Hot Rolling Cooling Control to Prevent Surface Undercooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In hot rolling mills, excessive cooling of rolled products in the intermediate roller table can lead to undercooling of surface regions, causing phase transformations that impair product quality, and existing cooling methods struggle to maintain a minimum surface temperature to prevent this.
Innovation Solution
A method and cooling section where the rolled product is cooled with a controlled coolant flow, simulated to maximize cooling while ensuring the surface temperature does not fall below a predetermined minimum value, using a series of cooling devices with adjustable coolant delivery based on initial and calculated enthalpy and temperature distributions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If excessive cooling is applied to the rolled product in the intermediate roller table, then the cooling efficiency is improved, but the surface temperature falls below the minimum value causing undercooling and phase transformations that impair product quality
Solution Approach 1:
The cooling system applies different cooling intensities to different regions of the rolled product. By controlling the coolant flow rate for each cooling device individually, the system can deliver higher cooling capacity to the core while limiting cooling at the surface, thereby achieving efficient overall cooling without causing surface undercooling that would impair product quality
Solution Approach 2:
The cooling system dynamically adjusts the coolant flow rate based on real-time temperature measurements. The control unit continuously monitors the rolled product temperature and modifies the coolant flow rate accordingly, enabling the system to adapt to changing thermal conditions and maintain optimal cooling without exceeding the minimum surface temperature threshold
2Speed
If high coolant flow rate is used to achieve rapid cooling, then the cooling speed is improved, but the surface temperature drops below the minimum value causing harmful phase transformations
Solution Approach 1:
The system changes the coolant flow rate parameter dynamically based on temperature measurements. By adjusting this key parameter in real-time, the system can achieve rapid cooling when the rolled product temperature is high while reducing the coolant flow rate as the temperature approaches the minimum threshold, thereby preventing surface undercooling and harmful phase transformations
Solution Approach 2:
The control system implements feedback control by continuously measuring the rolled product temperature and using this information to adjust the coolant flow rate. This closed-loop control ensures that the cooling speed is optimized while preventing the surface temperature from dropping below the minimum value that would cause harmful phase transformations
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach optimizes cooling to prevent undercooling, maintaining product quality by ensuring the surface temperature remains above a minimum value, thus enhancing the metallurgical properties and surface quality of the rolled products.
Implementation Method 1
with each cooling device in its active region a coolant flow of a coolant can be delivered onto a rolled product surface of the rolled product
Implementation Method 2
the rolled product is cooled in a cooling section which is arranged upstream of a finishing train of a hot rolling mill
Data Source
AI summary
A method for cooling a rolled product in a cooling section which is located upstream of a finishing train of a hot rolling mill. The cooling section includes a cooling device which can deliver a coolant flow of a coolant onto a rolled product surface of the rolled product. In the method, a coolant flow is delivered, by means of each cooling device and in each cooling section pass, onto the rolled product surface, which flow is set to a set value that is assigned to the relevant cooling device for the cooling section pass. The set values for a cooling section pass are determined in a simulation of the cooling section pass so that surface temperatures, determined in the simulation, of the rolled product surface upon leaving active regions of the cooling device do not exceed a minimum value for a surface temperature of the rolled product surface.