Control box device for fresh air handling unit

Abstract

The utility model discloses a control box device for fresh air handling unit belongs to fresh air system control equipment technical field. The device includes the box body of installing in the one -way air duct of fresh air handling unit, and the opening direction of box body is perpendicular with the wind direction and has the outer open box door of hinged, and the door opening direction of box is the adverse wind direction, and the door closing assembly contains the vertical pressure -bearing plate, and one end is fixed to the outside of box door, and the other end is inclined to the direction of away from the box body and forms the pressure -bearing surface. The component of force that the airflow acts on the inclined pressure -bearing surface generates is converted into the door closing moment, realizes the automatic locking of box door. The problem that the control box in the air duct leads to the sealing failure of air flow impact, the operation difficult problem is solved, and the box door is locked by wind energy, and the sealing reliability is improved significantly, and the stability of equipment under the vibration, high pressure difference working condition is enhanced.

Description

Technical Field

[0001] This utility model relates to the technical field of fresh air system control equipment, and in particular to a control box device for fresh air units. Background Technology

[0002] As the core equipment of a building's ventilation system, the environmental stability of the electrical control box of a fresh air handling unit is crucial. Considering the air pressure and relatively stable temperature conditions in the duct during the operation of the fresh air handling unit, the control box can be installed directly inside the duct. However, this installation method faces many problems.

[0003] During operation of the fresh air handling unit, a continuous unidirectional high-speed airflow exists within the duct, accompanied by pressure fluctuations caused by the fan's start and stop. Traditional control box doors use simple hinges and manual locks, which are prone to vibration and displacement under long-term airflow impact, leading to seal failure. This significantly increases the risk of dust and moisture entering the box, causing short circuits or corrosion of electrical components.

[0004] The inverters, contactors, and other components inside the control box generate concentrated heat during operation. Existing technologies mainly rely on three heat dissipation solutions: natural convection cooling depends on the surface area of ​​the box, but the control box is enclosed within the air duct, resulting in extremely limited effective heat dissipation area; forced air cooling requires the addition of fans, which not only increases energy consumption and potential failure points, but also interferes with the airflow field of the main air duct; and ventilation through openings in the air duct walls compromises the airtightness of the air duct. All three solutions struggle to balance heat dissipation efficiency with system reliability.

[0005] Current industry attempts include optimizations such as strengthening the mechanical strength of door latches, increasing the number of sealing strips, and using high thermal conductivity metal back plates. However, mechanical reinforcement can only delay, not eliminate, vibration-induced seal failure and increases operational burden; the heat-conducting back plate offers limited improvement in heat dissipation without forced airflow. Therefore, there is an urgent need for a control box design that can simultaneously address the issues of sealing and self-locking under airflow conditions and efficient passive heat dissipation. Utility Model Content

[0006] This invention overcomes the problems of sealing failure and operational difficulties caused by airflow impact in the control box inside the air duct. It utilizes wind energy to achieve self-locking of the box door, significantly improving sealing reliability. The design of opening the door against the wind prioritizes safety locking. It also enhances the stability of the equipment under vibration and high pressure differential conditions.

[0007] To achieve the above objectives, the present invention adopts the following solution: Control box device for fresh air handling units, comprising: The enclosure is installed in the unidirectional air duct of the fresh air unit. The inside of the enclosure is the area for installing control components and is equipped with a wiring interface. The opening direction of the enclosure is perpendicular to the airflow direction in the air duct. The enclosure opening is hinged with an outward-opening door and is equipped with a locking mechanism. The door opens in the opposite direction of the wind. The door closing assembly includes a vertically arranged pressure plate, one end of which is connected to the outside of the door, and the other end of which extends along the airflow direction and away from the box body, forming a pressure surface with an inclined angle to the wind direction.

[0008] Preferably, the pressure plate is connected to the free end of the door via a sliding structure, and the sliding direction is horizontal. The locking mechanism includes a socket and a pin. The socket is located on the edge of the leeward side panel of the box, and the pin is fixedly connected to the pressure plate. The pin is inserted into or removed from the socket when the pressure plate slides.

[0009] Preferably, the sliding structure includes a transverse sliding groove at the door, and the pin is U-shaped and includes an outer section and an inner section. The outer section is fixedly connected to the pressure plate, and the inner section is slidably positioned in the transverse sliding groove. The end of the inner section is provided with a wedge-shaped inclined surface for retracting under pressure when the door is closed. The wedge-shaped inclined surface is located on the side in contact with the box body.

