Valve welding temperature closed-loop intelligent control method and system

Abstract

This invention discloses a closed-loop intelligent control method and system for valve welding temperature, relating to the field of valve heating and welding technology. The specific steps of the method are: threshold setting, local preheating, intelligent judgment, ready triggering, and constant temperature supplementary heating. This invention uses a thermometer to collect real-time temperature data and analyzes and determines derived indicators, which together constitute the through-burning judgment index data. Combining the through-burning judgment data and preheating process data, the index detection value is compared with the threshold and the preheating target temperature range one by one. The comprehensive judgment of through-burning state and preheating temperature is completed by calculation. If the target is not met, the relevant valve parameters are dynamically adjusted and the judgment is repeated. During the welding stage, the temperature set value is determined based on the lower limit of the preheating target temperature range. Combined with the actual welding temperature change, the appropriate supplementary heating flame temperature is determined by formula and targeted supplementary heating is carried out. This constructs a temperature control logic from data acquisition, comprehensive judgment to parameter adjustment and dynamic supplementary heating.

Description

Technical Field

[0001] This invention relates to the field of valve heating and welding technology, specifically to a closed-loop intelligent control method and system for valve welding temperature. Background Technology

[0002] As the core control component of fluid transport systems, valves are widely used in industries such as petroleum, chemical, and metallurgy. Due to the core requirement of wear resistance on the mating surfaces, welded valves need to improve structural strength and service life by overlaying wear-resistant materials. Temperature control in the overlay welding process is the key to ensuring the welding quality of valves, which is directly related to the performance of valves and the safety and stability of industrial production. The research and optimization of related temperature control methods has become an important direction in the valve manufacturing field. The industry's requirements for the accuracy and intelligence of welding temperature control are also continuously increasing with industrial development.

[0003] However, current technologies for valve welding temperature control lack an intelligent management system. The setting of burn-through judgment indicators is not supported by historical process data related to valve welding and materials, relying heavily on subjective experience. Furthermore, only single temperature data is collected, without combining derived indicators to form a comprehensive judgment system. The temperature replenishment stage is not adapted to actual welding temperature changes; the preheating and replenishment temperature parameters are disconnected, lacking clear temperature range control logic. Equipment parameter adjustments are also not combined with the thermal conductivity characteristics of the valve material, resulting in a severe lack of targeted and scientific temperature control. The absence of an intelligent and comprehensive burn-through judgment system and coherent temperature control makes it impossible to achieve precise and dynamic temperature control during the welding process. This makes it difficult to match the welding process requirements of valves made of different materials, failing to guarantee the accuracy of burn-through judgment and achieving stable temperature control throughout the welding process, thus hindering the standardization and intelligent development of valve welding technology.

[0004] Therefore, a closed-loop intelligent control method and system for valve welding temperature is developed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a closed-loop intelligent control method and system for valve welding temperature. This invention uses a thermometer to collect real-time temperature data and analyzes and determines derived indicators to form burn-through judgment index data. Combining burn-through judgment data and preheating process data, the index detection values ​​are compared with thresholds and preheating target temperature ranges one by one. Through calculation, a comprehensive judgment of burn-through state and preheating temperature is completed. If the target is not met, the relevant valve parameters are dynamically adjusted and the judgment is repeated. During the welding stage, the temperature setpoint is determined based on the lower limit of the preheating target temperature range. Combined with the actual welding temperature change, the appropriate supplementary heating flame temperature is determined by formula and targeted supplementary heating is carried out. This constructs a temperature control logic from data acquisition, comprehensive judgment to parameter adjustment and dynamic supplementary heating, which solves the problems of single temperature data judgment, disconnect between preheating and supplementary heating parameters and lack of adaptive temperature adjustment in existing technologies.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: On one hand, a closed-loop intelligent control method for valve welding temperature, the specific steps of which are as follows:

[0007] Threshold setting: Based on the historical welding process data of valve overlay welding, a burn-through judgment index is set for the preheating area of ​​the overlay welding part. Combining the historical welding process data of the valve material to be welded and the thermal conductivity characteristics of the material itself, a corresponding burn-through judgment threshold is set for each burn-through judgment index. At the same time, the target preheating temperature range is set to generate burn-through judgment data.

[0008] Local preheating: The gas mixing combustion nozzle is used to locally preheat the parts of the valve that need to be welded and the surrounding fixed area. The parameters of the gas ratio regulating valve and the gas flow regulating valve are adjusted to control the complete combustion of the fuel gas and the combustion-supporting gas, so that the flame temperature of the gas mixing combustion nozzle is adapted to the preheating requirements, and preheating process data is generated.

