Drying equipment energy-saving transformation method based on permanent magnet synchronous high-speed fan

Abstract

The invention discloses a drying equipment energy-saving transformation method based on a permanent magnet synchronous high-speed fan, and relates to the technical field of drying equipment control and airflow conveying, and the drying equipment energy-saving transformation method comprises the steps that adjacent drying grooves are divided into a drying groove group; original hot-air blowers of all the drying grooves are detached, and permanent magnet synchronous high-speed blowers are installed; an electric heating bag is arranged in a communicating pipeline between the main air pipe and the plurality of branch air pipes; a tank body temperature sensor, a heating bag outlet temperature sensor, an exhaust temperature and humidity sensor and an exhaust valve are arranged and connected into the electrical control device; control software is operated in the electrical control device to control the operation frequency of the permanent magnet synchronous high-speed fan, the heating power of the electric heating bag and the opening degree of the exhaust valve. A large number of original air heaters which are independently installed are omitted, the situation that airflow is unstable due to performance differences of the multiple air heaters is reduced, the air volume and the air pressure in the same drying groove set are kept consistent, the overall stability of air supply is improved, and the number of vibration sources caused by parallel operation of the multiple air heaters is reduced.

Description

Technical Field

[0001] This invention relates to the field of control and airflow conveying technology for drying equipment, specifically to an energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan. Background Technology

[0002] In existing drying equipment, multiple drying tanks are typically equipped with independent hot air blowers. Each hot air blower supplies air to its corresponding drying tank individually. The hot air blower draws air from the ambient environment, heats it through an internal heating structure, and then sends the air into the drying tank. In this structure, the air paths between each drying tank are independent, and there are a large number of blowers installed along the equipment. This type of structure is used in many wet process production lines and continuous drying equipment, constituting a common drying air supply method.

[0003] However, the aforementioned independent hot air supply structure will encounter several technical problems during long-term operation: due to differences in performance, operating conditions, and installation conditions among different hot air blowers, the air volume and pressure of each drying tank are difficult to maintain consistently during actual operation, easily leading to fluctuations in air supply. Furthermore, the parallel operation of multiple blowers complicates the mechanical structure, with each blower creating multiple vibration sources. The superimposed vibrations of the frame and piping structure reduce system stability. In addition, the large number of blowers increases maintenance workload, resulting in a greater number of independent components requiring attention during equipment operation and management, thus increasing maintenance complexity. These problems limit the stability of the existing independent blower air supply structure.

[0004] Based on this, an energy-saving retrofit method for drying equipment based on permanent magnet synchronous high-speed fans is now provided, which can eliminate the drawbacks of existing technical solutions. Summary of the Invention

[0005] The purpose of this invention is to provide an energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan, so as to solve the problem that the existing independent fan air supply structure has limitations in terms of stable air supply as mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The method for energy-saving retrofit of drying equipment based on permanent magnet synchronous high-speed fan is applied to drying equipment with multiple drying tanks set along the production line direction. Each of the multiple drying tanks includes a tank body, an air inlet and an exhaust pipe, and hot air is delivered into the tank body through the original hot air fan. The energy-saving retrofit method for the drying equipment specifically includes the following steps: Step S1: Divide several adjacent drying tanks into a drying tank group, and a drying tank group includes at least two drying tanks; Step S2: Remove the original hot air blowers of each drying tank in the drying tank group, and install a permanent magnet synchronous high-speed fan in the drying tank group. The outlet of the permanent magnet synchronous high-speed fan is connected to multiple branch air ducts through the main air duct. The multiple branch air ducts are respectively connected to the air inlet of each drying tank in the drying tank group. Step S3: Install an electric heating pack in the connecting pipe between the main air duct and multiple branch air ducts, so that the air delivered by the permanent magnet synchronous high-speed fan is heated by the electric heating pack and then enters each drying tank through multiple branch air ducts. Step S4: Install at least one tank temperature sensor inside the tank of each drying tank, install a heating pack outlet temperature sensor on the outlet pipe of the electric heating pack, and install an exhaust temperature and humidity sensor and an exhaust valve on the exhaust pipe of each drying tank. Step S5: Connect the permanent magnet synchronous high-speed fan, electric heating pack, tank temperature sensor, heating pack outlet temperature sensor, exhaust temperature and humidity sensor, and exhaust valve to the electrical control device; Step S6: Run the control software in the electrical control device to obtain the tank temperature collected by the tank temperature sensor, the heating pack outlet temperature collected by the heating pack outlet temperature sensor, and the exhaust relative humidity collected by the exhaust temperature and humidity sensor. Perform closed-loop regulation based on the tank temperature, heating pack outlet temperature, and exhaust relative humidity to control the operating frequency of the permanent magnet synchronous high-speed fan, the heating power of the electric heating pack, and the opening degree of the exhaust valve, respectively.

