Double-valve control method and system based on bell-type furnace cooling fan

Abstract

The invention provides a double-valve control method and system based on a bell-type furnace cooling fan, and the method comprises the following steps: a non-cooling step: comparing a rear-end cooling butterfly valve with an initial set opening degree, opening or closing the rear-end cooling butterfly valve through pulses, and slowly opening a front-end cooling butterfly valve until the front-end cooling butterfly valve is fully opened after the rear-end cooling butterfly valve is opened; a cooling step: controlling the rear-end cooling butterfly valve through PI adjustment, and slowly opening the front-end cooling butterfly valve until the front-end cooling butterfly valve is fully opened; and a full-speed cooling step: the rear-end cooling butterfly valve is relatively quickly opened through pulses until the valve is fully opened, and the front-end cooling butterfly valve is relatively slowly opened until the valve is fully opened. The front-end cooling butterfly valve is added, control over a silicon steel bell-type furnace cooling fan valve is perfected, suction of heat exchange gas quantity is effectively controlled, the gas volume in a heating cover can be kept balanced, and the production requirement can be better met; through control from multiple stages and multiple aspects, the method can cope with scenes with more control requirements, and is suitable for most of related atmospheres to enter equipment systems after heat exchange through a heat exchanger.

Description

Technical Field

[0001] The present invention belongs to the technical field of bell-type furnace equipment, and specifically, relates to a dual-valve control method and system based on a cooling fan of a bell-type furnace. Background Art

[0002] At present, only a cooling regulating butterfly valve is installed in the outlet pipeline of the cooling fan used on the heating hood of the silicon steel bell-type furnace in the market, which is called the rear-end cooling butterfly valve. After the cooling fan is started, the opening of this valve is adjusted according to requirements. When the cooling fan is running, since there is no valve at the inlet of the fan for adjustment, the high-temperature gas in the heating hood directly enters the inlet of the fan after being cooled by the heat exchanger. However, since there is a rear-end cooling butterfly valve at the outlet for opening adjustment, it will cause a sudden drop in the pressure in the heating hood.

[0003] A sudden drop in the pressure in the heating hood may cause many problems. The pressure in the heating hood needs to be controlled stably. After the pressure drops suddenly, nitrogen needs to be replenished. Otherwise, it will cause the pressure in the heating hood to fluctuate within a short time, resulting in deformation, cracking or other defects, affecting the product quality, especially having a greater impact on precision materials, affecting the heating effect, material properties and product quality. The temperature control fails, affecting the gas convection and heat conduction in the heating hood, resulting in uneven temperature distribution and uneven heating of the material. If the pressure drops suddenly to a very low level, external air will enter. The normal atmosphere in the heating hood is nitrogen and hydrogen. The entry of air will cause the oxygen content to increase, not only affecting the product quality but also being dangerous. It may also damage the heating hood or the furnace body structure, increasing the risk of equipment failure, causing gas leakage or explosion, especially when dealing with flammable and explosive gases, the danger is higher, shortening the service life; in some cases, it will affect the stability of process parameters, resulting in production interruption or efficiency reduction. To restore the pressure, the system may require additional energy, resulting in increased energy consumption and cost.

[0004] Although the traditional heating hood is equipped with a rear-end cooling butterfly valve, when the cooling fan starts, the high-temperature gas in the heating hood is sucked into the heat exchanger for cooling and then blown into the heating hood. After the original high-temperature gas in the heating hood is cooled by the heat exchanger, due to thermal expansion and contraction, the gas volume will be compressed. For example, the volume of 100 cubic meters of high-temperature gas after heat exchange must be less than 100 cubic meters. The rear-end cooling butterfly valve can only control the amount of gas blown into the heating hood per hour and cannot control the amount of gas sucked into the heat exchanger from the heating hood per hour, which will cause the actual gas volume in the heating hood to decrease, resulting in a sudden drop in pressure.

[0005] The patent document "A Cooling System and Cooling Control Method for a Bell-Type Annealing Furnace Heating Hood" (CN118932166A) discloses that the cooling system adds a bypass pipe that does not pass through the heat exchanger in the middle of the cold air pipe of the inlet heat exchanger and merges it into the hot air distribution loop pipe, so that part of the cold combustion-supporting air is directly blown into the furnace through the burner. At the same time, it is coordinated with the regulating valve provided on the bypass pipe. However, when the valve exceeds / is lower than the set opening degree during the non-cooling stage, the valve immediately operates, resulting in frequent fluctuations in the furnace pressure, and the detection of temperature difference changes is cumbersome and the control is rough.