[0009] Intelligent judgment: Real-time temperature data of the preheating area is collected by a thermometer. Based on the burn-through judgment data and preheating process data, the burn-through status and preheating temperature of the weld overlay are judged in real time by calculation. If the standard is not met, the parameters of the gas ratio regulating valve and the gas flow regulating valve are adjusted, the flame temperature of the gas mixing combustion nozzle is changed and the preheating time is extended. The data collection and burn-through judgment are repeated continuously. If the standard is met, the burn-through judgment result data is generated.

[0010] Ready to trigger: Based on the burn-through determination data, when the weld overlay is determined to have reached the burn-through state and the preheating temperature reaches the preheating target temperature range, a welding ready signal is issued to start the welding process.

[0011] Constant temperature heating: Throughout the welding process, the temperature of the weld overlay is monitored by a temperature measuring instrument. When the temperature is found to be lower than the set temperature value, the weld overlay is heated by a gas mixing combustion nozzle until the temperature of the weld overlay rises back to above the set temperature value.

[0012] Furthermore, in the threshold setting, based on historical welding process data of valve overlay welding, the real-time temperature value, temperature rise rate, and temperature holding time at the preheating point of the overlay welding area are used as through-burning judgment indicators. The real-time temperature value represents the basic compliance of the heat input at the overlay welding area, the temperature rise rate represents the uniformity of heat conduction at the overlay welding area, and the temperature holding time represents the stable state of heat penetration at the overlay welding area. The through-burning judgment threshold is differentiated and matched according to the historical welding process data of the valve material to be welded, setting corresponding numerical ranges for the real-time temperature value, temperature rise rate, and temperature holding time at the preheating point of the overlay welding area. When setting the through-burning judgment threshold and the preheating target temperature range, the influence weight of each through-burning judgment indicator is determined based on the historical welding process data of the valve material to be welded and the material's own thermal conductivity characteristics, combined with the historical welding process data of valve overlay welding. A basic numerical range is defined for each through-burning judgment indicator based on the influence weight, serving as the initial value of the threshold. Combined with the structural characteristics of the valve overlay welding area, the through-burning judgment threshold is calculated using a comprehensive calculation formula, and the preheating target temperature range is simultaneously determined. The through-burning judgment threshold and the preheating target temperature range are then integrated to form through-burning judgment data.

[0013] Furthermore, in the threshold setting, the comprehensive calculation formula for the burn-through determination threshold is as follows: ,in, For the first The threshold for determining the degree of burning is specified in the following indicators: For the first The initial threshold value of the ignition point determination index. The thermal conductivity coefficient of the valve material to be welded. The coefficient of thermal expansion of the valve material to be welded. All were determined using historical welding process data of the valve material to be welded. The structural coefficient for the weld overlay of the valve is determined through finite element simulation analysis based on the wall thickness and bevel angle of the weld overlay. This is the correction factor for the bevel depth of the valve weld overlay, determined based on the bevel depth of the valve weld overlay combined with historical welding process data of the valve weld overlay.

[0014] Furthermore, in the local preheating process, the fixed range around the valve to be welded is 50mm. The flame of the gas mixing combustion nozzle is directly aimed at the welded area and the surrounding 50mm preheating area. When adjusting the parameters of the gas ratio regulating valve and the gas flow regulating valve, the mixing ratio of the gas and the combustion-supporting gas is first set based on the historical welding process data of the valve weld, and then the output flow of the gas and the combustion-supporting gas is controlled. When adjusting the flame temperature, the initial value of the flame temperature of the gas mixing combustion nozzle is determined based on the historical welding process data of the valve material to be welded, the material of the valve to be welded, and the actual area of ​​the welded area. The gas ratio regulating valve is adjusted to the set mixing ratio, and then the gas flow regulating valve is adjusted to change the output flow of the gas and the combustion-supporting gas. The flame combustion state of the gas mixing combustion nozzle is observed, and the gas flow regulating valve is finely adjusted according to the flame combustion state until the flame temperature reaches the initial value and the combustion state is stable. The adjustment parameters of the gas ratio regulating valve and the gas flow regulating valve, the flame temperature parameters of the gas mixing combustion nozzle, and the range parameters of the preheating area are integrated to generate preheating process data.

