Control method and equipment of automobile coating drying system and storage medium

Abstract

The embodiment of the invention provides a control method and equipment of an automobile coating drying system and a storage medium. The method comprises the following steps that the actual residual oxygen amount of flue gas exhausted by the incinerator is obtained; according to the actual residual oxygen amount, the air volume of the exhaust fan is adjusted, so that the actual residual oxygen amount of flue gas exhausted by the incinerator is maintained in an expected residual oxygen state; the actual air pressure in the drying furnace is obtained; and according to the adjusted air volume of the exhaust fan and the actual air pressure, the air volume of the air inlet fan is adjusted, so that the actual air pressure in the drying furnace is maintained in an expected negative pressure state. According to the resource processing method provided by the embodiment of the invention, the energy consumption can be reduced, and the production safety and the production stability can be improved.

Description

Technical Field

[0001] The present application relates to the field of control technology, and in particular to a control method, device and storage medium for an automobile paint drying system. Background Art

[0002] Painting is an important process and high energy consumption link in vehicle manufacturing. After the frame is sprayed with paint, it needs to be sent to the drying furnace, which creates a high temperature environment to dry the wet paint on the frame. The drying furnace requires a large amount of gas, and its energy consumption accounts for more than 40% of the energy consumption of the entire painting workshop.

[0003] Currently, existing control solutions for drying furnaces have the problem of high energy consumption. Summary of the invention

[0004] In view of the above problems, the present application is proposed to provide a control method, device and storage medium for an automobile paint drying system that solves the above problems or at least partially solves the above problems.

[0005] Therefore, in one embodiment of the present application, a control method for an automobile paint drying system is provided, wherein the automobile paint drying system comprises: an incinerator, a drying furnace, and a heat supply pipe connected to the smoke outlet of the incinerator; the heat supply pipe is used to supply heat to the drying furnace; the exhaust port of the drying furnace is connected to the first air inlet of the incinerator through an exhaust pipe and an exhaust fan; a second air inlet is provided at the automobile frame inlet and the automobile frame outlet of the drying furnace; an air inlet fan is provided corresponding to the second air inlet, which is used to form an air curtain to isolate the air inside and outside the drying furnace and to provide new air into the drying furnace; the method comprises:

[0006] Obtaining the actual residual oxygen content of the flue gas discharged from the incinerator;

[0007] According to the actual residual oxygen content, adjusting the air volume of the exhaust fan to maintain the actual residual oxygen content of the flue gas discharged from the incinerator at a desired residual oxygen state;

[0008] Obtaining the actual air pressure in the drying furnace;

[0009] The air volume of the air inlet fan is adjusted according to the adjusted air volume of the exhaust fan and the actual air pressure, so as to maintain the actual air pressure in the drying oven at a desired negative pressure state.

[0010] In another embodiment of the present application, an electronic device is provided. The electronic device includes: a memory and a processor, wherein:

[0011] The memory is used to store programs;

[0012] The processor is coupled to the memory, and is used to execute the program stored in the memory to implement any of the control methods described above.

[0013] In another embodiment of the present application, a computer-readable storage medium storing a computer program is provided, and when the computer program is executed by a computer, any of the control methods described above can be implemented.

[0014] The drying furnace is heated by burning natural gas in the incinerator. The higher the combustion efficiency of the natural gas in the incinerator, the more energy-efficient the entire system is. In the technical solution provided in the embodiment of the present application, the combustion efficiency of the natural gas in the incinerator is obtained by detecting the residual oxygen content of the flue gas discharged from the incinerator, and the air volume of the exhaust fan corresponding to the drying furnace is adjusted according to the detected actual residual oxygen content of the flue gas discharged from the incinerator, so as to maintain the actual residual oxygen content of the flue gas discharged from the incinerator at the desired residual oxygen state, that is, to maintain the combustion efficiency of the natural gas in the incinerator at the desired combustion state. In addition, after adjusting the air volume of the exhaust fan of the incinerator, it is also necessary to consider the air pressure in the drying furnace and the air volume of the air inlet fan of the drying furnace, so that the actual air pressure in the drying furnace is maintained at the desired negative pressure state, thereby ensuring production safety and stability. It can be seen that the technical solution provided in the embodiment of the present application can not only reduce energy consumption, but also increase production safety and production stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 A schematic diagram of the structure of a car paint drying system provided in one embodiment of the present application;

[0017] Figure 2 A flow chart of a control method provided in one embodiment of the present application;

[0018] Figure 3 A graph showing the relationship between efficiency or loss and air-fuel ratio provided in one embodiment of the present application;

[0019] Figure 4 An example diagram of a control loop provided in an embodiment of the present application;

[0020] Figure 5 A structural block diagram of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below according to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0022] In addition, some of the processes described in the specification, claims and the above-mentioned figures of the present application include multiple operations that appear in a specific order, and these operations may not be executed in the order in which they appear in this article or may be executed in parallel. The serial numbers of the operations, such as 101, 102, etc., are only used to distinguish between different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations may be executed in sequence or in parallel. It should be noted that the descriptions of "first", "second", etc. in this article are used to distinguish different messages, devices, modules, etc., do not represent the order of precedence, and do not limit the "first" and "second" to be different types.

