A pre-conditioning air unit for an aircraft

Abstract

The application is suitable for air conditioning field, and discloses a pre-processing air unit for aircraft, which comprises a supply air system, a main control box and a plurality of full variable frequency modules, the full variable frequency modules are distributed between an air inlet and an air outlet, the full variable frequency module comprises a refrigeration module and a module control box, the refrigeration module comprises a direct-current variable frequency compressor, a condenser, an axial flow fan assembly, an expansion valve and an evaporator, the direct-current variable frequency compressor, the condenser, the expansion valve and the evaporator are connected in series, the axial flow fan assembly is arranged on the condenser, the module control box comprises a direct-current variable frequency driver and a module control panel, the direct-current variable frequency driver is connected with the direct-current variable frequency compressor, and the module control panel is connected with the main control box, the direct-current variable frequency driver, the axial flow fan assembly and the expansion valve respectively; the refrigeration module of the full variable frequency module adopts the direct-current variable frequency compressor and the axial flow fan assembly, so that the pre-processing air unit can be directly powered by commercial power, the equipment circuit structure is simplified, and the complexity of the system is reduced.

Description

Technical Field

[0001] This invention relates to the field of air conditioning, and more particularly to a pre-treatment air unit suitable for aircraft. Background Technology

[0002] Aircraft ground air conditioning units (PCAs) are dedicated air conditioning units for airport ground services used to regulate the air inside the aircraft cabin. PCAs are a key advantage in avoiding the use of auxiliary power units (APUs) to drive the air conditioning equipment. However, most PCAs currently on the market use fixed-frequency compressors, AC axial fans, and several non-modular refrigeration systems, employing hot gas bypass defrosting, energy regulation, and electric heating in winter. Using fixed-frequency compressors results in large fluctuations in outlet air temperature and high energy consumption. Using AC axial fans to control condensing pressure leads to frequent start-stop cycles at low temperatures, causing high and low pressure fluctuations in the refrigeration system. Non-modular refrigeration systems are difficult to maintain and require long repair times. Furthermore, using fixed-frequency compressors and AC axial fans necessitates the addition of pulse rectifiers and DC modules, increasing the overall system circuitry. Summary of the Invention

[0003] The purpose of this invention is to provide a pre-treatment air unit suitable for aircraft, which adopts a DC inverter compressor and an axial flow fan assembly, so that the pre-treatment air unit can be directly powered by mains power, simplifying the equipment circuit structure and reducing the complexity of the system.

[0004] To achieve the above objectives, the solution provided by the present invention is as follows:

[0005] A pre-treatment air unit suitable for aircraft includes an air supply system, a main control box, and several fully variable frequency modules. The air supply system includes an air duct and a blower installed in the air duct. The blower is connected to the main control box. The air duct is provided with an air inlet and an air outlet. The blower is used to deliver pre-treated air from the air inlet to the air outlet. Several fully variable frequency modules are distributed between the air inlet and the air outlet. Each fully variable frequency module includes a refrigeration module and a module control box. The number of module control boxes corresponds to the number of refrigeration modules. The refrigeration module includes a DC inverter compressor, a condenser, an axial flow fan assembly, an expansion valve, and an evaporator. The axial flow fan assembly is used to provide cooling air to the condenser. The DC inverter compressor, condenser, expansion valve, and evaporator are connected end to end. The axial flow fan assembly is mounted on the condenser. The module control box includes a DC inverter driver and a module control board. The DC inverter driver is connected to the DC inverter compressor. The module control board is connected to the main control box, the DC inverter driver, the axial flow fan assembly, and the expansion valve.

[0006] Preferably, the pre-treatment air unit includes four fully variable frequency modules, namely a first fully variable frequency module, a second fully variable frequency module, a third fully variable frequency module, and a fourth fully variable frequency module. The air duct includes a first sub-air duct, a second sub-air duct, and a third sub-air duct connected in sequence. The blower is disposed in the second sub-air duct. The first and second fully variable frequency modules are respectively disposed on both sides of the first sub-air duct and are respectively connected to the first sub-air duct. The third and fourth fully variable frequency modules are respectively disposed on both sides of the third sub-air duct and are respectively connected to the third sub-air duct. The module control boards of the first, second, third, and fourth fully variable frequency modules are respectively connected to the main control box.