[0010] Preferably, the inner side of the back panel of the enclosure is provided with a heating device installation area, and the outer side of the back panel is provided with an air guide plate at the position corresponding to the heating device installation area. The air guide plate and the back panel are spaced apart and the spacing decreases along the airflow direction. The air guide plate and the back panel of the enclosure together form a concentrating air heat dissipation channel.

[0011] Preferably, the back panel is provided with an L-shaped connector, which includes a lateral extension section and a flat mounting section. The length of the lateral extension section is greater than the distance between the outer side of the air guide plate and the back panel of the housing. The flat mounting section is provided with mounting holes and is fixed to the side panel of the fresh air unit by bolts that cooperate with the mounting holes.

[0012] Preferably, there are at least two wind deflectors, with two adjacent wind deflectors connected in series along the wind direction, and the inlet of the wind deflector in the downwind area is aligned with the outlet of the wind deflector in the upwind area.

[0013] This utility model has at least the following beneficial effects: (1) By converting the kinetic energy of the airflow into the closing torque through the pressure plate, the door is automatically locked, which significantly improves the sealing reliability under the conditions of airflow vibration and pressure fluctuation, and avoids the problem caused by incomplete closing; (2) The sliding locking mechanism composed of the U-shaped pin and the wedge-shaped inclined surface automatically completes the pin alignment and insertion under the drive of airflow, effectively avoiding the locking failure caused by mechanical tolerance, and reducing the risk of abnormal opening of the door under strong vibration conditions; (3) The gradually narrowing air-gathering channel formed by the air guide plate and the back plate utilizes The Venturi effect accelerates airflow to achieve passive enhanced heat dissipation, significantly improving the thermal reliability of high-power devices, while avoiding the increase of failure points caused by external heat dissipation equipment; (4) The L-shaped connector, combined with the elongated hole mounting structure, absorbs the vibration energy of the air duct through elastic deformation, greatly reducing the mechanical stress transmitted to the control element, extending the life of electronic devices and simplifying the installation and adjustment process; (5) The multi-stage series air guide plate accelerates the airflow step by step and divides the thermal management zone, breaks through the single-stage heat dissipation limit, eliminates the temperature gradient of the back panel of the box, and realizes the directional temperature control optimization of the high heat flux density area. Attached Figure Description

[0014] Figure 1 This is a side view of the control box device of this utility model; Figure 2 This is a top view of the control box device of this utility model; Figure 3 This is a front view of the control box device of this utility model; Figure 4 This is a schematic diagram of the rear structure of the control box device of this utility model; Figure 5 This is a schematic diagram of the pin and socket structure of this utility model; Figure 6 This is a schematic diagram of the locking method of this utility model.

[0015] In the diagram: 1. Box body; 2. Box door; 3. Pressure plate; 4. Pin; 5. Socket; 6. Air guide plate. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0017] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0018] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the materials described are commercially available unless otherwise specified. In the description of this utility model, it should be noted that, unless otherwise explicitly stated and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0019] like Figure 1-4 As shown, the control box device for a fresh air handling unit provided by this utility model includes: The enclosure 1 is installed in the unidirectional air duct of the fresh air unit. The inside of the enclosure 1 is the area for installing control components and is equipped with internal and external wiring interfaces. The opening direction of the enclosure 1 is perpendicular to the airflow direction in the air duct. The opening of the enclosure 1 is hinged to an outward-opening door 2 and is equipped with a locking mechanism. The opening direction of the door 2 is against the wind direction. The door closing assembly includes a vertically arranged pressure plate 3, one end of which is connected to the outside of the door 2, and the other end of which extends along the airflow direction and is inclined away from the box body 1 to form a pressure surface with an inclined angle to the wind direction.

[0020] This control box is designed specifically for the operating characteristics of fresh air handling units. Utilizing the continuous air pressure and relatively stable temperature environment within the ductwork during operation, a specific structural design addresses the issues of sealing, ease of operation, and environmental adaptability within the control box. The device mainly comprises two core components: the housing and the door closing assembly.