[0023] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0024] In practical applications, the control system needs to meet the following control requirements:

[0025] (1) Safety

[0026] The drying furnace is in a high-temperature environment during production and the gas in the furnace is toxic. The inlet and outlet air volumes must be balanced and the pressure P inside the furnace must be kept at a slightly negative pressure state; the safety of the incinerator itself must be ensured.

[0027] (2) Stability

[0028] The section temperature T4 in the drying furnace needs to meet the requirements of the frame heating curve, and the temperature fluctuation deviation is within the process tolerance range;

[0029] The incinerator combustion temperature must be stable to ensure that VOCs are completely burned and no toxic substances are released;

[0030] The stability of the temperature of the inlet and outlet air curtains (i.e. the actual temperature T3 of the new air heated by the inlet air heat exchanger mentioned below) is the guarantee for meeting the production process requirements.

[0031] (3) Energy saving

[0032] Reduce natural gas consumption while ensuring safety and stability.

[0033] In order to meet the above control requirements, an embodiment of the present application provides a new control solution for an automobile paint drying system.

[0034] Before introducing the control method provided in the embodiment of the present application, the automobile paint drying system involved in the method provided in the embodiment of the present application is introduced. Figure 1 As shown, the automobile paint drying system includes: an incinerator 11, a drying furnace 12 and a heating pipe 13 connected to the smoke outlet 110 of the incinerator 11; the heating pipe 13 is used to provide heat for the drying furnace 12; the exhaust port 120 of the drying furnace 12 is connected to the first air inlet 111 of the incinerator 11 through an exhaust pipe 121 and an exhaust fan 122; a second air inlet 125 is provided at the automobile frame inlet 123 and the automobile frame outlet 124 of the drying furnace 12; the second air inlet 125 is correspondingly provided with an air inlet fan 126, which is used to form a wind curtain to isolate the air inside and outside the drying furnace 12 and to provide new air into the drying furnace 12.

[0035] In actual applications, the wet paint on the car frame will volatilize volatile organic compounds (VOC) during the drying process in the drying furnace. In order to reduce the air pollution caused by these volatile organic compounds, the exhaust gas discharged from the drying furnace can be introduced into the incinerator as a combustion-supporting gas during the production process of the drying furnace to decompose the VOC.

[0036] Wind curtains are formed at the automobile frame inlet and the automobile frame outlet of the drying furnace to isolate the air inside and outside the drying furnace. This not only isolates the flow of air inside and outside the drying furnace, plays a role in heat insulation and preventing leakage of toxic gases in the furnace, but also provides new air for the drying furnace.

[0037] In the actual production process, workshop staff need to perform inspections and maintenance near the car frame entrance and exit of the drying furnace. In order to further ensure the safety of workshop staff, it is necessary to ensure that the drying furnace is maintained at a slightly negative pressure state. In this way, the toxic gas in the drying furnace will not leak through the car frame entrance or exit because the air pressure inside the furnace is lower than the air pressure outside the furnace.

[0038] In actual application, the structure of the drying furnace at the inlet and outlet of the automobile frame can be designed so that all the new air forming the air curtain can enter the drying furnace.

[0039] Figure 2The flowchart of the control method of the automobile coating drying system provided in the embodiment of the present application is shown. Figure 2 As shown, the method includes:

[0040] 201. Obtain the actual residual oxygen content of the flue gas discharged by the incinerator.

[0041] 202. According to the actual residual oxygen content, adjust the air volume of the exhaust fan to maintain the actual residual oxygen content of the flue gas discharged from the incinerator at a desired residual oxygen state.

[0042] 203. Obtain the actual air pressure in the drying furnace.

[0043] 204. According to the adjusted air volume of the exhaust fan and the actual air pressure, adjust the air volume of the air inlet fan to maintain the actual air pressure in the drying furnace at a desired negative pressure state.

[0044] In the above 201, the actual residual oxygen content of the flue gas discharged by the incinerator can be obtained by detecting the residual oxygen detection unit. Figure 1 As shown, the residual oxygen detection unit can be set at the smoke outlet 110 of the incinerator or at any position in the heating pipeline 13, for example: at the smoke outlet 130 of the heating pipeline 13.

[0045] In one example, the residual oxygen detection unit is used to detect the residual oxygen content of the flue gas discharged from the flue gas outlet of the heating pipeline. The residual oxygen content of the flue gas discharged from the flue gas outlet of the heating pipeline is also the residual oxygen content of the flue gas discharged from the incinerator.

[0046] In the above 202, the essence of achieving energy saving through the air volume loop is to control the external air volume of the incinerator, and then the combustion controller corresponding to the incinerator controls the combustion temperature of the incinerator and the amount of natural gas used. In other words, as long as the external air volume can be changed in time according to the working conditions, the amount of natural gas used will reach a stable energy-saving state at the fastest speed.

[0047] Note: The combustion controller corresponding to the incinerator will adjust the amount of natural gas used according to the combustion temperature of the incinerator to maintain the combustion temperature of the incinerator at the desired combustion temperature state, for example: above 720 degrees Celsius. The combustion temperature of the incinerator is related to the amount of natural gas used and the air volume entering the air inlet of the incinerator.