[0007] Preferably, the main control box includes a main control board, a frequency converter driver, and a touch screen. The main control board is connected to the module control board of each of the full frequency conversion modules, the frequency converter driver is connected to the blower, and the touch screen is connected to the main control board.

[0008] Preferably, the full frequency conversion module further includes a base, a first bracket, a second bracket, a third bracket, and a top plate. The first bracket is located at the lower right of the base, the second bracket is located to the left of the first bracket and connected to the first bracket, the condenser is installed behind the second bracket, the axial flow fan assembly is installed in front of the second bracket, the third bracket is located in front of the axial flow fan assembly, the top plate is installed on top of the first bracket, the second bracket, and the third bracket, the DC frequency conversion compressor is installed on the base and located in front of the first bracket, the module control box is installed on the first bracket, and the expansion valve is installed on the second bracket.

[0009] Preferably, the full frequency conversion module further includes a connecting bracket, which is mounted on the second bracket and extends to the side of the third bracket, and the expansion valve is mounted on the connecting bracket.

[0010] Preferably, the module control box further includes a housing, and the DC frequency converter driver and the module control board are both disposed in the housing. Mounting parts are provided on both sides of the housing, and the mounting parts are screwed to the first bracket.

[0011] Preferably, the system further includes a housing, in which the air duct is formed, the air inlet and the air outlet are respectively located on two different sides of the housing, the blower and the main control box are respectively located in the middle of the housing, and a plurality of the full frequency conversion modules are arranged in the housing along the air supply direction.

[0012] Preferably, the air inlet and the air outlet are respectively located on two opposite sides of the housing.

[0013] Preferably, the axial fan assembly includes an EC axial fan, which is mounted on the condenser and connected to the module control board.

[0014] Preferably, the axial flow fan assembly includes an AC axial flow fan and an axial flow fan speed controller. The AC axial flow fan is mounted on the condenser, and the axial flow fan speed controller is mounted in the module control box. The axial flow fan speed controller is connected to both the AC axial flow fan and the module control board.

[0015] The pre-treatment air unit control system provided by this invention includes a main control box and module control boxes. The main control box outputs commands to the module control boxes, and each fully variable frequency module is individually controlled by its corresponding module control box. After providing air supply to the evaporator, each fully variable frequency module can operate independently. This hierarchical structure makes system control more flexible and efficient. Several fully variable frequency modules are distributed between the air inlet and outlet, and through intelligent control and variable frequency technology, they can accurately adjust parameters such as air temperature and humidity to meet the air environment requirements of different areas and time periods inside the aircraft. Moreover, the cooling module of the fully variable frequency module adopts a DC variable frequency compressor and an axial flow fan assembly, and provides DC power and frequency regulation to the DC variable frequency compressor through a DC variable frequency driver. It features overcurrent and overtemperature protection, and the axial fan assembly's airflow can be steplessly adjusted via a modular control board. This allows the pretreatment air handling unit to be directly powered by mains electricity without the need for a pulse rectifier or DC module, greatly simplifying the equipment's circuit structure and reducing system complexity. Compared to traditional AC fixed-frequency compressors and their associated variable frequency drives, it offers a wider adjustment range, better adjustment performance, and higher energy efficiency. Furthermore, the modular design allows for convenient mass production and testing of the pretreatment air handling unit, significantly reducing production and testing time and improving overall production efficiency. During maintenance, the fully variable frequency modules can operate independently, facilitating easy module replacement and greatly shortening maintenance time, thus improving maintenance efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a pre-treatment air unit suitable for aircraft provided in an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of the full frequency conversion module provided in an embodiment of the present invention. Attached image description:

[0020] 10. Main control box; 20. Air supply fan; 31. First sub-duct; 32. Second sub-duct; 33. Third sub-duct; 34. Air inlet; 35. Air outlet; 41. First full-frequency conversion module; 411. Variable frequency compressor; 412. EC axial flow fan; 413. Expansion valve; 414. Evaporator; 415. Base; 416. First bracket; 417. Second bracket; 418. Third bracket; 419. Top plate; 420. Fan mounting base; 42. Second full-frequency conversion module; 43. Third full-frequency conversion module; 44. Fourth full-frequency conversion module; 45. Module control box; 60. Housing. Detailed Implementation

[0021] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention 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 so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus 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 apparatus.

