Air duct structure of air conditioning unit, air conditioning unit and control method

Abstract

The invention provides an air channel structure of an air conditioning unit, the air conditioning unit and a control method. The air duct structure comprises an air supply pipe, an air return pipe, a lower air pipe, an upper air pipe and an air pipe switching assembly. The lower air pipe and the upper air pipe are arranged on the lower portion and the upper portion of the bin correspondingly. The air pipe switching assembly is communicated with the air supply pipe and the air return pipe and is communicated with the lower air pipe and the upper air pipe, when the air pipe switching assembly is switched to the first state, the air pipe switching assembly is communicated with the air supply pipe and the lower air pipe and is communicated with the air return pipe and the upper air pipe, and when the air pipe switching assembly is switched to the second state, the air pipe switching assembly is communicated with the air supply pipe and the upper air pipe and is communicated with the air return pipe and the lower air pipe. According to the air pipe switching assembly, the communication direction of the air supply path and the air return path can be switched, and switching of the air supply path and the air return path in the refrigerating and heating modes is achieved. Cold air naturally diffuses and sinks through upper air supply during refrigeration, hot air naturally rises through lower air supply preferentially during heating, and it is ensured that airflow and indoor air are fully mixed at different heights for heat exchange.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and specifically to an air duct structure of an air conditioner unit, an air conditioner unit and a control method. Background Art

[0002] In recent years, air conditioners for ship cargo holds such as those for LNG (liquefied natural gas) ship cargo holds have been increasingly used in China. However, the application scenarios of ships are significantly different from those of land-based air conditioners. Traditional air duct systems generally adopt a fixed supply and return air path design. For example, a combination mode of top supply air and top return air, or a combination mode of bottom supply air and bottom return air is used, and it is difficult to dynamically adjust the air flow organization form according to the actual cooling / heating demand.

[0003] Under the cooling condition, if the fixed supply and return air mode (such as top supply air + top return air) is continuously adopted, it is easy to cause the cold air short-circuit effect - the cold air sinks and is drawn away from the system by the return air outlet before being effectively collected, resulting in the formation of a local low-temperature area; similarly, under the heating condition, if the bottom supply air + bottom return air mode is maintained, the hot air rises and is not fully recovered and stays at the top of the cabin, causing a local high-temperature area. Such a static supply and return air system cannot achieve the dynamic matching of air flow organization and heat load changes, directly affecting the regulation efficiency of the cabin thermal environment and the energy utilization economy. Summary of the Invention

[0004] In order to solve the technical problem of poor energy utilization efficiency of air duct supply and return air in the above-mentioned prior art, the present invention provides an air duct structure of an air conditioner unit, an air conditioner unit and a control method.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention provides an air duct structure of an air conditioner unit, including: a supply air duct and a return air duct, the supply air duct is connected to the supply air side of the air conditioner unit, and the return air duct is connected to the return air side of the air conditioner unit; further including:

[0007] A lower air duct and an upper air duct, which are respectively arranged at the lower part and the upper part of the cabin;

[0008] An air duct switching component, which connects the supply air duct and the return air duct, and connects the lower air duct and the upper air duct. When the air duct switching component is switched to the first state, it connects the supply air duct and the lower air duct, and connects the return air duct and the upper air duct. When it is switched to the second state, it connects the supply air duct and the upper air duct, and connects the return air duct and the lower air duct.

[0009] Specifically, the air duct switching assembly includes: a first branch pipe, a second branch pipe, a third branch pipe, and a fourth branch pipe. The first branch pipe connects the air supply duct and the lower air duct and is provided with a first air valve; the second branch pipe connects the air return duct and the upper air duct and is provided with a second air valve; the third branch pipe connects the air supply duct and a position on the second branch pipe between the second air valve and the upper air duct; the fourth branch pipe connects the air return duct and a position on the first branch pipe between the first air valve and the lower air duct.