[0021] The enclosure 1 serves as the mounting carrier for the control components, and its installation location is limited to inside the unidirectional air duct of the fresh air handling unit, with the enclosure 1 directly situated within the airflow environment. The internal space of enclosure 1 is specifically designed as a control component installation area, accommodating core components such as electrical switches, controllers, and wiring terminals. It also features internal and external wiring interfaces to facilitate the connection and exit of power lines, signal lines, and other conduits, ensuring the realization of control functions. Enclosure 1 has an opening, the orientation of which is designed to be perpendicular to the airflow direction within the duct (i.e., unidirectional airflow) (generally understood as a 90-degree angle, allowing for certain engineering tolerances, such as ±5 degrees). Figure 3As shown, at the opening, a hinged door 2 that can open outwards is connected, and a locking mechanism is provided between the housing 1 and the door 2 to lock the door 2 after it is closed. Crucially, the opening direction of the door 2 (i.e., the direction in which the door 2 rotates around the hinge axis) is set against the airflow direction (backwind direction). This directional design is fundamental to ensuring the effective operation of the subsequent door closing assembly. The door 2 is typically only opened during line maintenance, at which time the fresh air unit is pre-shut down. In the off state, there is no airflow in the duct, allowing the door 2 to be opened freely without the operator needing to overcome airflow thrust.

[0022] The main purpose of placing enclosure 1 in the air duct is to make full use of the spare space within the air duct, to use the continuous air pressure within the air duct during the operation of the fresh air unit to keep the door tightly closed, and to use the relatively stable temperature environment within the air duct to dissipate heat from enclosure 1. Even under high external temperatures, the airflow temperature in the fresh air duct is always at a relatively low temperature that is comfortable for the human body, thus eliminating the need for additional heat dissipation equipment for the control box. The design of the angle and structure of enclosure 1 is based on the following considerations: 1) Electrical components inside the control box are typically housed on the back panel for easy installation, inspection, and maintenance. Therefore, the critical heat dissipation area of ​​the control box is on the back panel. To ensure the box's airtightness, direct heat dissipation to the component surfaces is not feasible; instead, indirect heat dissipation occurs through the back panel. Therefore, airflow on the outer surface of the back panel must be ensured. Consequently, the back panel should not be positioned leeward, but rather facing the wind or parallel to the wind direction. 2) The door 2 needs to remain normally closed, and its closure must be stable. Conventional thinking might suggest positioning the outer surface of door 2 facing the wind to utilize wind pressure for stable closure. However, this clearly contradicts the aforementioned back panel angle requirement. Furthermore, the box body 1 is usually relatively flat, and positioning door 2 facing the wind would occupy more of the air duct cross-section. Also, the box body 1 is typically positioned against the inner wall of one side of the air duct, and a lateral angle facilitates access for maintenance via a port on the opposite side of the air duct. Therefore, considering these two aspects, the control box is designed with its opening perpendicular to the airflow direction within the air duct. The specific structures described below are designed based on this fundamental structural consideration.

[0023] The door closing assembly is the core mechanism ensuring the reliable closure of the enclosure door 2 in the duct environment. This assembly includes a vertically positioned pressure plate 3 (approximately perpendicular to the bottom of the duct). One end of the pressure plate 3 is fixedly connected to the outer surface of the enclosure door 2 (i.e., the side facing the airflow direction). The other end of the pressure plate 3 (usually the upper end or the free end away from the hinge of the enclosure door 2) extends along the direction of airflow, and this extension is not parallel or perpendicular to the airflow, but rather inclined away from the main body of the enclosure 1. This inclined design makes the pressure plate 3 form a pressure surface with a specific angle of inclination to the airflow direction. This angle of inclination (typically between 30 and 60 degrees, with 45 degrees being a common and effective choice) is crucial. When the fresh air unit is operating, generating a continuous unidirectional airflow within the duct, the airflow directly impacts this inclined pressure surface. According to fluid mechanics principles, the force of the airflow acting on the inclined surface can be decomposed into a component parallel to the surface (friction, smaller) and a component perpendicular to the surface (normal force). The component perpendicular to the pressure surface generates a force, the direction of which is guided by the inclination angle of the pressure plate 3, and ultimately transforms into a torque that drives the door 2 to rotate in the closing direction. The pressure plate 3 transmits this torque to the door 2 through its connection point, pushing the door 2 to overcome the resistance or slight deformation of the box body 1, thereby pressing it tightly against the opening sealing surface of the box body 1.