[0022] In this embodiment of the invention, a pre-treatment air unit suitable for aircraft is provided.

[0023] Please see Figure 1The pre-treatment air unit for aircraft according to this embodiment of the invention includes an air supply system, a main control box 10, and several fully variable frequency modules. The air supply system includes an air duct and a blower 20 installed in the air duct. The blower 20 is connected to the main control box 10. The air duct is provided with an air inlet 34 and an air outlet 35. The blower 20 is used to transport pre-treated air from the air inlet 34 to the air outlet 35. Several fully variable frequency modules are distributed between the air inlet 34 and the air outlet 35. Each fully variable frequency module includes a cooling module and a module control box 45. The number of module control boxes 45 corresponds to the number of cooling modules. The cooling module includes a DC inverter compressor 411, a condenser (not shown), an axial fan assembly, an expansion valve 413, and an evaporator 414. The axial fan assembly provides cooling air to the condenser. The DC inverter compressor 411, condenser, expansion valve 413, and evaporator 414 are connected end to end. The axial fan assembly is mounted on the condenser. The module control box includes a DC inverter driver and a module control board. The DC inverter driver is connected to the DC inverter compressor 411, and the module control board is connected to the main control box 10, the DC inverter driver, the axial fan assembly, and the expansion valve 413.

[0024] In this embodiment, the DC inverter driver is used to provide DC power, frequency regulation, and overcurrent and overtemperature protection for the DC inverter compressor 411.

[0025] In this embodiment, the axial fan assembly includes an EC axial fan 412, which is mounted on the condenser. The EC axial fan 412 is used to provide cooling air to the condenser and can achieve 0~100% speed regulation through signals such as 0~10V and PWM. The air volume can be steplessly adjusted through the module control board to meet the heat dissipation requirements under different loads.

[0026] In another embodiment, the axial fan assembly includes an AC axial fan and an axial fan speed controller (not shown). The AC axial fan is mounted on the condenser, and the axial fan speed controller is mounted in the module control box. The axial fan speed controller is connected to both the AC axial fan and the module control board. The axial fan speed controller, installed in the module control box, enables the AC axial fan to operate at 10% to 100% speed according to the high-pressure signal received from the module control board, thereby achieving stepless adjustment of the airflow and meeting the heat dissipation requirements under different loads.

[0027] In this embodiment, the evaporators 414 of several fully variable frequency modules are placed sequentially in the air duct for cooling or heating the pretreated air.

[0028] In this embodiment, the module control board is used to control and regulate the DC inverter compressor 411, the axial flow fan assembly, and the expansion valve 413.

[0029] In this embodiment, since each full frequency conversion module can operate independently, the full frequency conversion module can be equipped with a heat pump function, and heat pump heating can be used instead of heater heating in winter, which greatly reduces heating energy consumption.

[0030] It should be noted that the number of variable frequency compressors 411, condensers, axial flow fan assemblies, expansion valves 413, and evaporators 414 in each full variable frequency module can be the same or different, and can be increased according to actual needs, and is not limited to a fixed number.

[0031] The working principle of the pre-treatment air unit in this embodiment is as follows:

[0032] Air enters the air duct through the air inlet 34 and is delivered to the air outlet 35 by the blower 20. During the delivery process, the air is cooled by several full-frequency conversion modules. Each full-frequency conversion module, according to the instructions of the main control box 10, cools the air to the set temperature through the coordinated work of components such as the DC inverter compressor 411, condenser, axial fan assembly, expansion valve 413 and evaporator 414. The cooled air is then delivered through the air outlet 35 for use inside the aircraft.