[0015] Furthermore, in the intelligent judgment process, the temperature probe of the thermometer is directly in contact with the preheated surface of the weld overlay, and real-time temperature data of the preheated area of ​​the weld overlay is collected. Based on the collected real-time temperature data, the temperature rise rate and temperature holding time are determined and combined with the real-time temperature data to form the burn-through judgment index data. The real-time detection values ​​of each burn-through judgment index are extracted. Based on the burn-through judgment data and preheating process data, the real-time detection values ​​are compared one by one with the burn-through judgment threshold and the preheating target temperature range. The compared data are integrated by calculating the burn-through state comprehensive judgment formula to determine whether the weld overlay has reached the burn-through state and whether the preheating temperature meets the standard. If the judgment result is not up to standard, the gas ratio regulating valve is adjusted to increase the proportion of combustion-supporting gas in the mixed gas, and the gas output of the gas flow regulating valve is increased. The adjustment range of the two valve parameters is determined in combination with the historical welding process data of the valve material to be welded. The flame temperature is changed by the gas mixing combustion nozzle and the preheating time is extended. The data collection and judgment are repeated. When the judgment result is up to standard, burn-through judgment result data is generated.

[0016] Furthermore, in the intelligent determination, the comprehensive determination formula for the burn-through state is: ,in, The comprehensive judgment value for the burnt state is when When the weld overlay is deemed to have reached the through-burning state and the preheating temperature is within the specified range, When a weld overlay is deemed not to have reached the fully heated state or the preheating temperature is not up to standard, a threshold of 0.85 is used. This threshold is determined by analyzing multiple sets of qualified and unqualified weld samples, combined with historical welding process data of valve weld overlays. For the first The influence weights of each burn-through criterion are determined by combining historical welding process data of valve weld overlays and based on the degree of influence of each burn-through criterion on the quality of valve weld overlays. For the first Real-time detection values ​​of the indicators for determining burn-through. For the first The threshold for determining the degree of burning is specified in the following indicators: This represents the total number of indicators for determining burnout.

[0017] Furthermore, in the ready triggering, the welding ready signal is a combination of electrical and acoustic-optical signals. After the burn-through determination result data shows that the standard is met, the combined signal is triggered to be output. The combined signal is continuously output until the welding process is officially started, and the parameter adjustment of the gas ratio regulating valve and the gas flow regulating valve is stopped.

[0018] Furthermore, in the constant temperature heating process, when the temperature of the weld overlay is detected by a temperature measuring instrument, the temperature setpoint of the weld overlay is first determined. This temperature setpoint is consistent with the lower limit of the preheating target temperature range. Then, the temperature detection of the weld overlay is started, and the temperature data of the weld overlay is collected in real time. When the temperature of the weld overlay is detected to be lower than the temperature setpoint, the appropriate heating flame temperature is determined by the heating flame temperature matching formula. The gas mixing combustion nozzle is then used to heat the cooled area of ​​the weld overlay. When the temperature of the weld overlay is detected to rise back above the temperature setpoint, the heating is stopped.

[0019] Furthermore, in the constant-temperature heating process, the formula for adapting the heating flame temperature is as follows: ,in, To match the temperature of the supplementary heating flame, This is the initial value of the flame temperature. This is the temperature setpoint for the weld overlay area. For real-time temperature monitoring of the weld overlay area, The heat loss coefficient of the weld overlay is determined based on historical welding process data of the valve weld overlay and the wind speed and humidity of the welding environment. The real-time cooling rate of the weld overlay area is determined by continuous temperature data collected by a thermometer.

[0020] On the other hand, a closed-loop intelligent control system for valve welding temperature includes:

[0021] Threshold setting module: Based on the historical welding process data of valve overlay welding, set the burn-through judgment index for the preheating area of ​​the overlay welding part. Combined with the historical welding process data of the valve material to be welded and the thermal conductivity characteristics of the material itself, set the corresponding burn-through judgment threshold for each burn-through judgment index. At the same time, set the preheating target temperature range and generate burn-through judgment data.

[0022] Local preheating module: The gas mixing combustion nozzle performs local preheating on the parts of the valve that need to be welded and the surrounding fixed area, and adjusts the parameters of the gas ratio regulating valve and the gas flow regulating valve to control the full combustion of the fuel gas and the combustion-supporting gas, so that the flame temperature of the gas mixing combustion nozzle is adapted to the preheating requirements, and generates preheating process data.

[0023] Intelligent Judgment Module: Utilizes a thermometer to collect real-time temperature data at the preheating point. Based on the burn-through judgment data and preheating process data, it calculates and judges the burn-through status and preheating temperature of the weld overlay in real time. If the standard is not met, it adjusts the parameters of the gas ratio regulating valve and the gas flow regulating valve, changes the flame temperature of the gas mixing combustion nozzle, and extends the preheating time. It continuously repeats data collection and burn-through judgment. If the standard is met, it generates burn-through judgment result data.

