Hot rolling area high-pressure water descaling frequency conversion adjusting method and system based on rolling rhythm

Abstract

The invention provides a hot rolling area high-pressure water descaling frequency conversion adjusting method and system based on the rolling rhythm. The method comprises the steps that the time when strip steel reaches the next descaling point is calculated; according to the arrival time, the next starting time of the whole-line descaling point is calculated, and the gap time of whole-line descaling is obtained; according to the current descaling pump frequency, the frequency increasing / decreasing rate of the descaling pump and the descaling interval time, the lowest frequency decreasing frequency and the frequency increasing time are calculated; and according to the lowest down-conversion frequency and the up-conversion time, a set frequency is issued to the descaling PLC. According to the rolling rhythm prediction and descaling regulation of the whole line, the starting time of the variable frequency pump can be accurately judged, the down-conversion frequency can be accurately predicted, the lowest frequency protection time can be adjusted, it is guaranteed that the variable frequency pump cannot be directly converted from down-conversion to up-conversion, and the frequency converter is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of strip steel processing, and in particular to a method and system for frequency conversion regulation of high-pressure water descaling in a hot rolling area based on rolling rhythm. Background Art

[0002] High-pressure water descaling uses high-pressure water generated by a high-pressure pump, which is sprayed out through the injection valve in the descaling box and hits the high-temperature slab. The high-pressure water is first rapidly cooled on the slab, causing a temperature difference between the iron oxide scale and the slab body, resulting in mechanical descaling by cracking the iron oxide scale on the surface, and then the iron scale on the surface of the slab is removed by the impact force generated by the high-pressure water.

[0003] In the prior art, the entire descaling system is composed of multiple high-pressure descaling pumps, each of which contains an outlet valve, a minimum flow valve, a lubrication pump and some sensors. When the descaling pump is turned on, the corresponding outlet valve will also open. The outlet valves are connected to the main pipeline to send high-pressure water to the injection valve. When the slab reaches the descaling box, the hot rolling main line PLC controls the injection valve to open. If the liquid level of the accumulator reaches the minimum set value, the high-pressure liquid level gauge (or high-pressure differential pressure gauge) sends a signal to the control system, and the control system automatically closes the minimum liquid level valve to prevent high-pressure gas from entering the pipeline system. At this time, the minimum liquid level valve has the function of a one-way valve, that is, high-pressure water can only enter the accumulator; when the accumulator water level returns to normal, the minimum liquid level valve returns to normal; if the accumulator liquid level reaches the maximum set value and the pressure value reaches the lower limit of the specified range, the control system automatically starts the air compressor to replenish air to the accumulator.

[0004] In a Chinese patent document with publication number CN103909103A, a slab descaling pump system and method are disclosed, which describes a method of adjusting the frequency change by calculating the total water output when a power frequency pump is connected in parallel with a variable frequency pump. However, the prior art does not adjust the frequency of the descaling pump according to the position of the slab, resulting in high energy consumption of the system. Summary of the invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a method and system for variable frequency regulation of high-pressure water descaling in a hot rolling area based on rolling rhythm.

[0006] According to the present invention, a variable frequency regulation method for high pressure water descaling in a hot rolling area based on rolling rhythm is provided, comprising:

[0007] Step S1: Calculate the time when the strip reaches the next descaling point;

[0008] Step S2: Calculate the next opening time of the descaling points of the entire line according to the arrival time to obtain the interval time of descaling of the entire line;

[0009] Step S3: Calculate the minimum frequency reduction and frequency increase time according to the current descaling pump frequency, the frequency increase / decrease rate of the descaling pump, and the descaling interval time;

[0010] Step S4: According to the minimum frequency reduction and frequency increase time, the set frequency is sent to the descaling PLC.

[0011] Preferably, the descaling area is distributed as follows: after the strip steel comes out of the furnace, it includes the roughing descaling box HSB, the rack descaling R1, the rack descaling R2 and the finishing descaling box FSB in sequence;

[0012] The step S1 comprises:

[0013] Step S1.1: Get the current time t now ;

[0014] Step S1.2: Obtain the current position of the strip and determine the area that needs to be descaled next time;

[0015] Step S1.3: Calculate the time when the head reaches / the tail leaves the next area to be descaled.