[0006] Therefore, there is an urgent need for a control method and system based on the cooling fan of the bell-type furnace, which can effectively control the intake of heat exchange gas volume and maintain the balance of the gas volume in the heating hood. Summary of the Invention

[0007] Aiming at the defects in the prior art, the purpose of the present invention is to provide a dual-valve control method and system based on the cooling fan of the bell-type furnace.

[0008] According to a dual-valve control method based on the cooling fan of the bell-type furnace provided by the present invention, it includes:

[0009] Non-cooling step: Compare the opening degree of the rear cooling butterfly valve with the initial set opening degree, receive the open or close command and open or close through a pulse. After the rear cooling butterfly valve is opened, the front cooling butterfly valve receives the open command and slowly opens until it is fully opened;

[0010] Cooling step: The rear cooling butterfly valve is controlled by PI regulation, and the front cooling butterfly valve receives the open command and slowly opens until it is fully opened;

[0011] Full-speed cooling step: The rear cooling butterfly valve receives the open command through a pulse and opens relatively quickly until it is fully opened, and the front cooling butterfly valve receives the open command and opens relatively slowly until it is fully opened.

[0012] Preferably, judge the operation condition of the cooling fan. If the cooling fan is running and there is no fault, open the rear cooling butterfly valve. If the cooling fan is not running or a fault occurs, close the rear cooling butterfly valve.

[0013] If the cooling fan is not running or a fault occurs or the front cooling butterfly valve has no open command, the front cooling butterfly valve receives the close command. If the cooling fan is running without a fault and the front cooling butterfly valve receives the open command, the front cooling butterfly valve intercepts the close command and does not execute it.

[0014] Preferably, in the non-cooling step, the rear cooling butterfly valve is adjusted according to the initial set opening degree, compare the actual opening degree with the initial set opening degree. If the actual opening degree is greater than the initial set opening degree, after a delay time, the rear cooling butterfly valve is intermittently closed. If the actual opening degree is less than or equal to the initial set opening degree, after a delay time, the rear cooling butterfly valve is intermittently opened.

[0015] The front-end cooling butterfly valve opens when the rear-end cooling butterfly valve is not in the closed position, the cooling fan is running and there is no fault. When it is detected that the pressure in the heating hood continuously remains below 1 Mbar for more than 180 seconds, the front-end cooling butterfly valve closes intermittently, and the pressure in the heating hood is continuously detected. When the pressure is maintained at 2.5 Mbar with a fluctuation of plus or minus 0.2 Mbar for 180 seconds, the opening degree of the front-end cooling butterfly valve is maintained.

[0016] The set value of the delay time is greater than 180 seconds.

[0017] When it is detected that the pressure in the heating hood continuously remains below 1 Mbar for more than 30 seconds, the initial set opening value minus the fixed value N is used as the new set opening value and compared with the set lower limit value. If the set opening value is greater than or equal to the lower limit value, the set opening value remains unchanged. If the set opening value is less than the lower limit value, the lower limit value is used as the set opening value.

[0018] The fixed value N is set according to the temperature thermal expansion and contraction ratio, and the value obtained by rounding up (1 - B) * 10 is the value of N;

[0019] Where B represents the compression ratio after gas cooling.

[0020] Preferably, if the detected actual temperature minus the set temperature is greater than 7 degrees Celsius and lasts for 3 minutes, the cooling step is executed. The cooling fan runs, and the opening degree of the rear-end cooling butterfly valve is controlled by outputting pulses through PI control for the opening / closing command. If the actual temperature is less than or equal to the set temperature and 3 minutes later, the cooling fan stops and the rear-end cooling butterfly valve closes.

[0021] The set temperature is calculated according to the input process curve.

[0022] In the cooling step, when the cooling fan is running and there is no fault, the actual opening value X of the rear-end cooling butterfly valve is detected. According to the set fixed value M, the result of X + M is assigned to Y, and Y is used as the opening degree set value of the front-end cooling butterfly valve and output to open the front-end cooling butterfly valve to the opening degree set value.

[0023] The set fixed value M is set according to the temperature thermal expansion and contraction ratio, and the value obtained by rounding up the value of B * 20 is the value of M;

[0024] Where B represents the compression ratio after gas cooling.