[0024] When maintenance or operation of internal components of the control box is required, the operator must first operate the door locking mechanism to unlock it. Although door 2 opens outwards and faces the wind, the unit has been shut down before maintenance. The operator does not need to overcome the oncoming airflow force; simply pulling door 2 outwards manually will open it normally. After the operation is complete, the operator only needs to gently push door 2 inwards (towards the wind) to bring it into its closed position. Even if door 2 is not closed, once the fresh air unit starts operating, the air pressure in the duct will push door 2 to close. When door 2 closes to a certain angle (at which point the pressure plate 3 begins to be more exposed to the airflow), the continuously flowing airflow in the duct will act on the inclined pressure-bearing surface of the pressure plate 3. The component force perpendicular to the pressure-bearing surface generated by the airflow is effectively converted into a strong closing torque through the rigid connection between the pressure plate 3 and door 2. This torque will continue to act, assisting or even automatically pushing door 2 completely to the closed position and ensuring that the sealing strip at the edge of door 2 fits tightly against the opening of the housing 1. Once properly engaged, the automatic locking mechanism will lock the door 2, completing the closing process. Even when the fan is running, the strong airflow under the force transformation of the pressure plate 3 provides a continuous closing force, ensuring that the door 2 will not be accidentally opened due to vibration or negative pressure.

[0025] Compared to existing control boxes installed within air ducts (whose doors typically use simple hinges and locks without dedicated pneumatic assistance), this device offers significant advantages. With existing control boxes directly installed within the air duct, especially in high-velocity or pressure-fluctuating environments, high external wind speeds create significant negative pressure inside and outside the box, pushing the door outwards. Even when locked, there's usually a certain clearance, making the door prone to vibration, poor sealing, or even accidental opening due to airflow impact and negative pressure. This not only affects equipment reliability but also poses safety hazards. The closing component in this design cleverly utilizes the existing airflow energy within the air duct, converting it into the power to automatically close the door. This design significantly enhances the closing reliability and sealing performance of the enclosure door 2 in airflow environments. The continuous pressure applied by the airflow effectively counteracts the tendency of the enclosure door 2 to loosen due to vibration or negative pressure. The airflow automatically assists in completing the closing stroke of the enclosure door 2 and keeps it tightly closed, avoiding problems caused by forgetting to close the door or not closing it completely. It improves the environmental adaptability of the equipment, especially in airflow conditions with high wind speeds or unstable pressure, and can more reliably protect sensitive internal control components from external environmental factors (dust, moisture, foreign objects). At the same time, the priority of opening the door against the wind ensures the maximum utilization of the door closing assistance and the priority of safety interlocking. Overall, this design achieves highly reliable operation and convenient maintenance of the control box in harsh airflow environments, solving key pain points in existing technologies.

[0026] In another technical solution, such as Figure 5 and Figure 6 As shown, the pressure plate 3 is connected to the free end of the door 2 via a sliding structure, and the sliding direction is horizontal. The locking mechanism includes a socket 5 and a pin 4. The socket 5 is located on the edge of the leeward side plate of the box body 1. The pin 4 is fixedly connected to the pressure plate 3, and the pin 4 is inserted into or removed from the socket 5 when the pressure plate 3 slides.

[0027] The cabinet door uses an embedded hinge design, with a raised section inside the cabinet that rests against when the door is closed. A lateral sliding structure is introduced to link the closing assembly and the locking mechanism. This structure is directly connected to the free end of the cabinet door 2 (the side furthest from the hinge, typically the side with the door handle and lock). The sliding structure usually consists of a lateral groove (a rectangular cross-section groove) on the cabinet door 2, allowing the pressure plate 3 to move horizontally along the plane of the cabinet door 2. The insertion hole 5 is located on the edge of the leeward side panel of the cabinet body 1 (the panel of the cabinet body 1 downstream of the airflow), its position precisely corresponding to the movement trajectory of the pressure plate 3 when the cabinet door 2 is closed. The pin 4 is a rigid metal rod (such as a stainless steel cylindrical pin, with a diameter of 6-10mm), its base fixedly connected to the pressure plate 3. When the door 2 is closed, the pressure plate 3 moves towards the insertion hole 5 under the thrust of the airflow. Simultaneously, through the lateral displacement of the sliding structure, it causes the latch 4 to slide synchronously, ensuring that the end of the latch 4 is precisely inserted into the insertion hole 5, forming a mechanical lock. Due to the continuous force of the airflow, the latch 4 will not disengage. When opening the door in the opposite direction, pushing the pressure plate 3 in the opposite direction of the airflow will disengage the latch 4 from the insertion hole 5, releasing the lock. The pressure plate 3 also functions as a handle, allowing for quick opening. This design converts pneumatic force into locking force, achieving an automated process of "locking upon closing the door."

