A display cabinet with cyclical defrosting

Abstract

The present application relates to the technical field of display cabinet, specifically to a display cabinet capable of circulating defrosting, comprising a cabinet, an evaporator, a variable air duct assembly, a liftable baffle assembly and a driving assembly; the variable air duct assembly comprises a top air duct and a bottom air duct, the air outlet of the top air duct is arranged on the top of the cabinet adjacent to the glass door, the air outlet of the bottom air duct is arranged on the rear of the cabinet adjacent to the storage area, and the airflow temperature in the top air duct is higher than that in the bottom air duct. In the display cabinet capable of circulating defrosting, the double-temperature-zone variable air duct structure of the top high-temperature air duct and the bottom low-temperature air duct is arranged, and the liftable baffle assembly is used to switch the air path, so that the bottom low-temperature airflow is used to rapidly reduce the temperature and improve the refrigeration efficiency during normal refrigeration; the top high-temperature airflow is introduced to efficiently melt frost during defrosting, and an electric heating defrosting device is not needed to be additionally arranged, so that the energy consumption of the frost melting link is fundamentally reduced, and energy saving and emission reduction are realized.

Description

Technical Field

[0001] This invention relates to the field of display cabinet technology, and more specifically, to a display cabinet with recyclable defrosting capability. Background Technology

[0002] Currently, in commercial refrigerated display cases, frost easily forms on the evaporator surface during long-term operation. This frost increases air resistance, reduces heat exchange efficiency, leads to increased cooling energy consumption, and worsens temperature uniformity within the cabinet. Therefore, defrosting performance and energy consumption control have become core technical indicators in the industry. Existing display cases mostly use timed defrosting control logic, which cannot dynamically start and stop the defrosting program based on the actual frost status of the evaporator. This easily leads to problems such as defrosting without frost, insufficient defrosting, or excessive defrosting, resulting in significant energy waste. Furthermore, traditional display cases often use a single fixed air duct structure, which can only achieve single-path airflow and cannot match the airflow to the corresponding temperature zones according to different cooling and defrosting conditions. It is difficult to balance cooling and defrosting efficiency, and an unreasonable air duct layout can also lead to high operating noise and uneven internal temperature distribution.

[0003] Among existing related technologies, authorized patent CN116195857B discloses a display cabinet with an adaptive adjustable air duct. It achieves air delivery angle and air volume adjustment through the cooperation of variable air duct and adjustable fan blades, which can improve the uniformity of air delivery in the cabinet to a certain extent. However, this technology only focuses on air delivery adaptation under cooling conditions and does not design a dedicated air path switching structure for defrosting conditions. It cannot utilize airflow in different temperature zones in the cabinet to achieve circulating defrosting and still relies on external heating or timed defrosting methods. It does not solve the core defects of high defrosting energy consumption and the inability to intelligently switch airflow between defrosting and cooling conditions. Furthermore, it does not set up a precise defrosting judgment mechanism based on the evaporator frost status, resulting in limited energy-saving effect and defrosting stability. Summary of the Invention

[0004] The purpose of this invention is to provide a display cabinet with cyclic defrosting capability, in order to solve the problems of the technologies proposed in the background art that only focus on air supply adaptation under refrigeration conditions, do not design a dedicated air path switching structure for defrosting conditions, cannot utilize airflow in different temperature zones inside the cabinet to achieve cyclic defrosting, still rely on external heating or timed defrosting methods, and do not solve the core defects of high defrosting energy consumption and the inability to intelligently switch airflow between defrosting and refrigeration conditions.