[0025] Preferably, in the full-speed cooling step, when the cooling fan is running and there is no fault and after a delay of the rated time, the rear-end cooling butterfly valve and the front-end cooling butterfly valve are opened to full open.

[0026] The range of the rated time is 5 - 10 seconds.

[0027] A dual-valve control system based on a cooling fan of a bell-type furnace according to the present invention includes:

[0028] Non-cooling module: The opening of the rear cooling butterfly valve is compared with the initial set opening, and it receives an open or close command to open or close through a pulse. After the rear cooling butterfly valve is opened, the front cooling butterfly valve receives an open command and slowly opens until it is fully opened.

[0029] Cooling module: The rear cooling butterfly valve is controlled by PI regulation, and the front cooling butterfly valve receives an open command and slowly opens until it is fully opened.

[0030] Full-speed cooling module: The rear cooling butterfly valve receives an open command through a pulse and opens relatively quickly until it is fully opened, and the front cooling butterfly valve receives an open command and opens relatively slowly until it is fully opened.

[0031] Preferably, the operation condition of the cooling fan is judged. If the cooling fan is running and there is no fault, the rear cooling butterfly valve is opened. If the cooling fan is not running or a fault occurs, the rear cooling butterfly valve is closed.

[0032] If the cooling fan is not running or a fault occurs or the front cooling butterfly valve has no open command, the front cooling butterfly valve receives a close command. If the cooling fan is running without a fault and the front cooling butterfly valve receives an open command, the front cooling butterfly valve intercepts the close command and does not execute it.

[0033] Preferably, in the non-cooling module, the rear cooling butterfly valve is adjusted according to the initial set opening. The actual opening is compared with the initial set opening. If the actual opening is greater than the initial set opening, after a delay time, the rear cooling butterfly valve is intermittently closed. If the actual opening is less than or equal to the initial set opening, after a delay time, the rear cooling butterfly valve is intermittently opened.

[0034] The front cooling butterfly valve opens when the rear cooling butterfly valve is not in the closed position, the cooling fan is running and there is no fault. When it is detected that the pressure in the heating hood continuously remains below 1 Mbar for more than 180 seconds, the front cooling butterfly valve is intermittently closed, and the pressure in the heating hood is continuously detected. When the pressure is maintained at 2.5 Mbar with a fluctuation of plus or minus 0.2 Mbar for 180 seconds, the opening of the front cooling butterfly valve is maintained.

[0035] The set value of the delay time is greater than 180 seconds.

[0036] When it is detected that the pressure in the heating hood continuously remains below 1 Mbar for more than 30 seconds, the value of the initial set opening minus a fixed value N is used as the new set opening and compared with the set lower limit value. If the set opening is greater than or equal to the lower limit value, the set opening remains unchanged. If the set opening is less than the lower limit value, the lower limit value is used as the set opening.

[0037] The fixed value N is set according to the thermal expansion and contraction ratio of temperature, and the value of N is obtained by rounding up the result of (1 - B) * 10.

[0038] Among them, B represents the compression ratio after the gas is cooled.

[0039] Preferably, if the detected actual temperature minus the set temperature is greater than 7 degrees Celsius and lasts for 3 minutes, the cooling module is triggered, the cooling fan runs, and the opening degree of the rear cooling butterfly valve is controlled by outputting pulses through PI control for opening / closing commands. If the actual temperature is less than or equal to the set temperature and after 3 minutes, the cooling fan stops and the rear cooling butterfly valve closes.

[0040] The set temperature is calculated according to the input process curve.

[0041] In the cooling module, when the cooling fan is running and there is no fault, the actual opening value X of the rear cooling butterfly valve is detected. According to the set fixed value M, the result of X + M is assigned to Y, and Y is used as the opening set value of the front cooling butterfly valve and is output to open the front cooling butterfly valve to the opening set value.

[0042] The set fixed value M is set according to the thermal expansion and contraction ratio of temperature, and the value of M is obtained by rounding up the value after B * 20;

[0043] Among them, B represents the compression ratio after the gas is cooled.

[0044] Preferably, in the full-speed cooling module, when the cooling fan is running and there is no fault and after a delay of the rated time, the rear cooling butterfly valve and the front cooling butterfly valve are opened to full open.

[0045] The rated time range is 5 - 10 seconds.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. By controlling from multiple stages, the present invention improves the situation of the sudden drop in pressure inside the heating hood when the cooling fan is running, and can be applied to the equipment system where the atmosphere enters after heat exchange through the heat exchanger.