[0010] When the air duct switching assembly switches to the first state, the control instruction is to open the first air valve and the second air valve and close the third air valve and the fourth air valve; when switching to the second state, the control instruction is to open the third and fourth air valves and close the first air valve and the second air valve.

[0011] Furthermore, static pressure boxes are provided on both the first branch pipe and the second branch pipe. The third branch pipe is connected to the static pressure box of the second branch pipe, and the fourth branch pipe is connected to the static pressure box of the first branch pipe.

[0012] Furthermore, fire dampers are provided at positions on the first branch pipe and the second branch pipe close to the inside of the bin.

[0013] Furthermore, the lower air duct and the upper air duct extend horizontally, and a plurality of air outlets are provided at intervals in the length direction.

[0014] The present invention also provides an air conditioner unit including the above air duct structure. The present invention also provides a control method for an air conditioner unit using the above air conditioner unit, including the steps of:

[0015] Obtain the real-time temperature T inside the bin;

[0016] When the set temperature T_set inside the bin is less than the real-time temperature T, run the cooling mode and control the air duct switching assembly to switch to the second state;

[0017] When the set temperature T_set inside the bin is greater than the real-time temperature T, run the heating mode and control the air duct switching assembly to switch to the first state.

[0018] Furthermore, when the air duct switching assembly performs a state switch, first execute the instruction to open the air valve in the instruction, and then execute the instruction to close the air valve in the instruction.

[0019] Furthermore, after the air conditioner unit is started, first run the cooling mode, and after running for a preset duration, then execute the step of judging the temperature inside the bin.

[0020] Furthermore, after the air conditioner unit is started, it further includes the steps of:

[0021] Obtain the oxygen content O2 detected by oxygen detectors at different positions in the room, and calculate the average value of the oxygen content O2;

[0022] Judge the preset interval where the average value of the oxygen content O2 is located, and adjust the opening degree of the fresh air valve according to the fresh air valve adjustment logic corresponding to the preset interval.

[0023] Furthermore, when the oxygen content O2 detected by any oxygen detector is less than or equal to the preset minimum oxygen content O2min, control the fresh air valve to be fully open.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The combined structure of the branch pipe and the air valve. The air duct switching component can switch the connection direction of the air supply and return paths, realizing the switching of the air supply and return paths in the cooling and heating modes. When cooling, it preferentially uses the upper air supply to make the cold air naturally diffuse and sink. When heating, it preferentially uses the lower air supply to make the hot air naturally rise, ensuring that the air flow and the indoor air are fully mixed and heat exchanged at different heights. This design avoids the problem of uneven local heat exchange caused by the fixed air supply and return paths in the traditional air duct, making the temperature distribution in the space more uniform, improving the overall heat exchange efficiency and reducing energy consumption.

[0026] 2. By dynamically adjusting the opening degree of the fresh air valve, the indoor oxygen content is maintained within a safe range in real time, ensuring the health of personnel or the safe operation of equipment (such as a storage environment sensitive to oxygen). Intelligently adjust the fresh air volume according to the actual oxygen content demand, avoiding energy waste caused by a fixed opening degree, especially improving energy efficiency in a closed space or a scenario with changing personnel density. Multi-point detection and average value calculation can reduce the influence of single-point sensor errors and ensure the reliability of decision-making. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0028] Figure 1 It is the system diagram of the embodiment of the present invention;

[0029] Figure 2 It is the system diagram of the heating mode in the embodiment of the present invention;

[0030] Figure 3 It is the system diagram of the cooling mode in the embodiment of the present invention;

[0031] Figure 4 It is the flowchart of temperature control in the embodiment of the present invention;

[0032] Figure 5 It is the flowchart of oxygen concentration control in the embodiment of the present invention;

[0033] Figure 6 is the flow chart in the embodiment of the present invention;

[0034] 11. Supply air duct; 12. Return air duct; 13. Lower air duct; 14. Upper air duct;

