Air cooling system and method for controlling temperature of cooling medium at air cooling outlet

Abstract

An air cooling system and an air cooling outlet cooling medium temperature control method belong to the technical field of temperature control systems, and comprise a heat treatment furnace, a circulation pipeline, a bypass pipeline, a first temperature measuring element and a first temperature control unit; the inlet end of the circulating pipeline is communicated with the gas outlet of the heat treatment furnace, and the outlet end is communicated with the gas inlet of the heat treatment furnace through the heat exchanger for conveying the cold medium gas cooled by the heat exchanger to form circulation of the cold medium gas; the bypass pipeline is connected with the heat exchanger in parallel and used for conveying hot medium gas not cooled by the heat exchanger, and a temperature control valve is arranged on the bypass pipeline. The first temperature measuring element is arranged at an air cooling outlet of the circulating pipeline and is used for detecting the temperature of medium gas after the cold medium gas and the hot medium gas are mixed; a cooling process curve is pre-stored in the first temperature control unit, and the first temperature control unit is connected with the first temperature measuring element and the temperature control valve and used for controlling the opening degree of the temperature control valve according to the set value of the cooling process curve and the detection temperature of the first temperature measuring element.

Description

Technical Field

[0001] This application belongs to the field of temperature control system technology, specifically relating to an air-cooled system and a method for controlling the temperature of the cooling medium at the air-cooled outlet. Background Technology

[0002] In the field of heat treatment and quenching processes for metallic materials, workpieces after heat treatment require rapid cooling at high temperatures. This rapid cooling causes the workpiece surface to form a fine-grained structure, effectively improving surface hardness and meeting the performance requirements for subsequent processing and use. However, in actual quenching and cooling processes, a faster cooling rate is not always better. If rapid cooling is used throughout, the internal grains of the workpiece may become too dense, leading to negative effects such as deformation, cracking, and insufficient toughness. Therefore, the industry typically adjusts the cooling rhythm in the middle of the quenching and cooling process, employing a temperature-controlled air-cooling process to achieve segmented cooling—rapid cooling in the early stage and slow, temperature-controlled cooling in the middle stage—balancing workpiece hardness and internal structural stability.

[0003] In related technologies, there are two conventional operating methods: one is to simultaneously heat the workpiece during air cooling, maintaining the cooling temperature through heating compensation; the other is to not perform auxiliary heating, but simply reduce the air speed of the air-cooling fan to slow down the cooling rate and achieve slow cooling. However, both of these traditional processes have obvious technical defects: on the one hand, the combination of auxiliary heating and air cooling leads to turbulent airflow in the furnace temperature field, with irregular mixing of hot and cold air, making it impossible to form a uniform and stable temperature field environment. This results in significant temperature differences at different locations within the heat treatment furnace, with large real-time temperature fluctuations, making precise control difficult. On the other hand, the slow cooling method of simply reducing the air speed cannot effectively control the ratio of hot and cold air, resulting in inconsistent cooling rates across the workpiece surface, poor surface temperature uniformity, and a high risk of localized insufficient hardness. Furthermore, the unstable temperature control method prolongs the overall quenching processing time, increases energy consumption, leads to energy waste and increased production costs, and cannot guarantee the uniformity of processing quality for batches of workpieces. Summary of the Invention

[0004] In view of this, this application aims to provide an air-cooling system and a method for controlling the temperature of the cooling medium at the air-cooling outlet, so as to adapt to the process requirements of segmented cooling for heat treatment quenching, realize precise and controllable adjustment of the temperature in the middle section of quenching cooling, optimize the temperature field and airflow distribution in the furnace, ensure the uniformity of cooling temperature on the surface of the workpiece, optimize process energy consumption control, reduce the overall processing time, and improve the quality stability and production efficiency of batch workpiece heat treatment.

[0005] To achieve the above objectives, this application mainly provides the following technical solutions: One aspect of this application provides an air-cooled system, comprising: Heat treatment furnace; The circulation pipeline has its inlet connected to the outlet of the heat treatment furnace and its outlet connected to the inlet of the heat treatment furnace via a heat exchanger. The circulation pipeline is used to transport the cold medium gas cooled by the heat exchanger and to form a circulation of the cold medium gas. A bypass pipeline is provided, one end of which is connected to the gas outlet of the heat treatment furnace, and the other end is connected to a pipe section in the circulation pipeline located downstream of the heat exchanger. The bypass pipeline is used to transport hot medium gas that has not been cooled by the heat exchanger, so that the hot medium gas is mixed with the cold medium gas in the circulation pipeline. A temperature control valve is provided on the bypass pipeline. The first temperature sensing element is disposed at the air-cooled outlet of the circulation pipeline. The first temperature sensing element is used to detect the temperature of the medium gas after the cold medium gas and the hot medium gas are mixed. The first temperature control unit has a pre-stored cooling process curve and is connected to the first temperature measuring element and the temperature control valve respectively. The first temperature control unit is used to control the opening degree of the temperature control valve according to the set value of the cooling process curve and the detected temperature of the first temperature measuring element.

