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CN-122007363-A - Method for realizing adjustment of water temperature difference by automatically adjusting water quantity of crystallizer

CN122007363ACN 122007363 ACN122007363 ACN 122007363ACN-122007363-A

Abstract

The invention discloses a method for realizing adjustment of water temperature difference by automatically adjusting water quantity of a crystallizer, and belongs to the technical field of continuous casting of ferrous metallurgy. The method adopts the following technical scheme that default cooling water flow (the pulling speed is more than or equal to 1.3m/min and is set in two steps of <1.3 m/min) of the wide surface and the narrow surface of the crystallizer is set according to the continuous casting pulling speed, the water inlet and outlet temperature difference of the wide surface and the narrow surface is monitored in real time, when the temperature difference of the wide surface is more than 9 ℃, the water inlet and outlet temperature difference of the wide surface is increased step by step, the water inlet and outlet temperature difference of the wide surface is 50L/min each time, the interval is 1min, the pulling speed is reduced by 0.1m/min after the two times of adjustment are still overrun, the pulling speed is reduced after the two times of adjustment are still overrun, the water inlet and outlet temperature difference is not changed when the temperature difference is less than 9 ℃, and a visual warning signal is sent out when the temperature difference is abnormal. The invention realizes the dynamic zoning accurate regulation of the cooling water quantity, establishes a multistage protection mechanism of 'first water increasing and then speed reducing', obviously reduces the surface cracks of casting blanks and improves the hot delivery rate and the production safety of the casting machine.

Inventors

  • FENG HAITAO
  • CHEN GUOQUAN
  • FAN YONG
  • XU SHUQIANG
  • LIU YU
  • YU JIE
  • DENG JIXIANG
  • YANG FU

Assignees

  • 重庆钢铁股份有限公司

Dates

Publication Date
20260512
Application Date
20260313

Claims (10)

  1. 1. The method for realizing the adjustment of the temperature difference of water by automatically adjusting the water quantity of the crystallizer is characterized by comprising the following steps of: setting default cooling water flow of the wide surface and the narrow surface of the crystallizer according to the continuous casting pulling speed; Acquiring the water inlet and outlet temperature difference of the wide surface and the water inlet and outlet temperature difference of the narrow surface of the crystallizer in real time; When the water temperature difference of the wide surface is larger than a first preset temperature difference threshold value, carrying out incremental adjustment on the flow of the cooling water of the wide surface at least once, increasing a first preset water value each time, waiting for a first preset time interval after adjustment, and continuing the next incremental adjustment if the water temperature difference of the wide surface is still larger than the first preset temperature difference threshold value, and reducing the continuous casting drawing speed set value if the water temperature difference of the wide surface is still larger than the first preset temperature difference threshold value after the incremental adjustment of preset times; when the water temperature difference of the narrow surface is larger than a second preset temperature difference threshold value, carrying out incremental adjustment on the cooling water flow of the narrow surface at least once, increasing a second preset water value each time, waiting for a second preset time interval after adjustment, continuing to carry out the next incremental adjustment if the water temperature difference of the narrow surface is still larger than the second preset temperature difference threshold value, and reducing the continuous casting drawing speed set value if the water temperature difference of the narrow surface is still larger than the second preset temperature difference threshold value after the incremental adjustment of preset times.
  2. 2. The method for realizing the automatic regulation of the water quantity of the crystallizer according to claim 1, wherein the current cooling water flow rate is kept unchanged when the wide water inlet and outlet temperature difference is smaller than or equal to the first preset temperature difference threshold value and the narrow water inlet and outlet temperature difference is smaller than or equal to the second preset temperature difference threshold value.
  3. 3. The method for automatically adjusting the water quantity of the crystallizer according to claim 1 or 2, wherein the default cooling water flow is set in at least two steps according to whether the pulling speed reaches or exceeds a preset pulling speed threshold value, and the water quantity of the wide surface and the narrow surface of the higher pulling speed step is respectively larger than the corresponding water quantity of the lower pulling speed step.
  4. 4. The method for realizing the automatic regulation of the water quantity of the crystallizer according to claim 3, wherein the preset pull rate threshold value is 1.3 m/min.
  5. 5. The method for automatically adjusting the water quantity of a crystallizer according to claim 1, wherein the first preset temperature difference threshold value and the second preset temperature difference threshold value are both 9 ℃.
  6. 6. The method for automatically adjusting the water quantity of a crystallizer to realize the adjustment of the water temperature difference according to claim 1, wherein the first preset water quantity value of each increment of the wide surface is larger than the second preset water quantity value of each increment of the narrow surface.
  7. 7. The method for automatically adjusting the water quantity of the crystallizer according to claim 1 or 6, wherein the increment of the wide cooling water flow is 50L/min each time, and the increment of the narrow cooling water flow is 30L/min each time.
  8. 8. The method for automatically adjusting the water quantity of a crystallizer to realize the adjustment of the water temperature difference according to claim 1, wherein the first preset time interval and the second preset time interval are 1 min.
  9. 9. The method for realizing the automatic regulation of the water quantity of the crystallizer according to claim 1, wherein the amplitude of the set value of the continuous casting pulling speed is reduced to be 0.1 m/min.
  10. 10. The method for automatically adjusting the water quantity of the crystallizer according to any one of claims 1 to 9, further comprising the step of sending out a visual warning signal when the temperature difference is abnormal.

