Air duct structure and display cabinet using same

Abstract

The invention relates to the technical field of display cabinets, in particular to an air duct structure and a display cabinet using the air duct structure. The water receiving box is fixed to the bottom of the evaporator and used for receiving water defrosted by the evaporator, and a drainage hole is formed in the bottom of the water receiving box and connected with a drainage pipeline; and the foam air duct is arranged towards the evaporator and located below the water receiving box, and the air outlet opening corresponds to the evaporator. According to the air duct structure and the display cabinet using the air duct structure, through the innovative air duct structure design, the heat exchange efficiency of the display cabinet and the utilization rate of the draught fan are greatly improved. The curved surface dome type foam air duct is adopted to be matched with the sectional type layout of the flow collecting air duct, the first-order diffusion air duct, the air inducing air duct and the second-order diffusion air duct, size parameters of an evaporation fan are accurately matched, the problems of heat exchange dead angles and vortexes of a traditional air duct are solved, and airflow is guided to evenly cover an evaporator through the Coanda effect.

Description

Technical Field

[0001] This invention relates to the field of display cabinet technology, and more specifically, to a duct structure and a display cabinet using the same. Background Technology

[0002] Display cases, as core equipment in the commercial retail sector (such as supermarkets, convenience stores, and fruit shops) for food refrigeration and product display, directly impact the quality of stored goods and the operating costs of businesses due to their refrigeration performance, energy efficiency, and user experience, thus occupying a crucial position in the commercial distribution process. The air duct structure, a key component of the display case's refrigeration system, plays a vital role in guiding airflow for efficient heat exchange with the evaporator and achieving uniform distribution of cooling capacity within the case. Its rational design directly determines the display case's refrigeration efficiency, energy consumption, and operational stability.

[0003] Currently, the air duct design of mainstream display cases on the market generally suffers from numerous technical defects, making it difficult to meet increasingly stringent energy efficiency standards and user demands. Traditional display cases mostly adopt an air supply mode of "top suction - evaporator cooling - oblique exhaust from the top and rear," with the fan cover typically installed at an angle and the internal air duct structure simplified, lacking a scientific air guiding design. This structure results in the air suction direction being distributed obliquely downwards, easily forming local heat exchange dead zones within the cabinet, preventing the airflow from fully contacting the evaporator and significantly reducing heat exchange efficiency. Although some products directly mount the fan on the air duct plate, the lack of a reasonable air guiding structure easily leads to eddies and stagnant areas in the airflow within the duct, not only weakening the effective airflow utilization rate of the fan but also causing uneven cooling effects and affecting the stability of the internal temperature of the display case.

[0004] To compensate for insufficient cooling efficiency, some manufacturers increase airflow by increasing fan speed. However, this practice not only significantly increases power consumption, violating current industry trends of energy conservation and emission reduction and new energy efficiency standards, but also leads to a significant increase in operating noise, severely impacting the user experience. Furthermore, traditional air ducts are often made of ordinary materials, lacking effective insulation and anti-frost design, making them prone to condensation and ice buildup on the inner walls, further hindering airflow and shortening equipment lifespan. The angled fan covers and duct layouts also result in a cluttered appearance, failing to meet the aesthetic requirements of modern commercial settings and gradually eroding market competitiveness.

[0005] Furthermore, the structural defects of traditional air ducts lead to severe vibrations during airflow, exacerbating noise pollution and potentially causing loosening of equipment components, thus affecting the long-term operational reliability of the display case. With the continuous improvement of national requirements for energy efficiency ratings of home appliances and the increasing consumer demand for low-noise, aesthetically pleasing, and highly stable equipment, the existing air duct structure has become a core bottleneck restricting the upgrading of display case products. Therefore, developing a new air duct structure that maximizes fan utilization while ensuring efficient heat exchange, low-noise operation, insulation against frost, and an aesthetically pleasing layout has become an urgent technical problem to be solved in the display case industry. Summary of the Invention

[0006] The purpose of this invention is to provide a display cabinet with an air duct structure and its application, addressing the problem mentioned in the background art where traditional display cabinets often employ a "top suction - evaporator cooling - oblique exhaust from the rear" airflow pattern. The fan shroud is typically installed at an angle, the internal air duct structure is simplified, and a scientific airflow design is lacking. This structure results in a downward-sloping airflow distribution, easily creating localized heat exchange dead zones within the cabinet, preventing sufficient contact between the airflow and the evaporator, and significantly reducing heat exchange efficiency.