[0007] Furthermore, the main air duct extends along the arrangement direction of the drying tank group, and the outlet of the main air duct is connected to multiple branch air ducts through a distribution structure. Each branch air duct is equipped with a branch air volume regulating valve to regulate the air flow rate entering each drying tank.

[0008] Furthermore, the drying equipment includes a frame, and the permanent magnet synchronous high-speed fan is installed on the side of the frame of the drying equipment and connected to the foundation through a vibration damping structure to reduce the transmission of vibrations generated by high-speed rotation to the frame.

[0009] Furthermore, the electric heating pack includes a shell, an electric heating element disposed inside the shell, and a heat insulation structure disposed outside the shell. One end of the shell is connected to the outlet of the permanent magnet synchronous high-speed fan, and the other end is connected to the distribution structure. The heat insulation structure includes heat insulation material and an outer protective layer for fixing the heat insulation material. The heat insulation structure is used to reduce heat loss and allow the heated air to enter the distribution structure at a stable temperature.

[0010] Furthermore, the probe of the tank temperature sensor extends into the tank to collect the tank temperature. The heating pack outlet temperature sensor collects the heating pack outlet temperature before entering the drying tank to reflect the hot air temperature after being heated by the electric heating pack. The control software performs tank temperature control and heating pack outlet temperature control based on the tank temperature and heating pack outlet temperature, respectively. The probe of the exhaust temperature and humidity sensor extends into the exhaust pipe to collect the exhaust temperature and exhaust relative humidity. The control software adjusts the opening of the exhaust valve based on the humidity deviation between the exhaust relative humidity and the exhaust relative humidity setpoint. The exhaust valve is installed in the downstream pipe of the exhaust temperature and humidity sensor and receives control signals from the electrical control device through the actuator.

[0011] Furthermore, the electrical control device is installed in an electrical control cabinet, which contains a main incoming circuit breaker, an AC contactor for the drying tank group, a fuse, a solid-state relay, and a frequency converter. The main incoming circuit breaker is connected to an external power supply, and its output terminal is connected to the input terminal of the AC contactor for the drying tank group. The output terminal of the AC contactor for the drying tank group is divided into two branches. One branch is connected to the input terminal of the frequency converter via a fuse. The output terminal of the frequency converter is connected to the motor terminal of the permanent magnet synchronous high-speed fan. The other branch is connected to the input terminal of the solid-state relay via a fuse. The output terminal of the solid-state relay is connected to the electric heating element of the electric heating pack.

[0012] Furthermore, the signal terminals of the tank temperature sensor, the heating pack outlet temperature sensor, and the exhaust temperature and humidity sensor are respectively connected to the analog input terminal of the electrical control device, and the input terminal of the actuator is connected to the analog or digital output terminal of the electrical control device.

[0013] Furthermore, the control software in step S6 includes an input acquisition program, an operation mode management program, a closed-loop control program, and an energy consumption statistics program, which are used to read data from each sensor within a preset fixed sampling period.

