Energy-saving control method for air curtain cabinet

Abstract

The present invention belongs to the technical field of refrigeration equipment, and specifically relates to an energy-saving control method for air curtain cabinets. The method includes: setting a temperature sensor at the return air inlet of the air curtain cabinet, setting a baffle assembly on the outside of the return air inlet, and the baffle assembly is set in a U-shape, including a bottom baffle and two side baffles respectively connected to the left and right ends of the bottom baffle; the return air inlet temperature threshold, temperature tolerance value, side baffle height threshold, control time interval, etc. are preset in the control system, and the control system regularly reads the return air inlet temperature detected by the temperature sensor, and compares it with the preset return air inlet temperature threshold to adjust the height of the two side baffles, reduce the return air inlet temperature and keep it stable. The present invention solves the problem of serious cold leakage on the left and right sides of the existing air curtain cabinet body, reduces the heat load and power consumption of the air curtain cabinet, and realizes energy-saving operation of the air curtain cabinet.

Description

Technical Field

[0001] The present invention belongs to the technical field of refrigeration equipment, and in particular relates to an energy-saving control method for an air curtain cabinet. Background Art

[0002] Air curtain cabinets, also known as cold air cabinets, are mainly used for low-temperature refrigeration of food, beverages, medicines, etc., and are commonly found in supermarkets, restaurants, laboratories and other places. Figure 1 As shown, the opening on the air curtain cabinet body 1a directly faces the outside environment, and a return air vent 11a is provided below the opening. When the air curtain cabinet is working, the return air vent 11a will suck in a large amount of hot and humid air, resulting in a high temperature at the return air vent 11a. The temperature of the return air vent 11a is directly related to the heat load and power consumption of the air curtain cabinet. Existing air curtain cabinets generally have a baffle 2a on the outside of the return air vent 11a, and the top surface height of the baffle 2a is H. B The height H0 of the top surface of the return air outlet 11a is higher than that of the top surface of the return air outlet 11a, so as to reduce the suction volume of the return air outlet 11a, reduce the temperature of the return air outlet 11a, and further reduce the heat load and power consumption of the air curtain cabinet. B It cannot be too high, otherwise it will affect the loading and unloading of goods at the bottom of the cabinet 1a; nor can it be too low, otherwise it will not effectively reduce the suction volume of the return air outlet 11a, and thus the temperature at the return air outlet 11a. B The maximum height is set to meet the need for direct access to the bottom layer of the inner cavity of the cabinet 1a. This will not affect the direct access to the bottom layer of the goods, but can also minimize the suction volume of the return air outlet 11a, thereby reducing the temperature of the return air outlet 11a.

[0003] However, the air curtain of the air curtain cabinet also has an end wall effect; due to the effect of friction, the airflow organization will generate vortices when it meets the end walls 12a on the left and right sides of the cabinet 1a, resulting in serious cooling leakage at the end walls 12a on the left and right sides of the cabinet 1a and a large amount of cooling waste; Figure 2 From the 10°C isosurface diagram of the existing air curtain cabinet obtained after CFD simulation analysis, it can be seen that the isosurfaces bulge outward significantly at the lower positions of the left and right end walls of the cabinet body 1a, indicating that cold leakage is relatively serious at these positions and cold energy is wasted. This is not conducive to reducing the temperature of the return air outlet 11a, increasing the heat load of the air curtain cabinet and the power consumption of the air curtain cabinet. Summary of the Invention

[0004] In response to the shortcomings in the relevant technology, the present invention provides an energy-saving control method for an air curtain cabinet, which aims to solve the problem of serious cold leakage at the left and right end walls of the existing air curtain cabinet, reduce the heat load and power consumption of the air curtain cabinet, and achieve energy-saving operation of the air curtain cabinet.

[0005] The air curtain cabinet energy-saving control method of the present invention is applicable to the air curtain cabinet, which includes a control system, a cabinet body, and a baffle assembly; wherein a temperature sensor is provided at the return air outlet of the cabinet body to detect the return air outlet temperature in real time; the temperature sensor is electrically connected to the control system; the baffle assembly is arranged in a U-shape, including a bottom baffle and two oppositely arranged side baffles; the bottom baffle is installed on the outer side of the return air outlet, and its length is consistent with the width of the inner cavity of the cabinet body; the two side baffles are slidably connected to the left and right ends of the bottom baffle, and can be raised and lowered under the control of the control system;

[0006] The energy-saving control methods of air curtain cabinets include:

[0007] S1. In the control system, preset the return air outlet temperature threshold T M and temperature tolerance dT M , preset side guard height threshold H max , preset control time interval t;

[0008] S2. Move the two side baffles to their top surface height H and reach the initial height H. A ; Initial height H A Less than the side guard height threshold H max , but greater than the top surface height H of the bottom baffle B ;

[0009] S3, the control system reads the return air outlet temperature T detected by the temperature sensor R ;

[0010] If T R =T M ±dT M , the current heights of the two side baffles remain unchanged;

[0011] If T R <T M -dT M , then lower the two side baffles by ΔH down When the top surface height H of the side baffle is reduced to the top surface height H of the bottom baffle, B Once level, it will no longer lower;

[0012] If T R >T M +dT M , determine whether the top surface height H of the side baffle is less than H max If not, the control system will issue an alarm indicating that the control exceeds the limit; if so, the two side baffles will be raised by ΔH up ; When the top surface height H of the side baffle rises to H max Then it no longer rises;

[0013] S4, continue timing, and repeat step S3 after each control time interval t, so that the control system can adjust the temperature of the return air outlet according to the temperature T R The height H of the two side baffles can be adjusted according to the real-time situation.

[0014] In some embodiments, the side guard height threshold H max Set according to formula (1);

[0015] H max =H0+c×ΔH S (1)

[0016] In formula (1), H0 is the top height of the return air outlet, ΔH S is the height difference from the top to the bottom of the cabinet cavity, c is the control coefficient, c = 0.3 ~ 0.7.

[0017] In some embodiments, the control coefficient c is 0.5.

[0018] In some embodiments, the width of each side baffle is 5%-10% of the width of the cabinet cavity.

[0019] In some embodiments, the width of each side baffle is 8% of the width of the cabinet cavity.

[0020] In some embodiments, an infrared detector is provided at the middle of the top surface of the bottom baffle, and the infrared detector is electrically connected to the control system; when the infrared detector detects that a user is approaching the baffle assembly, the two side baffles are lowered to a height H between their top surfaces and the top surface height H of the bottom baffle. B Then, when the infrared detector detects that the user has moved away from the baffle assembly, the two side baffles rise to their top surface height H and return to the height before they fell.

[0021] In some embodiments, eight temperature sensors are arranged at the return air inlet, and the eight temperature sensors are arranged in two rows, with four temperature sensors in each row evenly distributed along the width of the cabinet cavity; wherein the two temperature sensors on the left and right sides of each row are respectively close to the two side baffles; the return air inlet temperature T R Equal to the average temperature measured by eight temperature sensors.

[0022] In some embodiments, both side panels are transparent glass panels.

[0023] Based on the above technical solution, the energy-saving control method for the air curtain cabinet in the embodiment of the present invention, by respectively arranging liftable side baffles at the left and right ends of the bottom baffle, enables the control system to automatically adjust the height of the two side baffles according to the return air outlet temperature, thereby solving the problem of serious cold leakage at the left and right end walls of the existing air curtain cabinet body, and effectively controlling the return air outlet temperature within a preset range and keeping it stable, thereby reducing the heat load and power consumption of the air curtain cabinet, and realizing energy-saving operation of the air curtain cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 It is a three-dimensional diagram of the basic structure of the existing air curtain cabinet;

[0026] Figure 2 This is the 10℃ isosurface diagram obtained after CFD simulation analysis of the existing air curtain cabinet;

[0027] Figure 3 This is a three-dimensional diagram of the basic structure of the air curtain cabinet in the present invention;

[0028] Figure 4 This is a front view of the air curtain cabinet in the present invention;

[0029] Figure 5 A top view of the return air outlet of the air curtain cabinet in the present invention;

[0030] Figure 6 This is a flow chart of the air curtain cabinet energy-saving control method of the present invention.

[0031] Figure 1-Figure 2 Middle: 1a, cabinet body; 11a, return air vent; 12a, end wall; 2a, baffle;

[0032] Figure 3-Figure 5 Middle: 1. Cabinet; 11. Return air vent; 12. End wall; 13. Temperature sensor; 2. Baffle assembly; 21. Bottom baffle; 22. Side baffle; 23. Infrared detector. DETAILED DESCRIPTION

[0033] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", "left", "right", "front", "back", "vertical", "horizontal", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0036] The energy-saving control method of the air curtain cabinet of the present invention is applicable to Figure 3-Figure 5 The air curtain cabinet shown in FIG. The air curtain cabinet includes a control system, a cabinet body 1 and a baffle assembly 2.

