Circulating air duct of an air-cooled medical refrigerator

Abstract

The present invention discloses a circulating air duct for an air-cooled medical refrigerator, comprising a refrigerator hood and an air duct formed by an air duct plate. The refrigerator hood is provided with an air inlet, an evaporator is installed in the refrigerator hood, and a top side air outlet is provided on the side of the refrigerator hood. The air duct is arranged on the side wall of the storage space, and the air duct is connected to the refrigerator hood. A middle front air outlet is provided on the middle front of the air duct, a middle side air outlet is provided on the middle side of the air duct, and a bottom air outlet is provided at the bottom of the air duct. A fan is installed in the refrigerator hood, and the air intake of the fan is oriented toward and close to the air inlet of the refrigerator hood. The present invention solves the problem of icing of the fan blower and evaporator; increases the air circulation speed and vortex level by reducing the diameter of the air duct; and ensures that the temperature uniformity and fluctuation in a large-volume refrigerator meet expectations through the arrangement of multiple air outlets.

Description

Technical Field

[0001] The present invention belongs to the technical field of refrigerators, and in particular relates to a circulating air duct of an air-cooled medical refrigerator. Background Art

[0002] Medical refrigerators are mainly used to store medicines, reagents or vaccines that have strict requirements on storage temperature. The temperature control range is 2 to 8°C, the temperature uniformity inside the box is less than 2°C, and the fluctuation is less than 3°C.

[0003] The circulation air duct of medical refrigerators varies depending on the refrigeration method. Refrigeration methods can be divided into direct cooling and air cooling.

[0004] Direct cooling method uses built-in evaporator in foam layer ( Figure 1 ) or plate evaporator in box ( Figure 2 ) obtains cooling capacity by self-circulating the cold air downward or by a built-in fan in the box for weak air volume circulation, without special air ducts or with simple air ducts; direct cooling method ( Figure 1 , Figure 2 The main disadvantage is that the fan's transfer of cooling power is weak, resulting in poor temperature uniformity within the cabinet and large temperature fluctuations. This can easily lead to frost or ice accumulation on the outer side of the lining corresponding to the foam layer evaporator or on the surface of the plate evaporator, requiring manual removal. Temperature uniformity and fluctuation are also poor, affecting user experience and the quality of stored items. Although some products incorporate a simple fan structure into the direct cooling method, this does not increase the air circulation speed within the cabinet and cannot solve the problem of frost or ice accumulation.

[0005] Air cooling utilizes a finned evaporator within the refrigerator, which then circulates high volumes of air through an adjacent fan. This requires specific air duct design, as described in "A Circulating Air Duct for an Air-Cooled Refrigerator" (200610072064.8). This method offers superior cooling capacity, good temperature uniformity within the refrigerator, and minimal fluctuations. Air circulation distributes cooling directly to all corners of the refrigerator, and with a well-designed design, prevents frost or ice buildup. Application No. 200610072064.8 discloses a circulating air duct for an air-cooled refrigerator. The application adopts a fully air-cooled circulating air duct. However, in this solution, the fan draws air from the evaporator, and the air outlet direction is directed to the back of the cabinet. The amount of cold taken away from the evaporator is relatively small, which can easily cause the evaporator to freeze and block the air circulation. The temperature uniformity and fluctuation in the cabinet are large, and the temperature control level is weak. This method of absorbing cold air from the evaporator by suction can also cause the fan motor to freeze, affecting the rotation operation and having a high failure rate. The air outlet is single, and the temperature uniformity and fluctuation at various points in the cabinet are poor, and the specified temperature cannot be reached. This patent does not explain the impact of changes in the duct diameter on the circulating wind speed and temperature uniformity. Summary of the Invention

[0006] The object of the present invention is to provide a circulating air duct for an air-cooled medical refrigerator in response to the deficiencies in the prior art.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A circulating air duct for an air-cooled medical refrigerator. The refrigerator is a device that provides gas circulation and transfers cold energy for the gas in the storage space formed by the door body and the box lining. The cold energy in the box is insulated by the foam layer, and the small amount of accumulated water generated is discharged through a drain pipe.