[0007] To achieve the above objectives, the present invention provides an air duct structure and a display cabinet for use therein, including a cabinet body, wherein an evaporator is installed on the top of the cabinet body; A water receiving box is fixed to the bottom of the evaporator and is used to collect water after the evaporator defrosts. The bottom of the water receiving box is provided with a drain hole, which is connected to a drain pipe. The foam air duct is positioned facing the evaporator and below the water collection box, with the air outlet corresponding to the evaporator. The foam air duct is formed by splicing the left and right parts of the foam air duct through an interlocking structure to form a curved dome structure. The foam air duct is sequentially divided into a collection air duct, a first-stage diffuser air duct, an exhaust air duct, an inner air duct bottom, and a second-stage diffuser air duct. The foam air duct is also equipped with a water-blocking edge and a water collection box insulation board. An evaporating fan is mounted on a fan cover via a fan bracket, and the evaporating fan is located in the middle of the air inlet of the foam air duct.

[0008] This design utilizes an integrated structure comprising "box body - water collection box - foam duct - evaporator fan" to clearly define the spatial position and connection relationship of each component: the evaporator is positioned on top to ensure a reasonable layout of the refrigeration core; the water collection box accurately collects defrost water and discharges it through the drain pipe to avoid water interference; the foam duct adopts a curved dome design with left and right interlocking to form a continuous flow channel, while the evaporator fan is placed in the middle of the air inlet to ensure the symmetry and stability of airflow intake, thus avoiding the problems of chaotic layout and disordered flow of traditional ducts from the overall structure.

[0009] As a preferred embodiment of the present invention, the bottom of the inner air duct is provided with an inclination angle β, and the inclination angle β of the bottom of the inner air duct is set in a direction that causes the residual water in the air duct to converge towards the water receiving box side, and the height h of the water-blocking side is higher than the height of the water receiving box.

[0010] This design utilizes gravity to tilt the bottom of the inner air duct at an angle β, guiding residual condensate in the duct towards the water collection box. By setting a water-blocking edge higher than the water collection box, a physical barrier is formed to prevent condensate from flowing freely in the duct or overflowing to other components.

[0011] As a preferred embodiment of the present invention, the diameter D of the collecting duct is 1.05-1.1 times the diameter D0 of the evaporator fan, the distance L1 between the bottom of the blades of the evaporator fan and the bottom of the collecting duct is 5-10mm, and the height L2 of the collecting duct is ≥2*H, where H is the axial height of the evaporator fan.

[0012] This setting is based on fluid mechanics principles, precisely setting the size ratio of the collection duct and the evaporator fan: the diameter D is 1.05-1.1 times the fan diameter D0, which avoids interference between the fan blades and the duct, and also prevents eddies from being generated due to excessive space; the distance L1 (5-10mm) between the bottom of the blades and the bottom of the duct reduces air intake disturbance, and the height L2 of the collection duct ≥ 2*H ensures that the airflow is fully converged and forms stable dynamic pressure, laying the foundation for subsequent airflow diffusion.

[0013] As a preferred embodiment of the present invention, the outer diameter of the starting circle of the first-order diffuser duct is D1 = (1.1-1.2) * D, and the height L3 of the first-order diffuser duct is 2-4 times L1.

[0014] Based on the fluid energy conversion law, this setting sets the outer diameter D1 of the initial circle of the first-order diffuser duct to (1.1-1.2)*D, and the height L3 to 2-4 times L1. Through reasonable spatial expansion, the efficient conversion of airflow pressure to static pressure is achieved, reducing the resistance loss of airflow in the duct and reducing the impact of fluid on the duct wall.

[0015] As a preferred embodiment of the present invention, the bending radius r of the air duct is 0.5*D, the extension curve D2 of the air duct is tangent to the diameter D1 of the first-order diffuser duct, and the extension curve D2 of the air duct is perpendicular to the opening where the foam duct connects to the evaporator.