Description

Method for realizing adjustment of water temperature difference by automatically adjusting water quantity of crystallizer Technical Field The invention belongs to the technical field of steelmaking continuous casting, and particularly relates to a method for realizing adjustment of water temperature difference by automatically adjusting water quantity of a crystallizer. Background In modern continuous casting production, a crystallizer is a key device for primary solidification of molten steel into a blank shell, and the heat extraction capacity of a cooling system directly determines the thickness uniformity and the surface quality of the primary blank shell and the safety and stability of the whole continuous casting process. The temperature difference of cooling water (delta T, i.e. water inlet and outlet temperature difference) of the crystallizer is one of the most direct and sensitive technological parameters reflecting the cooling intensity, the heat balance state and whether the heat load of the copper plate is in a reasonable range. The water temperature difference of a crystallizer is controlled within a certain range (usually less than or equal to 8-10 ℃ and depends on the characteristics of steel types, sections and casting powder) in the industry, and the water temperature difference is used as a basic requirement for guaranteeing the quality of casting blanks and preventing major production accidents. When the temperature difference of the crystallizer is high for a long time or instantaneously, multiple serious consequences are brought to the fact that firstly, the temperature of a hot surface of a copper plate is increased, thermal stress is increased, deformation, cracks and even local burning loss of the copper plate are easy to occur, secondly, the high temperature difference accelerates the deposition rate of scale such as calcium carbonate, silicate and the like in a cooling water channel, the heat resistance of a scale layer is rapidly increased, the heat exchange capacity is further weakened, typical vicious circle is formed, thirdly, the growth speed of a blank shell is slowed down, the liquid core is overlong, surface and subsurface defects such as longitudinal cracks, transverse cracks, star-shaped cracks and subcutaneous air holes are easy to occur in the vibration or withdrawal process, and in the worst case, adhesive steel leakage or leakage accidents occur when the blank shell is locally too thin and the strength is insufficient to bear the static pressure of molten steel, so that equipment is seriously damaged, long-time production is interrupted, huge economic loss and even serious safety accidents are caused. Conversely, if the cooling is excessive or uneven (particularly, if the cooling is too strong on the narrow surface), the blank shell may be too thick, the corner may be too cold, the internal stress may be concentrated, and the problems such as corner cracks, center cracks, bulging deformation and the like may be caused. In actual production, the pulling speed is the most important dynamic variable affecting the heat load of the crystallizer. The increase of the pulling speed can obviously increase the heat quantity transferred into the crystallizer in unit time, if the water quantity is regulated after delay, the temperature difference is rapidly exceeded, and if the water quantity is not reduced in time after the pulling speed is reduced, excessive cooling can be caused to influence the uniformity of the quality of the blank shell. The traditional crystallizer water quantity control mostly adopts a fixed parameter table or a manual experience adjustment mode, and has the following prominent problems: 1) The response speed to unsteady working conditions such as fluctuation of pulling speed, steel grade switching, change of mold flux consumption and the like is low, and an operator is usually required to observe the change of temperature difference and then manually adjust the mold flux consumption, so that obvious hysteresis exists; 2) The heat load difference between the wide surface (cambered surface) and the narrow surface (side surface) is large (the heat input of the wide surface is usually much higher than that of the narrow surface), but the traditional regulation usually adopts uniform water quantity or simple proportional regulation, so that the accurate control of the partition is difficult to realize; 3) The lack of an effective multistage protection mechanism, when the water quantity is added to the upper limit and the temperature cannot be controlled, the operation risk and the production fluctuation are increased only by means of manual emergency speed reduction or shutdown; 4) The regulation strategy is lack of standardization and intellectualization, and depending on personal experience, overregulation or insufficient regulation easily occurs, so that the quality fluctuation of casting blanks is large, the quality of head and tail blanks is reduced, an