[0024] Ready Trigger Module: Based on the burn-through determination result data, when it is determined that the weld overlay has reached the burn-through state and the preheating temperature has reached the preheating target temperature range, a welding ready signal is issued to start the welding process.

[0025] Constant temperature heating module: Throughout the welding process, the temperature of the weld overlay is monitored by a temperature measuring instrument. When the temperature is detected to be lower than the set temperature value, the weld overlay is reheated by a gas mixing combustion nozzle until the temperature of the weld overlay rises back to above the set temperature value.

[0026] Compared with existing technologies, this valve welding temperature closed-loop intelligent control method and system has the following advantages:

[0027] I. This invention utilizes a thermometer to collect real-time temperature data and analyzes and determines derived indicators, which together constitute the burn-through determination index data. Combining the burn-through determination data and preheating process data, the index detection values ​​are compared with thresholds and preheating target temperature ranges one by one. Through calculation, a comprehensive determination of the burn-through state and preheating temperature is completed. If the target is not met, the relevant valve parameters are dynamically adjusted and the data collection and determination are repeated. During the welding stage, the temperature setpoint is determined based on the lower limit of the preheating target temperature range. Combined with the actual temperature changes during welding, the appropriate supplementary heating flame temperature is determined through a formula and targeted supplementary heating is carried out. This constructs a temperature control logic from data acquisition, comprehensive determination to parameter adjustment and dynamic supplementary heating, solving the problems of single temperature data determination, disconnect between preheating and supplementary heating parameters, and lack of adaptive temperature adjustment in the existing technology.

[0028] Second, this invention sets multi-dimensional burn-through judgment indicators by combining historical welding process data of valve overlay welding. At the same time, it relies on the historical welding process data of the valve material to be welded and its own thermal conductivity characteristics to match corresponding burn-through judgment thresholds for each indicator. Furthermore, it combines the structural characteristics of the valve overlay welding part to calculate and determine the final threshold through formula and set the preheating target temperature range. This allows the setting of burn-through judgment indicators and thresholds to get rid of the subjective judgment mode based on experience. It enables the parameter setting to be supported by both actual process data and material characteristics throughout the process. At the same time, it makes the preheating temperature control form a clear range logic, which solves the problems of existing technology parameter setting without basis, without material characteristics, and without temperature range control.

[0029] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0031] Figure 1 A flowchart of a closed-loop intelligent control method for valve welding temperature;

[0032] Figure 2 This is a framework diagram of a closed-loop intelligent control system for valve welding temperature.

[0033] Figure 3 This is a framework diagram of intelligent judgment in a closed-loop intelligent control method for valve welding temperature. Detailed Implementation

[0034] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0035] Example:

[0036] In the processing of cast steel valves for oil pipelines at outdoor oilfield gathering and transportation stations, these valves transport crude oil for extended periods. The weld overlay is the valve sealing surface, which is highly susceptible to wear due to crude oil erosion and media friction. This places extremely high demands on the density and wear resistance of the weld overlay. Precise control of the welding temperature directly determines the valve's sealing performance and the operational safety of the crude oil pipeline. The weld overlay utilizes a heating tool consisting of a gas ratio regulating valve, a gas flow regulating valve, and a gas mixing and combustion nozzle.

[0037] First, historical welding process data of cast steel valves of the same specification and under the same operating conditions in the oilfield gathering and transportation station were retrieved. Real-time temperature, temperature rise rate, and temperature holding time were set as burn-through criteria for the preheating area of ​​the cast steel valve's welded section. Then, historical welding process data of the cast steel material and its thermal conductivity were retrieved to determine the influence weights of the three burn-through criteria. Based on these influence weights, a basic numerical range was defined for each criterion as the initial threshold value. Combining the structural characteristics of the valve's welded section, such as wall thickness and bevel angle, the final burn-through threshold was calculated using the comprehensive burn-through threshold calculation formula. The comprehensive burn-through threshold calculation formula is as follows: ,in, For the first The threshold for determining the degree of burning is specified in the following indicators: For the first The initial threshold value of the ignition point determination index. The thermal conductivity coefficient of the valve material to be welded. The coefficient of thermal expansion of the valve material to be welded. All were determined using historical welding process data of the valve material to be welded. The structural coefficient for the weld overlay of the valve is determined through finite element simulation analysis based on the wall thickness and bevel angle of the weld overlay. The bevel depth correction coefficient for the valve weld overlay is determined based on the bevel depth of the valve weld overlay and historical welding process data. Simultaneously, a preheating target temperature range is set for the weld overlay of cast steel valves. Based on historical welding process data of the valve material to be welded, corresponding through-burning judgment thresholds are matched to the different value ranges for each through-burning judgment index. Finally, all through-burning judgment thresholds are integrated with the preheating target temperature range to form through-burning judgment data, such as... Figure 1 As shown, the determination of weights makes the setting of each burn-through judgment index more in line with the actual process requirements of cast steel valve overlay welding, and the determination of the initial value of the threshold provides a basis for the final threshold calculation, so that the entire parameter setting process forms a complete logical system.