[0006] Optionally, the air outlet of the heat treatment furnace is located at the upper part of the heat treatment furnace, and the air inlet of the heat treatment furnace is located at the lower part of the heat treatment furnace.

[0007] Optionally, the air-cooling system further includes: A circulating power component is provided near the air inlet of the heat treatment furnace and is located on the main line of the circulating pipeline, but not in parallel with the bypass pipeline, for driving the medium gas to circulate between the pipeline and the heat treatment furnace.

[0008] Optionally, the air-cooling system further includes: The second temperature sensing element is used to detect the temperature inside the heat treatment furnace.

[0009] Optionally, the second temperature sensing element is disposed on the top of the heat treatment furnace.

[0010] Optionally, the air-cooling system further includes: The second temperature control unit is connected to the second temperature measuring element and is used to obtain the furnace temperature inside the heat treatment furnace.

[0011] Optionally, the air-cooling system further includes: The controller is connected to the second temperature control unit and the first temperature control unit respectively. The controller is used to determine the cooling process based on the temperature detected in the furnace, and when the preset switching temperature is reached, it controls the first temperature control unit to start the cooling process curve of the mid-stage slow cooling.

[0012] Another aspect of this application provides a method for controlling the temperature of the cooling medium at the air-cooled outlet, applied to the system described in any one of the above, comprising: The actual temperature of the medium gas after the cold medium gas and the hot medium gas are mixed is collected; Compare the set value of the cooling process curve with the actual temperature collected; Adjust the opening of the temperature control valve on the bypass pipeline according to the comparison results, and adjust the proportion of the mixed heat medium gas so that the temperature of the cooling medium at the air-cooled outlet follows the cooling process curve.

[0013] Optionally, before adjusting the temperature of the cooling medium, the method further includes: Obtain the furnace internal temperature of the heat treatment furnace; The cooling process is determined based on the temperature detected inside the furnace. When the furnace temperature reaches the preset switching temperature, the first temperature control unit is controlled to start the cooling process curve that adapts to the mid-section slow cooling.

[0014] Optionally, before initiating the cooling process curve for the intermediate slow cooling, the method further includes: Keep the temperature control valve closed to perform initial rapid cooling of the workpiece.

[0015] By employing the above technical solution, this application has at least the following beneficial effects: The air-cooling system and cooling medium temperature control method provided in this application, by setting up a circulation pipeline that cooperates with the heat exchanger and a bypass pipeline arranged in parallel, can flexibly adjust the proportion of hot medium gas mixed in the circulation pipeline by relying on the temperature control valve. Combined with the first temperature measuring element and the first temperature control unit with the pre-stored cooling process curve, a closed-loop control is formed. The temperature of the mixed medium gas entering the heat treatment furnace is matched and stably controlled in real time according to the cooling process curve, which is suitable for the processing requirements of segmented cooling in the quenching process. It can ensure that the workpiece has a fast cooling rate in the initial stage and improve the surface hardness of the workpiece, and achieve smooth and controllable cooling in the middle stage, reducing the probability of workpiece deformation and cracking. At the same time, it optimizes the airflow distribution and the cold and hot medium gas ratio in the heat treatment furnace, improves the temperature field and workpiece cooling uniformity in the heat treatment furnace, reduces processing energy consumption, shortens the cooling cycle, and stabilizes the heat treatment forming quality of batch workpieces. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an optional embodiment of the air-cooled system of this application; Figure 2 The flowchart of a method for controlling the temperature of the cooling medium at the air-cooled outlet is an optional embodiment of this application. Figure 3 The flowchart illustrates a method for controlling the temperature of the cooling medium at the air-cooled outlet, which is another optional embodiment of this application.