[0016] Preferably, in step S1.3, the time when the head of the strip arrives at / the tail of the strip leaves the HSB includes:

[0017] Step S1.3.1: Obtain the strip steel drawing furnace number;

[0018] Step S1.3.2: Calculate the distance L between the furnace outlet and the HSB inlet fuc_hsb , HSB length L hsb , slab length L slab ;

[0019] Step S1.3.3: Obtain roller conveying speed v fuc_hsb , HSB speed v hsb ;

[0020] Step S1.3.4: Calculate the time when the strip head reaches HSB: The time when the tail of the strip leaves HSB is

[0021] Preferably, in step S1.3, the time when the head of the strip arrives at / the tail leaves R1, and the time when the head of the strip arrives at / the tail leaves R2 includes:

[0022] Step S1.3.5: Get the distance L between HSB and R1 hsb_r1 , and roller conveying speed v hsb_r1 ;

[0023] Get the distance L between R1 and R2 r1_r2 , and roller conveying speed vr1_r2 ; R1 and R2 both include multiple passes in series, and the roller acceleration a of each pass 0_i , belt threading acceleration a 1_i , steel throwing deceleration a 2_i , roller deceleration a 3_i , threading speed v 0_i , throwing speed v 1_i , maximum speed v max_i , strip pass final length L slab_i , where i = 1, 2, ..., 8, is the number of rolling passes;

[0024] Step S1.3.6: Calculate roller acceleration time Roller acceleration distance

[0025] Step S1.3.7: Calculate the acceleration time Bite acceleration distance

[0026] Step S1.3.8: Calculate the steel throwing deceleration time Steel throwing deceleration distance

[0027] Step S1.3.9: Calculate the maximum speed time

[0028] Step S1.3.10: Calculate roller deceleration time Roller deceleration distance

[0029] Step S1.3.11: Calculate the time from HSB to R1

[0030] Step S1.3.12: Calculate the time from R1 to R2 i: number of rough rolling passes;

[0031] Step S1.3.13: Time t for the strip head to reach R1 1_a =t hsb_r1 +t 0_1 ;

[0032] Step S1.3.14: Time t at which the tail of the strip leaves each pass i_b =t i_a +t 1_i +t 2_i +t 3_i ;

[0033] Step S1.3.15: Time t for the strip head to reach each intermediate pass i_a =t i-1_b +t4i-1 +t 0_i ;

[0034] Step S1.3.16: Time t for the strip head to reach R2 i+1_a =t i_b +t r1_r2 +t 0_i i: Number of rough rolling passes.

[0035] Preferably, step S2 comprises:

[0036] Step S2.1: According to the strip steel model setting, the descaling rules of each descaling point in the whole line are obtained;

[0037] Step S2.2: Establishing a corresponding table between strip rolling rhythm and descaling rules;

[0038] Step S2.3: Obtaining the time for each steel strip in the current descaling area to reach the next descaling point;

[0039] Step S2.4: Calculate the time when the descaling points of the entire line are opened next time to obtain the interval time of descaling of the entire line;

[0040] Get the time t when each strip of steel in the whole line reaches the next descaling point piece_1 ,t piece_2 …t piece_N , get the time point closest to the current time, which is the interval time t for descaling the entire line gap , when there is no steel on the line, t gap Use a default large value.

[0041] Preferably, the step S2.3 comprises:

[0042] Step S2.3.1: Obtain the sequence of each strip steel piece1, piece2...pieceN on the line;

[0043] Step S2.3.2: Calculate the time t for each piece of steel to reach the next descaling point piece_i To find the next area with a descaling procedure of 1 starting from the current position of the strip, the start time of the area is obtained as the time when the strip arrives at the next descaling point.

[0044] Preferably, step S3 comprises:

[0045] Step S3.1: Obtain the descaling frequency f of the descaling pump, the current frequency f0 of the descaling pump, and the standby frequency f of the descaling pump min , descaling pump frequency increase rate v up , descaling pump frequency reduction rate v dn , descaling pump minimum frequency protection time t0, descaling pump frequency increase protection time t1, descaling interval time t gap;

[0046] Step S3.2: Calculate the time t required for the descaling pump to increase its frequency up =(f - f min ) / v up ; Calculate the time t required for frequency reduction dn =(f0 - f min ) / v dn ; Calculate the total time t required to reduce to the standby frequency tatol =t0 + t1 + t up +t dn ; If the gap time t gap for full-line descaling is greater than or equal to the total time t required to reduce to the standby frequency tatol , obtain the frequency f dn for frequency reduction = f min ; Otherwise, further calculate the frequency for frequency reduction:

[0047] Calculate the time t for frequency increase and frequency reduction up +t dn =t gap -t0 - t1; The time t required for frequency increase up =(f - f dn ) / v up ; The time t required for frequency reduction dn =(f0 - f dn ) / v dn ; Calculate and obtain If the lowest frequency reached is less than the descaling frequency of the descaling pump, frequency reduction is allowed; otherwise, frequency reduction is not allowed;

[0048] Step S3.3: Calculate the time t for frequency increase; If f dn =f, obtain the current time as the start time t for frequency increase = t now ; If f dn <f, the time t required for frequency increase up =(f - f dn ) / v up , and the start time t for frequency increase = t now +t gap -t up -t1.

[0049] Preferably, the said step S4 includes:

[0050] Calculate that in the case where the site can reduce the frequency, send the frequency f dn for frequency reduction to the descaling PLC, and periodically determine whether it is time to start increasing the frequency. When it is time to increase the frequency, send the descaling frequency f to the descaling PLC.

[0051] According to a hot-rolling area high-pressure water descaling frequency conversion regulation system based on rolling rhythm provided by the present invention, it includes:

[0052] Module M1: Calculate the time when the strip reaches the next descaling point;

[0053] Module M2: Calculate the next opening time of the descaling points of the entire line according to the arrival time, and obtain the interval time of descaling of the entire line;

[0054] Module M3: Calculate the minimum frequency reduction and frequency increase time according to the current descaling pump frequency, the frequency increase / decrease rate of the descaling pump and the descaling interval time;

[0055] Module M4: Send the set frequency to the descaling PLC according to the minimum frequency reduction and frequency increase time.

[0056] According to a hot rolling area high pressure water descaling equipment provided by the present invention, the hot rolling area high pressure water descaling frequency conversion regulation method based on rolling rhythm is adopted.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] 1. Combining the present invention with actual conditions, the frequency reduction and low-frequency operation time of the descaling pump can be accurately calculated according to the actual number and location of descaling points on site, thereby achieving the goal of energy saving.

[0059] 2. According to the rolling rhythm prediction and descaling procedures of the entire line, the present invention can accurately determine the start-up time of the variable frequency pump, predict the frequency reduction frequency, and adjust the minimum frequency protection time to ensure that the variable frequency pump will not directly switch from frequency reduction to frequency increase, thereby protecting the frequency converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0061] Figure 1 It is a flow chart of the frequency conversion adjustment method of high-pressure water descaling in the hot rolling area based on the rolling rhythm in the present invention;

[0062] Figure 2 It is a block diagram of the frequency conversion regulation system of high-pressure water descaling in the hot rolling area based on the rolling rhythm in the present invention. DETAILED DESCRIPTION

[0063] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0064] The present invention provides a variable frequency regulation method for high-pressure water descaling in a hot rolling area based on rolling rhythm. The method accurately calculates the frequency reduction and low-frequency operation time of the descaling pump according to the actual number and location of descaling points on site to achieve the goal of energy saving.

[0065] Specifically, refer to Figure 1 and Figure 2 As shown, the variable frequency adjustment method for high pressure water descaling in the hot rolling area based on the rolling rhythm includes the following steps:

[0066] Step S1: predicting the time when the strip reaches the next descaling point.

[0067] The hot rolling line generally has up to 4 groups of high pressure descaling points, namely HSB inlet and outlet, R1 inlet and outlet, R2 inlet and outlet, and FSB inlet and outlet. After the slab is drawn and passes through each descaling point, the time for the strip to reach the subsequent descaling point is calculated based on the speed-position diagram of the strip.

[0068] Step S1.1: Get the current time as t now ;

[0069] Step S1.2: Obtain the current position of the strip and determine the area that needs to be descaled next time;

[0070] Step S1.3: Calculate the time when the head reaches / the tail leaves the next area to be descaled.