[0014] Furthermore, the control software in step S6 divides the drying process into a heating stage, a constant temperature drying stage, and a heat preservation standby stage. In the heating stage, the operating frequency of the permanent magnet synchronous high-speed fan and the heating power of the electric heating pack are increased. In the constant temperature drying stage, the tank temperature and exhaust relative humidity are maintained within a preset threshold range based on the tank temperature and exhaust relative humidity. In the heat preservation standby stage, the operating frequency of the permanent magnet synchronous high-speed fan and the heating power of the electric heating pack are reduced.

[0015] Furthermore, the specific operations for closed-loop adjustment in step S6 include: The operating frequency of the permanent magnet synchronous high-speed fan is adjusted based on the temperature deviation between the tank temperature and the set tank temperature. The heating power of the electric heating pack is adjusted based on the temperature deviation between the outlet temperature of the heating pack and the set outlet temperature of the heating pack. The opening of the exhaust valve is adjusted based on the exhaust relative humidity deviation between the exhaust relative humidity and the exhaust relative humidity set value.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The energy-saving renovation method for drying equipment based on permanent magnet synchronous high-speed fan divides adjacent drying tanks into drying tank groups and makes the permanent magnet synchronous high-speed fan undertake the centralized air supply task of multiple drying tanks. This eliminates a large number of independently installed original hot air fans, reduces the complexity of the overall mechanical structure, and the centralized air supply structure can reduce the airflow instability caused by the performance difference of multiple fans, keep the air volume and air pressure in the same drying tank group consistent, improve the overall stability of air supply, and reduce the number of vibration sources caused by the parallel operation of multiple fans. 2. This invention, by setting up a distribution structure between the main air duct and multiple branch air ducts, and by setting branch air volume regulating valves on each branch air duct, can adjust the air volume distribution of each drying tank, so that different drying tanks can obtain independent air volume regulation capabilities under the same fan supply conditions, making the airflow distribution more balanced, facilitating the control of the air path according to the actual needs of each drying tank, and reducing the local drying time deviation caused by inconsistent air volume. 3. This invention facilitates the collection of real-time operating parameters from multiple locations by installing corresponding sensors inside the tank, at the outlet of the electric heating pack, and on the exhaust pipe. This makes the drying process monitorable, and the control software can independently adjust based on the detection signals from different locations. This enables the drying process to obtain clear temperature and humidity distribution control capabilities, reduces manual intervention, obtains a stable temperature and humidity control range, and improves the uniformity and controllability of the drying environment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the method steps of the present invention; Figure 2 This is a schematic diagram of the overall structure of the drying equipment of the present invention; Figure 3 This is a schematic diagram of the connection structure between the permanent magnet synchronous high-speed fan and the duct of the present invention.

[0018] Figure 4 This is a schematic diagram showing the position of the electric heating pack of the present invention; Figure 5 This is a schematic diagram showing the position of the sensor in this invention; Figure 6 This is a schematic diagram of the electrical control device of the present invention; Figure 7This is a schematic diagram of the control software of the present invention; Figure 8 This is a flowchart illustrating the control software of the present invention; Figure 9 This is a schematic diagram of the energy consumption statistics process of the present invention.