[0009] The circulating air duct components include a refrigeration air hood, a fan, a fin evaporator, an air duct plate, and a box lining.

[0010] The refrigeration hood features an air inlet, four top and side outlets, a turbulence plate, and support blocks for the finned evaporator. The fan's air intake faces and is positioned close to the refrigeration hood's air inlet. The height and width of the refrigeration hood's top are designed to match the finned evaporator's, ensuring sufficient airflow through the evaporator for optimal heat exchange, improving heat exchange efficiency, avoiding dead zones, and minimizing the risk of frost and ice accumulation. An axial flow fan is preferred.

[0011] The fin spacing on the fin evaporator is about 5~10 mm. The fins are parallel to the airflow direction, which plays an airflow guiding role, allowing the air to fully contact the metal refrigeration tubes perpendicular to the fins and transfer heat.

[0012] The air duct plate is equipped with a middle front air outlet and a middle side air outlet. The position and number are adjusted according to the volume and height of the box. Considering the sinking of cold air, there are generally more air outlets on the top and fewer at the bottom.

[0013] There is a wind direction adjustment block at the bottom air outlet of the air duct plate in the box lining to change the direction of the wind.

[0014] The fan and finned evaporator are fixed to the constricted refrigeration hood to form an assembly, which is fixed to the top of the box lining. When the fan is working, a wind pressure chamber is formed between the refrigeration hood, the box lining and the front of the finned evaporator. The air duct plate is connected to the constriction of the refrigeration hood and fixed to the back of the box lining, forming an air duct and a bottom air outlet. The air duct is set on the side wall of the storage space and is connected to the refrigeration hood.

[0015] When the medical refrigerator is working, the fan and the fin evaporator work at the same time. The fan provides power for the air circulation in the storage space inside the refrigerator, and the fin evaporator provides cold air and transfers it to the surrounding air.

[0016] As the air flows, it continuously absorbs and releases cold air. The fan operates, creating negative pressure at the air inlet. This causes air to flow through the storage space, creating positive pressure in the plenum chamber. This positive pressure flows along the fins, exchanging heat with the refrigeration ducts of the finned evaporator. The air absorbs cold air, lowering its temperature. As the cold air flows toward the top corner of the liner, it becomes turbulent, achieving a uniform temperature. The air encounters the constricted bottom of the refrigerated hood, increasing its velocity. It then flows toward the turbulence plates, maintaining turbulence in the ductwork before exiting through the top, middle, and bottom vents. This creates turbulence within the storage space, creating a more uniform temperature and releasing cold air to the stored items. After releasing its cold air, the air absorbs heat from the items and re-enters the negative pressure zone of the air inlet, continuing the cycle.

[0017] To achieve a closed, encircling airflow, the layout of the air outlets significantly impacts the temperature inside the refrigerator, its uniformity, and its fluctuation. The top and side outlets on both sides of the refrigeration hood not only ensure sufficient air flow around the finned evaporator but also deliver cooling to the top of the storage space. The center front outlet on the duct plate delivers cooling to the front of the storage space, the center side outlets deliver cooling to the sides of the storage space, and the bottom outlet delivers cooling to the bottom.

[0018] The fan is always in the highest temperature gas in the storage space of the box, 2~8 degrees, without freezing and keeping in good working condition.

[0019] Temperature sensors inside medical refrigerators control the compressor's on / off function, providing intermittent cooling. Normally, the compressor operates when the temperature exceeds the setpoint of 6.5°C, and stops when it falls below 3.5°C. The fan, however, operates continuously. The air entering the plenum chamber contains moisture. When this moisture encounters the cooling pipes in the finned evaporator, it forms droplets or initial frost. As the compressed air in the plenum chamber heats up, it absorbs cold air and releases heat as it flows through the finned evaporator, melting the frost. The air eventually flows down the plenum chamber as droplets, draining out through the drainpipe.