[0028] In operation, when the door 2 is pushed from the open position to the closed position, the airflow continuously acts on the inclined surface of the pressure plate 3, generating two components: the pressure perpendicular to the plate surface drives the door 2 to rotate and close, while the force parallel to the plate surface is converted into the lateral displacement of the pressure plate 3 through the sliding structure (displacement of approximately 5-15mm). The lateral movement of the pressure plate 3 synchronously pulls the pin 4 to move along the slide track. The axis of the pin 4 is aligned with the center of the insertion hole 5, and the airflow pressure continuously pushes the pressure plate 3, eventually fully inserting the pin 4 into the insertion hole 5 (insertion depth recommended 8-12mm). At this time, the rigid fit between the pin 4 and the insertion hole 5 can resist the negative pressure suction or vibration impact that may occur in the air duct, and can still maintain a stable lock even when the unit is stopped and there is no air pressure. To unlock, the operator first pushes the pressure plate 3, which drives the pin 4 to slide in the opposite direction and disengage from the insertion hole 5, and then pulls the door 2 outward to fully open it. Compared to traditional bolt fixing or manual knob locking methods, this sliding door locking mechanism works in conjunction with the pressure plate 3 to automatically lock the door using wind pressure in the airflow environment. The closing process does not require manual operation of the lock. The rigid fit between the pin 4 and the socket 5 can effectively suppress the slight vibration of the door 2 caused by wind pressure pulsation, reducing the risk of seal failure. The sliding structure absorbs assembly tolerances and deformation, avoiding damage from hard collisions. The single-handed push and pull action of the pressure plate 3 can continuously unlock and open the door, simplifying the operation steps.

[0029] The sliding structure includes a transverse sliding groove at the door 2, and the pin 4 is U-shaped and includes an outer section and an inner section. The outer section is fixedly connected to the pressure plate 3, and the inner section is slidably positioned in the transverse sliding groove. The end of the inner section is provided with a wedge-shaped inclined surface for retracting under pressure when the door is closed. The wedge-shaped inclined surface is located on the side that contacts the box body 1.

[0030] A U-shaped pin 4 (e.g., made of bent φ5mm round steel) is used. This pin 4 consists of an outer section and an inner section arranged in parallel, connected by a transition section. The outer section is rigidly fixed to the pressure plate 3 (e.g., by welding or bolting) and directly transmits aerodynamic force. The inner section serves as a guide and actuator, with its end inserted into a transverse groove on the door 2, allowing it to slide freely within the groove. The U-shaped topology achieves force diversion within a limited space: the outer section bears the wind pressure load, while the inner section is dedicated to sliding guidance, avoiding deformation and jamming caused by single-point force. Furthermore, the U-shaped structure can hook onto the outer wall of the groove, preventing it from falling off.

[0031] At the end of the inner section (i.e., the end in contact with the housing 1), a wedge-shaped inclined surface is machined (the inclination angle can be selected from 30° to 45°). This inclined surface is located on the side of the pin 4 facing the housing 1, and its function is to achieve "soft alignment" at the end of the closing of the door 2. When the door 2 is close to the closed position (the gap between the door and the housing 1 is about 2-5mm), the wedge-shaped inclined surface first contacts the edge of the leeward side panel of the housing 1. The edge of the leeward side panel of the housing 1 can also be provided with an inclined chamfer that matches the inclined surface. As the door 2 continues to close, the inclined geometry of the inclined surface decomposes the longitudinal blocking force of the housing 1 on the pin 4 into two components, forcing the pin 4 to retract along the slide groove away from the insertion hole 5, and fully retract into the slide groove. After the door is fully closed, the force on the inclined surface disappears, and the pin 4 can slide into the insertion hole 5 under the wind pressure of the pressure plate 3. This process transforms mechanical interference into smooth displacement adjustment, including the following stages: Pre-closing stage: The airflow pushes the pressure plate 3 and the door 2. When the door 2 rotates to a small angle with the box body 1, the inner section of the latch 4 begins to enter the interference zone at the edge of the box body 1. Wedge insertion stage: The wedge-shaped inclined surface contacts the edge of the box 1. Under the action of inertia, the reaction force of the box 1 pushes the pin 4 through the inclined surface, forcing it to move outward along the slide groove. The box door 2 is not hindered by the pin 4 and closes normally.