[0005] To achieve the above objectives, the present invention provides a display cabinet with recirculating defrosting capability, comprising a cabinet body, an evaporator, a variable air duct assembly, a liftable baffle assembly, and a drive assembly. The variable air duct assembly includes a top air duct and a bottom air duct. The air outlet of the top air duct is located at the top of the cabinet near the glass door, and the air outlet of the bottom air duct is located at the rear of the cabinet near the storage area. The air temperature in the top air duct is higher than that in the bottom air duct. The liftable baffle assembly is located inside the variable air duct assembly. The drive assembly and the liftable baffle assembly are driven together. The liftable baffle assembly is configured to move up and down under the combined action of the driving force of the drive assembly and its own gravity to selectively open the top air duct or the bottom air duct. Under normal cooling conditions, the drive assembly stops working, and the liftable baffle assembly moves down under gravity and closes the top air duct, while the bottom air duct remains open to achieve a cooling cycle. Under defrosting conditions, the drive assembly starts, and the liftable baffle assembly moves up and closes the bottom air duct, while the top air duct remains open to achieve a defrosting cycle.

[0006] This setting can automatically switch the air path according to different operating conditions of cooling and defrosting, and use the airflow in the high and low temperature zones inside the box to achieve rapid cooling and efficient defrosting respectively, reducing energy waste and achieving energy saving and emission reduction.

[0007] As a preferred embodiment of the present invention, the variable air duct assembly further includes an air duct plate and an air duct cover plate. The air duct plate is provided with an upper air inlet communicating with the top air duct and a lower air inlet communicating with the bottom air duct. The air duct cover plate and the air duct plate are sealed together to form a closed air duct cavity. The air duct cover plate is used to increase the air intake flow area of ​​the bottom air duct.

[0008] This design creates a sealed and stable air duct structure, improves the air intake efficiency of the bottom air duct, and ensures sufficient airflow supply for the cooling cycle.

[0009] As a preferred embodiment of the present invention, the air duct plate is further provided with a baffle return port, which is located between the upper air inlet and the lower air inlet, and the flow area of ​​the baffle return port is smaller than the flow area of ​​the upper air inlet and the lower air inlet.

[0010] This setting can be used in conjunction with the baffle action to assist in airflow guidance, rationally allocate airflow direction, and improve the smoothness and accuracy of air duct switching.

[0011] As a preferred embodiment of the present invention, the liftable baffle assembly includes a fixed baffle and a movable baffle. The fixed baffle is fixedly connected to the top plate of the inner liner of the box. The movable baffle and the fixed baffle are rotatably coupled through bearings. The movable baffle is used to completely block the upper air inlet and partially block the baffle return port. The movable baffle is used to close or open the upper air inlet and adjust the conduction state of the baffle return port.

[0012] This feature enables flexible rotation and precise sealing of the baffle, reliably controlling the opening and closing of the upper air inlet and the baffle return outlet, and ensuring the effectiveness of air duct switching.

[0013] As a preferred embodiment of the present invention, both the fixed fan plate and the movable fan plate are made of lightweight heat-insulating plastic material. When the movable fan plate moves down, it fits and seals with the air duct plate. When the movable fan plate moves up, it separates from the air duct plate to form an airflow channel.

[0014] This setting reduces the weight of the baffle to improve the reliability of gravity reset, reduces heat exchange between air ducts, and ensures stable switching between sealed and open states.

[0015] As a preferred embodiment of the present invention, the driving component is a driving motor, the output end of the driving motor is connected to the liftable baffle assembly for transmission, when the driving motor starts, the output torque drives the fixed fan plate of the liftable baffle assembly to flip open, and when the driving motor stops, the fixed fan plate of the liftable baffle assembly automatically falls back under the action of gravity.

[0016] This feature enables the baffle to be electrically driven and automatically reset by gravity. The control method is simple and reliable, ensuring stable execution of the air duct switching action.

[0017] As a preferred embodiment of the present invention, the top air duct is a tapered channel structure, with the cross-section of the air duct gradually shrinking along the direction from the glass door to the rear of the cabinet.

[0018] This design utilizes the narrow tube effect to increase the airflow velocity in the top duct, enhancing the defrosting capability of the high-temperature airflow and improving defrosting efficiency.

