A paint spraying room circulating air temperature and humidity high-precision control system and control method

Abstract

The application discloses a kind of paint spraying room circulating air temperature and humidity high-precision control system and control method, comprising: paint spraying room, circulating air duct, fresh air unit, cold and hot adjusting mechanism, humidification and dehumidification mechanism, multiple measuring point temperature and humidity sensor and intelligent controller, using circulating air as main, fresh air auxiliary air supply mode and temperature and humidity decoupling, feed-back compound control strategy, circulating air proportion, cold and hot output and humidification and dehumidification intensity are adjusted in cooperation, effectively inhibit temperature and humidity coupling and external disturbance, realize high-precision stable control.The control precision of the present application can reach temperature ±1 ℃, humidity ±3% RH, circulating air utilization rate is high, energy saving is remarkable, environment is stable and uniform, greatly improve spraying quality and production stability, suitable for various industrial paint spraying room circulating air conditioning system.

Description

Technical Field

[0001] This invention relates to the field of industrial coating environment control technology, specifically to a high-precision control system and control method for the temperature and humidity of the circulating air in a spray booth. Background Technology

[0002] Spray booths require extremely high precision and stability in temperature and humidity control. Conventional control methods often employ 100% fresh air conditioning, single PID regulation, and independent control of heating, cooling, and humidification / dehumidification, which have the following drawbacks: First, strong coupling between temperature and humidity leads to large disturbances, significant control lag, and a tendency for overshoot and fluctuations, making it difficult to meet the high-precision process requirements of ±1℃ temperature and ±3% RH humidity. Second, low utilization of recirculated air and a high proportion of fresh air result in high energy consumption and operating costs. Third, the lack of coordinated optimization among multiple actuators leads to slow adjustment response and poor steady-state accuracy, easily causing defects such as paint film sagging, orange peel, and pinholes, affecting coating quality and yield. Existing technologies lack an integrated decoupling and high-precision coordinated control strategy for recirculated air, fresh air, heating, cooling, humidification, and dehumidification, making it impossible to quickly stabilize process environment parameters under strong disturbances. Summary of the Invention

[0003] The purpose of this invention is to propose a high-precision control system and method for the temperature and humidity of the circulating air in a spray booth to solve the problems mentioned in the background art.

[0004] To achieve the above-mentioned objectives, the first technical solution adopted by the present invention is: a high-precision control system for the temperature and humidity of the circulating air in a spray booth, comprising: a spray booth, a circulating air duct, a fresh air inlet, an air supply unit, a surface cooler, a heater, a humidifier, a dehumidifier, a temperature and humidity sensor group, an intelligent controller, and an exhaust unit; One end of the circulating air duct is connected to the return air vent of the paint spraying chamber, and the other end is connected to the inlet of the air supply unit. The fresh air inlet is connected to the inlet of the air supply unit via a fresh air regulating valve, where it mixes with the airflow in the circulating air duct. The outlet of the air supply unit is connected in sequence to a surface cooler, a heater, a humidifier, and a dehumidifier before being connected to the air outlet of the paint spray booth. The temperature and humidity sensor group is respectively arranged inside the paint spraying room, at the air supply outlet, the air return outlet and the fresh air inlet, and each sensor is electrically connected to the intelligent controller. The intelligent controller is connected to the air supply unit, surface cooler, heater, humidifier, dehumidifier, exhaust unit and fresh air regulating valve respectively; The exhaust unit is located on the upper part or side of the paint spraying booth and is connected to the intelligent controller. The intelligent controller uses a temperature and humidity decoupling algorithm and a feedforward-feedback composite adjustment strategy to coordinate the temperature and humidity of the recirculating air in the paint booth.

[0005] Furthermore, the control system adopts an air supply architecture that prioritizes recirculated air and supplements it with fresh air, with a recirculated air utilization rate of 70%–90%.

[0006] Furthermore, the temperature control accuracy of the control system is ±1℃, and the humidity control accuracy is ±3%RH.

[0007] Furthermore, the temperature and humidity sensor group includes at least 6 high-precision temperature and humidity sensors with a sampling frequency greater than or equal to 1Hz.

[0008] Furthermore, the air supply unit is equipped with a fresh air regulating valve for dynamically adjusting the fresh air mixing ratio, with the fresh air ratio being 10%–30%.