[0019] In the diagram: 10. Drying tank; 11. Tank body; 12. Air inlet; 13. Exhaust pipe; 14. Tank body temperature sensor; 15. Exhaust temperature and humidity sensor; 16. Exhaust valve; 17. Actuator; 20. Permanent magnet synchronous high-speed fan; 21. Main air duct; 22. Branch air duct; 23. Distribution structure; 30. Electric heating pack; 31. Housing; 32. Electric heating element; 33. Insulation structure; 34. Heating pack outlet temperature sensor; 40. Electrical control device; 50. Control software; 51. Input acquisition program; 52. Operation mode management program; 53. Closed-loop control program; 54. Energy consumption statistics program; 60. Electrical control cabinet; 61. Main incoming circuit breaker; 62. Drying tank group AC contactor; 63. Fuse; 64. Solid state relay; 65. Frequency converter. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1-9 In one embodiment, the present invention provides a technical solution: an energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan, which is applied to a drying equipment with multiple drying tanks 10 arranged along the production line direction. Each of the multiple drying tanks 10 includes a tank body 11, an air inlet 12 and an exhaust pipe 13, and hot air is delivered into the tank body 11 through the original hot air fan. The drying equipment includes a frame, and the permanent magnet synchronous high-speed fan 20 is installed on the side of the frame of the drying equipment and connected to the foundation through a vibration damping structure to reduce the transmission of vibration generated by high-speed rotation to the frame. Specifically, in the original structure of the drying equipment, each drying tank 10 is connected to the corresponding air inlet 12 through at least one original hot air blower. The original hot air blower draws in air from outside the drying equipment, heats it inside the original hot air blower, and then delivers hot air to the drying tank 10. Each drying tank 10 is supplied with air independently. The energy-saving retrofit method for drying equipment specifically includes the following steps: Step S1: In order to carry out energy-saving renovation of the drying equipment, several adjacent drying tanks 10 are divided into a drying tank group. A drying tank group includes at least two drying tanks 10. This renovation can reduce the number of fans and form a centralized air supply structure. Step S2: Remove the original hot air blowers of each drying tank 10 in the drying tank group, and install a permanent magnet synchronous high-speed fan 20 in the drying tank group. The air inlet of the permanent magnet synchronous high-speed fan 20 is connected to the air in the workshop through the air inlet pipe. A filter element is installed at the inlet of the air inlet pipe to filter solid particles in the air. The outlet of the permanent magnet synchronous high-speed fan 20 is connected to multiple branch air ducts 22 through the main air duct 21. The multiple branch air ducts 22 are respectively connected to the air inlet 12 of each drying tank 10 in the drying tank group. Step S3: Install an electric heating pack 30 in the connecting pipe between the main air duct 21 and multiple branch air ducts 22, so that the air delivered by the permanent magnet synchronous high-speed fan 20 is heated by the electric heating pack 30 and enters each drying tank 10 through multiple branch air ducts 22. Step S4: At least one tank temperature sensor 14 is installed inside the tank body 11 of each drying tank 10, a heating pack outlet temperature sensor 34 is installed on the outlet pipe of the electric heating pack 30, and an exhaust temperature and humidity sensor 15 and an exhaust valve 16 are installed on the exhaust pipe 13 of each drying tank 10. Step S5: Connect the permanent magnet synchronous high-speed fan 20, electric heating pack 30, tank temperature sensor 14, heating pack outlet temperature sensor 34, exhaust temperature and humidity sensor 15 and exhaust valve 16 to the electrical control device 40. Step S6: Run the control software 50 in the electrical control device 40 to acquire the tank temperature collected by the tank temperature sensor 14, the heating pack outlet temperature collected by the heating pack outlet temperature sensor 34, and the exhaust relative humidity collected by the exhaust temperature and humidity sensor 15. Perform closed-loop regulation based on the tank temperature, heating pack outlet temperature, and exhaust relative humidity to control the operating frequency of the permanent magnet synchronous high-speed fan 20, the heating power of the electric heating pack 30, and the opening degree of the exhaust valve 16, respectively.

[0022] Please see Figure 2 and Figure 3 The main air duct 21 extends along the arrangement direction of the drying trough group. The outlet of the main air duct 21 is connected to multiple branch air ducts 22 through the distribution structure 23. Each branch air duct 22 is equipped with a branch air volume regulating valve. The branch air volume regulating valve is installed in a section of the branch air duct 22 near the drying trough 10 and is used to regulate the air flow entering each drying trough 10. The distribution structure 23 can be a multi-port connector or a distribution box with multiple air outlets, etc. The branch air volume regulating valve can be a manual valve or a regulating valve driven by an electric drive mechanism. By adjusting the branch air volume regulating valve, each drying trough 10 can still obtain the corresponding air supply when the air volume demand is different, so as to achieve the air volume balance within the group.