[0019] As a preferred embodiment of the present invention, the display cabinet further includes a centrifugal fan and a temperature detection and control unit. The centrifugal fan is located in the closed air duct cavity formed by the air duct cover and the air duct plate. The temperature detection and control unit is located near the evaporator. The temperature detection and control unit controls the speed of the centrifugal fan and the start and stop of the drive component according to the frosting state of the evaporator.

[0020] This setting enables intelligent collaborative control of the fan and drive components, accurately triggering the defrosting program based on the actual frosting status, thus avoiding unnecessary energy consumption.

[0021] As a preferred embodiment of the present invention, the centrifugal fan operates at high speed in the cooling state to enhance the airflow circulation in the bottom air duct, and the centrifugal fan operates at low speed in the defrosting state to cooperate with the airflow in the top air duct to complete the defrosting of the evaporator.

[0022] This setting adapts to the airflow requirements of different operating conditions, improving cooling efficiency while ensuring stable defrosting airflow and optimizing the overall operating performance of the unit.

[0023] As a preferred embodiment of the present invention, when the top air duct is open, the high-temperature airflow in the box flows through the evaporator to achieve efficient defrosting, and when the bottom air duct is open, the low-temperature airflow in the box flows through the evaporator to achieve rapid cooling. By switching the air ducts, energy consumption is reduced and energy saving and emission reduction are achieved.

[0024] This design makes full use of the airflow within the cabinet's own temperature zone, eliminating the need for additional heating and defrosting, significantly reducing energy consumption and improving the overall performance of the display case.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This recirculating defrosting display cabinet addresses the technical problems of existing refrigerated display cabinets, such as high energy consumption during timed defrosting, inaccurate defrosting methods, increased wind resistance and decreased refrigeration efficiency after evaporator frosting, and the inability of traditional single fixed air ducts to adapt to the dual-mode operation of refrigeration and defrosting. It also combines the shortcomings of the comparative document CN116195857B, which only allows adjustment of the air supply angle and does not have a dedicated defrosting air path, and achieves significant technical effects that are in line with practical applications.

[0026] 2. This recirculating defrosting display cabinet features a dual-temperature zone variable air duct structure with a top high-temperature air duct and a bottom low-temperature air duct. Combined with a liftable baffle assembly, it enables air path switching. During normal cooling, the low-temperature airflow at the bottom is used for rapid cooling, improving cooling efficiency. During defrosting, the high-temperature airflow at the top is introduced for efficient defrosting, eliminating the need for an additional electric heating defrosting device. This fundamentally reduces energy consumption during the defrosting process, achieving energy conservation and emission reduction.

[0027] 3. In this recyclable defrosting display cabinet, the working conditions are switched by relying on the air duct structure and the mechanical action of the baffle, which avoids the problems of no-frost defrosting, incomplete defrosting and over-defrosting caused by timed defrosting. It can stably and reliably complete the defrosting of the evaporator and ensure the continuous and stable heat exchange efficiency.

[0028] 4. In this recirculating defrosting display cabinet, the liftable baffle adopts a combination of motor drive and gravity reset, which is simple in structure and stable in operation. Combined with the sealed air duct and the gradually narrowing air duct structure, it effectively reduces airflow turbulence and operating noise, reduces wind resistance, and improves the uniformity of the air field, so that the display cabinet maintains a stable cooling effect during long-term continuous operation.

[0029] 5. Compared with existing technologies, this patented display cabinet with recyclable defrosting achieves reliable switching between refrigeration and defrosting modes, taking into account rapid cooling, efficient defrosting, low-noise operation and energy saving. It has a durable structure, low failure rate, and is more suitable for the long-term high-intensity use needs of commercial scenarios such as supermarkets and convenience stores. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 For the present inventionFigure 1 A magnified view of a portion of point A in the middle; Figure 3 This is one of the structural schematic diagrams of the variable air duct assembly in this invention; Figure 4 This is the second schematic diagram of the variable air duct assembly in this invention; Figure 5 This is an exploded structural diagram of the variable air duct assembly in this invention; The meanings of the labels in the diagram are as follows: 1. Housing; 2. Evaporator; 3. Variable air duct assembly; 4. Liftable baffle assembly; 5. Drive assembly; 31. Top air duct; 32. Bottom air duct; 33. Air duct plate; 34. Air duct cover; 331. Upper air inlet; 332. Lower air inlet; 333. Baffle return port; 41. Fixed fan plate; 42. Movable fan plate; 43. Bearing; 6. Centrifugal fan; 7. Temperature detection and control unit. Detailed Implementation

[0031] 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.