[0017] The reference numerals in the attached figures are as follows: 1. Heat treatment furnace; 2. Circulation pipeline; 3. Heat exchanger; 4. Bypass pipeline; 5. Temperature control valve; 6. First temperature sensing element; 7. First temperature control unit; 8. Circulation power component; 9. Second temperature sensing element; 10. Second temperature control unit; 11. Controller. Detailed Implementation

[0018] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0020] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0022] See Figure 1 As shown, according to an embodiment of this application, an air-cooled system is provided, including a heat treatment furnace 1, a circulation pipeline 2, a bypass pipeline 4, a first temperature sensing element 6, and a first temperature control unit 7; the inlet of the circulation pipeline 2 is connected to the outlet of the heat treatment furnace 1, and the outlet of the circulation pipeline 2 is connected to the inlet of the heat treatment furnace 1 via a heat exchanger 3. The circulation pipeline 2 is used to transport the cold medium gas cooled by the heat exchanger 3 and form a circulation of the cold medium gas; one end of the bypass pipeline 4 is connected to the outlet of the heat treatment furnace 1, and the other end is connected to a section of the circulation pipeline 2 downstream of the heat exchanger 3. The bypass pipeline 4 is used to transport hot medium gas that has not been cooled by heat exchanger 3, so that the hot medium gas mixes with the cold medium gas in the circulation pipeline 2. A temperature control valve 5 is installed on the bypass pipeline 4. The first temperature sensing element 6 is installed at the air-cooled outlet of the circulation pipeline 2. The first temperature sensing element 6 is used to detect the temperature of the medium gas after the cold medium gas and the hot medium gas are mixed. The first temperature control unit 7 has a pre-stored cooling process curve and is connected to the first temperature sensing element 6 and the temperature control valve 5 respectively. The first temperature control unit 7 is used to control the opening degree of the temperature control valve 5 according to the set value of the cooling process curve and the detected temperature of the first temperature sensing element 6.

[0023] The air-cooling system provided in this embodiment, by setting up a circulation pipeline 2 that cooperates with the heat exchanger 3 and a bypass pipeline 4 arranged in parallel, can flexibly adjust the proportion of hot medium gas mixed in the circulation pipeline 2 by relying on the temperature control valve 5. Combined with the first temperature measuring element 6 and the first temperature control unit 7 with the pre-stored cooling process curve, a closed-loop control is formed. The temperature of the mixed medium gas entering the heat treatment furnace 1 is matched and stably controlled in real time according to the cooling process curve, which is suitable for the processing requirements of segmented cooling in the quenching process. It can ensure that the workpiece has a fast cooling rate in the initial stage and improve the surface hardness of the workpiece. It can also achieve smooth and controllable cooling in the middle stage, reducing the probability of workpiece deformation and cracking. At the same time, it optimizes the airflow distribution and the ratio of cold and hot medium gases in the heat treatment furnace 1, improves the temperature field and workpiece cooling uniformity in the heat treatment furnace 1, reduces processing energy consumption, shortens the cooling cycle, and stabilizes the heat treatment forming quality of batch workpieces.

[0024] Understandably, heat treatment furnace 1, as an integrated working chamber for workpiece quenching heat treatment and air cooling, can adopt a sealed, insulated furnace body structure, fixedly installed on the ground. The workpiece to be treated is placed inside, and a cooling water jacket cooling structure is configured on the outside. Continuous circulation of cooling water cools the surface of heat treatment furnace 1, preventing burns to personnel from the high temperature. Circulation pipeline 2 serves as a cooling medium transport channel. Its inlet is connected to the outlet of heat treatment furnace 1, and its outlet extends to the furnace body inlet after heat exchanger 3. The section of pipe connected to the furnace body inlet is the air-cooling outlet. This pipeline is used to transport the cooled medium gas after being cooled by heat exchanger 3, forming a closed-loop circulation transport path for the cold medium gas. Bypass pipeline 4 is an auxiliary pipeline connected in parallel to heat exchanger 3. One end is connected to the outlet of heat treatment furnace 1, and the other end is connected to the section of circulation pipeline 2 downstream of heat exchanger 3. It is used to bypass heat exchanger 3 and directly transport uncooled hot medium. The medium gas is connected to a bypass pipeline 4 equipped with a temperature control valve 5. The temperature control valve 5 can be a proportional regulating valve, which controls the on / off state and flow rate of the hot medium gas by adjusting the valve opening, thereby achieving flexible control of the mixing ratio of the cold and hot medium gases. The first temperature sensing element 6 can be a temperature sensor such as a thermocouple, which is fixedly installed at the air-cooled outlet of the circulation pipeline 2 to detect the temperature of the medium gas after the cold and hot medium gases are mixed in real time and feed back the temperature signal in real time. The medium gas after the cold and hot medium gases are mixed is the cooling medium. The first temperature control unit 7 can be a temperature control instrument with a built-in control program. It has a pre-stored cooling process curve adapted to the quenching process. At the same time, it establishes a signal connection with the first temperature sensing element 6 and the temperature control valve 5 through electrical circuits. It receives the detected temperature fed back by the first temperature sensing element 6, compares it with the set value of the cooling process curve, and outputs a control command to adjust the opening of the temperature control valve 5.