[0048] Figure 3 The combustion efficiency curve diagram is shown, which shows the relationship between combustion efficiency and air-fuel ratio. Figure 3 As shown in the figure, under different air / fuel ratio conditions, the combustion efficiency of the combustion material is quite different:

[0049] When the air-fuel ratio is small, that is, there is less air and more gas, the combustibles cannot be completely burned and the heat cannot be completely released;

[0050] On the contrary, when the air-fuel ratio is relatively large, that is, there is more air and less gas, the combustibles will be completely burned, but the released heat will mainly act in heating the air, and most of the heat will be consumed in the exhaust.

[0051] In different industrial production processes, the combustion efficiency is directly related to the gas composition, and it is impossible to give a unified air-fuel ratio value, but generally the exhaust gas after combustion is characterized by a low oxygen state.

[0052] According to thermal engineering analysis, during the production process of the drying furnace, if the exhaust gas of the incinerator is monitored for residual oxygen to ensure that it is always maintained in a low-oxygen state, it can theoretically maintain a higher combustion efficiency state. The specific expected residual oxygen value can be obtained through on-site combustion test analysis of the incinerator.

[0053] Combined with the principles of thermal energy engineering, the calorific value of natural gas in the incinerator is relatively stable, and the main factor affecting its combustion efficiency is the supply of combustion air (that is, the air volume of the exhaust fan 122).

[0054] like Figure 1 As shown, by adding a residual oxygen detection unit, it can be determined whether the incinerator is maintaining a good combustion efficiency state.

[0055] According to the actual residual oxygen content of the flue gas discharged by the incinerator, the adjusted air volume of the exhaust fan can be determined; the air volume of the exhaust fan is adjusted to the adjusted air volume of the exhaust fan. The air volume of the fan can be adjusted in one of the following three ways: adjusting the fan speed (that is, adjusting the fan frequency), adjusting the inlet and outlet valves of the fan, and adjusting the blade angle. The above adjustment process can be implemented by selecting a suitable control algorithm according to actual needs, and this application does not make specific limitations on this.

[0056] In the above 203 and 204, since the combustion air of the incinerator comes from the air in the drying furnace, it is constrained by the safety air pressure in the drying furnace. After the air volume of the exhaust fan is adjusted, the air volume of the air inlet fan needs to be adjusted to ensure that the air pressure in the drying furnace meets the production requirements. Generally, a negative pressure state refers to a gas pressure state lower than normal pressure (also known as one atmospheric pressure). Among them, under the desired negative pressure state, the actual air pressure in the drying furnace is less than the actual air pressure outside the drying furnace. Among them, the actual air pressure outside the drying furnace can be detected by setting an air pressure detection unit.

[0057] Specifically, the above step 204 may include: determining the pressure difference (P1-P2) between the actual air pressure P1 inside the drying oven and the actual air pressure P2 outside the drying oven; and adjusting the air volume of the air inlet fan according to the adjusted air volume of the exhaust fan and the pressure difference, so as to maintain the actual air pressure inside the drying oven in a desired negative pressure state. In the desired negative pressure state, the pressure difference is a negative value.

[0058] In one example, an air pressure detection unit may be provided in the drying furnace to detect the actual air pressure in the drying furnace.

[0059] Specifically, the adjusted air volume of the inlet fan is determined according to the adjusted air volume of the exhaust fan and the actual air pressure; and the air volume of the inlet fan is adjusted to the adjusted air volume of the inlet fan.

[0060] The above adjustment process can be implemented by selecting a suitable control algorithm according to actual needs, and the embodiments of the present application do not specifically limit this. In a specific example, an advanced process control (APC) algorithm can be used to implement it. The APC algorithm supports multivariable control and can effectively shorten the system stabilization time, thereby achieving energy saving.

[0061] The drying furnace is heated by burning natural gas in the incinerator. The higher the combustion efficiency of the natural gas in the incinerator, the more energy-efficient the entire system is. In the technical solution provided in the embodiment of the present application, the combustion efficiency of the natural gas in the incinerator is obtained by detecting the residual oxygen content of the flue gas discharged from the incinerator, and the air volume of the exhaust fan corresponding to the drying furnace is adjusted according to the detected actual residual oxygen content of the flue gas discharged from the incinerator, so as to maintain the actual residual oxygen content of the flue gas discharged from the incinerator at the desired residual oxygen state, that is, to maintain the combustion efficiency of the natural gas in the incinerator at the desired combustion state. In addition, after adjusting the air volume of the exhaust fan of the incinerator, it is also necessary to consider the air pressure in the drying furnace and the air volume of the air inlet fan of the drying furnace, so that the actual air pressure in the drying furnace is maintained at the desired negative pressure state, thereby ensuring production safety and stability. It can be seen that the technical solution provided in the embodiment of the present application can not only reduce energy consumption, but also increase production safety and production stability.

[0062] In addition, if Figure 1 As shown, a preheating heat exchanger 112 may also be provided in the incinerator 11, and the preheating heat exchanger 112 uses the flue gas generated by the incineration to preheat the combustion-supporting gas entering from the first air inlet 111 of the incinerator 11. The flue gas generated by the combustion in the incinerator 12 is collected into the flue gas outlet 110 of the incinerator through the flue gas main pipe or the flue gas branch pipe of the preheating heat exchanger 112, and then enters the heating pipeline 13. A third flue gas flow regulating valve 113, such as a damper, is provided on the flue gas main pipe, which is used to adjust the proportion of the flue gas generated by the combustion in the incinerator discharged through the flue gas main pipe and the flue gas branch pipe.