[0037] The front of the air curtain cabinet 1 is open, and below the opening, a return air vent 11 is provided on the bottom surface of the cabinet 1. A temperature sensor 13 is provided at the return air vent 11 to monitor the temperature of the return air vent 11 in real time. The temperature sensor 13 is electrically connected to a control system, which can read the real-time detection information from the temperature sensor 13.

[0038] The return air inlet 11 of the cabinet 1 is provided with a baffle assembly 2. The baffle assembly 2 is U-shaped and includes a bottom baffle 21 and two side baffles 22 arranged opposite to each other. The bottom baffle 21 is installed on the outside of the return air inlet 11 and extends along the width direction of the cabinet 1. Its length is consistent with the width of the inner cavity of the cabinet 1. The top surface height H of the bottom baffle 21 is 1 / 4. B The top surface height H0 of the return air outlet 11 is higher than the top surface height H0 of the bottom baffle 21. BIn order to meet the maximum height required for direct access to and placement of goods at the bottom of the inner cavity of the cabinet 1, the setting of the bottom baffle 21 does not affect the direct access to and placement of goods at the bottom, and can minimize the amount of hot and humid air sucked into the return air vent 11 from the outside, thereby reducing the temperature of the return air vent 11. The two side baffles 22 are slidably connected to the left and right ends of the bottom baffle 21, respectively. It can be understood that the outer side surfaces of the left and right side baffles 22 are flush with the left and right side surfaces of the bottom baffle 21, respectively, that is, the outer side surfaces of the left and right side baffles 22 are respectively in contact with the left and right end walls 12 of the cabinet 1; further, the setting of the left and right side baffles 22 blocks the areas where cold leakage is more serious at the left and right end walls 12 of the cabinet 1, thereby reducing cold leakage, avoiding large cold waste, and reducing the heat load of the air curtain cabinet. The two side baffles 22 can be raised and lowered along the height direction of the air curtain cabinet under the control of the control system; that is, the overall height of the U-shaped baffle assembly 2 is adjustable.

[0039] like Figure 6 As shown, the air curtain cabinet energy-saving control method includes the following steps:

[0040] S1. In the control system, preset the return air outlet 11 temperature threshold T M and temperature tolerance dT M , preset side guard height threshold H max , preset control time interval t;

[0041] It is understandable that the return air outlet 11 temperature threshold T M The expected ideal temperature of the return air outlet 11 is set, at which the power consumption of the air curtain cabinet can be maintained at a relatively low and reasonable level; the control time interval t can be set according to the needs of the air curtain cabinet energy-saving control, and the present invention does not make any special restrictions on this;

[0042] S2. Under the control of the control system, move the two side baffles 22 to their top surface height H and reach the initial height H. A ; It should be noted that the initial height H A Less than the side guard height threshold H max , but greater than the top surface height H of the bottom baffle 21 B ;

[0043] S3, the control system reads the return air outlet 11 temperature T detected by the temperature sensor 13 R ;

[0044] If T R =T M ±dT M , indicating that the temperature of the return air outlet 11 is within the ideal range, the current height of the two side baffles 22 is kept unchanged;

[0045] If TR <T M -dT M , indicating that the temperature of the return air outlet 11 is lower than the expected ideal temperature range, and the shielding effect of the side baffles 22 exceeds expectations. Therefore, the heights of the two side baffles 22 can be lowered to achieve a balance between the temperature of the return air outlet 11 and the height of the side baffles 22, reducing the impact of the height of the side baffles 22 on the display effect of the air curtain cabinet. The height reduction amount of the side baffles 22 is ΔH down It should be noted that when the top surface height H of the side baffle 22 is reduced to the top surface height H of the bottom baffle 21 B Once level, it will no longer lower;

[0046] If t R >T M +dT M , indicating that the temperature of the return air outlet 11 is higher than the expected ideal temperature range, and the shielding effect of the side baffles 22 is not as expected. It is necessary to increase the height of the two side baffles 22; but first, it is necessary to determine whether the top surface height H of the side baffles 22 is less than H max ;

[0047] If not, it means that the current height of the side baffle 22 has reached the maximum limit and the temperature of the return air outlet 11 has not reached the expected level. Therefore, the control system issues an alarm for over-limit control, prompting manual intervention for inspection. The inspection content includes but is not limited to whether there are any working faults in the various components of the air curtain cabinet. If there are no other faults, the side baffle height threshold H can be increased within a reasonable range. max Setting or adjusting the return air outlet 11 temperature threshold T M Settings;

[0048] If yes, it means that the current height of the side baffles 22 still has room to be raised, so the height of the two side baffles 22 is raised by ΔH. up It should be noted that when the top surface height H of the side baffle 22 rises to H max Then it no longer rises;

[0049] S4, continue timing, and repeat step S3 after each control time interval t, so that the control system can adjust the temperature of the return air outlet 11 according to the T R The height H of the two side baffles 22 is adjusted according to the real-time situation to control the temperature of the return air outlet 11 within the expected ideal temperature range and keep it relatively stable, so that the power consumption of the air curtain cabinet can be maintained at the expected reasonable level.