[0038] Subsequently, the gas-mixing combustion nozzle was used to locally preheat the sealing surface of the cast steel valve requiring welding and its surrounding 50mm area. First, the mixing ratio of the gas and oxidizing gas was set based on historical welding process data for the valve welding. The gas ratio regulating valve was adjusted to this preset mixing ratio and kept stable. Then, the gas flow regulating valve was adjusted to control the actual output flow of the gas and oxidizing gas. Combining historical welding process data of the cast steel material and the actual area of ​​the sealing surface, the initial flame temperature of the gas-mixing combustion nozzle was determined. The flame combustion state of the gas-mixing combustion nozzle was observed, and the gas flow regulating valve was fine-tuned based on the flame combustion stability until the flame temperature reached the set initial flame temperature value and the combustion state remained stable. Finally, the entire adjustment parameters of the gas ratio regulating valve and the gas flow regulating valve, the stable flame temperature parameters of the gas-mixing combustion nozzle, and the fixed range parameters of the preheating area were integrated to generate preheating process data, such as... Figure 2 As shown, the valve regulation method of first setting a certain proportion and then adjusting the flow rate allows for a more uniform mixing of gas and combustion-supporting gas. Real-time observation and fine-tuning of the flame combustion state ensures the stability of the preheating temperature. The local preheating method only heats the core area of ​​the weld overlay, effectively controlling the range of the heat-affected zone of the cast steel valve.

[0039] The temperature probe of the thermometer continuously collects real-time temperature data of the preheated surface of the weld overlay area of ​​the cast steel valve. Based on the collected real-time temperature data, the temperature rise rate and temperature holding time are determined. These two derived indicators, together with the real-time temperature data, constitute the burn-through determination index data. The real-time detection values ​​of each index are extracted from the burn-through determination index data. Combining the burn-through determination data and the preheating process data, the real-time detection values ​​of each index are precisely compared with the burn-through determination threshold and the preheating target temperature range. The compared data are then integrated using the burn-through state comprehensive determination formula to determine whether the weld overlay area has reached the burn-through state and whether the preheating temperature meets the standard. The burn-through state comprehensive determination formula is as follows: ,in, The comprehensive judgment value for the burnt state is when When the weld overlay is deemed to have reached the through-burning state and the preheating temperature is within the specified range, When a weld overlay is deemed not to have reached the fully heated state or the preheating temperature is not up to standard, a threshold of 0.85 is used. This threshold is determined by analyzing multiple sets of qualified and unqualified weld samples, combined with historical welding process data of valve weld overlays. For the first The influence weights of each burn-through criterion are determined by combining historical welding process data of valve weld overlays and based on the degree of influence of each burn-through criterion on the quality of valve weld overlays. For the first Real-time detection values ​​of the indicators for determining burn-through. For the first The threshold for determining the degree of burning is specified in the following indicators: This represents the total number of indicators for determining burn-through. When the result is unsatisfactory, the gas ratio regulating valve is adjusted to increase the proportion of combustion-supporting gas in the mixed gas. Simultaneously, the gas output of the gas flow regulating valve is increased. The parameter adjustment ranges of the gas ratio regulating valve and the gas flow regulating valve are strictly determined based on historical welding process data of the cast steel material. The flame temperature is changed and the preheating time is extended through the gas mixing combustion nozzle. The real-time temperature data acquisition and burn-through status determination operations are continuously repeated until the result is satisfactory. Then, burn-through determination result data is generated. Figure 3 As shown, the comparison of multiple indicators makes the determination of the burn-through state more comprehensive. The dynamic parameter adjustment and repeated judgment when the standard is not met form a closed-loop control, which effectively avoids defects such as welding porosity and lack of fusion caused by the failure to burn through the standard.