[0025] It is understandable that the air-cooling stage includes an initial rapid cooling stage and a mid-stage slow cooling stage. In the initial rapid cooling stage, the core objective is to meet the process requirements of rapid cooling of the workpiece in the initial stage of quenching and to improve surface hardness. At this time, the temperature control valve 5 on the bypass pipe 4 is in the closed state. All the inert medium gas filled in the heat treatment furnace 1 is transported to the heat exchanger 3 through the circulation pipe 2 to complete efficient cooling. After forming a low-temperature cold medium gas, it is returned to the furnace body from the pipe section connected to the air inlet of the heat treatment furnace 1 through the circulation pipe 2. No high-temperature hot medium gas is mixed in throughout the process, so as to achieve rapid quenching and cooling of the workpiece at the maximum cooling rate and ensure that the surface hardness of the workpiece meets the standard. After entering the intermediate slow cooling stage, to avoid deformation and cracking of the workpiece due to continuous rapid cooling, it is necessary to switch to a smooth and controllable cooling mode. At this time, the system enters a closed-loop temperature control state: the first temperature measuring element 6 continuously collects the actual temperature of the mixed medium gas, i.e., the cooling medium, at the air-cooling outlet in real time, and transmits the temperature signal synchronously to the first temperature control unit 7; the temperature control unit will detect the temperature in real time and compare the difference with the reference theoretical temperature at the same moment of the internally stored cooling process curve. Based on the real-time temperature difference value, the opening of the temperature control valve 5 on the bypass pipe 4 is dynamically adjusted, thereby controlling the flow rate of the hot medium gas that has not been cooled by the heat exchanger 3 in the bypass pipe 4 into the circulation pipe 2; by dynamically adjusting the mixing ratio of the cold medium gas and the hot medium gas, the temperature of the mixed medium gas about to enter the heat treatment furnace 1 is made to conform to the changing trend of the cooling process curve, and the temperature is continuously and controlled according to the preset cooling slope to achieve slow and uniform cooling of the workpiece, avoid the risk of deformation and cracking, and improve the stability and uniformity of the heat treatment quality of batch workpieces. Specifically, assuming that the set temperature of the mixed medium gas at a certain temperature control moment in the preset cooling process curve is 350℃, the first temperature sensing element 6 detects in real time that the actual temperature of the mixed medium gas at the air-cooled outlet of the circulation pipe 2 is 320℃. This detected temperature is lower than the set value of the cooling process curve, which means that the current cooling medium temperature is too low and the workpiece cooling rate is too fast. After receiving the temperature signal, the first temperature control unit 7 quickly calculates the temperature difference between the actual temperature and the set value, and then outputs a control command to appropriately increase the opening of the temperature control valve 5, increase the mixing flow rate of the hot medium gas in the bypass pipe 4, and increase the mixing flow rate of the cold medium gas and hot medium gas in the circulation pipe 2. The overall temperature after mixing is maintained until the actual temperature detected by the first temperature sensing element 6 matches the set value of 350℃. If the first temperature sensing element 6 subsequently detects that the actual temperature of the mixed medium rises to 380℃, which is higher than the set value at the same moment of the cooling process curve, the first temperature control unit 7 immediately reverses the adjustment, closing the opening of the temperature control valve 5 to reduce the amount of high-temperature hot medium gas mixed in and lower the overall temperature of the mixed medium gas. Through continuous temperature difference comparison and dynamic fine-tuning of valve opening, the temperature of the mixed medium gas entering the heat treatment furnace 1 always follows the set value of the cooling process curve, achieving precise and stable closed-loop temperature control, and adapting to the process requirements of segmented cooling throughout the process.

[0026] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the air outlet of the heat treatment furnace 1 is located at the upper part of the heat treatment furnace 1, and the air inlet of the heat treatment furnace 1 is located at the lower part of the heat treatment furnace 1.