[0016] This design employs a curved surface structure with a bending radius r = 0.5 * D, ensuring that the extension curve D2 of the exhaust duct is tangent to the diameter D1 of the first-order diffuser duct and perpendicular to the evaporator opening. This conforms to the principle of "smooth flow guidance" in fluid mechanics, preventing eddies from forming at the turning points and ensuring that the airflow flows directionally towards the evaporator.

[0017] As a preferred embodiment of the present invention, the second-order diffuser duct is formed by bending from bottom to top and outward at the end opening, with bending curves r1 and r2 respectively. The curved wall surface of the second-order diffuser duct is adapted to the Conrad effect to guide the airflow along the wall surface to the top and sides of the evaporator.

[0018] This design utilizes the Conrad effect (the characteristic of fluid flowing along a smooth wall) to design the second-order diffuser duct as a structure that "bends outward from bottom to top". The bending curves r1 and r2 guide the airflow to diffuse along the wall, achieving full coverage of the top and sides of the evaporator and avoiding insufficient local heat exchange.

[0019] As a preferred embodiment of the present invention, the foam duct is made of foam material with heat insulation, sound insulation and shock absorption properties.

[0020] This setup uses foam material with heat insulation, sound insulation, and shock absorption properties to make the air duct. The low thermal conductivity of the material reduces heat exchange between the air duct and the outside environment. The porous structure of the material absorbs fan vibration and airflow noise, while the elasticity of the material buffers vibration transmission.

[0021] As a preferred embodiment of the present invention, the air outlet size of the foam duct is the same as or larger than the inlet size of the evaporator.

[0022] This setting ensures that the size of the air outlet of the foam duct is the same as or slightly larger than that of the evaporator inlet, so that all the airflow discharged from the duct can enter the evaporator, avoiding airflow leakage or local airflow accumulation caused by mismatched openings, and achieving precise matching of "airflow supply - evaporator reception".

[0023] As a preferred embodiment of the present invention, an air inlet protective net is installed on the outer side of the fan cover.

[0024] This feature involves installing an air intake guard on the outside of the fan cover. On one hand, it filters dust and impurities in the air, preventing them from entering the air duct and contaminating components or clogging the duct. On the other hand, the grille structure of the guard stabilizes the airflow and reduces turbulence when the air enters.

[0025] As a preferred embodiment of the present invention, the side of the housing is equipped with a glass door, the interior is equipped with shelves, and the bottom is equipped with a compressor, a condenser, and a condensing fan in sequence.

[0026] This design features glass doors that ensure display functionality while minimizing cold air loss, and shelves that allow for layered product placement. The bottom of the unit houses a compressor, condenser, and condenser fan, forming a complete refrigeration cycle system. The compressor provides cooling power, the condenser facilitates heat exchange, and the condenser fan accelerates heat dissipation, ensuring efficient operation of the refrigeration system.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This air duct structure and the display cabinet it is used in achieve a significant improvement in heat exchange efficiency and fan utilization through innovative air duct structure design. It adopts a curved dome-shaped foam air duct, combined with a segmented layout of a collection air duct, a first-stage diffuser air duct, an exhaust air duct, and a second-stage diffuser air duct. This precisely matches the size parameters of the evaporator fan, not only eliminating the heat exchange dead zones and vortex problems of traditional air ducts, but also guiding the airflow to evenly cover the evaporator through the Conrad effect, ensuring that all the airflow drawn in by the fan effectively participates in heat exchange. Excellent cooling effect can be achieved without increasing the fan speed, completely solving the core pain point of low fan utilization in traditional structures.

[0028] 2. In terms of energy consumption and noise control, this invention demonstrates significant advantages in the air duct structure and the display cabinet it is used in. The optimized air duct path significantly reduces airflow resistance, allowing the fan to operate stably at low speeds, effectively reducing power consumption and meeting the requirements of the new energy efficiency standards. Simultaneously, the combination of sound-insulating and vibration-damping foam material with the smooth curved air duct design effectively absorbs vibrations and suppresses turbulence and eddy noise. Combined with the noise reduction effect of the air inlet guard, this significantly reduces the operating noise of the display cabinet and improves the user experience.