[0040] Once the through-burning determination results show that the weld overlay of the cast steel valve has reached the through-burning state and the preheating temperature has entered the preheating target temperature range, a welding ready combination signal combining electrical and audible / optical signals is immediately issued. This combination signal is continuously output until the welding process is officially started. During this period, parameter adjustments to the gas ratio regulating valve and the gas flow regulating valve are stopped.

[0041] After the welding process officially starts, the temperature setpoint for the weld overlay is first determined based on historical welding process data of the cast steel material. This temperature setpoint is consistent with the lower limit of the preheating target temperature range. Then, the temperature measuring instrument is started to monitor the temperature of the weld overlay in real time throughout the process, collecting temperature data in real time. When the temperature of the weld overlay is detected to be lower than the set temperature, the appropriate supplementary heating flame temperature is determined using the supplementary heating flame temperature adaptation formula. The supplementary heating flame temperature adaptation formula is as follows: ,in, To match the temperature of the supplementary heating flame, This is the initial value of the flame temperature. This is the temperature setpoint for the weld overlay area. For real-time temperature monitoring of the weld overlay area, The heat loss coefficient of the weld overlay is determined based on historical welding process data of the valve weld overlay and the wind speed and humidity of the welding environment. The real-time cooling rate of the weld overlay is determined by continuous temperature data collected by a thermometer. Based on the appropriate reheating flame temperature, the gas mixing and combustion nozzle is controlled to target the cooling area of ​​the weld overlay for targeted reheating. The temperature change of the weld overlay is continuously monitored until the temperature of the weld overlay rises above the set temperature value, at which point the reheating operation is immediately stopped. The real-time temperature monitoring and dynamic reheating throughout the process keep the temperature of the weld overlay within a reasonable range, ensuring the weld formation quality and the stability of the molten pool during the welding process, and allowing the sealing surface after weld overlay to match the high-pressure crude oil transportation conditions in the oilfield.

[0042] In summary, to address the welding requirements of cast steel valves in oil pipelines, historical welding process data on valve welding and cast steel materials were used to set the burn-through judgment indicators and thresholds. Preheating data was then generated through precise local preheating. Data was collected using a thermometer, and the burn-through status was comprehensively judged. Once the target was met, a welding ready signal was triggered. Dynamic temperature monitoring and targeted reheating were conducted throughout the welding process to adapt to the welding process requirements of cast steel valves, effectively ensuring the welding quality of the welded areas and enabling the finished valves to meet the high-pressure and high-scouring conditions of oil transportation.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A valve welding temperature closed-loop intelligent control method, characterized in that, The specific steps of this method are as follows: Threshold setting: Based on the historical welding process data of valve overlay welding, a burn-through judgment index is set for the preheating area of ​​the overlay welding part. Combining the historical welding process data of the valve material to be welded and the thermal conductivity characteristics of the material itself, a corresponding burn-through judgment threshold is set for each burn-through judgment index. At the same time, the target preheating temperature range is set to generate burn-through judgment data. Local preheating: The gas mixing combustion nozzle is used to locally preheat the parts of the valve that need to be welded and the surrounding fixed area. The parameters of the gas ratio regulating valve and the gas flow regulating valve are adjusted to control the complete combustion of the fuel gas and the combustion-supporting gas, so that the flame temperature of the gas mixing combustion nozzle is adapted to the preheating requirements, and preheating process data is generated. Intelligent judgment: Real-time temperature data of the preheating area is collected by a thermometer. Based on the burn-through judgment data and preheating process data, the burn-through status and preheating temperature of the weld overlay are judged in real time by calculation. If the standard is not met, the parameters of the gas ratio regulating valve and the gas flow regulating valve are adjusted, the flame temperature of the gas mixing combustion nozzle is changed and the preheating time is extended. The data collection and burn-through judgment are repeated continuously. If the standard is met, the burn-through judgment result data is generated. Ready to trigger: Based on the burn-through determination data, when the weld overlay is determined to have reached the burn-through state and the preheating temperature reaches the preheating target temperature range, a welding ready signal is issued to start the welding process. Constant temperature heating: Throughout the welding process, the temperature of the weld overlay is monitored by a temperature measuring instrument. When the temperature is found to be lower than the set temperature value, the weld overlay is heated by a gas mixing combustion nozzle until the temperature of the weld overlay rises back to above the set temperature value.