[0048] 2. The present invention adds a front cooling butterfly valve, improves the control of the cooling fan valve of the silicon steel bell-type furnace, effectively controls the intake of the heat exchange gas volume, can keep the gas volume inside the heating hood balanced, and better meets the production requirements.

[0049] 3. The present invention includes multiple aspects of control, can cope with control scenarios with more control requirements, and is applicable to production processes with control requirements for the pressure inside the heating hood and the temperature during the cooling process. Brief Description of the Drawings

[0050] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments read in conjunction with the accompanying drawings:

[0051] Figure 1 Schematic diagram of a dual-valve control system based on a bell-type furnace cooling fan;

[0052] Figure 2 Schematic diagram of the control process of the rear-end cooling butterfly valve in the non-cooling stage;

[0053] Figure 3 Schematic diagram of the control process of the rear-end cooling butterfly valve in the cooling stage;

[0054] Figure 4 Schematic diagram of the control process of the front-end cooling butterfly valve in the non-cooling stage;

[0055] Figure 5 Schematic diagram of the control process of the front-end cooling butterfly valve in the cooling stage. Detailed implementation manners

[0056] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0057] Taking Figure 1 as an example, a butterfly valve is added to the inlet pipeline of the cooling fan, which is called the front-end cooling butterfly valve. According to a dual-valve control method based on a bell-type furnace cooling fan provided by the present invention, it is divided into 3 control stages, including: non-cooling step, cooling step, and full-speed cooling step. Corresponding controls are carried out according to different stages.

[0058] The non-cooling step, that is, the non-cooling stage includes:

[0059] The rear-end cooling butterfly valve is compared with the set opening degree, and is opened or closed by a pulse. The front-end cooling butterfly valve is slowly opened until it is fully opened when the rear-end cooling butterfly valve has a certain opening degree. Adding the front-end cooling butterfly valve can effectively control the intake of heat exchange gas volume. Coupled with the continuous replenishment of hydrogen / nitrogen in the heating hood, the gas volume in the heating hood can be maintained in balance.

[0060] Specifically, taking Figure 2For example, when the rear-end cooling butterfly valve is in the non-cooling stage, it is adjusted according to the set opening degree to agitate the gas in the heating hood. The actual opening degree of the rear-end cooling butterfly valve is compared with the set opening degree. If the actual opening degree is greater than the set opening degree and after a certain time delay, the rear-end cooling butterfly valve closes intermittently; if the actual opening degree is less than or equal to the set opening degree and after a certain time delay, the rear-end cooling butterfly valve opens intermittently.

[0061] By adopting a time-delay action and controlling in conjunction with the furnace pressure situation, the set value of the time delay is greater than the set time (180 seconds) considered for the furnace pressure to be stable, so as to ensure that the valve does not act when the furnace pressure is not yet stable, thereby causing the furnace pressure to fluctuate more.

[0062] If it is detected that the pressure in the heating hood continuously remains below 1 Mbar for a certain time (30 s) during the non-cooling stage, the initial opening degree set value minus a fixed value N% is used as the new set value. If the set value is lower than the lower limit value, the lower limit value is used as the set value; the fixed value N is set according to different temperature ranges, and the higher the temperature range, the larger the value of N.

[0063] The fixed value N is set according to the temperature thermal expansion and contraction ratio. The value obtained by rounding up (1 - B) * 10 is the value of N. Specifically:

[0064] When the furnace temperature range is 100 - 200, the compression ratio B of the gas after cooling is 0.72; when the furnace temperature range is 200 - 300, the compression ratio B of the gas after cooling is 0.58; when the furnace temperature range is 300 - 400, the compression ratio B of the gas after cooling is 0.5; when the furnace temperature range is 400 - 500, the compression ratio B of the gas after cooling is 0.43; when the furnace temperature range is 500 - 600, the compression ratio B of the gas after cooling is 0.38; when the furnace temperature range is 600 - 700, the compression ratio B of the gas after cooling is 0.34; when the furnace temperature range is 700 - 800, the compression ratio B of the gas after cooling is 0.32; when the furnace temperature range is 800 - 900, the compression ratio B of the gas after cooling is 0.29; when the furnace temperature range is 900 - 1000, the compression ratio B of the gas after cooling is 0.27; when the furnace temperature range is 1000 - 1100, the compression ratio B of the gas after cooling is 0.25; when the furnace temperature range is 1100 - 1200, the compression ratio B of the gas after cooling is 0.24.