[0035] 21. First branch pipe; 22. Second branch pipe; 23. Third branch pipe; 24. Fourth branch pipe; 211. First air valve; 221. Second air valve; 231. Third air valve; 241. Fourth air valve; 25. Fire damper; 26. Static pressure box;

[0036] 3. Air handling unit;

[0037] 31. Fresh air valve. Specific embodiments

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] The principle and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0040] In the existing air conditioning system for warehouse temperature control, in the refrigeration and heating working conditions, a fixed supply and return air mode (such as top supply + top return) is continuously adopted. For example, in the refrigeration mode, it is easy to cause the cold air short - circuit effect - the cold air sinks and is drawn away from the system by the return air outlet before being effectively collected, resulting in the formation of a local low - temperature area; this static supply and return air system cannot achieve the dynamic matching of air flow organization and heat load changes, directly affecting the regulation efficiency of the warehouse thermal environment and the energy utilization economy.

[0041] In response to this, as Figure 1 shown, the present invention proposes an air duct structure of an air conditioning unit, including: a supply air duct 11, a return air duct 12, a lower air duct 13, an upper air duct 14 and an air duct switching component. Among them:

[0042] The supply air duct 11 is connected to the supply air side of the air handling unit, and the return air duct 12 is connected to the return air side of the air handling unit, forming a basic supply and return air path. The lower air duct 13 and the upper air duct 14 are respectively arranged at the lower and upper parts of the warehouse to form a vertically evenly distributed air flow channel. The air duct switching component simultaneously connects the supply air duct 11 and the return air duct 12, and connects the lower air duct 13 and the upper air duct 14. The switching component realizes two working states by changing the internal passage: in the first state, the air duct switching component connects the supply air duct 11 and the lower air duct 13, and at the same time connects the return air duct 12 and the upper air duct 14; in the second state, the air duct switching component connects the supply air duct 11 and the upper air duct 14, and at the same time connects the return air duct 12 and the lower air duct 13.

[0043] like Figure 3 As shown, when the cooling mode is running, the air duct switching assembly switches to the second state, so that the air supply duct 11 is connected to the upper air duct 14, and the return air duct 12 is connected to the lower air duct 13. At this time, the cold air is sent to the upper part of the room through the upper air duct 14, and naturally sinks due to the high density of the cold air. After fully exchanging heat with the indoor air, the mixed air that sinks to the ground flows back to the return air duct 12 through the lower air duct 13. Figure 2 As shown, when the heating mode is running, the air duct switching assembly switches to the first state, so that the air supply duct 11 is connected with the lower air duct 13, and the return air duct 12 is connected with the upper air duct 14. The hot air is sent to the lower part of the chamber through the lower air duct 13, and naturally rises due to the low density of the hot air. After fully exchanging heat with the indoor air, the mixed air that rises to the top flows back to the return air duct 12 through the upper air duct 14.

[0044] Through the above structure, the air duct system realizes the switching of the air supply and return air paths in cooling and heating modes. In cooling, the upper air supply is preferentially used to make the cold air naturally diffuse and sink, and in heating, the lower air supply is preferentially used to make the hot air naturally rise, ensuring that the airflow and indoor air are fully mixed and heat exchanged at different heights. This design avoids the problem of local uneven heat exchange caused by the fixed air supply and return air paths in traditional air ducts, making the temperature distribution in the space more uniform, improving the overall heat exchange efficiency and reducing energy loss.

[0045] In the first embodiment, the air duct switching assembly includes: a first branch pipe 21, a second branch pipe 22, a third branch pipe 23, a fourth branch pipe 24 and four groups of air valves. The first branch pipe 21 connects the air supply pipe 11 and the lower air pipe 13, and a first air valve 211 is installed on its passage; the second branch pipe 22 connects the return air pipe 12 and the upper air pipe 14, and a second air valve 221 is installed on its passage; the third branch pipe 23 connects the air supply pipe 11 and the pipe section between the second air valve 221 of the second branch pipe 22 and the upper air pipe 14; the fourth branch pipe 24 connects the return air pipe 12 and the pipe section between the first air valve 211 of the first branch pipe 21 and the lower air pipe 13.