[0033] During the refrigeration process, the full frequency conversion module precisely controls the DC frequency conversion compressor 411 through the DC frequency conversion driver, and precisely controls components such as the DC frequency conversion driver, axial flow fan assembly and expansion valve 413 through the module control board, to ensure the stable operation and high efficiency and energy saving of the pre-treatment air unit.

[0034] In this embodiment, the overall control system of the pre-treatment air unit includes a main control box 10 and a module control box 45. The main control box 10 outputs commands to the module control box 45, and each full-frequency conversion module is individually controlled by its corresponding module control box 45. After each full-frequency conversion module provides air to the evaporator 414, it can operate independently. This hierarchical structure makes the system control more flexible and efficient. Several full-frequency conversion modules are distributed between the air inlet 34 and the air outlet 35, and through intelligent control and frequency conversion technology, they can accurately adjust parameters such as air temperature and humidity to meet the air environment requirements of different areas and time periods inside the aircraft. Moreover, the cooling module of the full-frequency conversion module adopts a DC inverter compressor 411 and an axial flow fan assembly, and the DC inverter compressor 411 is powered by a DC inverter driver. It provides DC power supply, frequency regulation, and overcurrent and overtemperature protection. The axial fan assembly's airflow is infinitely adjustable via a modular control board, allowing the pretreatment air unit to be directly powered by mains electricity without the need for a pulse rectifier or DC module. This significantly simplifies the equipment's circuit structure and reduces system complexity. Compared to traditional AC fixed-frequency compressors and their associated variable-frequency drives, it offers a wider adjustment range, better regulation performance, and higher energy efficiency. Furthermore, the modular design facilitates mass production and testing of the pretreatment air unit, greatly reducing production and testing time and improving overall production efficiency. During maintenance, the fully variable-frequency modules can operate independently, allowing for easy module replacement and significantly shortening maintenance time, thus improving maintenance efficiency.

[0035] Please see Figure 1 As shown, in some embodiments, exemplarily, the pre-treatment air unit includes four fully variable frequency modules, namely a first fully variable frequency module 41, a second fully variable frequency module 42, a third fully variable frequency module 43, and a fourth fully variable frequency module 44. The air duct includes a first sub-air duct 31, a second sub-air duct 32, and a third sub-air duct 33 connected in sequence. The blower 20 is disposed in the second sub-air duct 32. The first fully variable frequency module 41 and the second fully variable frequency module 42 are respectively disposed on both sides of the first sub-air duct 31 and are respectively connected to the first sub-air duct 31. The third fully variable frequency module 43 and the fourth fully variable frequency module 44 are respectively disposed on both sides of the third sub-air duct 33 and are respectively connected to the third sub-air duct 33. The module control boards of the first fully variable frequency module 41, the second fully variable frequency module 42, the third fully variable frequency module 43, and the fourth fully variable frequency module 44 are respectively connected to the main control box 10.

[0036] As the core of the main control box 10, the main control board connects to the module control boards of each full frequency conversion module. It can centrally control and manage various parts of the system, providing a high degree of integration and flexibility, allowing the system to be configured and adjusted as needed.

[0037] When the blower 20 delivers air into the first sub-duct 31, the first full-frequency conversion module 41 and the second full-frequency conversion module 42 operate simultaneously to refrigerate the air. Based on the control signal from the main control box 10, the DC inverter driver adjusts the speed of the DC inverter compressor 411, thereby controlling the refrigerant flow and pressure to achieve precise regulation of the cooling capacity. Simultaneously, the axial fan assembly provides cooling air to the condenser, ensuring effective heat dissipation of the refrigerant within the condenser.

[0038] Similarly, when the blower 20 delivers air into the third sub-duct 33, the third full frequency conversion module 43 and the fourth full frequency conversion module 44 work simultaneously to cool the air.

[0039] Understandably, if the first full frequency conversion module 41 or the second full frequency conversion module 42 can meet the air cooling needs by working independently, then only the first full frequency conversion module 41 or the second full frequency conversion module 42 needs to be turned on. Similarly, if the third full frequency conversion module 43 or the fourth full frequency conversion module 44 can meet the air cooling needs by working independently, then only the third full frequency conversion module 43 or the fourth full frequency conversion module 44 needs to be turned on.

