CN-117193422-B - Temperature control method and temperature control device for manufacturing thick-wall seamless pipe

CN117193422BCN 117193422 BCN117193422 BCN 117193422BCN-117193422-B

Abstract

The invention provides a temperature control method for a thick-wall seamless pipe, which comprises a heating step and a cooling step, wherein the heating step is to heat the outer wall of the thick-wall seamless pipe by utilizing high-temperature flame, calculate local temperature difference according to the measured temperature value of the thick-wall seamless pipe, judge whether to start an induction coil or continue high-temperature flame heating according to the relation between the local temperature difference and the sustainable maximum local temperature difference, and finish heating the pipe. And the cooling step is to calculate the local maximum temperature difference according to the temperature value of the thick-wall seamless pipe, compare the magnitude relation between the local maximum temperature difference and the bearable maximum local temperature difference and judge whether the cooling step is normal or not, thereby completing the cooling of the thick-wall seamless pipe. The temperature control device is based on electromagnetic induction auxiliary heating under infrared temperature measurement control, the intervention time of electromagnetic induction heating is judged through temperature, and meanwhile, the penetration depth of different magnetic fields is correspondingly adjusted, so that the local temperature difference in the pipe in the heating and cooling steps is controlled within the material bearing range.

Inventors

Niu Xuanyu
WEI YULIN
LI ZEKAI
SHEN ZHEN

Assignees

河北数孪科技有限公司

Dates

Publication Date: 20260512
Application Date: 20231009

Claims (9)