[0050] The above-mentioned schematic embodiment can automatically adjust the height of the two side baffles 22 according to the temperature of the return air outlet 11, thereby solving the problem of serious cold leakage and large cold waste at the left and right end walls 12 of the existing air curtain cabinet body 1, further reducing the temperature of the return air outlet 11, and effectively controlling the temperature of the return air outlet 11 within a preset range and keeping it stable, thereby reducing the heat load and power consumption of the air curtain cabinet and realizing energy-saving operation of the air curtain cabinet.

[0051] In some embodiments, the side guard height threshold H max Set according to formula (1);

[0052] H max =H0+c×ΔH S (1)

[0053] In formula (1), H0 is the top height of the return air outlet 11, ΔH S is the height difference from the top to the bottom of the inner cavity of the cabinet 1, c is the control coefficient, c=0.3~0.7; the control coefficient c can be selectively set to any one of 0.3, 0.4, 0.5, 0.6, and 0.7 according to actual needs.

[0054] In the above exemplary embodiment, by associating the side baffle height threshold with the interior height of the cabinet body 1, the maximum height of the side baffle 22 is limited. This achieves energy-saving operation of the air curtain cabinet while also preventing the side baffle 22 from excessively impacting the display and user experience of the air curtain cabinet. Furthermore, in some embodiments, the control coefficient c is 0.5, achieving an optimized setting of the control coefficient.

[0055] In some embodiments, the width of each side baffle 22 is 5%-10% of the width of the inner cavity of the cabinet 1, and can be selectively set to any one of 5%, 6%, 7%, 8%, 9%, and 10% according to actual conditions. In this exemplary embodiment, the provision of two slender side baffles 22 on the left and right sides can block the areas of the left and right end walls 12 of the cabinet 1 where cold leakage is more serious. That is, by blocking the cabinet 1 with a smaller area, the heat load of the air curtain cabinet is greatly reduced, cold leakage is reduced, the temperature of the return air outlet 11 is further reduced, and the power consumption of the air curtain cabinet is reduced. Specifically, in some embodiments, the width of each side baffle 22 is 8% of the width of the inner cavity of the cabinet 1, achieving an optimized setting of the width of the side baffle 22.

[0056] like Figure 3-Figure 5As shown, in some embodiments, an infrared detector 23 is provided at the middle of the top surface of the bottom baffle 21. The infrared detector 23 is electrically connected to the control system. It is understood that the infrared detector 23 can use infrared sensing technology to detect whether a user is approaching the baffle assembly 2. When the infrared detector 23 detects that a user is approaching the baffle assembly 2, it sends a signal to the control system. Under the control of the control system, the two side baffles 22 are lowered to a height H between their top surfaces and the top surface height H of the bottom baffle 21. B Then, when the infrared detector 23 detects that the user has moved away from the baffle assembly 2, it sends a signal to the control system, which controls the two side baffles 22 to rise to their top surface height H and then return to their pre-lowering height. In this exemplary embodiment, the provision of the infrared detector 23 enables the two side baffles 22 to automatically descend when the user approaches, making it easier for the user to take and place goods within the cabinet 1.

[0057] like Figure 5 As shown, in some embodiments, eight temperature sensors 13 are arranged at the return air outlet 11. The eight temperature sensors 13 are arranged in two rows, four in each row. The four temperature sensors 13 in each row are evenly distributed along the width of the inner cavity of the cabinet 1; wherein, the two temperature sensors 13 on the left and right sides of each row are respectively close to the two side baffles 22. The temperature T of the return air outlet 11 R It is equal to the average value of the temperatures measured by the eight temperature sensors 13, thereby enabling the control system to obtain the temperature of the return air outlet 11 more accurately and comprehensively, further improving the energy-saving control level of the air curtain cabinet.

[0058] In some embodiments, both side panels 22 are transparent glass panels; the bottom panel 21 may also be a transparent glass panel. The use of transparent glass panels ensures that the side panels 22 do not affect the display effect of the goods in the cabinet.