2. The valve welding temperature closed-loop intelligent control method according to claim 1, characterized in that, In the threshold setting, based on historical welding process data of valve overlay welding, the real-time temperature value, temperature rise rate, and temperature holding time of the preheating area of ​​the overlay welding part are used as through-burning judgment indicators. The real-time temperature value represents the basic compliance of the heat input of the overlay welding part, the temperature rise rate represents the uniformity of heat conduction of the overlay welding part, and the temperature holding time represents the stable state of heat penetration of the overlay welding part. The through-burning judgment threshold is matched differently according to the historical welding process data of the valve material to be welded, and corresponding numerical ranges are set for the real-time temperature value, temperature rise rate, and temperature holding time of the preheating area of ​​the overlay welding part. When setting the through-burning judgment threshold and the preheating target temperature range, the influence weight of each through-burning judgment indicator is determined based on the historical welding process data of the valve material to be welded and the material's own thermal conductivity characteristics, combined with the historical welding process data of valve overlay welding. The basic numerical range of each through-burning judgment indicator is defined according to the influence weight as the initial value of the threshold. Combined with the structural characteristics of the valve overlay welding part, the through-burning judgment threshold is calculated by the comprehensive calculation formula of the through-burning judgment threshold. The preheating target temperature range is determined simultaneously, and the through-burning judgment threshold and the preheating target temperature range are integrated to form through-burning judgment data.

3. The valve welding temperature closed-loop intelligent control method according to claim 2, characterized in that, The threshold setting, the transparent burning judgment threshold comprehensive calculation formula is: Wherein, is the transparent burning judgment threshold of the first transparent burning judgment index, is the threshold initial value of the first transparent burning judgment index, is the thermal conductivity coefficient of the valve material to be welded, is the thermal expansion coefficient of the valve material to be welded, are determined by the historical welding process data of the valve material to be welded, is the structure coefficient of the valve hardfacing position, which is determined by the wall thickness and the bevel angle of the valve hardfacing position through finite element simulation analysis, is the bevel depth correction coefficient of the valve hardfacing position, which is determined according to the bevel depth of the valve hardfacing position combined with the historical welding process data of the valve hardfacing.

4. The valve welding temperature closed-loop intelligent control method according to claim 1, characterized in that, In the local preheating process, the fixed range around the valve to be welded is 50mm. The flame of the gas mixing combustion nozzle is directly aimed at the welded area and the surrounding 50mm preheating area. When adjusting the parameters of the gas ratio regulating valve and the gas flow regulating valve, the mixing ratio of the fuel gas and the combustion-supporting gas is first set based on the historical welding process data of the valve welded, and then the output flow rate of the fuel gas and the combustion-supporting gas is controlled. When adjusting the flame temperature, the initial flame temperature of the gas mixing combustion nozzle is determined based on the historical welding process data of the valve material to be welded, the material of the valve to be welded, and the actual area of ​​the welded area. The gas ratio regulating valve is adjusted to the set mixing ratio, and then the gas flow regulating valve is adjusted to change the output flow rate of the fuel gas and the combustion-supporting gas. The flame combustion state of the gas mixing combustion nozzle is observed, and the gas flow regulating valve is finely adjusted according to the flame combustion state until the flame temperature reaches the initial flame temperature value and the combustion state is stable. The adjustment parameters of the gas ratio regulating valve and the gas flow regulating valve, the flame temperature parameters of the gas mixing combustion nozzle, and the range parameters of the preheating area are integrated to generate preheating process data.

5. The valve welding temperature closed-loop intelligent control method according to claim 1, characterized in that, In the intelligent judgment process, real-time temperature data of the preheating area of ​​the weld overlay is collected using a temperature probe of a thermometer. Based on the collected real-time temperature data, the temperature rise rate and temperature holding time are determined and combined with the real-time temperature data to form the burn-through judgment index data. The real-time detection values ​​of each burn-through judgment index are extracted. Based on the burn-through judgment data and preheating process data, the real-time detection values ​​are compared one by one with the burn-through judgment threshold and the preheating target temperature range. The compared data are integrated using the burn-through state comprehensive judgment formula to determine whether the weld overlay has reached the burn-through state and whether the preheating temperature meets the standard. If the judgment result is not up to standard, the gas ratio regulating valve is adjusted to increase the proportion of combustion-supporting gas in the mixed gas, and the gas output of the gas flow regulating valve is increased. The adjustment range of the two valve parameters is determined in combination with the historical welding process data of the valve material to be welded. The flame temperature is changed and the preheating time is extended by the gas mixing combustion nozzle. The data collection and judgment are repeated. When the judgment result is up to standard, burn-through judgment result data is generated.