[0032] This invention provides a display cabinet with recyclable defrosting capability, such as... Figures 1-5 As shown, the system includes a housing 1, an evaporator 2, a variable air duct assembly 3, a liftable baffle assembly 4, a drive assembly 5, a centrifugal fan 6, and a temperature detection and control unit 7. The variable air duct assembly 3 is located inside the housing 1 and is used to create an independent airflow channel. The liftable baffle assembly 4 is located inside the variable air duct assembly 3 and is used to control the opening and closing of the air duct. The drive assembly 5 and the liftable baffle assembly 4 form a transmission cooperation to provide power for the baffle movement. The centrifugal fan 6 is integrated inside the air duct cavity and is responsible for driving the airflow circulation within the housing. The temperature detection and control unit 7 is located near the evaporator 2 and is used to regulate the operating conditions of the equipment. The temperature detection and control unit 7 adopts a combination structure of a temperature sensor and a single-chip microcomputer control module, and is fixedly installed on the outer periphery of the evaporator 2. It can sense the surface temperature changes of the evaporator 2 in real time and switch the operation of the drive assembly 5 and the centrifugal fan 6 based on mechanical control logic. It does not require a complex intelligent control structure, but only relies on the temperature threshold to complete the operating condition switching control. The structure is simple, the operation is stable, and it can effectively avoid potential failures during long-term operation.

[0033] The variable air duct assembly 3 includes a top air duct 31 and a bottom air duct 32, which correspond to the airflow channels in different areas of the housing 1, respectively; the liftable baffle assembly 4 consists of a fixed fan plate 41, a movable fan plate 42 and a bearing 43, and relies on the mechanical structure to realize the opening and closing of the air duct; the drive assembly 5 is a power drive component that can cooperate with the mechanical structure to complete the air duct switching action; the centrifugal fan 6 is the power source for airflow circulation and can adjust the air volume according to the operating status.

[0034] The variable air duct assembly 3 is located inside the cavity of the housing 1 to construct two independent airflow circuits for cooling and defrosting; the liftable baffle assembly 4 is installed in a key position inside the variable air duct assembly 3 to selectively open and close the air duct; the drive assembly 5 provides mechanical driving force, and combined with the structural weight, it realizes the stable action of the baffle; the centrifugal fan 6 provides power support for airflow circulation and ensures stable airflow within the air duct.

[0035] Through the modular design of each functional component, the overall structure is compact and reasonable, and each component has a clear division of labor. It can switch the air duct circuit according to the operation requirements and use the airflow in different temperature zones inside the cabinet to complete the cooling and defrosting operations, effectively improving the equipment operating efficiency, reducing energy consumption, and ensuring the long-term stable operation of the display cabinet.

[0036] In this embodiment, the variable air duct assembly 3 includes an air duct plate 33 and an air duct cover plate 34. The air duct plate 33 is the main supporting structure of the air duct. The plate surface is regularly provided with an upper air inlet 331, a lower air inlet 332 and a baffle return port 333. The positions of each air inlet are arranged in zones, and the structural layout is reasonable. The top air duct 31 is directly connected to the upper air inlet 331 to form a high-temperature airflow channel. The bottom air duct 32 is connected to the lower air inlet 332 to form a low-temperature airflow circulation path, ensuring that the two airflows of different temperatures are isolated from each other and transported independently.