[0020] In this invention, the evaporator is a finned evaporator, integrally placed within a circulating air duct, with the airflow directly contacting it. The fan outlet is directed toward the finned evaporator. The duct utilizes an inverted L-shaped tapered opening, with a turbulent flow structure. Adding vents of varying heights, orientations, and quantity not only increases wind speed but also enhances the agitation rate and cooling transfer of the airflow. The number and arrangement of vents should also be subject to practical testing. Changing the angle of the turbulent flow structure (0-45°) can reduce wind resistance and increase the degree of airflow turbulence. The specific design should be determined by balancing the tapered opening cross-section and the size of the turbulent flow structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a structural diagram of the background technology;

[0022] Figure 2 It is a structural diagram of the background technology;

[0023] Figure 3 This is a schematic diagram of the side structure of the air duct of the present invention;

[0024] Figure 4 It is a schematic diagram of the front structure of the air duct of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the embodiments.

[0026] like Figure 3 and Figure 4 The illustrated inverted L-shaped, tapered air-cooled medical refrigerator's circulation duct. The layout of the air inlet, fan, evaporator, and duct outlet eliminates icing issues on the fan and evaporator. Reducing the duct diameter increases air circulation speed and eddy currents. The multiple duct arrangements ensure consistent temperature uniformity and fluctuation within the large refrigerator volume. These measures ensure a storage temperature of 2-8°C, with a temperature uniformity of less than 2°C and a fluctuation of less than 3°C.

[0027] An inverted L-shaped air-cooled medical refrigerator circulation duct is a device that provides gas circulation and transfers cold energy for the gas in the storage space 1 formed by the door body 13 and the box lining 9. The cold energy in the box is insulated by the foam layer 12, and the small amount of accumulated water generated is discharged through the drain pipe 11. The specific appearance is shown in Figure 3 and Figure 4 .

[0028] The circulating air duct components include a refrigeration air hood 14, a fan motor 3, a fin evaporator 6c, an air duct plate 7, a box lining 9, etc.

[0029] The refrigeration hood 14 has an air inlet 2, four top and side air outlets 15a on either side, a turbulence plate 16, and a support block for the finned evaporator 6c. The height and width of the top of the refrigeration hood are comparable to those of the finned evaporator 6c, ensuring sufficient airflow through the evaporator, facilitating effective heat exchange, improving heat exchange efficiency, avoiding dead zones, and eliminating the risk of frost and ice accumulation.

[0030] The fan motor 3 is preferably an axial flow fan.

[0031] The fin spacing on the fin evaporator 6c is about 5~10 mm. The fins are parallel to the airflow direction, which plays an airflow guiding role, allowing the air to fully contact the metal refrigeration tubes perpendicular to the fins and transfer heat.

[0032] The air duct plate 7 is provided with a middle front air outlet 15b and a middle side air outlet 15c. The position and number are adjusted according to the volume and height of the box. Considering the sinking of cold air, there are generally more at the top and fewer at the bottom.

[0033] The box lining 9 has a wind direction adjustment boss 17 at the bottom air outlet 15d of the air duct plate 7 for changing the direction of wind flow.

[0034] The fan motor 3 and finned evaporator 6c are attached to the tapered refrigeration hood 14 to form an assembly, which is then secured to the top of the refrigerator liner 9. When the fan motor 3 is in operation, a wind pressure chamber 4 is formed at the front of the refrigeration hood 14, the refrigerator liner 9, and the finned evaporator 6c. The air duct plate 7 is connected to the tapered edge of the refrigeration hood 14 and secured to the back of the refrigerator liner 9, forming an air duct 8 and a bottom air outlet 15d.

[0035] When the medical refrigerator is in operation, the fan motor 3 and the fin evaporator 6c work simultaneously. The fan motor 3 provides power for the air circulation in the storage space 1 in the refrigerator, and the fin evaporator 6c provides cooling capacity and transfers it to the surrounding air.