[0009] Furthermore, the surface cooler includes cooling and dehumidification functions, the heater is electric heating or hot water heating type, the humidifier is dry steam or high-pressure micro-mist humidification, and the dehumidifier is refrigeration dehumidification or adsorption dehumidification.

[0010] Furthermore, the exhaust unit is linked to the fresh air inlet for control, maintaining a slightly positive pressure state in the paint spraying chamber with a pressure difference of 5–15 Pa.

[0011] To achieve the aforementioned objectives, the second technical solution adopted by this invention is: a high-precision control method for the temperature and humidity of circulating air in a spray booth, applied in a high-precision control system for the temperature and humidity of circulating air in a spray booth, comprising the following steps: Temperature and humidity signal acquisition: The temperature and humidity signals of multiple points in the paint spraying room, air supply outlet, air return outlet and fresh air side are collected in real time through a group of temperature and humidity sensors and transmitted to the intelligent controller. Signal processing: The intelligent controller receives the collected signals, performs temperature and humidity decoupling calculations, and combines a feedforward-feedback composite adjustment strategy for dynamic optimization; Multi-mechanism coordinated adjustment: The intelligent controller synchronously outputs control commands to dynamically adjust the circulating air ratio, fresh air volume, surface cooler cooling capacity, heater heating capacity, humidifier humidification capacity, and dehumidifier dehumidification capacity; Steady-state maintenance: Temperature and humidity control is performed to maintain the temperature and humidity inside the spray booth within the process setting range of 22–26℃ and 60%–65%RH.

[0012] Furthermore, the temperature and humidity decoupling operation adopts a multivariable decoupling PID or model predictive control algorithm, and the feedforward compensation is calculated in advance by the fresh air temperature and humidity, door status, and workpiece signal.

[0013] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: By efficiently utilizing circulating air and decoupling temperature and humidity for high-precision control, the spray booth temperature control accuracy can be stably achieved at ±1℃ and humidity control accuracy at ±3%RH, with fast response, small overshoot, and stable steady-state operation. The proportion of circulating air is significantly increased, which significantly reduces energy consumption for heating, cooling, humidification, and dehumidification, resulting in outstanding energy-saving effects. The coordinated operation of multiple actuators reduces frequent start-stop and vibration, extending the service life of the equipment. The stable and uniform temperature and humidity environment effectively reduces the paint film defect rate, improves coating consistency and product qualification rate, and is suitable for continuous and stable operation of automated spraying production lines. It has strong versatility and high reliability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a high-precision control system for circulating air temperature and humidity in a paint spraying booth according to the present invention.

[0015] In the diagram, 1 is the paint spray booth; 2 is the circulating air duct; 3 is the fresh air inlet; 4 is the air supply unit; 5 is the surface cooler; 6 is the heater; 7 is the humidifier; 8 is the dehumidifier; 9 is the temperature and humidity sensor group; 10 is the intelligent controller; and 11 is the exhaust unit. Detailed Implementation

[0016] 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 with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0017] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or system that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or systems.

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] like Figure 1As shown, the present invention proposes a high-precision control system for the temperature and humidity of the circulating air in a spray booth, comprising: a spray booth 1, a circulating air duct 2, a fresh air inlet 3, an air supply unit 4, a surface cooler 5, a heater 6, a humidifier 7, a dehumidifier 8, a temperature and humidity sensor group 9, an intelligent controller 10, and an exhaust unit 11. One end of the circulating air duct 2 is connected to the return air vent of the paint spraying chamber 1, and the other end is connected to the inlet of the air supply unit 4. Fresh air inlet 3 is connected to the inlet of air supply unit 4 through fresh air regulating valve, and mixes with the airflow in circulating air duct 2; The outlet of the air supply unit 4 is connected in sequence to the surface cooler 5, heater 6, humidifier 7, dehumidifier 8, and then connected to the air outlet of the paint spraying chamber 1. Temperature and humidity sensor group 9 is respectively arranged in the paint spraying chamber 1, air supply outlet, air return outlet and fresh air inlet 3, and each sensor is electrically connected to the intelligent controller 10. The intelligent controller 10 is connected to the air supply unit 4, the surface cooler 5, the heater 6, the humidifier 7, the dehumidifier 8, the exhaust unit 11, and the fresh air regulating valve. The exhaust unit 11 is located on the upper part or side of the paint spraying chamber 1 and is connected to the intelligent controller 10 for control. The intelligent controller 10 uses a temperature and humidity decoupling algorithm and a feedforward-feedback composite regulation strategy to coordinate the temperature and humidity of the circulating air in the paint booth 1.