[0037] In this embodiment, the top air duct 31 is stably arranged in a fixed area near the glass door at the top of the cabinet 1, making full use of the ambient airflow in the upper part of the cabinet. The bottom air duct 32 is set at the rear of the cabinet 1 near the storage area, relying on the low-temperature airflow in the storage area to form a stable dual air duct layout. The temperature of the airflow inside the top air duct 31 is generally higher than the temperature of the airflow inside the bottom air duct 32, providing a basic condition for the separate operation of refrigeration and defrosting.

[0038] Specifically, the liftable baffle assembly 4 includes a fixed fan plate 41 and a movable fan plate 42. The fixed fan plate 41 is securely installed on the top plate of the inner liner of the housing 1 using a fastening structure to form a fixed support base. The movable fan plate 42 and the fixed fan plate 42 are rotatably connected through a bearing 43 to ensure smooth and stable fan rotation, reduce mechanical resistance, and facilitate the opening and closing adjustment of the air duct.

[0039] Specifically, when the movable fan plate 42 is in a stable, naturally drooping state, it can fit tightly against the surface of the air duct plate 33 to achieve a tight seal. It can completely cover and block the upper air inlet 331, while also partially blocking the baffle return port 333 in the middle position, effectively limiting the airflow range and precisely controlling the opening and closing state of the air duct.

[0040] Furthermore, both the fixed fan plate 41 and the movable fan plate 42 are made of lightweight heat-insulating plastic material in one piece. The material itself has the characteristics of being lightweight and having good structural strength. It also has heat insulation properties, which can reduce heat transfer between air ducts. The overall structure is durable and stable, and can withstand reciprocating rotation for a long time without easily deforming or structural damage.

[0041] Furthermore, the movable fan plate 42 has a lightweight structural design, which can reliably rely on its own gravity to fall back stably. After falling back, it forms a tight and sealed structure with the surface of the air duct plate 33, effectively blocking the airflow inside the top air duct 31, preventing airflow from crossing, and ensuring the stability of the airflow circulation in the bottom air duct under cooling conditions.

[0042] Furthermore, the drive component 5 is a fixed-design drive motor. The motor output shaft and the liftable baffle component 4 form a stable mechanical transmission structure. The transmission is closely matched, the power transmission is smooth, and it can continuously output mechanical torque to stably drive the movable fan plate 42 to complete the upward flipping action and accurately realize the opening and conduction of the top air duct.

[0043] Furthermore, after the drive component 5 stops operating, the external driving force is completely released, and the movable fan plate 42 no longer bears the external force. It can automatically fall back to its original position based on its own structural weight and gravity, quickly restore the initial closed state, and stably achieve the airtight closure of the air duct structure. No additional auxiliary reset structure is required, simplifying the overall mechanical structure.

[0044] Furthermore, the top air duct 31 adopts a gradually narrowing channel structure design. Along the glass end of the box 1 towards the rear of the box, the overall cross-sectional width of the air duct gradually and uniformly narrows, forming a streamlined airflow channel. This effectively constrains the airflow direction, constructs a stable airflow guiding structure, and improves airflow delivery efficiency.

[0045] Furthermore, the air duct plate 33 and the air duct cover plate 34 are connected by a sealed splicing structure, with the edges tightly fitted to form a complete and sealed closed air duct cavity. The internal space of the cavity is regular, and the centrifugal fan 6 is stably installed in a fixed position inside the cavity to ensure stable operation of the fan and reduce vibration interference.

[0046] Furthermore, the baffle return port 333 is fixedly installed on the surface of the air duct plate 33, located in the middle area between the upper air inlet 331 and the lower air inlet 332. The spatial layout is reasonable, and the flow area of ​​the baffle return port 333 is smaller than the opening area of ​​the upper air inlet 331 and the lower air inlet 332, which can reasonably control the airflow and avoid excessive airflow diversion.

[0047] Furthermore, the centrifugal fan 6 and the temperature detection and control unit 7 form a stable electrical connection structure. The control unit can adjust the fan's operating status according to changes in operating conditions. In the cooling mode, the centrifugal fan 6 maintains high-speed operation to enhance the low-temperature airflow circulation intensity. In the defrosting mode, it automatically switches to low-speed operation to smoothly deliver high-temperature airflow and stably adapt to the airflow requirements of different operating conditions.