[0065] With Figure 4For example, when the front-end cooling butterfly valve is in the non-cooling stage, to solve the situation of a sudden drop in pressure inside the heating hood, it needs to be opened when the back-end cooling butterfly valve has a certain opening degree or is not in the closed position, and the cooling fan is running and there is no fault. Otherwise, a large amount of high-temperature gas will shrink in volume after heat exchange through the heat exchanger, resulting in an imbalance in the gas volume introduced into the heating hood, which will cause a sudden drop in pressure inside the heating hood. Therefore, if it is detected that the pressure inside the heating hood continuously remains below 1 Mbar for a certain period of time during the non-cooling stage, the front-end cooling butterfly valve is controlled to close intermittently, and at the same time, the pressure inside the heating hood is continuously detected conventionally. The pressure inside the heating hood has a certain impact on the product quality. After the pressure returns to normal for a certain period of time, the current opening degree is maintained. The pressure inside the heating hood should be maintained at 2.5 Mbar, allowing a fluctuation of plus or minus 0.2 Mbar; the certain period of time is set to 180 seconds.

[0066] The cooling control steps, that is, the cooling control stage, specifically include:

[0067] The back-end cooling butterfly valve is controlled by PI regulation, and the front-end cooling butterfly valve is slowly opened until fully opened, so as to achieve the temperature control effect.

[0068] Specifically, by collecting the set temperature and the actual temperature, the valve is controlled through PI regulation to make the temperature control more accurate and smooth. For Figure 3 example, when the back-end cooling butterfly valve is in the cooling stage, when the actual temperature minus the set temperature is greater than K and lasts for a certain period of time, the cooling control is activated, the cooling fan runs, and the opening / closing command of the back-end cooling butterfly valve is controlled by the output pulse of PI control, so as to achieve the temperature control effect. When the actual temperature is less than or equal to the set temperature and lasts for a certain period of time, the cooling control is deactivated, the cooling fan stops, and the back-end cooling butterfly valve follows and closes.

[0069] The set temperature is calculated based on the input process curve; the process requirement is that the temperature difference is not greater than 7 degrees Celsius, and the allowable difference time is 3 minutes.

[0070] For Figure 5 example, when the front-end cooling butterfly valve is in the cooling stage, after the cooling fan runs and there is no fault, the actual opening degree value X% of the back-end cooling butterfly valve is detected. A fixed value M is set according to different temperature ranges, and the smaller the temperature range, the smaller the value of M. The result of X + M is assigned to Y, and Y% is used as the opening degree set value of the front-end cooling butterfly valve. The opening degree set value is output to the front-end cooling butterfly valve through analog quantity. The set fixed value M is set according to the temperature thermal expansion and contraction ratio, and the value of M is the ceiling of the value after B * 20.

[0071] The full-speed cooling steps include:

[0072] The back-end cooling butterfly valve is relatively quickly opened by pulses until fully opened, and the front-end cooling butterfly valve is relatively slowly opened until fully opened to maximize the cooling effect.

[0073] Specifically, during the full-speed cooling stage of the rear-end cooling butterfly valve, when the cooling fan is running and there is no fault, it will open to the fully open position after a certain time delay. This time is for detecting whether the fan starts normally and can be set to 5 - 10 seconds to ensure that the cooling capacity reaches the maximum.

[0074] During the full-speed cooling stage of the front-end cooling butterfly valve, when the cooling fan is running and there is no fault, it will open to the fully open position after a certain time delay to ensure that the cooling capacity reaches the maximum.

[0075] By optimizing the equipment and controlling it in multiple stages, the sudden drop in pressure inside the heating hood during the operation of the cooling fan has been greatly improved. At the same time, the control of the valves of the cooling fan for the silicon steel bell-type furnace has been improved, enabling the equipment to better meet the production requirements.

[0076] Only when the cooling fan operates without faults in all stages can an opening command be sent to the rear-end cooling butterfly valve, otherwise a closing command is sent. The closing command for the front-end cooling butterfly valve can only be output to the valve when there is no opening command, or the cooling fan is not running, or there is a fault.