[0032] When the door 2 is fully closed, the latch 4 retracts to its limit position within the slide groove, aligning its axis with the insertion hole 5. Airflow pressure immediately pushes the pressure plate 3 back to its original position, causing the end of the latch 4 to quickly insert into the insertion hole 5, completing the final locking. The entire process requires no precise alignment; the system automatically compensates for assembly deviations.

[0033] This design provides a revolutionary improvement for high-vibration and easily deformable air duct conditions. The wedge-shaped bevel allows for millimeter-level positional deviation between the pin 4 and the socket 5, solving the problem of "pin 4 hitting the socket". The beveled contact replaces hard collision, significantly reducing wear between the pin 4 and the housing 1. The pin 4 retraction mechanism can avoid obstructing the closing of the door 2.

[0034] In another technical solution, a heating device mounting area is provided on the inner side of the back panel of the housing 1, and an air guide plate 6 is provided on the outer side of the back panel at a position corresponding to the heating device mounting area. The air guide plate 6 is spaced apart from the back panel and the spacing decreases along the airflow direction. The air guide plate 6 and the back panel of the housing 1 together form a concentrating airflow and heat dissipation channel.

[0035] To address the temperature rise issue of heat-generating components (such as frequency converters and power modules) within the control box, an active cooling system has been added to the structure of box 1. A dedicated mounting area for heat-generating components (typically located in the center of the back panel, occupying 40%-60% of the back panel area) is planned on the inner side of the back panel for centralized mounting of high-power electronic components. On the corresponding location on the outer side of the back panel, one or more air guide plates 6 are added parallel to the back panel and spaced apart (a spacing of 5-15mm is recommended). Figure 1 , Figure 2 and Figure 4 As shown, the air guide plate 6 extends outward from the surface of the back plate, and its cross-section gradually narrows along the airflow direction (the inlet spacing is greater than the outlet spacing, and the contraction angle is about 5°-15°). The space between the air guide plate 6 and the back plate of the housing 1 forms an air-gathering and heat dissipation channel. The structural design of this channel, with a large inlet and a small outlet, follows the Venturi effect principle.

[0036] When the fresh air unit is running, unidirectional airflow flows through the outer side of the back panel of housing 1. The wide-inlet air guide structure captures a wider range of airflow, while the tapering channel forces the airflow to accelerate (increasing the wind speed by 1.5-3 times). The accelerated airflow flows tightly against the outer surface of the back panel, forming a high-speed shear layer. According to Newton's law of cooling, airflow velocity is positively correlated with heat dissipation efficiency. The high-speed airflow quickly carries away the heat from the heat-generating components inside the back panel through the metal back panel (usually a 2-3mm aluminum plate). The tapering design of the air guide plate 6 also generates a low-pressure adsorption effect, enhancing the stability of the airflow penetration channel and avoiding heat dissipation dead zones caused by eddies.

[0037] In actual operation, ambient temperature airflow enters through the inlet of the air guide plate 6 (spacing approximately 10-20mm). As it flows through a channel 100-300mm long, the spacing gradually narrows to 3-8mm at the outlet. The airflow velocity increases from an initial 2m / s to 5-8m / s, forming a continuous, highly efficient forced convection layer on the outer surface of the backplate. Heat is conducted from the heating element to the inner wall of the backplate, and then exchanged with the high-speed airflow through the outer wall. Under a duct velocity of 1.5m / s, this structure can reduce the backplate temperature by more than 15°C compared to a design without the air guide plate 6, and improve temperature distribution uniformity by over 30%. The entire heat dissipation process requires no additional energy consumption, fully utilizing the inherent airflow of the fresh air system. Compared to the passive heat dissipation (relying on natural convection of the metal casing) or independent fan heat dissipation of traditional air duct control boxes (which increases energy consumption and failure points), this design improves heat dissipation efficiency to more than 3 times that of natural convection by accelerating airflow, effectively preventing electronic components from overheating and failing; it eliminates the need for cooling fans and related circuits, reducing equipment complexity and failure rate; and the air-gathering channel maintains effective heat dissipation even under low wind speed conditions.