[0059] To sum up, the energy-saving control method of the air curtain cabinet of the present invention, by respectively arranging liftable side baffles 22 at the left and right ends of the bottom baffle 21, enables the control system to automatically adjust the height of the two side baffles 22 according to the temperature of the return air outlet 11, thereby solving the problem of serious cold leakage at the left and right end walls 12 of the existing air curtain cabinet body 1, and effectively controlling the temperature of the return air outlet 11 within a preset range and keeping it stable, thereby reducing the heat load and power consumption of the air curtain cabinet, and realizing energy-saving operation of the air curtain cabinet.

[0060] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to preferred embodiments, persons skilled in the art should understand that the specific implementation methods of the present invention may still be modified or some technical features may be replaced by equivalents without departing from the spirit of the technical solutions of the present invention, and all of these should fall within the scope of the technical solutions claimed for protection by the present invention.

Claims

1. An air curtain cabinet energy-saving control method, applicable to the air curtain cabinet, characterized in that: The air curtain cabinet includes a control system, a cabinet body, and a baffle assembly; wherein, a temperature sensor is provided at the return air outlet of the cabinet body to detect the return air outlet temperature in real time; the temperature sensor is electrically connected to the control system; the baffle assembly is U-shaped, including a bottom baffle and two oppositely arranged side baffles; the bottom baffle is installed on the outside of the return air outlet, and its length is consistent with the width of the inner cavity of the cabinet body; the two side baffles are respectively slidably connected to the left and right ends of the bottom baffle and can be raised and lowered under the control of the control system; The air curtain cabinet energy-saving control method includes: S1. In the control system, a return air outlet temperature threshold T is preset. M and temperature tolerance dT M , preset side guard height threshold H max , preset control time interval t; S2, move the two side baffles to their top surface height H to reach the initial height H A ; The initial height H A Less than the side guard height threshold H max , but greater than the top surface height H of the bottom baffle B ; S3, the control system reads the return air outlet temperature T detected by the temperature sensor R ; If T R =T M ±dT M , then keep the current heights of the two side baffles unchanged; If T R <T M -dT M , then lower the two side baffles by ΔH down When the top surface height H of the side baffle is reduced to the top surface height H of the bottom baffle B Once level, it will no longer lower; If T R >T M +dT M , determine whether the top surface height H of the side baffle is less than H max If not, the control system issues an alarm that the control exceeds the limit; if so, the two side baffles are raised by an amount of ΔH up When the top surface height H of the side baffle rises to H max Then it no longer rises; S4, continue timing, and repeat step S3 after each control time interval t, so that the control system is set according to the return air outlet temperature T R The height H of the two side baffles can be adjusted according to the real-time situation.

2. The air curtain cabinet energy-saving control method according to claim 1, characterized in that: The side guard height threshold H max Set according to formula (1); H max =H0+c×ΔH S (1) In formula (1), H0 is the top height of the return air outlet, ΔH S is the height difference from the top to the bottom of the inner cavity of the cabinet, c is the control coefficient, and c=0.3~0.

7.

3. The air curtain cabinet energy-saving control method according to claim 2, characterized in that: The control coefficient c is 0.

5.

4. The air curtain cabinet energy-saving control method according to claim 1, characterized in that: The width of each side baffle is 5%-10% of the width of the cabinet inner cavity.

5. The air curtain cabinet energy-saving control method according to claim 4, characterized in that: The width of each side baffle is 8% of the width of the cabinet inner cavity.

6. The air curtain cabinet energy-saving control method according to claim 1, characterized in that: An infrared detector is provided at the middle of the top surface of the bottom baffle, and the infrared detector is electrically connected to the control system; when the infrared detector detects that a user is approaching the baffle assembly, the two side baffles are lowered to a height H between their top surfaces and the top surface height H of the bottom baffle. B then, when the infrared detector detects that the user has moved away from the baffle assembly, the two side baffles rise to their top surface height H and return to the height before the drop.

7. The air curtain cabinet energy-saving control method according to claim 1, characterized in that: The return air outlet is provided with eight temperature sensors, which are arranged in two rows, and the four temperature sensors in each row are evenly distributed along the width of the cabinet cavity; wherein, the two temperature sensors on the left and right sides of each row are respectively close to the two side baffles; the return air outlet temperature T R Equal to the average temperature measured by eight temperature sensors.

8. The air curtain cabinet energy-saving control method according to claim 1, characterized in that: The two side baffles are both transparent glass plates.

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