[0063] The air volume of the main flue gas pipe is determined by the third flue gas flow regulating valve 113. If the third flue gas flow regulating valve 113 is opened relatively wide, it means that the amount of flue gas entering the preheating heat exchanger 112 is small, the heat absorbed by the heat exchange is small, and the flue gas outlet temperature T1 at the flue gas outlet of the incinerator 11 is high; on the contrary, if the third flue gas flow regulating valve 113 is opened relatively small, the amount of flue gas entering the preheating heat exchanger 112 is large, the heat absorbed by the heat exchange is large, and the flue gas outlet temperature T1 at the flue gas outlet of the incinerator 11 is low. However, since the preheating heat exchanger has a limited heat exchange efficiency, the flue gas outlet temperature T1 has a minimum limit. Usually, the incinerator also corresponds to an outlet temperature controller to ensure that the actual flue gas outlet temperature at the flue gas outlet of the incinerator is maintained at the desired flue gas outlet temperature state, for example: 400-500 degrees Celsius. In general, the outlet temperature controller of the incinerator is bound to the relationship between the flue gas outlet temperature T1 and the third flue gas flow regulating valve 113. When the desired flue gas outlet temperature state is set, the outlet temperature controller will automatically trigger the adjustment of the third flue gas flow regulating valve 113. Specifically, the outlet temperature controller adjusts the opening of the third flue gas flow regulating valve 113 according to the actual flue gas outlet temperature T1 at the flue gas outlet of the incinerator 11, so as to maintain the actual flue gas outlet temperature T1 at the flue gas outlet of the incinerator 11 at the desired flue gas outlet temperature state.

[0064] It should be noted that the combustion controller and outlet temperature control are built-in controllers of the incinerator. Since the incinerator is a high-risk device, in order to ensure production safety, the control logic of its built-in controller is generally fixed and unchanged, and modification is not allowed. Therefore, in this embodiment, the original combustion controller and outlet temperature controller in the incinerator are not changed during the transformation and implementation process. The safety constraints of the controllers corresponding to the incinerator are all factory settings and follow the factory maintenance rules, so it will not affect the safety of the incinerator itself.

[0065] like Figure 1 As shown, the two second air inlets 125 of the drying furnace 12 are arranged at the automobile frame inlet 123 and the automobile frame outlet 124. The second air inlet 125 is used to inject new air into the furnace, so the air pressure near it must be the highest air pressure in the furnace. Therefore, it is only necessary to ensure that the air pressure near the automobile frame inlet 123 and the automobile frame outlet 124 in the furnace meets the production requirements. Specifically, Figure 1 As shown, the drying furnace 12 is provided with a drying passage 127 between the automobile frame inlet 123 and the automobile frame outlet 124; air pressure detection units 128 are provided at positions close to the automobile frame inlet 123 and close to the automobile frame outlet 124 in the drying passage 127; the air pressure detection unit 128 is used to detect the actual air pressure in the drying furnace 12.

[0066] It should be noted that, generally speaking, Figure 1 As shown, the exhaust port 120 of the drying oven 12 is arranged between the two second air inlets 125, for example, at the middle position between the two. The exhaust port exhausts air, so the air pressure at the exhaust port in the drying oven can be considered as the lowest air pressure in the oven.

[0067] In the actual production process, there are many changes in the on-site production of the drying furnace. Through analysis, it is found that the drying furnace has the following production modes (or production states): full load (that is, full furnace), half load (that is, half furnace) and no load (that is, empty furnace). Regardless of whether the drying furnace is maintained at full load, half load, or no load, it automatically operates under full load conditions. Taking no load as an example, when the drying furnace is maintained at no load, there is no frame in the drying furnace that needs to take away heat, that is, the drying furnace has no heat exchange demand, then the air heated by the burner will be directly discharged to the outside, causing energy waste.

[0068] In order to avoid energy waste when the drying furnace is maintained in a non-full load state, the air volume discharged from the drying furnace can be reduced when the drying furnace is maintained in a non-full load state, that is, the air that needs to be heated by the incinerator is reduced. After the air that needs to be heated by the incinerator is reduced, the combustion controller corresponding to the incinerator will reduce the amount of natural gas used accordingly. Specifically, the above method may also include:

[0069] 205. When the current working mode of the drying furnace is no-load, determine the next working mode of the drying furnace according to the first vehicle frame sequence entering the drying furnace within a future preset time period.

[0070] 206. When the current air volume of the exhaust fan is not suitable for the next working mode, adjust the air volume of the exhaust fan to a target air volume suitable for the next working mode.

[0071] In the above 205, the current working mode of the drying oven can be determined once every preset time interval. The size of the preset time interval can be set according to actual needs, and the embodiment of the present application does not make any specific limitation on this.

[0072] When the current working mode of the drying furnace is no-load, this solution will make rough adjustments based on the working mode, which can save energy and will not affect production quality; when the current working mode of the drying furnace is full load or half load, this solution will not make rough adjustments to avoid affecting production quality.