[0027] In this embodiment, the outlet of the heat treatment furnace 1 is located at the upper part of the furnace 1, and the inlet is located at the lower part. This adapts to the media delivery logic of the circulation pipe 2 and the bypass pipe 4 in the air-cooling system, constructing a directional and stable airflow circulation path that flows in from the lower inlet and out from the upper outlet of the heat treatment furnace 1. This allows the mixed medium gas, i.e., the cooling medium, after closed-loop temperature control, to be evenly delivered into the furnace from the lower part, gradually covering and enveloping the workpiece to be processed. This significantly optimizes the airflow distribution inside the heat treatment furnace 1 and effectively avoids local gas imbalances within the furnace 1. The problem of turbulent flow and uneven temperature distribution is further improved by enhancing the overall uniformity of the temperature field within the heat treatment furnace 1. This ensures that the cooling rate differences between various parts of the workpiece are small, accurately adapting to the process requirements of segmented cooling during quenching. At the same time, it allows the hot medium gas in the heat treatment furnace 1 to be discharged more smoothly from the upper outlet and flow into the circulation pipeline 2 and bypass pipeline 4 efficiently, improving the transport, mixing, and heat exchange efficiency of the medium gas. This helps the first temperature control unit 7 achieve more precise dynamic closed-loop temperature control based on the temperature control valve 5, further reducing the probability of workpiece deformation and cracking, and improving the heat treatment forming quality of batch workpieces.

[0028] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the air-cooling system also includes a circulating power component 8. The air inlet of the circulating power component 8 near the heat treatment furnace 1 is located on the main line of the circulating pipeline 2 and is not connected in parallel with the bypass pipeline 4. It is used to drive the medium gas to circulate between the pipeline and the heat treatment furnace 1.

[0029] In this embodiment, the circulating power component 8 is positioned near the air inlet of the heat treatment furnace 1 on the main line of the circulating pipeline 2, and is not connected in parallel with the bypass pipeline 4. This effectively avoids the interference of the bypass pipeline 4's diversion effect on the driving efficiency of the circulating power component 8, allowing the driving force of the circulating power component 8 to be concentrated on the main line of the circulating pipeline 2. This stably drives the cold medium gas, the hot medium gas, and the medium gas mixed with the two, achieving forced and orderly circulation between the circulating pipeline 2, the bypass pipeline 4, and the heat treatment furnace 1. This ensures that the cold medium gas cooled by the heat exchanger 3 is smoothly transported to the section of the circulating pipeline 2 connected to the air inlet of the heat treatment furnace 1, and also ensures that the hot medium gas in the bypass pipeline 4 is stably integrated into the circulating pipeline 2. The circulation pipeline 2 completes uniform mixing, and in conjunction with the layout of the heat treatment furnace 1 with air inlet at the bottom and air outlet at the top, it strengthens the airflow push, maintains the stability of the medium gas flow rate and flow, and avoids airflow fluctuations affecting the mixing ratio accuracy of the cold and hot medium gases. This ensures the accuracy of temperature detection by the first temperature sensing element 6, and helps the first temperature control unit 7 achieve more precise closed-loop temperature control by relying on the temperature control valve 5. This ensures that the temperature of the mixed medium gas entering the heat treatment furnace 1 always matches the cooling process curve, while improving the overall medium gas circulation efficiency, shortening the cooling cycle, further ensuring the uniformity of workpiece cooling, reducing the probability of workpiece deformation and cracking, and improving the overall operational stability of the air cooling system and the heat treatment effect.

[0030] It is understandable that the circulating power component 8 can be a wind-cooled fan, which is composed of a wind-cooled motor and an impeller assembly.

[0031] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the air-cooling system also includes a second temperature measuring element 9, a second temperature control unit 10, and a controller 11; the second temperature measuring element 9 is used to detect the temperature inside the heat treatment furnace 1; the second temperature control unit 10 is connected to the second temperature measuring element 9 and is used to obtain the detected temperature inside the heat treatment furnace 1; the controller 11 is connected to the second temperature control unit 10 and the first temperature control unit 7 respectively, and the controller 11 is used to determine the cooling process based on the detected temperature inside the furnace, and when the preset switching temperature is reached, control the first temperature control unit 7 to start the mid-section slow cooling cooling process curve.

[0032] In this embodiment, the temperature inside the heat treatment furnace 1 is detected by the second temperature sensing element 9, and the second temperature control unit 10 acquires the detected temperature inside the heat treatment furnace 1. The controller 11 is connected to the second temperature control unit 10 and the first temperature control unit 7 respectively. It can accurately determine the cooling process based on the detected temperature inside the furnace, and directly control the first temperature control unit 7 to start the mid-stage slow cooling cooling process curve when the temperature inside the furnace reaches the preset switching temperature. On the one hand, it realizes the automated and precise control of the cooling stage switching of the air-cooled system, eliminating the need for manual judgment and operation, and avoiding timing deviations and operational delays caused by human intervention. The subsequent issues ensure a smooth transition between the initial rapid cooling stage and the intermediate slow cooling stage according to process requirements. On the other hand, it works in synergy with the existing closed-loop temperature control system of the first temperature control unit 7, making the temperature control logic of the entire quenching and cooling process more coherent and the stage switching more in line with process requirements. This not only ensures the effect of improving the surface hardness of the workpiece in the initial rapid cooling stage, but also continuously and stably meets the requirements of smooth and controllable cooling after switching to the slow cooling stage, further reducing the probability of workpiece deformation and cracking, improving the automation level of the overall operation of the air cooling system and the accuracy of heat treatment temperature control, and improving the heat treatment forming quality of batch workpieces.