[0046] The switching component realizes two working modes by controlling the opening and closing of the air valve:

[0047] In the first state, the first air valve 211 and the second air valve 221 are in the open state, and the third air valve 231 and the fourth air valve 241 are in the closed state. At this time, the air supply path is: the air supply side of the air conditioning unit → the air supply pipe 11 → the first branch pipe 21 → the lower air pipe 13 (air supply to the lower part of the chamber); the return air path is: the upper air pipe 14 → the second branch pipe 22 → the return air pipe 12 → the return air side of the air conditioning unit.

[0048] In the second state, the third air valve 231 and the fourth air valve 241 are in the open state, and the first air valve 211 and the second air valve 221 are in the closed state. At this time, the air supply path is as follows: the air supply side of the air conditioner unit → the air supply duct 11 → the third branch pipe 23 → the upper air duct 14 (supplying air to the upper part of the chamber); the air return path is as follows: the lower air duct 13 → the fourth branch pipe 24 → the air return duct 12 → the air return side of the air conditioner unit.

[0049] Through the combined structure of the above-mentioned branch pipes and air valves, the air duct switching component can quickly switch the connection direction of the air supply and air return paths, and at the same time solve the problem that the air valve gets stuck and cannot be opened during the switching of the cold and hot air ducts, making it safer and more reliable to use. The independent control of each air valve ensures the accurate switching of the air flow path under different modes, avoiding air flow conflicts during the switching of the cooling / heating modes. The segmented design of the branch pipes ensures the airtightness of each pipeline during the switching process, reducing air volume loss. This structure enables the air conditioner unit to direct the cold / hot air flow to the optimal air supply height according to the cooling or heating demand, and collect the air after heat exchange through the air return openings at the corresponding height, further optimizing the space heat exchange efficiency.

[0050] In the second embodiment, the air duct switching component includes a first branch pipe 21, a second branch pipe 22, a third branch pipe 23, a fourth branch pipe 24 and four groups of air valves. The first branch pipe 21 connects the air supply duct 11 and the lower air duct 13, and a first air valve 211 is installed on its passage; the second branch pipe 22 connects the air return duct 12 and the upper air duct 14, and a second air valve 221 is installed on its passage. Static pressure boxes 26 are provided on both the first branch pipe 21 and the second branch pipe 22 for balancing the air flow pressure and stabilizing the air supply distribution. One end of the third branch pipe 23 is connected to the static pressure box 26 of the second branch pipe 22, and the other end is connected to the pipe section between the second air valve 221 of the second branch pipe 22 and the upper air duct 14 and the air supply duct 11; one end of the fourth branch pipe 24 is connected to the static pressure box 26 of the first branch pipe 21, and the other end is connected to the pipe section between the first air valve 211 of the first branch pipe 21 and the lower air duct 13 and the air return duct 12.

[0051] By adding static pressure boxes 26 to the first branch pipe 21 and the second branch pipe 22, and connecting the third branch pipe 23 and the fourth branch pipe 24 to the static pressure boxes 26 of the corresponding branch pipes respectively, the static pressure boxes 26 can not only buffer the air flow impact during the switching process, but also improve the overall stability through air flow diversion and confluence. During the switching of the cooling / heating modes, this design uses the buffering effect of the static pressure boxes 26 to reduce air flow disorder, and at the same time ensures the rapid response of the air supply and air return paths, further improving the system operation efficiency and heat exchange uniformity.

[0052] In a further embodiment, fire dampers 25 are provided at one end of the first branch pipe 21 and the second branch pipe 22 close to the interior of the chamber, for automatically or manually cutting off the air flow passage in case of an abnormal fire. By adding fire dampers 25 at the positions of the first branch pipe 21 and the second branch pipe 22 close to the interior of the chamber, while ensuring the air flow switching function, the fire safety of the air duct system of the air conditioner unit is strengthened. The independent control logic of the fire damper 25 does not affect the switching logic of the air valve, remains open during normal operation, and only quickly responds and closes when a fire is triggered, which not only meets the requirements of safety codes but also avoids interfering with the normal air supply and return functions.