[0073] When the current working mode of the drying furnace is no-load, the next working mode of the drying furnace is determined according to the number of frames involved in the first frame sequence entering the drying furnace within a preset time period in the future. Specifically, when the number of frames involved in the first frame sequence entering the drying furnace within a preset time period in the future is zero, the next working mode of the drying furnace is determined to be no-load; when the number of frames involved in the first frame sequence entering the drying furnace within a preset time period in the future is greater than zero and less than a preset full load number, the next working mode of the drying furnace is determined to be half load; when the number of frames involved in the first frame sequence entering the drying furnace within a preset time period in the future is a preset full load number, the next working mode of the drying furnace is determined to be full load.

[0074] In the above 206, when the current air volume of the exhaust fan is not suitable for the next working mode, the air volume of the exhaust fan is adjusted to a target air volume suitable for the next working mode. The target air volume of the exhaust fan suitable for different working modes is different.

[0075] In this embodiment, the air volume of the exhaust fan is roughly adjusted in advance before the next working mode arrives to adapt to the next working mode that is about to come. During the rough adjustment, since the system needs a certain period of time to stabilize, in order to ensure the production quality, the system needs to stabilize before the next working mode arrives. Specifically, the preset time interval and the size of the future preset time period can be reasonably designed according to the system stabilization time. In this way, not only can energy be saved, but also production quality can be guaranteed. In one example, the preset time interval can be 1 minute, and the future preset time period can be 30 minutes.

[0076] In practical applications, the above method may further include:

[0077] 207. Determine, at every preset time interval, a first frame sequence entering the drying oven within the future preset time period and a second frame sequence currently in the drying oven.

[0078] 208. Determine a current working mode of the drying oven according to a current second frame sequence in the drying oven.

[0079] In the above 207, the process of setting the specific values ​​of the above preset time interval and the future preset time period can refer to the above corresponding content, which will not be repeated here.

[0080] In one example, the production plan, production line structure and mechanical transportation information of the automobile coating production line can be obtained; according to the production plan, production line structure and mechanical transportation information of the automobile coating production line, the first frame sequence entering the drying furnace in the future preset time period and the second frame sequence currently in the drying furnace are predicted. Among them, the first frame sequence can be called the pre-furnace sequence; the second frame sequence can be called the in-furnace sequence. In a specific example, a frame sequence prediction model can be trained in advance based on the historical data of the production plan, production line structure and mechanical transportation information of the automobile coating production line. In this way, the real-time production plan, production line structure and mechanical transportation information of the automobile coating production line can then be input into the trained frame sequence prediction model, so that the frame sequence prediction model can predict the first frame sequence entering the drying furnace in the future preset time period and the second frame sequence currently in the drying furnace. In one example, the frame sequence prediction model can also predict the third frame sequence (which can be called the post-furnace sequence) output by the drying furnace. Among them, the third frame sequence can be used to verify the accuracy of the previously predicted pre-furnace sequence and in-furnace sequence.

[0081] In one example, the above method may further include the following steps:

[0082] When the current temperature control parameters of the automobile coating and drying system are not suitable for the next working mode, the temperature control parameters of the automobile coating and drying system are adjusted to target temperature control parameters suitable for the next working mode.

[0083] Energy saving is achieved by adjusting the temperature control parameters, which may include the flue gas outlet temperature at the flue gas outlet of the incinerator, the desired temperature state corresponding to the heating box described below, the desired temperature state corresponding to the air inlet heat exchanger, and the like.

[0084] In one example, if Figure 1 As shown, the drying channel 127 in the drying furnace 12 between the automobile frame inlet 123 and the automobile frame outlet 124 is divided into a plurality of drying sections; each drying section corresponds to a heating box 14 and a first flue gas flow regulating valve 15; the heating box 14 is connected to the heating pipe 13 through the first flue gas flow regulating valve 15, so as to utilize the flue gas provided by the heating pipe 13 to heat the air in the corresponding drying section. The heating box 14 may specifically include a heat exchanger, which transfers the heat of the flue gas in the heating pipe 13 to the air in the corresponding drying section through heat exchange. The specific structure and specific heat exchange principle of the heat exchanger can be found in the prior art and will not be described in detail here. The first flue gas flow regulating valve 15 may specifically include: a proportional valve. The above method may also include:

[0085] 209. Obtain the actual temperature of the air after being heated by the heating box.

[0086] 210. According to the actual temperature of the air after being heated by the heating box, adjust the first flue gas flow regulating valve to maintain the actual temperature of the air after being heated by the heating box at the desired temperature state corresponding to the current state of the heating box.

[0087] In actual application, the multiple drying sections include: the first heating section, the second heating section, the third insulation section and the fourth insulation section arranged in sequence. The first heating section is close to the entrance of the automobile frame. During the heat exchange process of the heating pipeline, it is necessary to ensure that the air temperature after being heated by the heater corresponding to each drying section meets the process requirements, so as to ensure that the frame meets the temperature rise curve in the drying furnace and ensure product quality.

[0088] In the above 210, specifically, the adjusted opening of the first flue gas flow regulating valve can be determined according to the actual temperature of the air after heating by the heating box; and the opening of the first flue gas flow regulating valve can be adjusted to the adjusted opening.

[0089] The above adjustment process can be implemented by selecting a suitable control algorithm according to actual needs, and the embodiments of the present application do not make any specific limitations on this.