[0036] During the gas flow process, it continuously absorbs and releases cold energy. When the fan motor 3 is running, a negative pressure is formed at the air inlet 2, the air in the storage space 1 in the box begins to flow, and a positive pressure is formed in the wind pressure bin 4. The positive pressure airflow follows the fins and fully exchanges heat with the refrigeration pipe of the fin evaporator 6c. The gas absorbs cold energy and the temperature drops. When the cold gas flows to the top corner of the lining, turbulence occurs and the temperature becomes uniform. The airflow encounters the bottom constriction of the refrigerated air hood 14, the gas flow rate increases, and flows to the turbulent plate. It maintains a turbulent state in the air duct 8, flows out through the air vents at the top, middle and bottom, and stirs the air flow turbulence in the storage space 1 in the box, forming a relatively uniform temperature, and releasing cold energy to transfer it to the stored items. After releasing the cold energy, the gas absorbs the heat of the items and enters the negative pressure area of the air inlet again, and circulates continuously.

[0037] To achieve a closed, encircling airflow, the layout of the air outlets significantly impacts the temperature inside the refrigerator, its uniformity, and its fluctuation. The top side outlets 15a on either side of the refrigeration hood 14 not only ensure sufficient air flow around the finned evaporator 6c but also deliver cooling energy to the air above the storage space 1. The center front outlet 15b of the air duct plate 7 delivers cooling energy to the air in front of the storage space 1, the center side outlets 15c deliver cooling energy to the sides of the storage space 1, and the bottom outlet 15d delivers cooling energy to the bottom.

[0038] The fan motor 3 is always in the highest temperature gas of the storage space 1 in the box, 2 to 8 degrees, and will not freeze, keeping in good working condition.

[0039] The temperature sensor inside the medical refrigerator controls the start and stop of the compressor, providing cooling capacity intermittently. Under normal circumstances, when the temperature exceeds the set value of 6.5°C, it works for cooling, and when it is below 3.5°C, it stops and does not cool. The working state of the fan motor 3 is continuous and uninterrupted. The gas entering the wind pressure bin 4 contains humid water vapor. When the water vapor encounters the cold refrigeration pipe in the fin evaporator 6c, it will form water droplets or initial frost. Since the gas in the wind pressure bin 4 is compressed and its temperature rises, when it flows through the fin evaporator 6c, it not only absorbs cold energy and releases heat, but also melts frost. Finally, it flows down in the form of water droplets and flows out of the box through the drain pipe 11.

[0040] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Simple modifications and substitutions by those skilled in the art without departing from the spirit and scope of the present invention are within the scope of protection of the present invention.

Claims

1. A circulating air duct of an air-cooled medical refrigerator, comprising a refrigeration air hood and an air duct formed by an air duct plate, characterized in that An air inlet is provided on the refrigeration hood, a fin evaporator is installed in the refrigeration hood, top side air outlets are provided on the sides of the refrigeration hood, and the top side air outlets are located on both sides of the refrigeration hood corresponding to the fin evaporator, the air duct is provided on the side wall of the storage space, the air duct is connected to the refrigeration hood, a middle front air outlet is provided on the middle front side of the air duct, a middle side air outlet is provided on the middle side of the air duct, and a bottom air outlet is provided at the bottom of the air duct, a fan is installed in the refrigeration hood, and the air suction port of the fan is directed toward and close to the air inlet of the refrigeration hood; The height and width of the top of the refrigerated air hood are equivalent to those of the fin evaporator, the bottom of the refrigerated air hood is constricted, the air duct plate is connected to the constriction of the refrigerated air hood, a turbulence plate is installed in the air duct and a drain pipe is provided at the bottom of the box.

2. The circulating air duct of the air-cooled medical refrigerator according to claim 1 is characterized in that : A wind direction adjustment block is provided at the bottom air outlet of the air duct.

3. The circulating air duct of the air-cooled medical refrigerator according to claim 2 is characterized in that :The wind direction adjustment block is movably connected to the lining of the storage space.

4. The circulating air duct of the air-cooled medical refrigerator according to claim 1 is characterized in that The air duct is fixedly enclosed by the air duct plate.

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