[0038] The back panel is equipped with an L-shaped connector, which includes a lateral extension section and a flat mounting section. The length of the lateral extension section is greater than the distance between the outer side of the air guide plate 6 and the back panel of the housing 1. The flat mounting section is provided with mounting holes and is fixed to the side panel of the fresh air unit by bolts that cooperate with the mounting holes.

[0039] An L-shaped connector is used as a bridge between the air guide plate 6 and the side panel of the fresh air unit. This connector is formed by bending a single piece of metal sheet (such as 2mm galvanized steel sheet) and includes mutually perpendicular lateral extension sections (length L1) and a flat mounting section. One end of the lateral extension section is fixed to the back panel of the housing 1, and the other end cantilevered out. Its core dimensional constraint is that the length L1 of the lateral extension section must be greater than the distance D between the outermost side of the air guide plate 6 and the back panel of the housing 1 (i.e., L1>D+1~3mm margin), ensuring that there is no contact friction between the air guide plate 6 and the inner wall of the air duct.

[0040] The planar mounting section has several mounting holes for fastening to the side plate of the fresh air unit with bolts. The cantilever characteristic of the L-shaped structure gives the system vibration resistance: when the duct vibrates at low frequencies due to the start and stop of the fan, the lateral extension section can undergo slight elastic deformation (deformation of about 0.1-0.5mm) to absorb vibration energy. At the same time, the mounting holes are designed as elongated holes (the length is along the main axis of vibration, and the hole length is 10-15mm), allowing the bolts to have a displacement margin of ±2mm within the hole, further eliminating interference caused by assembly stress and thermal expansion and contraction.

[0041] During installation, first weld the air guide plate 6 to the designated position on the back panel of the housing 1, and measure the maximum distance D from the outer edge of the air guide plate 6 to the back panel. Select an L-shaped connector with L1=D+(2±0.5)mm and weld its lateral extension to the four corners of the back panel. Push the housing 1 into the air duct installation position and adjust the position to maintain a 1-3mm gap between the air guide plate 6 and the inner wall of the air duct. Then, insert bolts (M6-M8 grade recommended) into the elongated holes of the flat installation section, pre-tighten to 50% torque, start the fan and observe the vibration of the air guide plate 6, and finally tighten to 80%-100% of the design torque according to the gradient. This process ensures that the heat dissipation channel maintains the optimal gap under dynamic operating conditions.

[0042] Compared to traditional rigid welding or integral bracket installation, flexible connections reduce the vibration acceleration transmitted to electronic components, significantly extending device lifespan; the cantilever structure absorbs the expansion stress generated by the temperature rise of the metal backplate, preventing the connectors from cracking.

[0043] like Figure 4 As shown, there are at least two wind guide plates 6, and two adjacent wind guide plates 6 are connected in series along the wind direction, with the inlet of the wind guide plate 6 in the downwind area aligned with the outlet of the wind guide plate 6 in the upwind area.

[0044] The single-stage air guide vane 6 is upgraded to a series multi-stage air guiding system, which includes at least two air guide vanes 6 (typically 2-3 stages), arranged sequentially along the airflow direction. Each stage air guide vane 6 is an independent tapering channel, and an airflow relay zone is formed between adjacent stages. The inlet centerline of the lower stage air guide vane 6 must be precisely aligned with the outlet centerline of the upper stage air guide vane 6 (alignment tolerance ≤ 1.5mm) to form a seamless airflow guiding path.

[0045] When the airflow passes through the first-stage guide vane 6, it undergoes initial acceleration (e.g., from 2 m / s to 4 m / s) and preliminary heat dissipation. The airflow exiting the first-stage outlet maintains a high velocity and is directly injected into the inlet of the second-stage guide vane 6. Since the cross-sectional area of ​​the second-stage inlet is larger than that of the first-stage outlet (area ratio recommended to be 1.1:1 to 1.3:1), the airflow briefly diffuses and slows down in the transition zone, and is then accelerated again in the second-stage converging channel. This multi-stage acceleration creates a stepped increase in wind speed, breaking through the speed limit of a single-stage structure. Simultaneously, the front-stage guide vane 6 pre-cools the base temperature of the back panel, while the rear-stage guide vane 6 enhances heat dissipation in high-temperature areas, achieving refined division of thermal management.