[0071] In a specific embodiment, the time when the head of the strip arrives at / the tail leaves the HSB includes:

[0072] Step S1.3.1: Obtain the strip steel drawing furnace number;

[0073] Step S1.3.2: Calculate the distance L between the furnace outlet and the HSB inlet fuc_hsb , HSB length L hsb , slab length L slab ;

[0074] Step S1.3.3: Obtain roller conveying speed v fuc_hsb , HSB speed v hsb ;

[0075] Step S1.3.4: Calculate the time when the strip head reaches HSB: The time when the tail of the strip leaves HSB is

[0076] The time when the head of the strip arrives at / the tail leaves R1, and the time when the head of the strip arrives at / the tail leaves R2 includes:

[0077] Step S1.3.5: Get the distance L between HSB and R1 hsb_r1, and roller conveying speed v hsb_r1 ;

[0078] Get the distance L between R1 and R2 r1_r2 , and roller conveying speed v r1_r2 ; R1 and R2 both include multiple passes in series, and the roller acceleration a of each pass 0_i , belt threading acceleration a 1_i , steel throwing deceleration a 2_i , roller deceleration a 3_i , threading speed v 0_i , throwing speed v 1_i , maximum speed v max_i , strip pass final length L slab_i In a preferred embodiment, R1 includes 3 passes, R2 includes 5 passes, and a total of 8 passes, where i=1, 2, ..., 8, is the number of rolling passes. For the sake of distinction, R1 includes 1-3 passes, and R2 includes 4-8 passes. The threading acceleration is: the acceleration from the threading speed to the maximum speed, the steel throwing deceleration is: the deceleration from the maximum speed to the steel throwing speed, and the roller deceleration is: the deceleration from the steel throwing speed to the slab stopping; the threading speed is: the speed of the strip when the head of the strip enters the frame, the steel throwing speed is: the speed of the strip when the tail of the strip leaves the frame, the maximum speed is the maximum speed of the strip in the process of passing through the frame, and the strip pass end length is the strip length after rolling, which can also be called the exit length.

[0079] Step S1.3.6: Calculate roller acceleration time Roller acceleration distance

[0080] Step S1.3.7: Calculate the acceleration time Bite acceleration distance

[0081] Step S1.3.8: Calculate the steel throwing deceleration time Steel throwing deceleration distance

[0082] Step S1.3.9: Calculate the maximum speed time

[0083] Step S1.3.10: Calculate roller deceleration time Roller deceleration distance

[0084] Step S1.3.11: Calculate the time from HSB to R1

[0085] Step S1.3.12: Calculate the time from R1 to R2 i: number of rough rolling passes;

[0086] Step S1.3.13: Time t for the strip head to reach R1 1_a =t hsb_r1 +t 0_1 ;

[0087] Step S1.3.14: Time t at which the tail of the strip leaves each pass i_b =t i_a +t 1_i +t 2_i +t 3_i ;

[0088] Step S1.3.15: Time t for the strip head to reach each intermediate pass i_a =t i-1_b +t 4i-1 +t 0_i ;

[0089] Step S1.3.16: Time t for the strip head to reach R2 i+1_a =t i_b +t r1_r2 +t 0_i i: Number of rough rolling passes.

[0090] Step S1.4: Calculate the time when the head of the strip arrives at / the tail leaves the FSB;

[0091] Step S1.5: For production lines with hot coil boxes, when the hot coil box is uncoiling, the time when the head of the strip arrives at / the tail of the strip leaves the FSB is corrected.

[0092] Step S2: Calculate the descaling interval time of the entire line.

[0093] When there is no descaling point in the whole line in the descaling state, the time when the descaling points of the whole line are turned on next time is calculated to obtain the interval time of descaling of the whole line.

[0094] Step S2.1: According to the strip steel model setting, the descaling rules of each descaling point in the whole line are obtained;

[0095] Step S2.2: Establishing a corresponding table between strip rolling rhythm and descaling rules;

[0096] HSB R11 R12 R13 R21 R22 R23 R24 R25 FSB Current location 0 1 2 3 4 5 6 7 8 9 Start time <![CDATA[t 0_a ]]> <![CDATA[t 1_a ]]> <![CDATA[t 2_a ]]> <![CDATA[t 3_a ]]> <![CDATA[t 4_a ]]> <![CDATA[t 5_a ]]> <![CDATA[t 6_a ]]> <![CDATA[t 7_a ]]> <![CDATA[t 8_a ]]> <![CDATA[t 9_a ]]> End Time <![CDATA[t 0_b ]]> <![CDATA[t 1_b ]]> <![CDATA[t 2_b ]]> <![CDATA[t 3_b ]]> <![CDATA[t 4_b ]]> <![CDATA[t 5_b ]]> <![CDATA[t 6_b ]]> <![CDATA[t 7_b ]]> <![CDATA[t 8_b ]]> <![CDATA[t 9_b ]]> Descaling procedures 0 / 1 0 / 1 0 / 1 0 / 1 0 / 1 0 / 1 0 / 1 0 / 1 0 / 1 0 / 1