[0077] The present invention also provides a dual-valve control system based on the cooling fan of the bell-type furnace. The dual-valve control system based on the cooling fan of the bell-type furnace can be implemented by executing the process steps of the dual-valve control method based on the cooling fan of the bell-type furnace. That is, those skilled in the art can understand the dual-valve control method based on the cooling fan of the bell-type furnace as the preferred implementation manner of the dual-valve control system based on the cooling fan of the bell-type furnace.

[0078] A dual-valve control system based on the cooling fan of the bell-type furnace according to the present invention includes:

[0079] Non-cooling module: The opening degree of the rear-end cooling butterfly valve is compared with the initial set opening degree, and it receives an opening or closing command to open or close through a pulse. The front-end cooling butterfly valve receives an opening command and slowly opens until it is fully open after the rear-end cooling butterfly valve is opened;

[0080] Cooling module: The rear-end cooling butterfly valve is controlled by PI regulation, and the front-end cooling butterfly valve receives an opening command and slowly opens until it is fully open;

[0081] Full-speed cooling module: The rear-end cooling butterfly valve receives an opening command through a pulse and opens relatively quickly until it is fully open, and the front-end cooling butterfly valve receives an opening command and opens relatively slowly until it is fully open.

[0082] In more preferred examples, the operating condition of the cooling fan is judged. If the cooling fan is running and there is no fault, the rear-end cooling butterfly valve is opened. If the cooling fan is not running or there is a fault, the rear-end cooling butterfly valve is closed.

[0083] If the cooling fan is not running or fails, or there is no opening command for the front-end cooling butterfly valve, the front-end cooling butterfly valve receives a closing command. If the cooling fan is running without failure and the front-end cooling butterfly valve receives an opening command, the front-end cooling butterfly valve intercepts the closing command and does not execute it.

[0084] In more preferred examples, the rear-end cooling butterfly valve in the non-cooling module is adjusted according to the initial set opening, and the actual opening is compared with the initial set opening. If the actual opening is greater than the initial set opening, after a delay duration, the rear-end cooling butterfly valve closes intermittently. If the actual opening is less than or equal to the initial set opening, after a delay duration, the rear-end cooling butterfly valve opens intermittently.

[0085] The front-end cooling butterfly valve opens when the rear-end cooling butterfly valve is not in the closed position, the cooling fan is running and there is no failure. When it is detected that the pressure in the heating hood continuously remains below 1 Mbar for more than 180 seconds, the front-end cooling butterfly valve closes intermittently, and continuously detects the pressure in the heating hood. When the pressure is maintained at 2.5 Mbar with a fluctuation of plus or minus 0.2 Mbar for 180 seconds, the opening of the front-end cooling butterfly valve is maintained.

[0086] The set value of the delay duration is greater than 180 seconds.

[0087] When it is detected that the pressure in the heating hood continuously remains below 1 Mbar for more than 30 seconds, the value of the initial set opening minus a fixed value N is used as the new set opening and compared with the set lower limit value. If the set opening is greater than or equal to the lower limit value, the set opening remains unchanged. If the set opening is less than the lower limit value, the lower limit value is used as the set opening.

[0088] The fixed value N is set according to the temperature thermal expansion and contraction ratio, and the value obtained by rounding up (1 - B) * 10 is the value of N;

[0089] Where B represents the compression ratio after gas cooling.

[0090] In more preferred examples, if the detected actual temperature minus the set temperature is greater than 7 degrees Celsius and lasts for 3 minutes, the cooling module is triggered, the cooling fan runs, and the opening of the rear-end cooling butterfly valve is controlled by outputting pulses through PI control for opening / closing commands. If the actual temperature is less than or equal to the set temperature and 3 minutes later, the cooling fan stops and the rear-end cooling butterfly valve closes.

[0091] The set temperature is calculated according to the input process curve.

[0092] In the cooling module, when the cooling fan is running and there is no failure, the actual opening value X of the rear-end cooling butterfly valve is detected. According to the set fixed value M, the result of X + M is assigned to Y, and Y is used as the opening set value of the front-end cooling butterfly valve and output to the front-end cooling butterfly valve to open to the opening set value.

[0093] The set value M is set according to the thermal expansion and contraction ratio of temperature, and the value after rounding up the value of B * 20 is the value of M;

[0094] Wherein, B represents the compression ratio after the gas is cooled.

[0095] In more preferred examples, in the full-speed cooling module, when the cooling fan is running and there is no fault for a rated time delay, the rear cooling butterfly valve and the front cooling butterfly valve are opened to fully open.