[0048] When using the recirculating defrosting display cabinet of this utility model, the equipment is first installed and deployed as follows: the evaporator 2 is fixedly installed in the designated position inside the cabinet 1, the air duct plate 33 and the air duct cover plate 34 are sealed together to complete the overall assembly of the variable air duct assembly 3; the fixed fan plate 41 is fixed to the top plate of the inner liner of the cabinet 1, and the movable fan plate 42 is connected through the bearing 43 to complete the assembly of the liftable baffle assembly 4; the drive assembly 5 is connected to the movable fan plate 42 for transmission, the centrifugal fan 6 is fixed inside the air duct cavity, and the temperature detection and control unit 7 is installed in the vicinity of the evaporator 2 to complete the overall structural assembly.

[0049] After the equipment is installed, perform overall debugging: connect the power supply to the equipment, and check the operation status of the drive component 5, the flipping action of the liftable baffle component 4, and the operating condition of the centrifugal fan 6 in sequence. Confirm that the air duct switching is smooth, the cavity is sealed and intact, and the airflow circulation is normal. After the debugging is qualified, it will enter the normal operation state.

[0050] During the normal operation of the equipment, under normal cooling conditions, the drive component 5 stops running, the movable fan plate 42 closes under the action of gravity, completely blocking the upper air inlet 331, the bottom air duct 32 remains unobstructed, the centrifugal fan 6 runs at high speed, the low-temperature airflow at the rear of the box 1 circulates along the bottom air duct 32, flows through the evaporator 2 to complete heat exchange, and achieves rapid cooling.

[0051] When frost forms on the surface of evaporator 2, the equipment switches to defrosting mode. Drive component 5 starts running, causing movable fan plate 42 to flip upward, opening the upper air inlet 331 and baffle return port 333, closing the bottom air duct 32, and centrifugal fan 6 runs at low speed. High-temperature airflow from the top of the housing 1 flows along the top air duct 31 and continuously flows over the surface of evaporator 2, using the high-temperature airflow to complete the defrosting operation.

[0052] After the defrosting process is completed, the drive component 5 stops working, the movable fan plate 42 automatically falls back to its original position by gravity, re-closes the upper air inlet 331, and the equipment resumes cooling operation, and the cooling and defrosting operations are completed alternately in a cycle.

[0053] During long-term operation, the variable air duct component 3 stably separates the airflow in different temperature zones, the liftable baffle component 4 stably completes the air duct switching by means of mechanical structure, and the centrifugal fan 6 adjusts its speed according to the operating conditions. All structures work together to ensure the stable operation of the equipment.

[0054] After the equipment stops running, the overall power supply is cut off, all moving parts stop working, the baffle structure remains closed, the air duct system is stationary, and the interior of the housing 1 and the air duct structure can be cleaned and maintained. The entire equipment returns to standby mode, and the entire equipment operation process ends.

[0055] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A display cabinet with recyclable defrosting capability, characterized in that: The system includes a housing (1), an evaporator (2), a variable air duct assembly (3), a liftable baffle assembly (4), and a drive assembly (5). The variable air duct assembly (3) includes a top air duct (31) and a bottom air duct (32). The air outlet of the top air duct (31) is located at the top of the housing (1) near the glass door, and the air outlet of the bottom air duct (32) is located at the rear of the housing (1) near the storage area. The air temperature in the top air duct (31) is higher than the air temperature in the bottom air duct (32). The liftable baffle assembly (4) is located inside the variable air duct assembly (3). The drive assembly (5) and the liftable baffle assembly (4) are connected to the variable air duct assembly (3). The plate assembly (4) is driven and coordinated, and the liftable baffle assembly (4) is configured to move up and down under the combined action of the driving force of the drive assembly (5) and its own gravity, so as to selectively open the top air duct (31) or the bottom air duct (32); under normal cooling conditions, the drive assembly (5) stops working, the liftable baffle assembly (4) moves down under the action of gravity and closes the top air duct (31), and the bottom air duct (32) is opened to realize the cooling cycle; under defrosting conditions, the drive assembly (5) starts, the liftable baffle assembly (4) moves up and closes the bottom air duct (32), and the top air duct (31) is opened to realize the defrosting cycle.