[0029] 3. Regarding the issues of frost formation and condensation residue in traditional air ducts, this invention offers an effective solution through multiple design elements. The insulation performance of the foam air duct, combined with the insulation board of the water collection box, reduces frost formation caused by temperature differences at the source. The inclined angle design at the bottom of the inner air duct guides condensation to converge in the water collection box, and the water-blocking edge higher than the water collection box prevents condensation from accumulating and freezing, ensuring long-term stable operation of the equipment and extending the service life of core components.

[0030] 4. This air duct structure and its display case also optimize product appearance and ease of assembly and maintenance. The curved dome structure allows for a neat, flat-top layout on the display case, replacing the cluttered design of traditional sloping fan covers, thus enhancing product aesthetics and market competitiveness. The foam air duct uses a left-right interlocking splicing method, making assembly efficient and simple. The integrated design of the water collection box and drainage pipes also facilitates later maintenance, reducing production and after-sales costs. Overall, this invention achieves a synergistic upgrade in heat exchange efficiency, energy consumption control, noise suppression, operational stability, and appearance design, demonstrating significant technological advancement and practical application value. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a top view of the structure of the present invention; Figure 3This is a schematic diagram of the exploded structure of the foam duct in this invention; Figure 4 This is a schematic diagram of the overall structure of the foam duct in this invention; Figure 5 This is a side view of the foam duct structure in this invention. Figure 6 This is a top view of the foam duct structure in this invention; The meanings of the labels in the diagram are as follows: 1. Housing; 2. Evaporator; 3. Water collection box; 4. Drainage pipe; 5. Foam duct; 51. Left side of foam duct; 52. Right side of foam duct; 53. Interlocking structure; 54. Collecting duct; 55. First-stage diffuser duct; 56. Exhaust duct; 57. Bottom of inner duct; 58. Second-stage diffuser duct; 59. Water-blocking edge; 510. Water collection box insulation board; 6. Evaporator fan; 61. Fan bracket; 62. Fan cover; 63. Inlet protective net. Detailed Implementation

[0032] 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.

[0033] This invention provides an air duct structure and a display cabinet for its use, such as... Figures 1-6 As shown, it includes a housing 1, and an evaporator 2 is installed on the top of the housing 1; Water collection box 3 is fixed to the bottom of evaporator 2 and is used to collect water after defrosting of evaporator 2. The bottom of water collection box 3 is provided with a drain hole, which is connected to a drain pipe 4. Foam duct 5 is set facing the evaporator 2 and located below the water receiving box 3. The air outlet is corresponding to the evaporator 2. Foam duct 5 is formed by splicing the left part 51 and the right part 52 of foam duct through the interlocking structure 53 to form a curved dome structure. Foam duct 5 is divided into a collection duct 54, a first-stage diffuser duct 55, an exhaust duct 56, an inner duct bottom 57, and a second-stage diffuser duct 58 in sequence. Foam duct 5 is also provided with a water baffle 59 and a water receiving box insulation board 510. Evaporator 6 is mounted on fan cover 62 via fan bracket 61, and is located in the middle of the air inlet of foam duct 5.

[0034] By constructing an integrated structure of "box 1 - water collection box 3 - foam air duct 5 - evaporator fan 6", the spatial position and connection relationship of each component are clearly defined: the evaporator 2 is placed on top to ensure the reasonable layout of the refrigeration core; the water collection box 3 accurately receives the defrosting water of the evaporator 2 and discharges it through the drain pipe 4 to avoid water interference; the foam air duct 5 adopts a curved dome design with the left part 51 and the right part 52 of the foam air duct spliced ​​by the interlocking structure 53 to form a continuous flow channel. At the same time, the evaporator fan 6 is installed on the fan cover 62 through the fan bracket 61 and is located in the middle of the air inlet of the foam air duct 5 to ensure the symmetry and stability of airflow intake. From the overall structure, the problems of chaotic layout and disordered flow of traditional air ducts are avoided.