[0097] Step S2.3: Obtaining the time for each steel strip in the current descaling area to reach the next descaling point;

[0098] A. Get the sequence of each strip steel piece1, piece2...pieceN on the line;

[0099] B. Calculate the time t for each piece of steel to reach the next descaling pointpiece_i To find the next area with a descaling procedure of 1 starting from the current position of the strip, the start time of the area is obtained as the time when the strip arrives at the next descaling point.

[0100] Step S2.4: Calculate the time when the descaling points of the entire line are opened next time to obtain the interval time of descaling of the entire line;

[0101] Get the time t when each strip of steel in the whole line reaches the next descaling point piece_1 ,t piece_2 …t piece_N , get the time point closest to the current time, which is the interval time t for descaling the entire line gap , when there is no steel on the line, t gap Use a default large value.

[0102] Step S3: Calculate the descaling pump frequency reduction and frequency increase time.

[0103] The minimum frequency reduction and frequency increase time are calculated according to the current descaling pump frequency, the frequency increase / decrease rate of the descaling pump and the descaling gap.

[0104] Step S3.1: Obtain the descaling frequency f of the descaling pump, the current frequency f0 of the descaling pump, and the standby frequency f of the descaling pump min , descaling pump frequency increase rate v up , descaling pump frequency reduction rate v dn , descaling pump minimum frequency protection time t0, descaling pump frequency increase protection time t1, descaling interval time t gap ;

[0105] Step S3.2: Calculate the descaling pump frequency reduction;

[0106] A. Calculate whether it can be reduced to standby frequency;

[0107] 1. Calculate the time t required for upscaling up =(ff min ) / v up ;

[0108] 2. Calculate the time t required for frequency reduction dn =(f0-f min ) / v dn ;

[0109] 3. Calculate the total time t required to drop to the standby frequency tatol =t0+t1+t up +t dn ;

[0110] 4. Determine the interval time t for descaling the entire line gap Is it greater than the total time t required to drop to the standby frequency? tatolIf it is greater than or equal to, it means that the standby frequency can be reduced, and the downscaled frequency f is obtained. dn = f min ; If it is less than, it means that the standby frequency cannot be reduced, and the downscaled frequency needs to be further calculated.

[0111] B. In the case where the standby frequency cannot be reduced, calculate the downscaled frequency.

[0112] 1. Calculate the time t for upscaling and downscaling. up + t dn = t gap - t0 - t1;

[0113] 2. The time t required for upscaling is up = (f - f dn ) / v up ;

[0114] 3. The time t required for downscaling is dn = (f0 - f dn ) / v dn ;

[0115] 4. Calculate and obtain

[0116] 5. Determine whether the lowest frequency that can be reduced is less than the descaling frequency of the descaling pump. If it is less, it means that the frequency can be reduced during the idle time; if it is greater than or equal to, it means that the idle time is not enough to reduce the frequency, f dn = f;

[0117] Step S3.3: Calculate the upscaling time t;

[0118] A. If f dn = f, obtain the current time as the upscaling start time t = t now ;

[0119] B. If f dn < t, the time t required for upscaling is up = (f - f dn ) / v up , and the upscaling start time f = t now + t gap - t up - t1;

[0120] Step S4: Send the set frequency to the descaling PLC.

[0121] When calculating that the frequency can be reduced on-site, send the downscaled frequency f dn to the descaling PLC, and periodically judge whether it is time to start upscaling. When it reaches the upscaling time, send the descaling frequency f to the descaling PLC.

[0122] The present invention also provides a hot rolling area high-pressure water descaling frequency conversion regulation system based on rolling rhythm. The hot rolling area high-pressure water descaling frequency conversion regulation system based on rolling rhythm can be realized by executing the process steps of the hot rolling area high-pressure water descaling frequency conversion regulation method based on rolling rhythm, that is, technical personnel in this field can understand the hot rolling area high-pressure water descaling frequency conversion regulation method based on rolling rhythm as the preferred implementation mode of the hot rolling area high-pressure water descaling frequency conversion regulation system based on rolling rhythm.