[0053] Specifically, the lower air duct 13 and the upper air duct 14 are respectively arranged at the lower and upper parts of the chamber; and extend horizontally, and at the same time have a plurality of air outlets arranged at intervals along the length direction. In addition, the lower air duct 13 and the upper air duct 14 may specifically include a plurality of branch pipes arranged side by side, so that the air inlet and outlet areas are larger and more uniform.

[0054] As Figure 1 、 2 、shown in FIG. 3, the present invention also provides an air conditioning system, including: an air duct structure, an air handling unit 3 (having a supply air side, a return air side and a fresh air side, and the fresh air side having a fresh air valve 31) and related control and detection devices. Among them:

[0055] The air duct structure includes a supply air duct 11, a return air duct 12, a lower air duct 13, an upper air duct 14 and an air duct switching assembly. The assembly includes a first branch pipe 21, a second branch pipe 22, a third branch pipe 23, a fourth branch pipe 24 and four groups of air valves, and the air supply and return paths are switched by opening and closing the air valves of each branch pipe.

[0056] When the air conditioner unit operates, the cooling / heating mode is switched by controlling the air valves:

[0057] In the cooling mode, the air duct switching assembly is in the second state, the third air valve 231 and the fourth air valve 241 are opened, and the first air valve 211 and the second air valve 221 are closed. At this time, the cold air is sent from the supply air duct 11 → the third branch pipe 23 → the upper air duct 14 to the upper part of the chamber, and after sinking, it returns to the air handling unit 3 through the lower air duct 13 → the fourth branch pipe 24 → the return air duct 12.

[0058] In the heating mode, the air duct switching assembly is switched to the first state, the first air valve 211 and the second air valve 221 are opened, and the third air valve 231 and the fourth air valve 241 are closed. The hot air is sent from the supply air duct 11 → the first branch pipe 21 → the lower air duct 13 to the lower part of the chamber, and after rising, it returns to the air handling unit 3 through the upper air duct 14 → the second branch pipe 22 → the return air duct 12.

[0059] This air conditioning unit realizes intelligent adjustment of the air supply and return air paths through an integrated switchable air duct structure. The fire damper 25 provides safety guarantee at key pipeline nodes, and the plenum chamber 26 balances the air pressure to optimize the heat exchange efficiency. This design enables the cold / hot air to always flow along the optimal path, ensuring uniform distribution of indoor temperature, while taking into account fire safety and rapid response requirements, significantly improving the space thermal comfort and equipment operation reliability.

[0060] In a preferred embodiment, this air conditioning unit is an air conditioner for a ship's liquid cargo hold, specifically an air conditioner for an LNG ship's liquid cargo hold.

[0061] As Figure 4 、 6 shown, the present invention also proposes a control method for an air conditioning unit, specifically including the following steps:

[0062] After the air conditioning unit is started, it first operates in the cooling mode for a preset duration (e.g., 120 s);

[0063] The current temperature value T in the cargo hold is collected in real time and compared with the temperature value T set by the user;

[0064] When it is detected that the set temperature T set is lower than the current temperature T, it is determined as a cooling demand. At this time, the system controls the air duct switching component to switch to the second state: open the third air valve and the fourth air valve, and close the first air valve and the second air valve;

[0065] When it is detected that the set temperature T set is higher than the current temperature T, it is determined as a heating demand. At this time, the system controls the air duct switching component to switch to the first state: open the first air valve and the second air valve, and close the third air valve and the fourth air valve.