[0035] The curved dome structure replaces the traditional inclined fan cover, laying the foundation for the efficient operation of the entire air duct system and realizing a flat top layout for the display cabinet, thus improving the aesthetics. The coordinated operation of each component enables the airflow to flow in a directional manner, initially solving the problem of heat exchange dead zones in traditional air ducts. At the same time, it provides structural support for the flow guidance, noise reduction, and anti-frost functions of the segmented structure such as the air collection duct 54 of the foam air duct 5 and the first-stage diffuser duct 55, ensuring the basic operational stability of the refrigeration system.

[0036] In this embodiment, the bottom 57 of the inner air duct is provided with an inclination angle β. The inclination angle β of the bottom 57 of the inner air duct is set in a direction that causes the residual water in the air duct to converge towards the water receiving box 3. The height h of the water blocking edge 59 is higher than the height of the water receiving box 3.

[0037] By utilizing gravity, the bottom 57 of the inner air duct is designed with an inclined angle β to guide the residual condensate in the air duct to converge towards the water collection box 3; by setting a water-blocking edge 59 with a height h higher than the water collection box 3, a physical barrier is formed to prevent condensate from flowing freely in the air duct or overflowing to other components.

[0038] This completely solves the problem of condensate retention and freezing in traditional air ducts, avoiding the impact of freezing on airflow and component lifespan. The inclination angle of the bottom 57 of the inner air duct and the cooperation of the water-blocking edge 59 ensure efficient drainage of condensate, reducing the risk of bacterial growth in the air duct, while ensuring long-term stable operation of the equipment and reducing maintenance costs caused by frost.

[0039] Specifically, the diameter D of the collecting duct 54 is 1.05-1.1 times the diameter D0 of the evaporator fan 6, the distance L1 between the bottom of the blades of the evaporator fan 6 and the bottom of the collecting duct 54 is 5-10mm, and the height L2 of the collecting duct 54 is ≥2*H, where H is the axial height of the evaporator fan 6.

[0040] Based on fluid mechanics principles, the size ratio of the collecting duct 54 to the evaporator fan 6 is precisely set: the diameter D of the collecting duct 54 is 1.05-1.1 times the diameter D0 of the evaporator fan 6, which avoids interference between the fan blades of the evaporator fan 6 and the collecting duct 54, and also prevents eddies from being generated due to excessive space; the distance L15-10mm between the bottom of the evaporator fan 6 blades and the bottom of the collecting duct 54 reduces air intake disturbance, and the height L2≥2*HH of the collecting duct 54 is the axial height of the evaporator fan 6 to ensure that the airflow is fully converged and forms stable dynamic pressure, laying the foundation for subsequent airflow diffusion.

[0041] It effectively reduces the risk of mechanical interference and eddy noise during the operation of the evaporator fan 6, and improves the smoothness of air intake; the stable dynamic pressure makes the airflow drawn into the evaporator fan 6 more concentrated, avoids air volume dispersion, significantly improves the fan utilization rate, and can obtain sufficient air volume without relying on increasing the speed, thus providing a guarantee for low-energy operation.

[0042] Furthermore, the outer diameter of the initial circle of the first-order diffuser duct 55 is D1 = (1.1-1.2) * D, and the height L3 of the first-order diffuser duct 55 is 2-4 times L1.

[0043] Based on the fluid energy conversion law, the outer diameter D1 of the initial circle of the first-order diffuser duct 55 is set to (1.1-1.2)*D, and the height L3 is 2-4 times L1. Through reasonable spatial expansion, the efficient conversion of airflow pressure to static pressure is achieved, reducing the resistance loss of airflow in the duct and reducing the impact of fluid on the duct wall.

[0044] Significantly reducing duct resistance lowers the ineffective energy consumption of the evaporator fan 6 due to overcoming resistance, further improving equipment energy efficiency; stable static pressure makes airflow smoother, reduces noise generated by turbulence, and provides stable airflow conditions for smooth guidance of the subsequent duct 56.

[0045] Furthermore, the bending radius r of the air duct 56 is 0.5*D, the extension curve D2 of the air duct 56 is tangent to the diameter D1 of the first-order diffuser duct 55, and the extension curve D2 of the air duct 56 is perpendicular to the opening where the foam duct 5 connects to the evaporator 2.