[0033] Understandably, the second temperature sensing element 9 can be a thermocouple or resistance temperature sensor adapted to the high-temperature operating conditions of the heat treatment furnace 1, unlike the first temperature sensing element 6 which detects the temperature of the mixed medium in the pipeline. The second temperature sensing element 9 is used to directly collect the actual ambient temperature of the internal cavity of the heat treatment furnace 1, conforming to the high-temperature and sealed working environment inside the heat treatment furnace 1, ensuring the stability and accuracy of temperature detection. The second temperature control unit 10 is a temperature control instrument or industrial control module with built-in signal acquisition and data processing programs. It has the functions of temperature signal reception, data calibration and real-time upload. It is used to process the furnace temperature data transmitted by the second temperature sensing element 9. It does not participate in the temperature regulation of the cooling medium and the opening adjustment of the temperature control valve 5. It is an intermediate signal transmission component connecting the second temperature sensing element 9 and the controller 11. The controller 11 is a programmable logic controller 11 or a dedicated quenching process industrial control controller 11. It has pre-stored the fast cooling to slow cooling switching temperature thresholds set for different workpiece materials. It has the functions of temperature value comparison, cooling process logic judgment and control command output.

[0034] Understandably, after the workpiece enters the air-cooling stage, it first enters the initial rapid cooling stage. At this time, the second temperature sensing element 9 continuously collects the temperature data inside the heat treatment furnace 1 in real time and transmits the analog or digital temperature detection signal synchronously to the second temperature control unit 10. The second temperature control unit 10, as the signal processing terminal, calibrates and organizes the received temperature signal and then uploads standardized real-time furnace temperature data to the controller 11 in real time. The controller 11 continuously compares the received furnace temperature with the internally stored rapid-to-slow-cooling switching temperature adapted to the workpiece material in real time. When the controller 11 passes the logic... When it is determined that the temperature inside the heat treatment furnace 1 has reached the preset switching temperature, i.e. the preset rapid cooling to slow cooling switching temperature, it is determined that the initial rapid cooling stage has achieved the process goal of improving the surface hardness of the workpiece, and it is necessary to switch to the smooth and controllable intermediate slow cooling stage. Immediately, the controller 11 sends the corresponding process switching control command to the first temperature control unit 7, directly triggering the first temperature control unit 7 to start the cooling process curve adapted to the intermediate slow cooling stage. Subsequently, the first temperature control unit 7 can dynamically adjust the opening of the temperature control valve 5 on the bypass pipeline 4 according to the cooling process curve and in combination with the mixed medium gas temperature detection data fed back in real time by the first temperature measuring element 6.

[0035] In the above embodiments, see Figure 1 As shown, the second temperature sensing element 9 is disposed on the top of the heat treatment furnace 1.

[0036] Understandably, placing the second temperature sensing element 9 at the top of the heat treatment furnace 1 allows it to adapt to the directional airflow circulation path of the furnace 1, which has air intake at the bottom and exhaust at the top. This avoids direct scouring and interference from the circulating medium gas inside the furnace 1, as well as local airflow disturbances. It accurately collects the true and uniform temperature of the furnace 1's internal cavity, preventing local temperature deviations from affecting the detection results. This ensures that the second temperature sensing element 9 outputs stable and accurate furnace temperature data, transmitting reliable temperature measurement signals to the second temperature control unit 10. Consequently, the controller 11 can efficiently determine the air-cooling process based on the accurate furnace temperature, and promptly issue instructions to the first temperature control unit 7 to start the mid-stage slow cooling process curve, improving the timeliness and accuracy of the cooling stage switching.

[0037] Furthermore, to clearly illustrate the control process of the above-mentioned air-cooled system, this application provides a method for controlling the temperature of the cooling medium at the air-cooled outlet, applicable to any of the above-mentioned air-cooled systems. See [link to relevant documentation]. Figure 2 As shown, the method includes: Step S101: Collect the actual temperature of the medium gas after the cold medium gas and the hot medium gas are mixed.