6. The valve welding temperature closed-loop intelligent control method according to claim 5, characterized in that, In the intelligent determination, the comprehensive determination formula for the burn-through state is as follows: ,in, The comprehensive judgment value for the burnt state is when When the weld overlay is deemed to have reached the through-burning state and the preheating temperature is within the specified range, When a weld overlay is deemed not to have reached the fully heated state or the preheating temperature is not up to standard, a threshold of 0.85 is used. This threshold is determined by analyzing multiple sets of qualified and unqualified weld samples, combined with historical welding process data of valve weld overlays. For the first The influence weights of each burn-through criterion are determined by combining historical welding process data of valve weld overlays and based on the degree of influence of each burn-through criterion on the quality of valve weld overlays. For the first Real-time detection values ​​of the indicators for determining burn-through. For the first The threshold for determining the through-burning of a certain indicator. This represents the total number of indicators for determining burnout.

7. The valve welding temperature closed-loop intelligent control method according to claim 1, characterized in that, In the ready triggering process, the welding ready signal is a combination of electrical and acoustic-optical signals. After the burn-through determination result data shows that the standard is met, the combined signal is triggered and output. The combined signal continues to be output until the welding process is officially started, and the parameter adjustment of the gas ratio regulating valve and the gas flow regulating valve is stopped.

8. The valve welding temperature closed-loop intelligent control method according to claim 1, characterized in that, In the constant temperature heating process, when the temperature of the weld overlay is detected by a temperature measuring instrument, the temperature setpoint of the weld overlay is first determined. This temperature setpoint is consistent with the lower limit of the preheating target temperature range. Then, the temperature detection of the weld overlay is started, and the temperature data of the weld overlay is collected in real time. When the temperature of the weld overlay is detected to be lower than the temperature setpoint, the appropriate heating flame temperature is determined by the heating flame temperature matching formula. The gas mixing combustion nozzle is then used to target the cooling area of ​​the weld overlay for heating. When the temperature of the weld overlay is detected to rise back above the temperature setpoint, the heating is stopped.

9. The valve welding temperature closed-loop intelligent control method according to claim 8, characterized in that, In the constant-temperature heating process, the formula for adapting the heating flame temperature is as follows: ,in, To match the temperature of the supplementary heating flame, This is the initial value of the flame temperature. This is the temperature setpoint for the weld overlay area. For real-time temperature monitoring of the weld overlay area, The heat loss coefficient of the weld overlay is determined based on historical welding process data of the valve weld overlay and the wind speed and humidity of the welding environment. The real-time cooling rate of the weld overlay area is determined by continuous temperature data collected by a thermometer.

10. A closed-loop intelligent control system for valve welding temperature, the system being applicable to the closed-loop intelligent control method for valve welding temperature as described in any one of claims 1-9, characterized in that, The system includes: Threshold setting module: Based on the historical welding process data of valve overlay welding, set the burn-through judgment index for the preheating area of ​​the overlay welding part. Combined with the historical welding process data of the valve material to be welded and the thermal conductivity characteristics of the material itself, set the corresponding burn-through judgment threshold for each burn-through judgment index. At the same time, set the preheating target temperature range and generate burn-through judgment data. Local preheating module: The gas mixing combustion nozzle performs local preheating on the parts of the valve that need to be welded and the surrounding fixed area, and adjusts the parameters of the gas ratio regulating valve and the gas flow regulating valve to control the full combustion of the fuel gas and the combustion-supporting gas, so that the flame temperature of the gas mixing combustion nozzle is adapted to the preheating requirements, and generates preheating process data. Intelligent Judgment Module: Utilizes a thermometer to collect real-time temperature data at the preheating point. Based on the burn-through judgment data and preheating process data, it calculates and judges the burn-through status and preheating temperature of the weld overlay in real time. If the standard is not met, it adjusts the parameters of the gas ratio regulating valve and the gas flow regulating valve, changes the flame temperature of the gas mixing combustion nozzle, and extends the preheating time. It continuously repeats data collection and burn-through judgment. If the standard is met, it generates burn-through judgment result data. Ready Trigger Module: Based on the burn-through determination result data, when it is determined that the weld overlay has reached the burn-through state and the preheating temperature has reached the preheating target temperature range, a welding ready signal is issued to start the welding process. Constant temperature heating module: Throughout the welding process, the temperature of the weld overlay is monitored by a temperature measuring instrument. When the temperature is detected to be lower than the set temperature value, the weld overlay is reheated by a gas mixing combustion nozzle until the temperature of the weld overlay rises back to above the set temperature value.

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