[0046] The air duct 56 is designed with a curved surface structure with a bending radius r=0.5*D, so that the extension curve D2 of the air duct 56 is tangent to the diameter D1 of the first-order diffuser duct 55 and perpendicular to the opening where the foam duct 5 connects to the evaporator 2. This conforms to the principle of "smooth flow guidance" in fluid mechanics, avoids the generation of vortices at the turning point of the airflow, and ensures that the airflow flows directionally to the evaporator 2.

[0047] Completely eliminates the vortex dead angle at the turn of the traditional air duct, reducing air volume waste; the design of vertical airflow guidance for evaporator 2 ensures that all the airflow drawn in by evaporator fan 6 participates in heat exchange, improving heat exchange efficiency; the smooth curved structure also reduces airflow impact noise, further optimizing quiet operation.

[0048] Furthermore, the second-order diffuser duct 58 is formed by bending from bottom to top and outward at the end opening, with bending curves r1 and r2 respectively. The curved wall surface of the second-order diffuser duct 58 is adapted to the Conrad effect to guide the airflow along the wall surface to the top and sides of the evaporator 2.

[0049] Utilizing the characteristic of fluid flowing along a smooth wall surface due to the Conda effect, the second-order diffuser duct 58 is designed as a structure that "bends outward from bottom to top". The airflow is guided to diffuse along the wall surface through the bending curves r1 and r2, so as to achieve full coverage of the top and sides of the evaporator 2 by the airflow and avoid insufficient local heat exchange.

[0050] The cold airflow is evenly distributed across the entire surface of the evaporator 2, completely solving the problem of dead zones in traditional air duct heat exchange and significantly improving heat exchange speed and efficiency; the secondary diffusion effect allows the cold air to be blown to a greater distance, ensuring uniform temperature in the upper and lower parts of the cabinet 1 and improving the refrigeration and preservation effect.

[0051] Furthermore, the foam duct 5 is made of foam material with heat insulation, sound insulation and shock absorption properties.

[0052] Foam duct 5 is made of foam material with heat insulation, sound insulation and shock absorption properties. The low thermal conductivity of the material reduces the heat exchange between the foam duct 5 and the outside world. The porous structure of the material absorbs the vibration and airflow noise of the evaporator fan 6, and the elasticity of the material buffers the transmission of vibration.

[0053] It suppresses frost formation on the inner wall of the foam duct 5 due to excessive temperature difference, ensuring smooth airflow; it significantly reduces the operating noise of the evaporator fan 6 and the noise of airflow vibration, improving the user experience; and its shock absorption performance reduces the wear and tear on equipment components and extends the overall service life of the display case.

[0054] Furthermore, the outlet size of the foam duct 5 is the same as or larger than the inlet size of the evaporator 2.

[0055] Make the outlet size of the foam duct 5 the same as or slightly larger than the inlet size of the evaporator 2, so that all the airflow discharged from the foam duct 5 can enter the evaporator 2, avoid airflow leakage or local airflow accumulation caused by mismatch of openings, and achieve precise matching of "airflow supply - evaporator 2 reception".

[0056] Maximize the use of the air volume output by the evaporator fan 6 to avoid air volume waste and further improve heat exchange efficiency; prevent the airflow from generating vortices at the opening to reduce energy loss, while ensuring the stable operation of the refrigeration system and ensuring sufficient cooling supply in the cabinet 1.

[0057] Furthermore, an air inlet protective net 63 is installed on the outside of the fan cover 62.

[0058] An air inlet screen 63 is installed on the outside of the fan cover 62. On the one hand, it filters dust and impurities in the air to prevent them from entering the foam air duct 5 and contaminating the components or blocking the air duct. On the other hand, the grille structure of the air inlet screen 63 stabilizes the airflow and reduces turbulence when the airflow enters.

[0059] Protecting the internal cleanliness of the evaporator fan 6 and foam duct 5 reduces the risk of malfunctions caused by impurity accumulation and extends the maintenance cycle; stabilizing the airflow further reduces airflow noise, working in synergy with the noise reduction design of the foam duct 5 to improve the overall quietness of the display case.