[0096] The rated time range is 5 - 10 seconds.

[0097] Those skilled in the art know that in addition to implementing the system and its various devices, modules, and units provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system and its various devices, modules, and units provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers, etc. to achieve the same functions. Therefore, the system and its various devices, modules, and units provided by the present invention can be regarded as a kind of hardware component, and the devices, modules, and units included therein for implementing various functions can also be regarded as the structures within the hardware component; the devices, modules, and units for implementing various functions can also be regarded as both software modules for implementing the method and the structures within the hardware component.

[0098] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0099] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined arbitrarily.

Claims

1. A double valve control method based on a bell-type furnace cooling fan, characterized in that: include: Non-cooling step: the opening of the rear cooling butterfly valve is compared with the initial setting opening, and the front cooling butterfly valve receives the opening command and opens or closes through pulses. After the rear cooling butterfly valve is opened, the front cooling butterfly valve receives the opening command and slowly opens until it is fully opened; Cooling steps: The rear cooling butterfly valve is controlled by PI regulation, and the front cooling butterfly valve receives the opening command and slowly opens until it is fully opened; Full-speed cooling steps: The rear cooling butterfly valve receives an opening command through a pulse and opens relatively quickly until it is fully opened, and the front cooling butterfly valve receives an opening command and opens relatively slowly until it is fully opened.

2. The double valve control method based on the bell-type furnace cooling fan according to claim 1 is characterized in that: Determine the operation status of the cooling fan. If the cooling fan is running and has no faults, open the rear cooling butterfly valve. If the cooling fan is not running or has a fault, close the rear cooling butterfly valve. If the cooling fan is not running or fails or there is no opening command for the front cooling butterfly valve, the front cooling butterfly valve receives a closing command. If the cooling fan runs without failure and the front cooling butterfly valve receives an opening command, the front cooling butterfly valve intercepts the closing command and does not execute it.

3. The double valve control method based on the bell-type furnace cooling fan according to claim 2 is characterized in that: In the non-cooling step, the rear cooling butterfly valve is adjusted according to the initial setting opening, and the actual opening is compared with the initial setting opening. If the actual opening is greater than the initial setting opening, the rear cooling butterfly valve is intermittently closed after a delay time. If the actual opening is less than or equal to the initial setting opening, the rear cooling butterfly valve is intermittently opened after a delay time. The front cooling butterfly valve is opened when the rear cooling butterfly valve is not in the closed position and the cooling fan is running and has no faults. When it is detected that the pressure in the heating hood is continuously lower than 1Mbar for more than 180 seconds, the front cooling butterfly valve is intermittently closed and the pressure in the heating hood is continuously detected. When the pressure is maintained at 2.5Mbar, fluctuating by plus or minus 0.2Mbar for 180 seconds, the front cooling butterfly valve is kept open; The delay time setting value is greater than 180 seconds; When it is detected that the pressure in the heating hood is continuously lower than 1Mbar for more than 30 seconds, the initial opening value minus the fixed value N% is used as the new opening setting and compared with the set lower limit value. If the opening setting is greater than or equal to the lower limit value, the opening setting remains unchanged; if the opening setting is less than the lower limit value, the lower limit value is used as the opening setting; The fixed value N is set according to the thermal expansion and contraction ratio of temperature, and (1-B)*10 is rounded up to the value of N; Wherein, B represents the compression ratio of the gas after cooling.

4. The double valve control method based on the bell-type furnace cooling fan according to claim 2 is characterized in that: If the actual temperature minus the set temperature is greater than 7 degrees Celsius and lasts for 3 minutes, the cooling step is executed, the cooling fan is running, and the opening / closing command is used to control the opening of the rear cooling butterfly valve through the PI control output pulse. If the actual temperature is less than or equal to the set temperature and after 3 minutes, the cooling fan stops and the rear cooling butterfly valve is closed; The set temperature is calculated based on the input process curve; In the cooling step, when the cooling fan is running and has no faults, the actual opening value X% of the rear cooling butterfly valve is detected, and according to the set value M, the result of X+M is assigned to Y%, and Y% is used as the opening setting value of the front cooling butterfly valve, and output to the front cooling butterfly valve to open to the opening setting value; The set value M is set according to the thermal expansion and contraction ratio of temperature, and the value after B*20 is rounded up to be the value of M; Wherein, B represents the compression ratio of the gas after cooling.