[0038] In this embodiment, a first temperature sensing element 6, located at the air-cooled outlet of the circulation pipe 2 and near the air inlet of the heat treatment furnace 1, can collect the actual temperature of the medium gas after it has been cooled by the heat exchanger 3 and the uncooled hot medium gas transported by the bypass pipe 4 in real time, thus completing the real-time detection and signal feedback of the cooling medium temperature. Here, the air-cooled outlet refers to the end outlet position where the circulation pipe 2 enters, faces, and is about to flow into the air inlet of the heat treatment furnace 1.

[0039] Step S102: Compare the set value of the cooling process curve with the actual temperature collected.

[0040] In this embodiment, the first temperature control unit 7, which has a pre-stored quenching segmented cooling process curve, can compare the temperature set value at the corresponding moment of the preset cooling process curve with the actual temperature of the mixed medium gas collected in real time by the first temperature measuring element 6, and calculate the temperature difference between the two to provide data basis for subsequent valve adjustment.

[0041] Step S103: Adjust the opening of the temperature control valve 5 set on the bypass pipeline 4 according to the comparison results, adjust the proportion of mixed heat medium gas, and make the temperature of the cooling medium at the air-cooled outlet follow the cooling process curve.

[0042] In this embodiment, the first temperature control unit 7 adjusts the opening of the temperature control valve 5 on the bypass pipeline 4 according to the temperature difference result obtained from the aforementioned temperature comparison, precisely controls the flow rate ratio of the hot medium gas mixed into the circulation pipeline 2, and dynamically adjusts the mixing ratio of the cold medium gas and the hot medium gas, so that the actual temperature of the cooling medium at the air-cooled outlet always follows the cooling process curve and changes smoothly, thereby achieving closed-loop precise temperature control.

[0043] By applying the technical solution of this embodiment, the first temperature sensing element 6 collects the actual temperature of the mixed medium gas in real time, the first temperature control unit 7 compares the difference between the set value and the measured temperature of the cooling process curve, and dynamically adjusts the opening of the bypass pipeline 4 temperature control valve 5 in a closed-loop control logic. This allows for precise control of the mixing ratio of cold medium gas and hot medium gas, ensuring that the temperature of the cooling medium entering the heat treatment furnace 1 strictly follows the preset cooling process curve and changes smoothly. This adapts to the segmented cooling process requirements of rapid cooling in the early stage and slow cooling in the middle stage of the quenching process. It ensures rapid cooling of the workpiece in the early stage of quenching to improve surface hardness, and achieves smooth and controllable cooling in the middle and later stages, significantly reducing the risk of workpiece deformation and cracking. At the same time, it improves the uniformity of the temperature field and workpiece cooling in the heat treatment furnace 1, ensuring stable and uniform heat treatment quality of batch workpieces. It also eliminates the need for manual intervention, realizing automated and precise control of cooling temperature, optimizing the medium gas circulation efficiency, shortening the cooling cycle, reducing processing energy consumption, and further improving the operational stability and temperature control accuracy of the air cooling system.

[0044] Furthermore, as a refinement and extension of the specific implementation of the above embodiments, and to fully illustrate the specific implementation process of this embodiment, another method for controlling the temperature of the cooling medium at the air-cooled outlet is provided, see [link to relevant documentation]. Figure 3 As shown, the method includes: Step S201: Keep the temperature control valve 5 in the closed state to perform initial rapid cooling of the workpiece; Step S202: Obtain the furnace internal temperature of heat treatment furnace 1; Step S203: Determine the cooling process based on the temperature detected inside the furnace; Step S204: When the furnace temperature reaches the preset switching temperature, control the first temperature control unit 7 to start the cooling process curve that adapts to the mid-section slow cooling. Step S205: Collect the actual temperature of the medium gas after the cold medium gas and the hot medium gas are mixed; Step S206: Compare the set value of the cooling process curve with the actual temperature collected; Step S207: Adjust the opening of the temperature control valve 5 set on the bypass pipeline 4 according to the comparison results, adjust the proportion of mixed heat medium gas, and make the temperature of the cooling medium at the air-cooled outlet follow the cooling process curve.