[0046] Taking a two-stage system as an example: the fresh airflow first enters the first-stage air guide plate 6 (inlet spacing 15mm, length 150mm, outlet spacing 8mm), reducing the temperature of the front section of the back panel to below 50℃. The airflow jets out at a speed of 4m / s and enters the second-stage air guide plate 6 (inlet spacing 10mm, length 120mm, outlet spacing 5mm) 20-40mm from the first-stage outlet. The second-stage channel accelerates the airflow to 7m / s, providing enhanced cooling for the rear section of the back panel (usually near high-temperature components). Compared to a single-stage structure, the two-stage system improves heat dissipation power by 15%-25% under the same airflow, and the longitudinal temperature difference of the back panel is reduced from ±8℃ in a single-stage system to within ±3℃. By increasing speed in stages, the airflow separation limit of a single-stage structure is overcome, enabling targeted cooling of areas with ultra-high heat flux density. Staged heat dissipation eliminates the longitudinal temperature gradient on the backplate, preventing premature failure of electronic components caused by local overheating. Compared to single-stage coarse compression, multi-stage progressive acceleration reduces the space occupied by the inlet and lowers the airflow whistling noise by 10-15 decibels. By adjusting the length ratio of each stage (e.g., 60% for the pre-stage and 40% for the post-stage), it can be adapted to different sizes of air duct space.

[0047] The number of devices and processing scale described herein are for the purpose of simplifying the description of this utility model. Applications, modifications, and variations of this utility model will be readily apparent to those skilled in the art.

[0048] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A control box device for a fresh air handling unit, characterized in that, include: The enclosure is installed in the unidirectional air duct of the fresh air unit. The inside of the enclosure is the area for installing control components and is equipped with internal and external wiring interfaces. The opening direction of the enclosure is perpendicular to the airflow direction in the air duct. The enclosure opening is hinged with an outward-opening door and is equipped with a locking mechanism. The door opens in the opposite direction of the wind. The door closing assembly includes a vertically arranged pressure plate, one end of which is connected to the outside of the door, and the other end of which extends along the airflow direction and is inclined away from the box body to form a pressure surface with an inclined angle to the wind direction.

2. The control box device for a fresh air handling unit according to claim 1, characterized in that, The pressure plate is connected to the free end of the door via a sliding structure, and the sliding direction is horizontal. The locking mechanism includes a socket and a pin. The socket is located on the edge of the leeward side panel of the box body, and the pin is fixedly connected to the pressure plate. The pin is inserted into or removed from the socket when the pressure plate slides.

3. The control box device for a fresh air handling unit according to claim 2, characterized in that, The sliding structure includes a transverse sliding groove at the door, and the pin is U-shaped and includes an outer section and an inner section. The outer section is fixedly connected to the pressure plate, and the inner section is slidably positioned in the transverse sliding groove. The end of the inner section is provided with a wedge-shaped inclined surface for retracting under pressure when the door is closed. The wedge-shaped inclined surface is located on the side in contact with the box body.

4. The control box device for a fresh air handling unit according to claim 1, characterized in that, The inner side of the back panel of the enclosure is provided with a heating device installation area, and the outer side of the back panel is provided with an air guide plate at the position corresponding to the heating device installation area. The air guide plate and the back panel are spaced apart and the spacing decreases along the airflow direction. The air guide plate and the back panel of the enclosure together form a concentrated air heat dissipation channel.

5. The control box device for a fresh air handling unit according to claim 4, characterized in that, The back panel is equipped with an L-shaped connector, which includes a lateral extension section and a flat mounting section. The length of the lateral extension section is greater than the distance between the outer side of the air guide plate and the back panel of the housing. The flat mounting section is provided with mounting holes and is fixed to the side panel of the fresh air unit by bolts that cooperate with the mounting holes.

6. The control box device for a fresh air handling unit according to claim 4, characterized in that, There are at least two wind guide plates, and two adjacent wind guide plates are connected in series along the wind direction. The inlet of the wind guide plate in the downwind area is aligned with the outlet of the wind guide plate in the upwind area.

Images