5. The double valve control method based on the bell-type furnace cooling fan according to claim 2 is characterized in that: In the full-speed cooling step, when the cooling fan is running and there is no fault delay for a rated time, the rear cooling butterfly valve and the front cooling butterfly valve are opened to full open; The nominal time range is 5-10 seconds.

6. A double valve control system based on a bell-type furnace cooling fan, characterized in that: include: Non-cooling module: The opening of the rear cooling butterfly valve is compared with the initial setting opening, and it is opened or closed by pulse upon receiving the opening or closing command. The front cooling butterfly valve receives the opening command after the rear cooling butterfly valve is opened and slowly opens until it is fully opened; Cooling module: The rear cooling butterfly valve is controlled by PI regulation, and the front cooling butterfly valve receives the opening command and slowly opens until it is fully opened; Full-speed cooling module: The rear cooling butterfly valve receives an opening command through a pulse and opens relatively quickly until it is fully opened, and the front cooling butterfly valve receives an opening command and opens relatively slowly until it is fully opened.

7. The double valve control system based on the bell-type furnace cooling fan according to claim 6 is characterized in that: Determine the operation status of the cooling fan. If the cooling fan is running and has no faults, open the rear cooling butterfly valve. If the cooling fan is not running or has a fault, close the rear cooling butterfly valve. If the cooling fan is not running or fails or there is no opening command for the front cooling butterfly valve, the front cooling butterfly valve receives a closing command. If the cooling fan runs without failure and the front cooling butterfly valve receives an opening command, the front cooling butterfly valve intercepts the closing command and does not execute it.

8. The double valve control system based on the bell-type furnace cooling fan according to claim 7 is characterized in that: The rear cooling butterfly valve in the non-cooling module is adjusted according to the initial setting opening, and the actual opening is compared with the initial setting opening. If the actual opening is greater than the initial setting opening, the rear cooling butterfly valve is intermittently closed after a delay time. If the actual opening is less than or equal to the initial setting opening, the rear cooling butterfly valve is intermittently opened after a delay time. The front cooling butterfly valve is opened when the rear cooling butterfly valve is not in the closed position and the cooling fan is running and has no faults. When it is detected that the pressure in the heating hood is continuously lower than 1Mbar for more than 180 seconds, the front cooling butterfly valve is intermittently closed and the pressure in the heating hood is continuously detected. When the pressure is maintained at 2.5Mbar, fluctuating by plus or minus 0.2Mbar for 180 seconds, the front cooling butterfly valve is kept open; The delay time setting value is greater than 180 seconds; When it is detected that the pressure in the heating hood is continuously lower than 1Mbar for more than 30 seconds, the initial opening value minus the fixed value N% is used as the new opening setting and compared with the set lower limit value. If the opening setting is greater than or equal to the lower limit value, the opening setting remains unchanged; if the opening setting is less than the lower limit value, the lower limit value is used as the opening setting; The fixed value N is set according to the thermal expansion and contraction ratio of temperature, and (1-B)*10 is rounded up to the value of N; Wherein, B represents the compression ratio of the gas after cooling.

9. The double valve control system based on the bell-type furnace cooling fan according to claim 7 is characterized in that: If the actual temperature minus the set temperature is greater than 7 degrees Celsius and lasts for 3 minutes, the cooling module is triggered and the cooling fan starts to run. The PI control output pulse is used to open / close the opening of the rear cooling butterfly valve. If the actual temperature is less than or equal to the set temperature and lasts for 3 minutes, the cooling fan stops and the rear cooling butterfly valve closes. The set temperature is calculated based on the input process curve; When the cooling fan in the cooling module is running and has no faults, the actual opening value X% of the rear cooling butterfly valve is detected, and according to the set value M, the result of X+M is assigned to Y%, and Y% is used as the opening setting value of the front cooling butterfly valve, and output to the front cooling butterfly valve to open to the opening setting value; The set value M is set according to the thermal expansion and contraction ratio of temperature, and the value after B*20 is rounded up to be the value of M; Wherein, B represents the compression ratio of the gas after cooling.

10. The double valve control system based on the bell-type furnace cooling fan according to claim 7, characterized in that: In the full-speed cooling module, when the cooling fan is running and there is no fault delay for a rated time, the rear cooling butterfly valve and the front cooling butterfly valve are opened to full opening; The nominal time range is 5-10 seconds.

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