[0020] According to an embodiment of the present invention, the control system adopts an air supply architecture with circulating air as the main component and fresh air as the auxiliary component, and the utilization rate of circulating air is 70%–90%.

[0021] According to an embodiment of the present invention, the temperature control accuracy of the control system is ±1℃, and the humidity control accuracy is ±3%RH.

[0022] According to an embodiment of the present invention, the temperature and humidity sensor group 9 includes at least 6 high-precision temperature and humidity sensors with a sampling frequency greater than or equal to 1Hz.

[0023] According to an embodiment of the present invention, the air supply unit 4 is provided with a fresh air regulating valve for dynamically adjusting the fresh air mixing ratio, wherein the fresh air ratio is 10%–30%.

[0024] According to an embodiment of the present invention, the surface cooler 5 includes cooling and dehumidification functions, the heater 6 is electrically heated or hot water heated, the humidifier 7 is dry steam or high-pressure micro-mist humidification, and the dehumidifier 8 is refrigeration dehumidification or adsorption dehumidification.

[0025] According to an embodiment of the present invention, the exhaust unit 11 is linked with the fresh air inlet 3 to maintain a slightly positive pressure state in the paint spraying chamber 1, with a pressure difference of 5–15 Pa.

[0026] To achieve the aforementioned objectives, the second technical solution adopted by this invention is: a high-precision control method for the temperature and humidity of circulating air in a spray booth, applied in a high-precision control system for the temperature and humidity of circulating air in a spray booth, comprising the following steps: Temperature and humidity signal acquisition: The temperature and humidity signals of multiple points inside the paint spraying booth 1, the air supply outlet, the return air outlet and the fresh air side are collected in real time through the temperature and humidity sensor group 9 and transmitted to the intelligent controller 10. Signal processing: The intelligent controller 10 receives the acquired signals, performs temperature and humidity decoupling calculations, and combines a feedforward-feedback composite adjustment strategy for dynamic optimization; Multi-mechanism coordinated adjustment: The intelligent controller 10 synchronously outputs control commands to dynamically adjust the circulating air ratio, fresh air volume, cooling capacity of the surface cooler 5, heating capacity of the heater 6, humidification capacity of the humidifier 7, and dehumidification capacity of the dehumidifier 8; Steady-state maintenance: Temperature and humidity control is performed to maintain the temperature and humidity inside the spray booth 1 within the process setting range of 22–26℃ and 60%–65%RH.

[0027] According to an embodiment of the present invention, the temperature and humidity decoupling operation adopts a multivariable decoupling PID or model predictive control algorithm, and the feedforward compensation is calculated in advance by the fresh air temperature and humidity, door status, and workpiece signal.

[0028] Specifically, an air supply architecture with recirculated air as the main component and fresh air as the auxiliary component is adopted. Through real-time acquisition of temperature and humidity at multiple measurement points, temperature and humidity decoupling algorithms, feedforward-feedback composite regulation, and collaborative control of multiple actuators, a control system is constructed, which includes a recirculated air channel, a fresh air conditioning unit, a surface cooler 5, a heater 6, a humidifier 7, a dehumidifier 8, high-precision sensors, and an intelligent controller 10. The controller collects temperature and humidity signals inside and outside the paint booth 1, as well as the supply and return air, in real time. After decoupling calculation and dynamic optimization, it outputs control commands to synchronously adjust the recirculated air ratio, fresh air volume, cooling and heating output, and humidification and dehumidification intensity. This achieves independent and stable temperature and humidity control, effectively suppresses coupling interference and sudden disturbances caused by door opening and closing and operating condition switching, significantly improves control accuracy and response speed, and reduces system energy consumption.

[0029] In summary, the present invention has the following advantages compared with the prior art: By efficiently utilizing circulating air and decoupling temperature and humidity for high-precision control, the spray booth can stably achieve a temperature control accuracy of ±1℃ and a humidity control accuracy of ±3%RH, with fast response, small overshoot, and stable steady-state operation. The proportion of circulating air is greatly increased, significantly reducing energy consumption for heating, cooling, humidification, and dehumidification, resulting in outstanding energy-saving effects. The coordinated operation of multiple actuators reduces frequent start-stop and vibration, extending the service life of the equipment. The stable and uniform temperature and humidity environment effectively reduces the paint film defect rate, improves coating consistency and product qualification rate, and is suitable for continuous and stable operation of automated spraying production lines. It has strong versatility and high reliability.