[0060] Furthermore, the side of the housing 1 is fitted with a glass door, the interior is fitted with shelves, and the bottom is fitted with a compressor, a condenser, and a condenser fan in sequence.

[0061] Glass doors are installed on the side of cabinet 1 to ensure display function while reducing cold loss. Shelves installed inside meet the needs of layered product display. At the bottom of cabinet 1, a compressor, condenser, and condenser fan are installed in sequence to form a complete refrigeration cycle system. The compressor provides cooling power, the condenser realizes heat exchange, and the condenser fan accelerates heat dissipation to ensure efficient operation of the refrigeration system.

[0062] It achieves the dual functions of "refrigeration and preservation - product display" to meet the core needs of commercial retail scenarios; the complete refrigeration cycle components, combined with the optimized foam air duct 5 structure, form a highly efficient synergy, ensuring stable temperature inside the cabinet 1, while improving the overall operating efficiency of the refrigeration system and further reducing energy consumption.

[0063] When using the air duct structure of the present invention and the display cabinet used therein, the steps are as follows: Refrigeration Start-up and Airflow Intake: After the display case is started, the compressor, condenser fan, and evaporator fan 6 operate synchronously. The compressor compresses the refrigerant into a high-temperature, high-pressure gas, which is then converted into a low-temperature, low-pressure liquid after being cooled by the condenser and delivered to the evaporator 2. At the same time, the evaporator fan 6 draws in air from the cabinet 1 through the air inlet screen 63 on the outside of the fan cover 62. The air inlet screen 63 filters dust and impurities in the air to prevent airflow blockage and stabilizes the airflow, reducing turbulence.

[0064] Airflow convergence and preliminary diffusion: The intake airflow enters the convergence duct 54 of the foam duct 5. Due to the precise matching (1.05-1.1 times) between the diameter D of the convergence duct 54 and the diameter D0 of the evaporator fan 6, and the reasonable distance of 5-10mm between the blade bottom and the bottom of the duct, the airflow fully converges within the convergence duct 54, forming stable dynamic pressure. Subsequently, the airflow enters the first-stage diffuser duct 55. Through its initial circle outer diameter of 1.1-1.2 times the diameter of the convergence duct and its height design of 2-4 times L1, it achieves efficient conversion of dynamic pressure to static pressure, reduces airflow resistance, and improves flow stability.

[0065] Directional Flow and Secondary Diffusion: After initial diffusion, the airflow flows along the induced draft duct 56, which has a bending radius r = 0.5 * D. The extended curve D2 is tangent to the first-order diffuser duct 55 and perpendicular to the opening of the evaporator 2, ensuring smooth airflow transitions without eddy current generation, and directing the airflow towards the evaporator 2. Upon reaching the second-order diffuser duct 58, the airflow flows along the wall surface that bends "from bottom to top and outwards" (utilizing the Conrad effect), diffusing towards the top and sides of the evaporator 2, achieving complete coverage of the evaporator 2 and ensuring sufficient heat exchange between the airflow and the evaporator 2.

[0066] Cold air distribution and circulation: After heat exchange on the surface of evaporator 2, the airflow is transformed into low-temperature cold air. Under the secondary diffusion effect of the second-stage diffuser duct 58, it is blown to various areas of the cabinet 1, achieving uniform cooling at the top and bottom, ensuring the refrigeration and preservation effect of the goods inside the cabinet. At the same time, the insulation performance of the foam duct 5 reduces cold air loss, and the water collection box insulation plate 510 further enhances the insulation of the evaporator 2 area and inhibits frost formation.

[0067] Condensate drainage and stable equipment operation: During the heat exchange process, the defrosting water generated by the evaporator 2 falls into the water collection box 3 at the bottom. The condensate remaining in the duct is guided by the bottom 57 of the inner duct at an inclined angle β, converging towards the water collection box 3. The water-blocking edge 59 prevents condensate overflow. Finally, the defrosting water is discharged from the housing 1 through the drain hole at the bottom of the water collection box 3 and the drain pipe 4. Throughout the operation, the sound insulation and vibration damping characteristics of the foam duct 5 absorb fan vibration and airflow noise. Combined with the smooth duct path design, this significantly reduces equipment operating noise and ensures long-term stable operation.