[0090] In order to reduce energy waste, the above method may further include:

[0091] 211. When the expected temperature state currently corresponding to the heating box is not suitable for the next working mode, modify the expected temperature state currently corresponding to the heating box to a target expected temperature state suitable for the next working mode.

[0092] The target desired temperature states of the heating box adapted to different working modes are different.

[0093] For example: when fully loaded, the desired temperature state of the heating box corresponding to the first heating section is about 110 degrees Celsius; the desired temperature state of the heating box corresponding to the second heating section is about 150 degrees Celsius; the desired temperature state of the heating box corresponding to the first insulation section and the desired temperature state of the heating box corresponding to the second insulation section are both about 155 degrees Celsius. When unloaded, the desired temperature states corresponding to the first heating section, the second heating section, the first insulation section and the second insulation section can be reduced to about 110 degrees Celsius. It should be noted that the temperature values ​​involved here are only exemplary and do not represent actual production conditions.

[0094] In one example, the automobile paint drying system further includes: an air inlet heat exchanger 16; the air inlet heat exchanger 16 is disposed at the smoke outlet end of the heating pipe 13, so as to utilize the smoke discharged from the smoke outlet 102 of the heating pipe to heat the new air entering the drying furnace 12; the air inlet heat exchanger 16 includes a smoke main pipe and a smoke branch pipe; a second smoke flow regulating valve 161 is disposed on the smoke main pipe, which is used to adjust the ratio of the smoke discharged from the smoke outlet of the heating pipe 13 through the smoke main pipe and the smoke branch pipe. Among them, the specific structure of the air inlet heat exchanger 16 can be designed according to actual needs, and the embodiment of the present application does not specifically limit this. The above method may also include:

[0095] 212. Obtain the actual temperature of the new air heated by the inlet air heat exchanger.

[0096] 213. According to the actual temperature of the new air heated by the inlet heat exchanger, adjust the second flue gas flow regulating valve to maintain the actual temperature of the new air heated by the inlet heat exchanger at the desired temperature state currently corresponding to the inlet heat exchanger.

[0097] In the above 213, a suitable control algorithm may be selected according to actual needs to implement the adjustment.

[0098] In one example, the first flue gas flow regulating valve and the second flue gas flow regulating valve can be adjusted according to the actual temperature of the air heated by the heating box and the actual temperature of the new air heated by the inlet heat exchanger using an advanced process control algorithm to maintain the actual temperature of the air heated by the heating box at the desired temperature state currently corresponding to the heating box and the actual temperature of the new air heated by the inlet heat exchanger at the desired temperature state currently corresponding to the inlet heat exchanger.

[0099] In another example, it was found through research that the smoke outlet temperature at the smoke outlet of the incinerator will also affect the temperature of the air heated by the heating box and the temperature of the new air heated by the inlet heat exchanger. Therefore, when adjusting the flow control valve, the smoke outlet temperature at the smoke outlet of the incinerator can be taken into account, which can improve the adjustment efficiency and thus achieve energy saving. Specifically, the actual smoke outlet temperature at the smoke outlet of the incinerator can be obtained; according to the actual smoke outlet temperature, the actual temperature of the air heated by the heating box and the actual temperature of the new air heated by the inlet heat exchanger, the first smoke flow control valve and the second smoke flow control valve are adjusted using an advanced process control algorithm to maintain the actual temperature of the air heated by the heating box at the desired temperature state currently corresponding to the heating box and the actual temperature of the new air heated by the inlet heat exchanger at the desired temperature state currently corresponding to the inlet heat exchanger.

[0100] The above method may further include:

[0101] 214. When the expected temperature state currently corresponding to the air inlet heat exchanger is not suitable for the next working mode, modify the expected temperature state currently corresponding to the air inlet heat exchanger to a target expected temperature state suitable for the next working mode.

[0102] The target desired temperature state of the air inlet heat exchanger adapted to different working modes is different.

[0103] In the above embodiments, the target air volume of the exhaust fan adapted to the next working mode, the target desired temperature state of the heating box adapted to the next working mode, and the target desired temperature state of the air inlet heat exchanger adapted to the next working mode can be obtained based on experience or learned through a machine learning algorithm. In one example, a parameter prediction model can be trained based on historical production data. Subsequently, the next working mode and the corresponding drying system state data can be input into the parameter prediction model to predict the parameters by the parameter prediction model, for example: the target air volume of the exhaust fan adapted to the next working mode, the target desired temperature state of the heating box adapted to the next working mode, and the target desired temperature state of the air inlet heat exchanger adapted to the next working mode. Among them, the drying system state data may include: the actual air volume of the exhaust fan, the actual air volume of the air inlet fan, the actual temperature of the air heated by the heating box, the actual temperature of the new air heated by the air inlet heat exchanger, the flue gas outlet temperature at the flue gas outlet of the incinerator, and so on.

[0104] In addition, when the current working mode of the drying furnace is shutdown and not started, the next working mode of the drying furnace can also be predicted according to the same method as the above embodiment; if the next working mode is half load or full load, the drying system is started with parameters adapted to the next working mode.

[0105] The shutdown of the drying system is generally controlled manually, and the startup of the drying system can be automatically controlled according to this solution. According to the above method, better startup parameters can be matched to ensure that the drying furnace enters the production state as quickly as possible and adapts to the next upcoming production mode.