[0023] Please see Figures 2 to 3 The electric heating pack 30 includes a housing 31, an electric heating element 32 disposed inside the housing 31, and a heat insulation structure 33 disposed outside the housing 31. One end of the housing 31 is connected to the outlet of the permanent magnet synchronous high-speed fan 20, and the other end is connected to the distribution structure 23. The air output by the permanent magnet synchronous high-speed fan 20 exchanges heat with the electric heating element 32 when passing through the inside of the electric heating pack 30, thereby obtaining a heated airflow. The heat insulation structure 33 includes heat insulation material and an outer protective layer for fixing the heat insulation material. The heat insulation structure 33 is used to reduce heat loss and allow the heated air to enter the distribution structure 23 at a stable temperature. An air rectification component can also be disposed inside the electric heating pack 30. The air rectification component includes a guide plate or a rectification net to make the air evenly distributed in the cross section, thereby improving the uniformity of airflow around the electric heating element 32.

[0024] Please see Figure 5 To obtain temperature and humidity parameters at various locations during the drying process, this application installs multiple sensors on the drying tank 10 and its pipelines. The probe of the tank temperature sensor 14 extends into the tank 11 to collect the tank temperature. The tank temperature is transmitted to the electrical control device 40 via a signal line. A heating pack outlet temperature sensor 34 is installed on the outlet pipeline of the electric heating pack 30 to collect the outlet temperature of the heating pack before it enters the drying tank 10, reflecting the temperature of the hot air after being heated by the electric heating pack 30. The control software 50 performs tank temperature control and heating pack outlet temperature control based on the tank temperature and the heating pack outlet temperature, respectively. The exhaust pipeline of each drying tank 10... An exhaust temperature and humidity sensor 15 and an exhaust valve 16 are installed on the exhaust pipe 13. The probe of the exhaust temperature and humidity sensor 15 extends into the interior of the exhaust pipe 13 to collect the exhaust temperature and relative humidity of the exhaust in the exhaust pipe 13. The control software 50 adjusts the opening of the exhaust valve 16 based on the humidity deviation between the exhaust relative humidity and the exhaust relative humidity set value. The exhaust valve 16 is installed in the downstream pipe of the exhaust temperature and humidity sensor 15. It receives control signals from the electrical control device 40 through the actuator 17 to adjust the exhaust volume. The actuator 17 of the exhaust valve 16 is an electric adjustment mechanism, which receives control signals (such as 4-20mA) from the analog output of the electrical control device 40 to accurately adjust the valve opening.

[0025] Please see Figure 6The electrical control device 40 is installed in the electrical control cabinet 60. The electrical control cabinet 60 is equipped with a main incoming circuit breaker 61, a drying tank group AC contactor 62, a fuse 63, a solid-state relay 64, and a frequency converter 65. The main incoming circuit breaker 61 is connected to an external power supply, and its output terminal is connected to the input terminal of the drying tank group AC contactor 62. The output terminal of the drying tank group AC contactor 62 is divided into two branches. One branch is connected to the input terminal of the frequency converter 65 after passing through the fuse 63. The output terminal of the frequency converter 65 is connected to the motor terminal of the permanent magnet synchronous high-speed fan 20. The other branch is connected to the input terminal of the solid-state relay 64 after passing through the fuse 63. The output terminal of the solid-state relay 64 is connected to the electric heating element 32 of the electric heating pack 30.

[0026] Please see Figure 5 and Figure 6 The signal terminals of the tank temperature sensor 14, the heating pack outlet temperature sensor 34, and the exhaust temperature and humidity sensor 15 are respectively connected to the analog input terminal of the electrical control device 40. The input terminal of the actuator 17 is connected to the analog or switch output terminal of the electrical control device 40. The outputs of the tank temperature sensor 14, the heating pack outlet temperature sensor 34, and the exhaust temperature and humidity sensor 15 are all analog signals (such as 4-20mA current signal or 0-10V voltage signal).