[0066] Through the above control logic, this method realizes that the air conditioning unit automatically adjusts the air supply and return air paths according to the actual heat load demand: in the cooling mode, the cold air is sent into the upper part of the cargo hold through the upper air duct, and after sinking, it flows back through the lower air duct; in the heating mode, the hot air is sent into the lower part of the cargo hold through the lower air duct, and after rising, it flows back through the upper air duct. Ensure that the air flow always flows along the optimized path, improve the accuracy of temperature regulation and heat exchange efficiency, and avoid energy waste caused by manual switching or fixed air ducts.

[0067] It should be noted that O21 - O210 in the figure are oxygen detectors; TH1 - TH10 are temperature and humidity sensors. The current temperature T can specifically be the average temperature.

[0068] When switching the state of the air duct switching component, a step-by-step control strategy is adopted:

[0069] The specific steps are as follows:

[0070] The system generates a target state instruction based on the temperature comparison result (such as the cooling mode needs to be switched to the second state), and specifies the air valves that need to be opened (such as the third air valve and the fourth air valve) and the air valves that need to be closed (such as the first air valve and the second air valve).

[0071] Prioritize the execution of the opening command: First send the opening action command to the air valve to be opened to ensure that the target air supply path is connected first. For example, when switching to the second state, the third and fourth air valves are opened first so that the air flow can flow through the new path immediately.

[0072] Delayed closing command execution: After the target air valve is fully opened, a closing command is sent to the original air valve to avoid air flow shock or pressure fluctuation caused by sudden path cutoff during the switching process. For example, the operation of closing the first and second air valves is executed after the third and fourth air valves are fully opened.

[0073] Through the sequence of "open first and then close", it is ensured that the airflow path is always connected during the switching process, avoiding airflow interruption or sudden pressure change caused by the simultaneous opening and closing of valves, and reducing system vibration and noise. The new path is opened in advance and then the old path is closed to maintain the continuity of the operation of the air-conditioning unit, especially in large air volume systems to prevent airflow short circuit or backflow, while reducing stress damage to the pipeline structure. It improves the reliability and user experience of the air-conditioning unit during mode switching, especially for scenes such as warehousing and data centers that require fast response and have high requirements for airflow stability.

[0074] like Figure 5 , 6 As shown, in a specific embodiment, multiple oxygen detectors are installed in different areas of the chamber (such as the upper part, the middle part, and the lower part, as shown in the figure, two in the upper and lower parts, and one in the middle part) to monitor the oxygen content O2 value at each point in real time;

[0075] After the unit is started, it also includes oxygen content monitoring and dynamic adjustment of the fresh air valve, including:

[0076] The system automatically collects data from each oxygen detector at preset intervals and calculates the average oxygen content O2;

[0077] Determine the preset interval where the oxygen content O2 is located, and adjust the opening of the fresh air valve according to the fresh air valve adjustment logic corresponding to the preset interval, for example:

[0078] Hypoxia zone (average O2 value ≤ O2a, O2a can be preferably 19.5% to 20.5%): increase the opening of the fresh air valve and increase the fan speed to quickly replenish fresh air;

[0079] Normal range (O2a≤O2 average≤O2b, O2b can be preferably 23.5% to 25.5%): maintain the current fresh air valve opening, and only make periodic fine adjustments to compensate for environmental changes;

[0080] Oxygen-rich zone (O2 average > O2b): Reduce the opening of the fresh air valve to avoid energy loss due to excessive ventilation.

[0081] By dynamically adjusting the opening of the fresh air valve, the indoor oxygen content is maintained within a safe range in real time to ensure the health of personnel or the safety of equipment operation (such as oxygen-sensitive storage environments). The fresh air volume is intelligently adjusted according to the actual oxygen content demand to avoid energy waste caused by fixed openings, especially to improve energy efficiency in confined spaces or scenarios with changing population density. Multi-point detection and mean calculation can reduce the impact of single-point sensor errors and ensure decision reliability. It is suitable for places with strict requirements on air quality, such as data center rooms, clean workshops, and cabins.