[0106] The following will be combined Figure 1 and Figure 4 The technical solution provided in the embodiments of the present application is described in detail:

[0107] like Figure 4 As shown, the energy-saving approach of the drying system can be developed from the air volume circuit and the temperature circuit respectively.

[0108] Air volume circuit:

[0109] The air volume controller 403 determines the adjusted air volume of the exhaust fan 122 according to the actual residual oxygen content in the flue gas discharged from the incinerator 11.

[0110] The negative pressure controller 404 determines the adjusted air volume of the air inlet fan 126 according to the actual air pressure in the drying oven and the adjusted air volume of the exhaust fan. The air inlet fan 126 is adjusted according to the adjusted air volume.

[0111] Temperature loop:

[0112] The outlet temperature controller 401 determines the adjusted opening of the third flue gas flow regulating valve 113 according to the actual flue gas outlet temperature T1 at the flue gas outlet of the incinerator 11 and the actual temperature T2 (also referred to as the tail gas exhaust temperature T2) of the flue gas discharged from the air inlet heat exchanger 16. The third flue gas flow regulating valve 113 is adjusted according to the adjusted opening.

[0113] The first temperature controller 402 determines the adjusted openings of the first smoke flow regulating valve 15 and the second smoke flow regulating valve 161 by using an advanced process control algorithm according to the actual temperature T4 of the air heated by each heating box of the drying furnace 12, the actual temperature T3 of the new air heated by the air inlet heat exchanger, and the actual smoke outlet temperature T1 at the smoke outlet of the incinerator 11. The first smoke flow regulating valve 15 and the second smoke flow regulating valve 161 are adjusted according to the corresponding adjusted openings.

[0114] Through independent step tests, the following mapping relationship table can be obtained:

[0115] Table 1:

[0116]

[0117] The drying channel includes four drying sections, which are arranged in sequence. The temperature of the air heated by the heating box corresponding to the first drying section is T4-1, which corresponds to heating valve 1, the temperature of the air heated by the heating box corresponding to the second drying section is T4-2, which corresponds to heating valve 2, the temperature of the air heated by the heating box corresponding to the third drying section is T4-3, which corresponds to heating valve 3, and the temperature of the air heated by the heating box corresponding to the fourth drying section is T4-4, which corresponds to heating valve 4. The "+" in the table represents a positive correlation, and the more "+" there are, the stronger the positive correlation is; "-" represents a negative correlation, and the more "-" there are, the stronger the negative correlation is.

[0118] The implementation path of multivariable control based on APC is: the temperature of the insulation box in a certain zone is low -> combined with the temperature of other zones and the incinerator -> intelligent selection and adjustment of the segmented proportional valve or air supply damper -> rapid and stable realization of edge control, thereby achieving energy saving.

[0119] After determining the above mapping relationship, a response model between valves and temperature is constructed. In the APC mode, each valve can be dynamically adjusted following the change of the temperature set value. The temperature control has obvious improvement before and after switching between APC and the existing PID (Proportional Integral Derivative), which can prove the superiority of the APC controller over the PID controller.

[0120] In summary, the overall intelligent control architecture of the drying furnace is designed based on advanced process control, and combined with the design of temperature and air volume loops, it is possible to control the complex coupling relationship model inside the drying furnace; the data link based on large industrial products can support the implementation of various algorithms and the construction of models, quickly reach the target value and run more stably.

[0121] Figure 5 FIG. 1 is a schematic diagram showing the structure of an electronic device provided by an embodiment of the present application. Figure 5 As shown, the electronic device includes a memory 1101 and a processor 1102. The memory 1101 can be configured to store various other data to support operations on the electronic device. Examples of these data include instructions for any application or method for operating on the electronic device. The memory 1101 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read only memory (EEPROM), an erasable programmable read only memory (EPROM), a programmable read only memory (PROM), a read only memory (ROM), a magnetic memory, a flash memory, a magnetic disk or an optical disk.

[0122] The memory 1101 is used to store programs;

[0123] The processor 1102 is coupled to the memory 1101 and is used to execute the program stored in the memory 1101 to implement the control methods provided by the above-mentioned method embodiments.

[0124] Further, if Figure 5 As shown, the electronic device also includes: a communication component 1103, a display 1104, a power component 1105, an audio component 1106 and other components. Figure 5Only some components are shown schematically, which does not mean that the electronic device only includes Figure 5 Components shown.

[0125] Accordingly, an embodiment of the present application further provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a computer, the steps or functions of the control method provided by the above-mentioned method embodiments can be implemented.

[0126] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0127] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM (Read Only Memory) / RAM (Random Access Memory), a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A control method for an automobile coating and drying system, characterized in that: The automobile coating drying system comprises: an incinerator, a drying furnace and a heating pipe connected to the smoke outlet of the incinerator; the heating pipe is used to supply heat to the drying furnace; the exhaust port of the drying furnace is connected to the first air inlet of the incinerator through the exhaust pipe and the exhaust fan; the automobile frame inlet and automobile frame outlet of the drying furnace are both provided with a second air inlet; the second air inlet is correspondingly provided with an air inlet fan, which is used to form an air curtain to isolate the air inside and outside the drying furnace and to provide new air into the drying furnace; the method comprises: Obtaining the actual residual oxygen content of the flue gas discharged from the incinerator; According to the actual residual oxygen content, adjusting the air volume of the exhaust fan to maintain the actual residual oxygen content of the flue gas discharged from the incinerator at a desired residual oxygen state; Obtaining the actual air pressure in the drying furnace; The air volume of the air inlet fan is adjusted according to the adjusted air volume of the exhaust fan and the actual air pressure, so as to maintain the actual air pressure in the drying oven at a desired negative pressure state.