[0123] The present invention discloses a hot rolling area high pressure water descaling frequency conversion regulation system based on rolling rhythm, comprising:

[0124] Module M1: Calculate the time when the strip reaches the next descaling point;

[0125] Module M2: Calculate the next opening time of the descaling points of the entire line according to the arrival time, and obtain the interval time of descaling of the entire line;

[0126] Module M3: Calculate the minimum frequency reduction and frequency increase time according to the current descaling pump frequency, the frequency increase / decrease rate of the descaling pump and the descaling interval time;

[0127] Module M4: Send the set frequency to the descaling PLC according to the minimum frequency reduction and frequency increase time.

[0128] The present invention also discloses a hot rolling area high pressure water descaling device, which adopts the above-mentioned hot rolling area high pressure water descaling frequency conversion adjustment method based on rolling rhythm, and the specific adjustment method is not described in detail here.

[0129] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A variable frequency adjustment method for high pressure water descaling in hot rolling area based on rolling rhythm, characterized in that: include: Step S1: Calculate the time when the strip reaches the next descaling point; Step S2: Calculate the next opening time of the descaling points of the entire line according to the arrival time to obtain the interval time of descaling of the entire line; Step S3: Calculate the minimum frequency reduction and frequency increase time according to the current descaling pump frequency, the frequency increase / decrease rate of the descaling pump, and the descaling interval time; Step S4: According to the minimum frequency reduction and frequency increase time, the set frequency is sent to the descaling PLC.

2. The variable frequency adjustment method for high pressure water descaling in hot rolling area based on rolling rhythm according to claim 1 is characterized in that: The descaling area is distributed as follows: after the strip steel comes out of the furnace, it includes the roughing descaling box HSB, the rack descaling R1, the rack descaling R2 and the finishing descaling box FSB in sequence; The step S1 comprises: Step S1.1: Get the current time t now ; Step S1.2: Obtain the current position of the strip and determine the area that needs to be descaled next time; Step S1.3: Calculate the time when the head reaches / the tail leaves the next area to be descaled.

3. The variable frequency adjustment method for high pressure water descaling in hot rolling area based on rolling rhythm according to claim 2 is characterized in that: In step S1.3, the time when the head of the strip arrives at / the tail leaves the HSB includes: Step S1.3.1: Obtain the strip steel drawing furnace number; Step S1.3.2: Calculate the distance L between the furnace outlet and the HSB inlet fuc_hsb , HSB length L hsb , slab length L slab ; Step S1.3.3: Obtain roller conveying speed v fuc_hsb , HSB speed v hsv ; Step S1.3.4: Calculate the time when the strip head reaches HSB: The time when the tail of the strip leaves HSB is 4. The method for variable frequency regulation of high pressure water descaling in hot rolling area based on rolling rhythm according to claim 1 is characterized in that: In step S1.3, the time when the head of the strip arrives at / the tail leaves R1, and the time when the head of the strip arrives at / the tail leaves R2 includes: Step S1.3.5: Get the distance L between HSB and R1 hsb_r1 , and roller conveying speed v hsb_r1 ; Get the distance L between R1 and R2 r1_r2 , and roller conveying speed v r1_r2 ; R1 and R2 both include multiple passes in series, and the roller acceleration a of each pass 0_i , belt threading acceleration a 1_i , steel throwing deceleration a 2_i , roller deceleration a 3_i , threading speed v 0_i , throwing speed v 1_i , maximum speed v max_i , strip pass final length L slab_i , where i = 1, 2, ..., 8, is the number of rolling passes; Step S1.3.6: Calculate roller acceleration time Roller acceleration distance Step S1.3.7: Calculate the acceleration time Bite acceleration distance Step S1.3.8: Calculate the steel throwing deceleration time Steel throwing deceleration distance Step S1.3.9: Calculate the maximum speed time Step S1.3.10: Calculate roller deceleration time Roller deceleration distance Step S1.3.11: Calculate the time from HSB to R1 Step S1.3.12: Calculate the time from R1 to R2 i: number of rough rolling passes; Step S1.3.13: Time t for the strip head to reach R1 1_a =t hsb_r1 +t 0_1 ; Step S1.3.14: Time t at which the tail of the strip leaves each pass i_b =t i_a +t 1_i +t 2_i +t 3_i ; Step S1.3.15: Time t for the strip head to reach each intermediate pass i_a =t i-1_b +t 4i-1 +t 0_i ; Step S1.3.16: Time t for the strip head to reach R2 i+1_a =t i_b +t r1_r2 +t 0_i i: Number of rough rolling passes.