[0068] Cycle Continuation and Shutdown: The above process continues until the temperature inside cabinet 1 reaches the set value. The control system adjusts the speed of the compressor and fan to maintain a constant temperature. When the display cabinet is closed, each component stops in sequence, completing the refrigeration cycle.

[0069] Finally, it should be noted that the electronic components in the evaporator fan 6 and other components in this embodiment are all general standard parts or parts known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components are connected by wires. The specific connection method should refer to the working order of each electrical component in the above working principle to complete the electrical connection. All of these are technologies known in the art.

[0070] 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 wind tunnel structure and a display cabinet using the same, characterized by: include Box (1), the top of which is equipped with an evaporator (2); Water receiving box (3) is fixed to the bottom of evaporator (2) and is used to receive water after defrosting of evaporator (2). The bottom of water receiving box (3) is provided with a drain hole, and the drain hole is connected to a drain pipe (4). Foam duct (5), the foam duct (5) is set facing the evaporator (2) and located below the water receiving box (3), the air outlet is corresponding to the evaporator (2), the foam duct (5) is spliced ​​by the left part (51) and the right part (52) of the foam duct through the interlocking structure (53) to form a curved dome structure, the foam duct (5) is divided into a collection duct (54), a first-stage diffuser duct (55), an exhaust duct (56), an inner duct bottom (57), and a second-stage diffuser duct (58) in sequence, and the foam duct (5) is provided with a water-blocking edge (59) and a water receiving box insulation board (510). Evaporation fan (6), the evaporation fan (6) is mounted on fan cover (62) by fan bracket (61), and the evaporation fan (6) is located in the middle of the air inlet of foam air duct (5).

2. The air duct structure and the display cabinet using the same according to claim 1, characterized in that: The bottom of the inner air duct (57) is provided with an inclination angle β. The inclination angle β of the bottom of the inner air duct (57) is set in a direction that causes the residual water in the air duct to converge towards the water receiving box (3). The height h of the water-blocking edge (59) is higher than the height of the water receiving box (3).

3. The air duct structure and its use in a display cabinet according to claim 1, characterized in that: The diameter D of the collecting duct (54) is 1.05-1.1 times the diameter D0 of the evaporator (6). The distance L1 between the bottom of the blade of the evaporator (6) and the bottom of the collecting duct (54) is 5-10 mm. The height L2 of the collecting duct (54) is ≥2*H, where H is the axial height of the evaporator (6).

4. The air duct structure and the display cabinet using the same according to claim 3, characterized in that: The outer diameter of the starting circle of the first-order diffuser duct (55) is D1 = (1.1-1.2) * D, and the height L3 of the first-order diffuser duct (55) is 2-4 times L1.

5. The air duct structure and the display cabinet using the same according to claim 4, characterized in that: The bending radius of the air duct (56) is r=0.5*D. The extension curve D2 of the air duct (56) is tangent to the diameter D1 of the first-order diffuser duct (55). The extension curve D2 of the air duct (56) is perpendicular to the opening where the foam duct (5) connects to the evaporator (2).

6. The air duct structure and its use in a display case according to claim 1, characterized in that: The second-order diffuser duct (58) is formed by bending from bottom to top and outward at the end opening, with bending curves r1 and r2 respectively. The curved wall of the second-order diffuser duct (58) is adapted to the Conrad effect to guide the airflow along the wall to the top and sides of the evaporator (2).

7. The air duct structure and its use in a display case according to claim 1, characterized in that: The foam duct (5) is made of foam material with heat insulation, sound insulation and shock absorption properties.

8. The air duct structure according to claim 1 and the display cabinet used therein, characterized in that: The air outlet size of the foam duct (5) is the same as or larger than the inlet size of the evaporator (2).

9. The air duct structure according to claim 1 and the display cabinet used therein, characterized in that: An air inlet guard net (63) is installed on the outside of the fan cover (62).

10. The air duct structure according to claim 1 and the display cabinet used therein, characterized in that: The side of the box (1) is fitted with a glass door, the inside is fitted with shelves, and the bottom is fitted with a compressor, a condenser, and a condenser fan in sequence.

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