2. The recyclable defrosting display cabinet according to claim 1, characterized in that: The variable air duct assembly (3) also includes an air duct plate (33) and an air duct cover plate (34). The air duct plate (33) is provided with an upper air inlet (331) that communicates with the top air duct (31) and a lower air inlet (332) that communicates with the bottom air duct (32). The air duct cover plate (34) and the air duct plate (33) are sealed together to form a closed air duct cavity. The air duct cover plate (34) is used to increase the air intake flow area of ​​the bottom air duct (32).

3. The recyclable defrosting display cabinet according to claim 2, characterized in that: The air duct plate (33) is also provided with a baffle return port (333), which is located between the upper air inlet (331) and the lower air inlet (332). The flow area of ​​the baffle return port (333) is smaller than the flow area of ​​the upper air inlet (331) and the lower air inlet (332).

4. The display cabinet with recyclable defrosting according to claim 1, characterized in that: The liftable baffle assembly (4) includes a fixed baffle (41) and a movable baffle (42). The fixed baffle (41) is fixedly connected to the top plate of the inner liner of the box (1). The movable baffle (42) and the fixed baffle (41) are rotatably connected through a bearing (43). The movable baffle (42) is used to completely block the upper air inlet (331) and partially block the baffle return port (333). The movable baffle (42) is used to close or open the upper air inlet (331) and adjust the conduction state of the baffle return port (333).

5. The display cabinet with recyclable defrosting according to claim 4, characterized in that: Both the fixed fan plate (41) and the movable fan plate (42) are made of lightweight heat-insulating plastic. When the movable fan plate (42) moves down, it fits and seals with the air duct plate (33). When the movable fan plate (42) moves up, it separates from the air duct plate (33) to form an airflow channel.

6. The display cabinet with recyclable defrosting according to claim 1, characterized in that: The drive component (5) is a drive motor. The output end of the drive motor is connected to the liftable baffle assembly (4) for transmission. When the drive motor starts, the output torque drives the fixed fan plate (41) of the liftable baffle assembly (4) to flip and open. When the drive motor stops, the fixed fan plate (41) of the liftable baffle assembly (4) automatically falls back under the action of gravity.

7. The display cabinet with recyclable defrosting according to claim 1, characterized in that: The top air duct (31) is a tapered channel structure, with the cross-section of the air duct gradually shrinking along the direction from the glass door to the rear of the box (1).

8. The display cabinet with recyclable defrosting according to claim 1, characterized in that: The display cabinet also includes a centrifugal fan (6) and a temperature detection and control unit (7). The centrifugal fan (6) is located in the closed air duct cavity formed by the air duct cover plate (34) and the air duct plate (33). The temperature detection and control unit (7) is located near the evaporator (2). The temperature detection and control unit (7) controls the speed of the centrifugal fan (6) and the start and stop of the drive component (5) according to the frosting state of the evaporator (2).

9. The display cabinet with recyclable defrosting according to claim 8, characterized in that: In the cooling state, the centrifugal fan (6) runs at high speed to enhance the airflow circulation in the bottom air duct (32). In the defrosting state, the centrifugal fan (6) runs at low speed to cooperate with the airflow in the top air duct (31) to complete the defrosting of the evaporator (2).

10. The recyclable defrosting display cabinet according to claim 1, characterized in that: When the top air duct (31) is open, the high-temperature airflow in the box flows through the evaporator (2) to achieve efficient defrosting. When the bottom air duct (32) is open, the low-temperature airflow in the box flows through the evaporator (2) to achieve rapid cooling. By switching the air ducts, energy consumption is reduced and energy saving and emission reduction are achieved.

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