[0027] Please see Figure 7 The control software 50 in step S6 includes an input acquisition program 51, an operation mode management program 52, a closed-loop control program 53, and an energy consumption statistics program 54, which are used to read data from each sensor within a preset fixed sampling period. The preset fixed sampling period can be adjusted according to actual needs. The logic control core of the electrical control device 40 is a programmable logic controller, and the control software 50 runs in the controller. Specifically, the sampling period is defined as Control software 50 at discrete times For data processing, this embodiment sets the tank temperature to... The tank temperature setting value is The temperature deviation of the tank is: ,in, Indicates the drying tank number, This indicates that at the current moment, the outlet temperature of the heating pack is set to... The heating pack outlet temperature setting value is The temperature deviation at the outlet of its heating pack is: ,in, Indicate the drying tank group number, and set the exhaust relative humidity to [value missing]. The exhaust relative humidity setting value is The relative humidity deviation of its exhaust gas is: ; In this embodiment, the control software 50 calculates the operating frequency command of the permanent magnet synchronous high-speed fan 20 based on the temperature deviation of the tank, and defines the operating frequency command of the permanent magnet synchronous high-speed fan 20 as follows: Its update uses proportional-integral calculation at discrete points, and the formula is: ,in, This is the proportionality coefficient. The integral coefficient is... This represents the combined value of the temperature deviation within the drying tank group. This combined value can be the average or maximum value of the deviation within the drying tank group. In this embodiment, the heating power control of the electric heating pack 30 adopts proportional control based on the temperature deviation at the outlet of the heating pack, and the heating power control amount of the electric heating pack 30 is defined as follows: This heating power control quantity can be used to represent the duty cycle of the solid-state relay 64, and the proportional control formula is: ,in, Based on the basic heating power control quantity This is the proportionality coefficient. For at any time The temperature deviation at the outlet of the heating pack; In this embodiment, the opening degree of the exhaust valve 16 is controlled based on the exhaust relative humidity deviation, and the opening degree of the exhaust valve 16 is defined as... The control formula is: ,in, Based on the opening degree of the basic exhaust valve, This is the proportionality coefficient. For at any time The relative humidity deviation of the exhaust gas; In this embodiment, please refer to Figure 9 The electrical control device 40 collects real-time power data of the permanent magnet synchronous high-speed fan 20 and the electric heating pack 30, and performs statistical calculations on the real-time power data through the energy consumption statistics program 54 in the control software 50. The energy consumption statistics program 54 is used to accumulate and calculate the electrical energy of the permanent magnet synchronous high-speed fan 20 and the electric heating pack 30 to obtain the energy consumption data of the drying equipment during the drying process, and defines the time of permanent magnet synchronous high-speed fan 20. The real-time power is Electric heating pack 30 at time The real-time power is During the observation time interval shared within There are 1 sampling point, and they satisfy 1 / 2 * ... The power consumption of the permanent magnet synchronous high-speed fan 20 is: The power consumption of the electric heating pack 30 is: The total power consumption is: ,in, The number of drying tanks is [number]. If the drying equipment includes a product counter, the number of products within the observation time interval is [number]. Then the unit product energy consumption is: The control software 50 stores the above statistical data in the memory of the electrical control device 40 for querying and subsequent process parameter adjustment.

[0028] Please see Figure 8 In step S6, the control software 50 divides the drying process into a heating stage, a constant temperature drying stage, and a heat preservation standby stage. In the heating stage, the operating frequency of the permanent magnet synchronous high-speed fan 20 and the heating power of the electric heating pack 30 are increased. In the constant temperature drying stage, the tank temperature and exhaust relative humidity are maintained within a preset threshold range based on the tank temperature and exhaust relative humidity. In the heat preservation standby stage, the operating frequency of the permanent magnet synchronous high-speed fan 20 and the heating power of the electric heating pack 30 are reduced. This invention can adjust the operating frequency and heating power as needed. In addition, the heat preservation design of the electric heating pack 30 significantly reduces heat loss and power consumption.