[0040] Understandably, the distribution positions of the first full frequency conversion module 41, the second full frequency conversion module 42, the third full frequency conversion module 43, and the fourth full frequency conversion module 44 can also be adjusted according to the actual situation. For example, the first full frequency conversion module 41, the second full frequency conversion module 42, the third full frequency conversion module 43, and the fourth full frequency conversion module 44 can be distributed sequentially along the air outlet direction of the air duct.

[0041] Understandably, in other embodiments, the number of full-frequency conversion modules can be set according to actual needs.

[0042] Please see Figure 1 As shown, the main control box 10 includes a main control board (not shown), a frequency converter (not shown), and a touch screen (not shown). The main control board is connected to the module control board of each full frequency converter module. The frequency converter is connected to the blower 20, providing power and frequency regulation to the blower 20. The touch screen is connected to the main control board. The main control board can receive operator commands through the touch screen and precisely control the operation of each full frequency converter module through communication with the frequency converter.

[0043] Please see Figure 2As shown, in some embodiments, exemplarily, the full frequency conversion module further includes a base 415, a first bracket 416, a second bracket 417, a third bracket 418, and a top plate 419. The first bracket 416 is located at the lower right of the base 415, the second bracket 417 is located to the left of the first bracket 416 and connected to the first bracket 416, the condenser is installed behind the second bracket 417, the EC axial flow fan 412 is installed in front of the second bracket 417, the third bracket 418 is located in front of the EC axial flow fan 412, and the top plate 419 is installed on the first bracket 416. The DC inverter compressor 411 is mounted on the base 415 and located in front of the first bracket 416, atop the second bracket 417 and the third bracket 418. The module control box is mounted on the first bracket 416, and the expansion valve 413 is mounted on the second bracket 417. The rational layout and installation of the first bracket 416, second bracket 417, and third bracket 418 ensures the stability and reliability of all components within the full inverter module. The entire module consists of multiple independently detachable and installable components, such as the base 415, brackets, condenser, and EC axial fan 412. This modular design makes the installation, maintenance, and replacement of components more convenient and faster. Simultaneously, the modular design improves the scalability of the equipment, allowing for the addition or removal of components as needed to meet different application requirements. Furthermore, the module control box, mounted on the first bracket 416, facilitates connection and control with key components such as the DC inverter compressor 411.

[0044] Optionally, the full frequency conversion module also includes a connecting bracket, which is mounted on the second bracket 417 and extends to the side of the third bracket 418, with the expansion valve 413 mounted on the connecting bracket. The design of the connecting bracket allows the expansion valve 413 to be installed in the space between the second bracket 417 and the third bracket 418, thereby optimizing the overall module layout. This layout not only saves space but also makes the connections between the various components more compact and orderly.

[0045] Optionally, the module control box 45 also includes a housing, in which the DC frequency converter driver and the module control board are housed. Mounting parts are provided on both sides of the housing, and the mounting parts are connected to the first bracket 416 by screws, making the connection simple and reliable.

[0046] Specifically, the EC axial fan 412 is mounted on the second bracket 417 by screws.

[0047] Please see Figure 1As shown, the pre-treatment air unit also includes a housing 60, with the blower 20 and main control box 10 located in the middle of the housing 60. The air inlet 34 and air outlet 35 are respectively located on two different sides of the housing 60. Several fully variable frequency modules are distributed along the air duct. The evaporator 414 of each fully variable frequency module is connected to the air duct and is used to cool or heat the pre-treated air in the air duct. The blower 20, located in the middle of the housing 60, can more effectively drive the air to circulate within the housing 60, ensuring the uniformity and efficiency of airflow. Simultaneously, the air inlet 34 and air outlet 35 being located on two different sides helps to form effective air convection and improve air exchange efficiency.

[0048] Specifically, the air inlet 34 and the air outlet 35 are respectively located on two opposite sides of the housing 60.

[0049] In other embodiments, the positions of the air supply system, main control box 10, and full frequency conversion module can also be set according to the actual situation.