5. The method for variable frequency regulation of high pressure water descaling in hot rolling area based on rolling rhythm according to claim 1 is characterized in that: The step S2 comprises: Step S2.1: According to the strip steel model setting, the descaling rules of each descaling point in the whole line are obtained; Step S2.2: Establishing a corresponding table between strip rolling rhythm and descaling rules; Step S2.3: Obtaining the time for each steel strip in the current descaling area to reach the next descaling point; Step S2.4: Calculate the time when the descaling points of the entire line are opened next time to obtain the interval time of descaling of the entire line; Get the time t when each strip of steel in the whole line reaches the next descaling point piece_1 ,t piece_2 …t piece_N , get the time point closest to the current time, which is the interval time t for descaling the entire line gap , when there is no steel on the line, t gap Use a default large value.

6. The variable frequency adjustment method for high pressure water descaling in hot rolling area based on rolling rhythm according to claim 5 is characterized in that: The step S2.3 comprises: Step S2.3.1: Obtain the sequence of each strip steel piece1, piece2...pieceN on the line; Step S2.3.2: Calculate the time t for each piece of steel to reach the next descaling point piece_i To find the next area with a descaling procedure of 1 starting from the current position of the strip, the start time of the area is obtained as the time when the strip arrives at the next descaling point.

7. The variable frequency regulation method for high pressure water descaling in hot rolling area based on rolling rhythm according to claim 1 is characterized in that: The step S3 comprises: Step S3.1: Obtain the descaling frequency f of the descaling pump, the current frequency f0 of the descaling pump, and the standby frequency f of the descaling pump min , descaling pump frequency increase rate v up , descaling pump frequency reduction rate v dn , descaling pump minimum frequency protection time t0, descaling pump frequency increase protection time t1, descaling interval time t gap ; Step S3.2: Calculate the time t required for the descaling pump to increase its frequency up =(ff min ) / v up ; Calculate the time required for frequency reduction t dn =(f0-f min ) / v dn ; Calculate the total time t required to drop to the standby frequency tatol =t0+t1+t up +t dn ; If the interval time of descaling the whole line is t gap Greater than or equal to the total time t required to drop to the standby frequency tatol , get the down-conversion frequency f dn =f min ; On the contrary, further calculate the down-clocking frequency: Calculate the time t used for upscaling and downscaling up +t dn =t gap -t0-t1; frequency upscaling takes time t up =(ff dn ) / v up ; Frequency reduction takes time t dn =(f0-f dn ) / v dn ; Calculated If the lowest frequency is lower than the descaling frequency of the descaling pump, the frequency reduction is allowed; otherwise, the frequency reduction is not allowed; Step S3.3: Calculate the frequency increase time t; if f dn = f, obtain the current time as the start time of frequency increase t = t now ;. If f dn < f, the time required for frequency increase t up = (f - f dn ) / v up , the start time of frequency increase t = t now + t gap - t up - t1.

8. The variable frequency regulation method for high pressure water descaling in hot rolling area based on rolling rhythm according to claim 1 is characterized in that: The step S4 comprises: If the frequency can be reduced on site, the frequency reduction frequency f dn It is sent to the descaling PLC, which periodically determines whether it is time to start the frequency increase. When the frequency increase time is reached, the descaling frequency f is sent to the descaling PLC.

9. A high-pressure water descaling frequency conversion regulation system for hot rolling area based on rolling rhythm, characterized in that: include: Module M1: Calculate the time when the strip reaches the next descaling point; Module M2: Calculate the next opening time of the descaling points of the entire line according to the arrival time, and obtain the interval time of descaling of the entire line; Module M3: Calculate the minimum frequency reduction and frequency increase time according to the current descaling pump frequency, the frequency increase / decrease rate of the descaling pump and the descaling interval time; Module M4: Send the set frequency to the descaling PLC according to the minimum frequency reduction and frequency increase time.

10. A hot rolling area high pressure water descaling equipment, characterized in that: A variable frequency regulation method for high pressure water descaling in a hot rolling area based on rolling rhythm is adopted as described in any one of claims 1 to 8.

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