[0030] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to the above embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0032] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-precision control system for temperature and humidity of circulating air in a paint spray booth, comprising: The spray booth, circulating air duct, fresh air inlet, air supply unit, surface cooler, heater, humidifier, dehumidifier, temperature and humidity sensor group, intelligent controller, and exhaust unit are characterized in that: One end of the circulating air duct is connected to the return air vent of the paint spraying chamber, and the other end is connected to the inlet of the air supply unit. The fresh air inlet is connected to the inlet of the air supply unit via a fresh air regulating valve, where it mixes with the airflow in the circulating air duct. The outlet of the air supply unit is connected in sequence to a surface cooler, a heater, a humidifier, and a dehumidifier before being connected to the air outlet of the paint spray booth. The temperature and humidity sensor group is respectively arranged inside the paint spraying room, at the air supply outlet, the air return outlet and the fresh air inlet, and each sensor is electrically connected to the intelligent controller. The intelligent controller is connected to the air supply unit, surface cooler, heater, humidifier, dehumidifier, exhaust unit and fresh air regulating valve respectively; The exhaust unit is located on the upper part or side of the paint spraying booth and is connected to the intelligent controller. The intelligent controller uses a temperature and humidity decoupling algorithm and a feedforward-feedback composite adjustment strategy to coordinate the temperature and humidity of the recirculating air in the paint booth.

2. The high-precision temperature and humidity control system for a spray booth circulating air as described in claim 1, characterized in that, The control system adopts an air supply architecture that prioritizes recirculated air and supplements it with fresh air, with a recirculated air utilization rate of 70%–90%.

3. The high-precision temperature and humidity control system for the circulating air in a spray booth as described in claim 1, characterized in that, The control system has a temperature control accuracy of ±1℃ and a humidity control accuracy of ±3%RH.

4. The high-precision temperature and humidity control system for circulating air in a spray booth as described in claim 1, characterized in that, The temperature and humidity sensor group includes at least 6 high-precision temperature and humidity sensors with a sampling frequency greater than or equal to 1Hz.

5. The high-precision temperature and humidity control system for circulating air in a spray booth as described in claim 1, characterized in that, The air supply unit is equipped with a fresh air regulating valve to dynamically adjust the fresh air mixing ratio, with the fresh air ratio being 10%–30%.

6. The high-precision temperature and humidity control system for circulating air in a spray booth as described in claim 1, characterized in that, The surface cooler includes cooling and dehumidification functions, the heater is electric or hot water heated, the humidifier is dry steam or high-pressure micro-mist humidification, and the dehumidifier is refrigeration dehumidification or adsorption dehumidification.

7. The high-precision temperature and humidity control system for a spray booth circulating air as described in claim 1, characterized in that, The exhaust unit is linked to the fresh air inlet for control, maintaining a slightly positive pressure in the paint spraying chamber with a pressure difference of 5–15 Pa.

8. A method for high-precision control of temperature and humidity of circulating air in a spray booth, applied in a high-precision control system for temperature and humidity of circulating air in a spray booth as described in any one of claims 1-7, characterized in that, Includes the following steps: Temperature and humidity signal acquisition: The temperature and humidity signals of multiple points in the paint spraying room, air supply outlet, air return outlet and fresh air side are collected in real time through a group of temperature and humidity sensors and transmitted to the intelligent controller. Signal processing: The intelligent controller receives the collected signals, performs temperature and humidity decoupling calculations, and combines a feedforward-feedback composite adjustment strategy for dynamic optimization; Multi-mechanism coordinated adjustment: The intelligent controller synchronously outputs control commands to dynamically adjust the circulating air ratio, fresh air volume, surface cooler cooling capacity, heater heating capacity, humidifier humidification capacity, and dehumidifier dehumidification capacity; Steady-state maintenance: Temperature and humidity control is performed to maintain the temperature and humidity inside the spray booth within the process setting range of 22–26℃ and 60%–65%RH.

9. A method for high-precision control of temperature and humidity of circulating air in a spray booth as described in claim 8, characterized in that, The temperature and humidity decoupling operation adopts a multivariable decoupling PID or model predictive control algorithm, and the feedforward compensation is calculated in advance by the fresh air temperature and humidity, door status, and workpiece signal.

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