1. A temperature control method for manufacturing thick-walled seamless tubes is characterized in that it comprises a heating step and a cooling step, The implementation substep of the heating step S1 includes: s11, determining the final temperature T, the upper temperature difference limit X1 and the fall-back temperature difference X2 of the heating according to the material properties of the thick-wall seamless pipe to be manufactured and the production requirements; S12, heating the outer wall of the thick-wall seamless pipe by utilizing high-temperature flame, recording an inner wall temperature value T1 of the thick-wall seamless pipe measured by an inner wall temperature monitoring infrared camera and an outer wall temperature value T2 of the thick-wall seamless pipe measured by an outer wall temperature monitoring infrared camera, and continuing step S13 if any one of the inner wall temperature value T1 and the outer wall temperature value T2 does not reach the final temperature T; s13, calculating the local temperature difference of the thick-wall seamless pipe according to the inner wall temperature value T1 of the thick-wall seamless pipe and the outer wall temperature value T2 of the thick-wall seamless pipe, which are measured in the step S12 If the local temperature is different If the temperature difference is smaller than the upper limit X1, continuously heating the outer wall of the thick-wall seamless pipe by using high-temperature flame until the temperature difference is locally reduced Greater than the upper limit X1 of the temperature difference, and the local temperature difference When the temperature difference is larger than the upper limit X1, stopping heating the outer wall of the thick-wall seamless pipe by high-temperature flame, folding the left induction coil group and the right induction coil group which are symmetrically arranged at two sides of the thick-wall seamless pipe towards the thick-wall seamless pipe until the left induction coil group and the right induction coil group are concentric with the thick-wall seamless pipe, and performing step S14; S14, respectively starting a left induction coil set and a right induction coil set, heating the thick-wall seamless pipe at the frequency H1 and the power W1, and recording an inner wall temperature value T1 of the thick-wall seamless pipe measured by an inner wall temperature monitoring infrared camera and an outer wall temperature value T2 of the thick-wall seamless pipe measured by an outer wall temperature monitoring infrared camera; S15, calculating the local induction temperature difference of the thick-wall seamless pipe according to the inner wall temperature value T1 of the thick-wall seamless pipe and the outer wall temperature value T2 of the thick-wall seamless pipe, which are measured in the step S14 If the temperature difference is locally induced If the temperature difference is larger than the upper limit X1 of the temperature difference, the left induction coil set and the right induction coil set are continuously utilized to heat the thick-wall seamless pipe, if the temperature difference is locally reduced If the temperature difference is smaller than the fall-back temperature difference X2, closing the left induction coil group and the right induction coil group; S16, judging whether the thick-wall seamless pipe to be manufactured meets the final temperature T or not on the basis of the step S15, if the thick-wall seamless pipe does not meet the final temperature, continuing the step S12 to heat, and if the thick-wall seamless pipe meets the final temperature, finishing the heating step; The implementation substep of the cooling step S2 comprises: s21, determining an initial temperature T3 of a thick-wall seamless pipe to be manufactured, setting a cooling final temperature T4 of the thick-wall seamless pipe to be manufactured, and setting the maximum value of a local maximum temperature difference T of the thick-wall seamless pipe to be manufactured as X3; S22, starting cooling in a set environment; S23, calculating a local maximum temperature difference T of the thick-wall seamless pipe according to an inner wall temperature value T1 of the thick-wall seamless pipe measured by the inner wall temperature monitoring infrared camera and an outer wall temperature value T2 of the thick-wall seamless pipe measured by the outer wall temperature monitoring infrared camera; S24, comparing the local maximum temperature difference fatly T with the maximum value X3 according to the local maximum temperature difference fatly T of the thick-wall seamless pipe obtained in the step S23, if the local maximum temperature difference fatly T is larger than the maximum value X3, considering that the thick-wall seamless pipe is cooled too fast under a set environment, starting a left induction coil group and a right induction coil group, heating the induction coil group at power W2 and frequency H2 until the local maximum temperature difference fatly T is smaller than the maximum value X3, and if the local maximum temperature difference fatly T is smaller than the maximum value X3, considering that the cooling speed of the thick-wall seamless pipe is normal, and continuing cooling under the set environment; S25, continuously detecting an inner wall temperature value T1 and an outer wall temperature value T2 of the thick-wall seamless pipe by using a temperature monitoring infrared camera, returning to the step S22 when any one of the inner wall temperature value T1 and the outer wall temperature value T2 does not reach the cooling final temperature T4, and finishing cooling when the inner wall temperature value T1 and the outer wall temperature value T2 are lower than the cooling final temperature T4.
2. The temperature control method for manufacturing a thick-walled seamless tube according to claim 1, wherein the material properties of the thick-walled seamless tube include an outer diameter of the thick-walled seamless tube, an inner diameter of the thick-walled seamless tube, an electrical resistivity of the thick-walled seamless tube, a relative permeability of the thick-walled seamless tube, and a curie temperature of the thick-walled seamless tube.
3. The temperature control method for manufacturing thick-walled seamless tubes according to claim 1 or 2, characterized in that in substep S14 of the heating step, the determination of the frequency H1 and the power W1 is: s141, drawing a temperature T-wall thickness depth S function relation curve of the thick-wall seamless pipe according to the inner wall temperature value T1 of the thick-wall seamless pipe and the outer wall temperature value T2 of the thick-wall seamless pipe, which are measured in the step S12, wherein the specific expression is as follows: ; Wherein T1 is the inner wall temperature of the thick-wall seamless pipe, T2 is the outer wall temperature of the thick-wall seamless pipe, R1 is the outer wall radius of the thick-wall seamless pipe, and R2 is the inner wall radius of the thick-wall seamless pipe; S142, determining the maximum heating depth corresponding to each electromagnetic frequency of the thick-wall seamless pipe according to the relative magnetic conductivity and the resistivity of the thick-wall seamless pipe, and drawing a frequency H-heating depth S curve expression of the thick-wall seamless pipe as follows: ; wherein p is the resistivity of the thick-walled seamless tube, Magnetic permeability of the thick-wall seamless pipe; s143, determining a heating depth S1 corresponding to a Curie point of the thick-wall seamless tube when the gradient T of the temperature along the radial direction of the thick-wall seamless tube is maximum and is lower than the Curie point of the thick-wall seamless tube according to the temperature T-wall thickness depth S function relation curve of the thick-wall seamless tube obtained in the step S141, and obtaining the depth to be heated of the induction coil group; S144, determining the power W1 of the induction coil set according to the heating depth S1 obtained in the step S143 and the corresponding temperature value at the moment, and then bringing S1 into the frequency H-heating depth S curve obtained in the step S142 to obtain the current frequency H1 in the coil at the moment.
4. The temperature control method for manufacturing a thick-walled seamless tube according to claim 1 wherein the temperature-wall thickness depth function curve of the thick-walled seamless tube is plotted as a circular tube steady-state heat conduction logarithmic curve distribution.
5. The temperature control method for manufacturing a thick-walled seamless tube according to claim 1, wherein the upper temperature difference limit X1 and the fall-back temperature difference X2 of the induction heating are set according to the material properties of the thick-walled seamless tube.
6. A temperature control method for manufacturing thick-walled seamless tubes according to claim 3 characterized in that in substep S24 of the cooling step the frequency H2 and the power W2 are determined as: s241, drawing a temperature-wall thickness depth function relation curve of the thick-wall seamless pipe according to the inner wall temperature value T1 of the thick-wall seamless pipe and the outer wall temperature value T2 of the thick-wall seamless pipe, which are measured in the step S23; S242, determining the maximum heating depth corresponding to each electromagnetic frequency of the thick-wall seamless pipe according to the relative magnetic conductivity and the resistivity of the thick-wall seamless pipe, and drawing a frequency-heating depth curve of the thick-wall seamless pipe; S243, determining a heating depth S2 corresponding to the Curie point of the thick-wall seamless tube when the gradient T of the temperature along the radial direction of the thick-wall seamless tube is maximum and is lower than the Curie point of the thick-wall seamless tube according to the temperature-wall depth function relation curve of the thick-wall seamless tube obtained in the step S241, and obtaining the depth to be heated of the induction coil group; S244, determining the frequency H2 according to the heating depth S2 obtained in the step S243 and the frequency-heating depth obtained in the step S242, and determining the power W2 of the induction coil group according to the temperature values of T1 and T2.
7. The method according to claim 6, wherein the power W1 of the induction coil assembly is proportional to the inner wall temperature value T1 and the outer wall temperature value T2, respectively, in the heating step, and the power W2 of the induction coil assembly is proportional to the inner wall temperature value T1 and the outer wall temperature value T2, respectively, in the cooling step.
8. The method according to claim 7, wherein in the heating step, the heating depth s1 is proportional to the power W1 of the induction coil assembly, and in the cooling step, the heating depth s2 is proportional to the power W2 of the induction coil assembly.
9. A temperature control device for a temperature control method for manufacturing a thick-walled seamless pipe according to any one of claims 1 to 8, comprising a left side induction coil set, a right side induction coil set, a bracket, an inner wall temperature monitoring infrared camera and an outer wall temperature monitoring infrared camera, wherein the left side induction coil set and the right side induction coil set are symmetrically distributed on both sides of the thick-walled seamless pipe, the inner wall temperature monitoring infrared camera is located at one side end of the thick-walled seamless pipe, the outer wall temperature monitoring infrared camera is located at the upper end of the thick-walled seamless pipe, and the thick-walled seamless pipe is fixed on the bracket.

