributor 30, which, depending on the obtained length L, determines the numbers of the OS sections through which the refrigerant is supplied to the strip as it moves along the outgoing roller conveyor. When this cross section of the strip after cooling in the VO and VO zones reaches the measuring point of the coiling temperature, meter 4 measures the coiling temperature, in case of deviation from the set value in adder 17, the signal of this deviation is determined. Depending on the magnitude and sign of this signal, block 29 adjusts the value of b for the following cross sections of the strip in order to compensate for the deviation of the coil temperature from the specified value.

After the start of the acceleration, the operation of the device differs in the operation of the time sensor 24 and the length sensor 28, in which the switching signals 45 and 50 are switched by the acceleration start signal coming from the sensor 11.

In the time sensor 24, the output of the switch 45 is connected to its first input, and the output signal of the sensor is determined by the output signal of dividing unit 39. The speed signal v in block 40 is squared, and in block 42, the product a (LI) is formed, which is fed to the massucking input of adder 43, in which the signal v - | - 2a (L-1) is generated, by which block 41 generates a signal equal to v - + - 2a () °. From this signal in the adder 44, the velocity signal V is subtracted, the resulting difference in block 39 is divided by a, and the correlating time lapse

0

five

0

five

T2z {+ 2a (L-- I) - vJ4 epe3 switch 45 is fed to the input of sensor 24. The formation of a signal corresponding to the time of T9 acceleration;) ein cooling, according to the time signal 2, occurs as in the case of rolling with a constant by speed.

Since the acceleration of the band time signals T | and G2l at the outputs of the sensors 23 and 24, time decreases due to an increase in the speed of movement of the strip, then, as can be seen from expression (1), the time T2 increases.

In sensor1 x 28 after the start of acceleration, switch 50 is closed, and the acceleration signal, and from the first sensor input, passes to the first input of multiplication unit 48. In block 46, the signaling time t., Arriving)) from the third input dat1-: cl. is squared and fed to a scaling input of a b.uk 48, in which a signal of 0.5-at2 is formed. In block 47 of the forms; the product v-T2 is ruled, and the adder 49 forms a signal of the required length | .

Process ioptory, 1. 1 iva / n.ioro strip cross section.

.Z

willow

Fig.Z

Fy

Claims (2)

1. A method of controlling accelerated cooling of a strip, including changing the flow rate of the refrigerant by changing the length of the accelerated cooling zone depending on the speed, temperature and thickness of the strip to ensure a given winding temperature, determining the required time for accelerated cooling, and then increasing the length of the accelerated cooling zone after the acceleration of the strip , characterized in that, in order to improve the quality of the strip by increasing the accuracy of regulation of the temperature of the winding, after the start is accelerated This strip increases the time of accelerated cooling by reducing the time of air cooling and further increasing the length of the zone of accelerated cooling of the strip. 1235579 A1 FIG. / 2. A control device for accelerated strip cooling, comprising thickness gauges, rolling end temperature and strip winding temperature, first and second setters, a correction unit, an adder whose inputs are connected to the strip winding temperature meter and the first setter, and the output to the input of the correction unit , division block, the first and second blocks of multiplication and a choking device, characterized by heme, which, in order to improve the quality of the strip by increasing the accuracy of controlling the temperature of the winding, additionally enter There are four adjusters, an acceleration start sensor, a tracking unit, a comparator, three adders, a band presence sensor, a shaper, two air cooling speed sensors, a switch, two time sensors, a length sensor and a distributor, and the speed meter is connected to the input of the tracking unit and to the first the input of the switch, the thickness gauge - with the first inputs of the air cooling speed sensors, the end temperature meter - with the second inputs of the first air cooling speed sensor and the second adder, the first the sensor is connected to the second input of the second air cooling speed sensor and the first input of the second adder, the second master is with the third inputs of the air cooling speed sensors, the third master is with the first input of the comparator, the fourth master is with the first input of the third adder, the fifth master is with the first inputs a second time sensor and a length sensor, a sixth setter with a first input of the fourth adder, an acceleration start sensor - with fourth inputs of a second time sensor and a length sensor, a strip presence sensor - with the first input of the first time sensor, the output of the tracking unit is connected to the second inputs of the comparator and the third adder, the output of which is connected to the second input of the switch, the input of the driver is connected to the output of the comparator, and the output is ..... with the second input of the first time sensor and with the control the input of the switch, the first output of which is connected to the second inputs of the second time sensor, and a length sensor, and the second output - with the third input of the second time sensor, the output of which is connected to the first input of the first multiplication unit, the output of the first Occupancy time connected to the first input of the second multiplier, a second input coupled to an output of the first cooling air velocity sensor and the output of -. the third input of the second adder, the fourth input of which is connected to the output of the first block umenozheniya. the output of the second air cooling speed sensor is connected to the second inputs of the first multiplication unit and the fourth adder, the first and second inputs of the division unit are connected to the outputs of the second and fourth adders, and the output to the third input of the length sensor, the output of which is connected to the second input of the correction unit, the input distributor - with the output of the correction unit, and the output - with a choking unit.