[0050] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A pre-treatment air unit suitable for aircraft, characterized in that, The system includes an air supply system, a main control box, and several fully variable frequency modules. The air supply system comprises an air duct and a blower installed within it. The blower is connected to the main control box. The air duct has an air inlet and an air outlet. The blower delivers pre-treated air from the air inlet to the air outlet. Several fully variable frequency modules are distributed between the air inlet and the air outlet. Each fully variable frequency module includes a refrigeration module and a module control box. The number of module control boxes corresponds to the number of refrigeration modules. Each refrigeration module includes a DC inverter compressor, a condenser, an axial fan assembly, an expansion valve, and an evaporator. The axial fan assembly provides cooling air to the condenser. The DC inverter compressor... The compressor, condenser, expansion valve, and evaporator are connected end-to-end. An axial fan assembly is mounted on the condenser. The module control box includes a DC inverter driver and a module control board. The DC inverter driver is connected to the DC inverter compressor, and the module control board is connected to the main control box, the DC inverter driver, the axial fan assembly, and the expansion valve. The pre-treatment air unit includes four fully variable frequency modules: a first fully variable frequency module, a second fully variable frequency module, a third fully variable frequency module, and a fourth fully variable frequency module. The air duct includes a first sub-duct, a second sub-duct, and a third sub-duct connected sequentially. The blower is located in the second sub-duct. The first and second full-frequency conversion modules are respectively located on both sides of the first sub-air duct and are respectively connected to the first sub-air duct. The third and fourth full-frequency conversion modules are respectively located on both sides of the third sub-air duct and are respectively connected to the third sub-air duct. The module control boards of the first, second, third, and fourth full-frequency conversion modules are respectively connected to the main control box. The full-frequency conversion module also includes a base, a first bracket, a second bracket, a third bracket, and a top plate. The first bracket is located at the lower right of the base. The second bracket is located to the left of the first bracket and is connected to the first bracket. The condenser is installed behind the second bracket. The axial flow fan assembly is installed in front of the second bracket. The third bracket is located in front of the axial flow fan assembly. The top plate is installed on top of the first, second, and third brackets. The DC inverter compressor is installed on the base and is located in front of the first bracket. The module control box is installed on the first bracket. The expansion valve is installed on the second bracket.

2. The pre-treatment air unit for aircraft as described in claim 1, characterized in that, The main control box includes a main control board, a frequency converter driver, and a touch screen. The main control board is connected to the module control board of each of the full frequency conversion modules, the frequency converter driver is connected to the blower, and the touch screen is connected to the main control board.

3. The pre-treatment air unit for aircraft as described in claim 1, characterized in that, The full frequency conversion module also includes a connecting bracket, which is mounted on the second bracket and extends to the side of the third bracket, and the expansion valve is mounted on the connecting bracket.

4. The pre-treatment air unit for aircraft as described in claim 1, characterized in that, The module control box also includes a housing, in which the DC frequency converter driver and the module control board are both housed. Mounting portions are provided on both sides of the housing, and the mounting portions are screwed to the first bracket.

5. The pre-treatment air unit for aircraft as described in claim 1, characterized in that, It also includes a housing, in which the air duct is formed, the air inlet and the air outlet are respectively located on two different sides of the housing, the blower and the main control box are respectively located in the middle of the housing, and several of the full frequency conversion modules are arranged in the housing along the air supply direction.

6. The pre-treatment air unit for aircraft as described in claim 5, characterized in that, The air inlet and the air outlet are respectively located on two opposite sides of the housing.

7. The pre-treatment air unit for aircraft as described in claim 1, characterized in that, The axial fan assembly includes an EC axial fan, which is mounted on the condenser and connected to the module control board.

8. The pre-treatment air unit for aircraft as described in claim 1, characterized in that, The axial flow fan assembly includes an AC axial flow fan and an axial flow fan speed controller. The AC axial flow fan is installed on the condenser, and the axial flow fan speed controller is installed in the module control box. The axial flow fan speed controller is connected to the AC axial flow fan and the module control board, respectively.

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