Description

Temperature control method and temperature control device for manufacturing thick-wall seamless pipe Technical Field The invention relates to the field of pipeline heating, in particular to a temperature control method for a thick-wall seamless pipe, and more particularly relates to a heating and cooling technology for the thick-wall seamless pipe, wherein the temperature distribution of the thick-wall seamless pipe is controlled by adding an electromagnetic induction coil, so that the local temperature difference in the pipe in the heating and cooling steps is controlled within a material bearing range. Background Thick-wall seamless tubes have the characteristics of excellent performance, high safety coefficient, high manufacturing cost and the like in the field of metal pipelines, and are widely used in various severe environments. Thick-walled seamless tubes operating at high pressure and the like typically have a relatively high pipe diameter (30% or more). The heat treatment or reaming is carried out before and after the heating or cooling, and the large wall thickness makes the temperature propagation speed difficult to control, and large thermal stress is easily generated in the inner part to cause cracking. In the prior art, the heating and cooling of the seamless pipe are usually slow heating, furnace cooling and other modes, and the economical efficiency is good, but for thick-wall workpieces, the heating and cooling speeds are controlled within a certain range, the temperature difference between the inner part and the outer part exceeding the range is too large, the thermal stress is easy to cause the cracking of the pipeline, and under the condition of natural cooling, the cooling speed is easy to be too fast, the temperature of the outer wall is fast to be reduced, larger residual stress is easy to be locally generated, and the heating speed is too slow to influence the production efficiency of the thick-wall seamless pipe. While conventional furnace heating has the advantage of low-cost heating, induction heating can achieve precise penetrating heating of different depths by adjusting the frequency, but induction heating is high in cost. The adoption of mixed energy sources in the production neighborhood of thick-wall pipelines has the unique advantage of realizing high efficiency and energy conservation. Disclosure of Invention Aiming at the problems existing in the prior art, the invention provides a temperature control method and a temperature control device for a thick-wall seamless pipe, which are characterized in that a left induction coil group and a right induction coil group are symmetrically arranged on two sides of the thick-wall seamless pipe, and the characteristics of magnetic field penetration and material Curie temperature are utilized to accurately heat the thick-wall seamless pipe, so that the diffusion mode of the temperature inside the thick-wall seamless pipe is changed, the heating time is shortened, and the thermal stress is reduced; the cooling state of the thick-wall seamless pipe is monitored in real time through the temperature monitoring infrared camera, whether the temperature difference is overlarge or not and the gradient of the temperature difference is largest are judged, meanwhile, the proper frequency can be determined, the induction coil group is enabled to be heated accurately and locally, the temperature difference is slowed down, and the generation of residual stress is reduced. The invention provides a temperature control method for manufacturing thick-wall seamless tubes, which comprises a heating step and a cooling step, The implementation substep of the heating step S1 includes: s11, determining the final temperature T, the upper temperature difference limit X1 and the fall-back temperature difference X2 of the heating according to the material properties of the thick-wall seamless pipe to be manufactured and the production requirements; S12, heating the outer wall of the thick-wall seamless pipe by utilizing high-temperature flame, recording an inner wall temperature value T1 of the thick-wall seamless pipe measured by an inner wall temperature monitoring infrared camera and an outer wall temperature value T2 of the thick-wall seamless pipe measured by an outer wall temperature monitoring infrared camera, and continuing step S13 if any one of the inner wall temperature value T1 and the outer wall temperature value T2 does not reach the final temperature T; s13, calculating the local temperature difference of the thick-wall seamless pipe according to the inner wall temperature value T1 of the thick-wall seamless pipe and the outer wall temperature value T2 of the thick-wall seamless pipe, which are measured in the step S12 If the local temperature is differentIf the temperature difference is smaller than the upper limit X1, continuously heating the outer wall of the thick-wall seamless pipe by using high-temperature flame until the temperature differ