[0029] Specifically, the closed-loop adjustment operation in step S6 includes: The operating frequency of the permanent magnet synchronous high-speed fan 20 is adjusted based on the temperature deviation between the tank temperature and the set temperature of the tank. The heating power of the electric heating pack 30 is adjusted based on the temperature deviation between the heating pack outlet temperature and the set value of the heating pack outlet temperature. The opening of the exhaust valve 16 is adjusted based on the exhaust relative humidity deviation between the exhaust relative humidity and the exhaust relative humidity setpoint. The above settings can all be set and adjusted based on different drying processes or material experience.

[0030] In summary, this invention effectively solves the limitations of traditional independent hot air supply modes by grouping drying tanks, centralized air supply, and multi-parameter closed-loop control. It replaces multiple independent hot air blowers with a single permanent magnet synchronous high-speed fan, eliminating the airflow instability caused by performance differences among multiple fans and achieving balanced and stable air volume and pressure within the same tank group. At the same time, by deploying sensors at key locations and combining them with software control logic, it achieves precise and controllable temperature and humidity during the drying process, reducing manual intervention. It is suitable for energy-saving upgrades and renovations of wet process production lines and continuous drying equipment, and has high practical value.

[0031] The above description is merely a specific embodiment of this application, but the scope of protection of this application 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 this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for energy-saving retrofit of drying equipment based on permanent magnet synchronous high-speed fan, applied to drying equipment with multiple drying tanks set along the production line direction, wherein each of the multiple drying tanks includes a tank body, an air inlet and an exhaust pipe, and hot air is delivered into the tank body through the original hot air fan; Its features are, The energy-saving retrofit method for the drying equipment specifically includes the following steps: Step S1: Divide several adjacent drying tanks into a drying tank group, and a drying tank group includes at least two drying tanks; Step S2: Remove the original hot air blowers of each drying tank in the drying tank group, and install a permanent magnet synchronous high-speed fan in the drying tank group. The outlet of the permanent magnet synchronous high-speed fan is connected to multiple branch air ducts through the main air duct. The multiple branch air ducts are respectively connected to the air inlet of each drying tank in the drying tank group. Step S3: Install an electric heating pack in the connecting pipe between the main air duct and multiple branch air ducts, so that the air delivered by the permanent magnet synchronous high-speed fan is heated by the electric heating pack and then enters each drying tank through multiple branch air ducts. Step S4: Install at least one tank temperature sensor inside the tank of each drying tank, install a heating pack outlet temperature sensor on the outlet pipe of the electric heating pack, and install an exhaust temperature and humidity sensor and an exhaust valve on the exhaust pipe of each drying tank. Step S5: Connect the permanent magnet synchronous high-speed fan, electric heating pack, tank temperature sensor, heating pack outlet temperature sensor, exhaust temperature and humidity sensor, and exhaust valve to the electrical control device; Step S6: Run the control software in the electrical control device to obtain the tank temperature collected by the tank temperature sensor, the heating pack outlet temperature collected by the heating pack outlet temperature sensor, and the exhaust relative humidity collected by the exhaust temperature and humidity sensor. Perform closed-loop regulation based on the tank temperature, heating pack outlet temperature, and exhaust relative humidity to control the operating frequency of the permanent magnet synchronous high-speed fan, the heating power of the electric heating pack, and the opening degree of the exhaust valve, respectively.

2. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 1, characterized in that, The main air duct extends along the arrangement direction of the drying tank group. The outlet of the main air duct is connected to multiple branch air ducts through a distribution structure. Each branch air duct is equipped with a branch air volume regulating valve to regulate the air flow rate entering each drying tank.

3. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 1, characterized in that, The drying equipment includes a frame, and the permanent magnet synchronous high-speed fan is installed on the side of the frame of the drying equipment and connected to the foundation through a vibration damping structure to reduce the transmission of vibration generated by high-speed rotation to the frame.

4. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 2, characterized in that, The electric heating pack includes a shell, an electric heating element disposed inside the shell, and a heat insulation structure disposed outside the shell. One end of the shell is connected to the outlet of the permanent magnet synchronous high-speed fan, and the other end is connected to the distribution structure. The heat insulation structure includes heat insulation material and an outer protective layer for fixing the heat insulation material. The heat insulation structure is used to reduce heat loss and allow the heated air to enter the distribution structure at a stable temperature.

5. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 1, characterized in that, The probe of the tank temperature sensor extends into the tank to collect the tank temperature. The heating pack outlet temperature sensor collects the outlet temperature of the heating pack before it enters the drying tank, reflecting the temperature of the hot air after being heated by the electric heating pack. The control software performs tank temperature control and heating pack outlet temperature control based on the tank temperature and heating pack outlet temperature, respectively. The probe of the exhaust temperature and humidity sensor extends into the exhaust pipe to collect the exhaust temperature and relative humidity within the exhaust pipe. The control software adjusts the opening of the exhaust valve based on the humidity deviation between the exhaust relative humidity and the exhaust relative humidity setpoint. The exhaust valve is installed in the downstream pipe of the exhaust temperature and humidity sensor and receives control signals from the electrical control device through an actuator.

6. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 4, characterized in that, The electrical control device is installed in an electrical control cabinet, which contains a main incoming circuit breaker, an AC contactor for the drying tank group, a fuse, a solid-state relay, and a frequency converter. The main incoming circuit breaker is connected to an external power supply, and its output terminal is connected to the input terminal of the AC contactor for the drying tank group. The output terminal of the AC contactor for the drying tank group is divided into two branches. One branch is connected to the input terminal of the frequency converter via a fuse. The output terminal of the frequency converter is connected to the motor terminal of the permanent magnet synchronous high-speed fan. The other branch is connected to the input terminal of the solid-state relay via a fuse. The output terminal of the solid-state relay is connected to the electric heating element of the electric heating pack.

7. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 5, characterized in that, The signal terminals of the tank temperature sensor, the heating pack outlet temperature sensor, and the exhaust temperature and humidity sensor are respectively connected to the analog input terminal of the electrical control device, and the input terminal of the actuator is connected to the analog or digital output terminal of the electrical control device.

8. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 1, characterized in that, The control software in step S6 includes an input acquisition program, an operation mode management program, a closed-loop control program, and an energy consumption statistics program, which are used to read data from each sensor within a preset fixed sampling period.

9. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 1, characterized in that, The control software in step S6 divides the drying process into a heating stage, a constant temperature drying stage, and a heat preservation standby stage. In the heating stage, the operating frequency of the permanent magnet synchronous high-speed fan and the heating power of the electric heating pack are increased. In the constant temperature drying stage, the tank temperature and exhaust relative humidity are maintained within a preset threshold range based on the tank temperature and exhaust relative humidity. In the heat preservation standby stage, the operating frequency of the permanent magnet synchronous high-speed fan and the heating power of the electric heating pack are reduced.

10. The energy-saving retrofit method for drying equipment based on a permanent magnet synchronous high-speed fan according to claim 1, characterized in that, The specific operations for closed-loop adjustment in step S6 include: The operating frequency of the permanent magnet synchronous high-speed fan is adjusted based on the temperature deviation between the tank temperature and the set tank temperature. The heating power of the electric heating pack is adjusted based on the temperature deviation between the outlet temperature of the heating pack and the set outlet temperature of the heating pack. The opening of the exhaust valve is adjusted based on the exhaust relative humidity deviation between the exhaust relative humidity and the exhaust relative humidity set value.

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