[0045] In this embodiment, the complete implementation process of the cooling medium temperature control method at the air-cooled outlet is as follows: First, the temperature control valve 5 on the bypass pipe 4 is kept completely closed. The medium gas in the heat treatment furnace 1 is cooled throughout the entire process through the circulation pipe 2 and the heat exchanger 3 to carry out the initial rapid cooling operation on the workpiece and improve the surface hardness of the workpiece. At the same time, the detection temperature inside the heat treatment furnace 1 is continuously acquired. The cooling process of the workpiece is determined in real time based on the detection temperature inside the heat treatment furnace 1. When the detection temperature inside the furnace reaches the preset rapid cooling to slow cooling switching temperature, the first temperature control unit 7 is immediately controlled to start the adaptive intermediate slow cooling. The cooling process curve is set in stages. Then, the actual temperature of the medium gas after mixing with the hot medium gas transported by the bypass pipeline 4 at the air-cooled outlet of the circulation pipeline 2 is collected in real time. The actual temperature is accurately compared with the set value at the corresponding moment of the cooling process curve. Finally, the opening of the temperature control valve 5 on the bypass pipeline 4 is dynamically adjusted according to the temperature comparison result to accurately control the mixing ratio of the hot medium gas. By adjusting the mixing ratio of the cold medium gas and the hot medium gas, the cooling medium temperature at the air-cooled outlet always follows the preset cooling process curve and changes smoothly, realizing smooth and controllable cooling in the middle section and avoiding the risk of workpiece deformation and cracking.

[0046] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0047] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. An air-cooled system, characterized in that, include: Heat treatment furnace; The circulation pipeline has its inlet connected to the outlet of the heat treatment furnace and its outlet connected to the inlet of the heat treatment furnace via a heat exchanger. The circulation pipeline is used to transport the cold medium gas cooled by the heat exchanger and to form a circulation of the cold medium gas. A bypass pipeline is provided, one end of which is connected to the gas outlet of the heat treatment furnace, and the other end is connected to a pipe section in the circulation pipeline located downstream of the heat exchanger. The bypass pipeline is used to transport hot medium gas that has not been cooled by the heat exchanger, so that the hot medium gas is mixed with the cold medium gas in the circulation pipeline. A temperature control valve is provided on the bypass pipeline. The first temperature sensing element is disposed at the air-cooled outlet of the circulation pipeline. The first temperature sensing element is used to detect the temperature of the medium gas after the cold medium gas and the hot medium gas are mixed. The first temperature control unit has a pre-stored cooling process curve and is connected to the first temperature measuring element and the temperature control valve respectively. The first temperature control unit is used to control the opening degree of the temperature control valve according to the set value of the cooling process curve and the detected temperature of the first temperature measuring element.

2. The system according to claim 1, characterized in that, The air outlet of the heat treatment furnace is located at the upper part of the heat treatment furnace, and the air inlet of the heat treatment furnace is located at the lower part of the heat treatment furnace.

3. The system according to claim 1, characterized in that, Also includes: A circulating power component is provided near the air inlet of the heat treatment furnace and is located on the main line of the circulating pipeline, but not in parallel with the bypass pipeline, for driving the medium gas to circulate between the pipeline and the heat treatment furnace.

4. The system according to claim 1, characterized in that, Also includes: The second temperature sensing element is used to detect the temperature inside the heat treatment furnace.

5. The system according to claim 4, characterized in that, The second temperature sensing element is disposed on the top of the heat treatment furnace.

6. The system according to claim 4, characterized in that, Also includes: The second temperature control unit is connected to the second temperature measuring element and is used to obtain the furnace temperature inside the heat treatment furnace.

7. The system according to claim 6, characterized in that, Also includes: The controller is connected to the second temperature control unit and the first temperature control unit respectively. The controller is used to determine the cooling process based on the temperature detected in the furnace, and when the preset switching temperature is reached, it controls the first temperature control unit to start the cooling process curve of the mid-stage slow cooling.

8. A method for controlling the temperature of the cooling medium at an air-cooled outlet, characterized in that, Applied to the system as described in any one of claims 1-7, comprising: The actual temperature of the medium gas after the cold medium gas and the hot medium gas are mixed is collected; Compare the set value of the cooling process curve with the actual temperature collected; Adjust the opening of the temperature control valve on the bypass pipeline according to the comparison results, and adjust the proportion of the mixed heat medium gas so that the temperature of the cooling medium at the air-cooled outlet follows the cooling process curve.

9. The method according to claim 8, characterized in that, Before adjusting the temperature of the cooling medium, the method further includes: Obtain the furnace internal temperature of the heat treatment furnace; The cooling process is determined based on the temperature detected inside the furnace. When the furnace temperature reaches the preset switching temperature, the first temperature control unit is controlled to start the cooling process curve that adapts to the mid-section slow cooling.

10. The method according to claim 9, characterized in that, Before initiating the cooling process curve for the intermediate slow cooling, the method further includes: Keep the temperature control valve closed to perform initial rapid cooling of the workpiece.

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