2. The method according to claim 1, characterized in that Also includes: Residual oxygen detection unit; The residual oxygen detection unit is used to detect the residual oxygen content of the smoke discharged from the smoke outlet of the heating pipeline.

3. The method according to claim 1, characterized in that The drying furnace is provided with a drying passage between the automobile frame inlet and the automobile frame outlet; An air pressure detection unit is provided at a position close to the entrance of the automobile frame and a position close to the exit of the automobile frame in the drying channel; The air pressure detection unit is used to detect the actual air pressure in the drying oven.

4. The method according to any one of claims 1 to 3, characterized in that Also includes: When the current working mode of the drying furnace is no-load, determining the next working mode of the drying furnace according to the first frame sequence entering the drying furnace within a preset time period in the future; When the current air volume of the exhaust fan is not suitable for the next working mode, the air volume of the exhaust fan is adjusted to a target air volume suitable for the next working mode.

5. The method according to claim 4, characterized in that Also includes: At every preset time interval, determining a first frame sequence entering the drying oven within the future preset time period and a second frame sequence currently in the drying oven; The current working mode of the drying oven is determined according to the current second frame sequence in the drying oven.

6. The method according to claim 4, characterized in that The drying passage between the automobile frame inlet and the automobile frame outlet in the drying furnace is divided into a plurality of drying sections; each drying section corresponds to a heating box and a first flue gas flow regulating valve; the heating box is connected to the heating pipe through the first flue gas flow regulating valve, so as to heat the air in the corresponding drying section by using the flue gas provided by the heating pipe; The method further comprises: Obtaining the actual temperature of the air heated by the heating box; According to the actual temperature of the air heated by the heating box, the first flue gas flow regulating valve is adjusted to maintain the actual temperature of the air heated by the heating box at the desired temperature state currently corresponding to the heating box.

7. The method according to claim 6, characterized in that Also includes: When the desired temperature state currently corresponding to the heating box is not suitable for the next working mode, the desired temperature state currently corresponding to the heating box is modified to a target desired temperature state suitable for the next working mode.

8. The method according to claim 6, characterized in that The automobile coating drying system further includes: an air inlet heat exchanger; the air inlet heat exchanger is arranged at the smoke outlet end of the heating pipeline to heat the new air entering the drying furnace by using the smoke discharged from the smoke outlet of the heating pipeline; the air inlet heat exchanger includes a smoke main pipe and a smoke branch pipe; the smoke main pipe is provided with a second smoke flow regulating valve for adjusting the proportion of the smoke discharged from the smoke outlet of the heating pipeline through the smoke main pipe and the smoke branch pipe; the method further includes: Obtaining the actual temperature of the new air heated by the air inlet heat exchanger; According to the actual temperature of the air heated by the heating box, adjusting the first flue gas flow regulating valve to maintain the actual temperature of the air heated by the heating box at the desired temperature state corresponding to the current state of the heating box, including: According to the actual temperature of the air heated by the heating box and the actual temperature of the new air heated by the inlet heat exchanger, the first flue gas flow regulating valve and the second flue gas flow regulating valve are adjusted using an advanced process control algorithm to maintain the actual temperature of the air heated by the heating box at the desired temperature state currently corresponding to the heating box and the actual temperature of the new air heated by the inlet heat exchanger at the desired temperature state currently corresponding to the inlet heat exchanger.

9. The method according to claim 8, characterized in that Also includes: When the desired temperature state currently corresponding to the inlet heat exchanger is not suitable for the next working mode, the desired temperature state currently corresponding to the inlet heat exchanger is modified to a target desired temperature state suitable for the next working mode.

10. The method according to claim 8, characterized in that According to the actual temperature of the air heated by the heating box and the actual temperature of the new air heated by the inlet heat exchanger, the first flue gas flow regulating valve and the second flue gas flow regulating valve are adjusted by using an advanced process control algorithm to maintain the actual temperature of the air heated by the heating box at the desired temperature state currently corresponding to the heating box and the actual temperature of the new air heated by the inlet heat exchanger at the desired temperature state currently corresponding to the inlet heat exchanger, including: Obtaining the actual flue gas outlet temperature at the flue gas outlet of the incinerator; According to the actual flue gas outlet temperature, the actual temperature of the air heated by the heating box and the actual temperature of the new air heated by the inlet heat exchanger, the first flue gas flow regulating valve and the second flue gas flow regulating valve are adjusted using an advanced process control algorithm to maintain the actual temperature of the air heated by the heating box at the desired temperature state currently corresponding to the heating box and the actual temperature of the new air heated by the inlet heat exchanger at the desired temperature state currently corresponding to the inlet heat exchanger.

11. An electronic device, characterized in that: include: A memory and a processor, wherein The memory is used to store programs; The processor is coupled to the memory, and is used to execute the program stored in the memory to implement the control method according to any one of claims 1 to 10.

12. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a computer, the control method according to any one of claims 1 to 10 can be implemented.

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