[0082] Taking the cabin as an example, workers consume oxygen when welding invar steel in a closed cabin, which reduces the oxygen in the cabin and may cause health risks to the workers and reduce the welding quality. If the oxygen content in the cabin is too high (exceeding the normal range), the risk of fire and explosion will increase significantly, and the metal surface will be more easily oxidized to form an oxide film, which will affect the quality of the weld and cause problems such as weak welds and easy rust.

[0083] The above method of the present invention also includes adding a single-point hypoxia emergency response mechanism in the oxygen monitoring link, specifically:

[0084] The system continuously collects real-time data from all oxygen detectors and makes separate determinations on the oxygen content O2 value at each independent detection point;

[0085] When the oxygen content O2 detected by any oxygen detector is less than or equal to the preset minimum oxygen content O2min, the system will execute the fresh air valve full-open instruction (opening 100%) with the highest priority, and link the fan speed to the preset maximum value to ensure the immediate introduction of the maximum amount of fresh air;

[0086] This instruction is independent of the conventional temperature control logic. Even if the system is currently in the process of switching between cooling and heating modes, it is necessary to interrupt the current air valve operation and give priority to responding to emergency oxygen needs. Through the single-point trigger mechanism, it can respond to sudden hypoxia in local areas (such as ventilation dead corners and equipment-intensive areas) in the first place, avoiding delays in the best treatment time due to reliance on mean calculations. This forms a double protection with the aforementioned mean control, which not only ensures the safety of the overall environment, but also "precisely intervenes" in local dangers, significantly improving system reliability.

[0087] This design is particularly applicable to scenarios where there is a risk of local oxygen consumption (such as in the use of inert gas fire extinguishing systems and storage environments for flammable substances). By means of single-point triggering combined with a forced full-open mechanism, the safety risk is controlled at the budding stage. At the same time, through multi-level alarm and recording functions, data support is provided for post-event analysis.

[0088] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0089] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0090] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0091] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above terms have no special meanings. Therefore, it should not be construed as a limitation on the protection scope of the present invention. The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An air duct structure of an air conditioning unit, comprising: A supply air duct and a return air duct, the supply air duct is connected to the supply air side of the air conditioning unit, and the return air duct is connected to the return air side of the air conditioning unit; characterized in that it further includes: A lower air duct and an upper air duct, respectively arranged at the lower and upper parts of the chamber; An air duct switching assembly, connecting the supply air duct and the return air duct, and connecting the lower air duct and the upper air duct. When the air duct switching assembly is switched to the first state, it connects the supply air duct and the lower air duct, and connects the return air duct and the upper air duct. When switched to the second state, it connects the supply air duct and the upper air duct, and connects the return air duct and the lower air duct.

2. The air duct structure of the air conditioner unit according to claim 1, characterized in that, The air duct switching assembly includes: a first branch pipe, a second branch pipe, a third branch pipe, and a fourth branch pipe. The first branch pipe connects the supply air duct and the lower air duct, and is provided with a first air valve; the second branch pipe connects the return air duct and the upper air duct, and is provided with a second air valve; the third branch pipe connects the supply air duct and a position on the second branch pipe between the second air valve and the upper air duct; the fourth branch pipe connects the return air duct and a position on the first branch pipe between the first air valve and the lower air duct. When the air duct switching assembly is switched to the first state, the control instruction is to open the first air valve and the second air valve, and close the third air valve and the fourth air valve; when switched to the second state, the control instruction is to open the third and fourth air valves, and close the first air valve and the second air valve.

3. The air duct structure of the air conditioner unit according to claim 2, characterized in that, Static pressure boxes are provided on both the first branch pipe and the second branch pipe. The third branch pipe is connected to the static pressure box of the second branch pipe, and the fourth branch pipe is connected to the static pressure box of the first branch pipe.

4. The air duct structure of the air conditioner unit according to claim 2, characterized in that, Fire dampers are provided at positions on the first branch pipe and the second branch pipe close to the inside of the chamber.

5. The air duct structure of the air conditioner unit according to claim 1, characterized in that, The lower air duct and the upper air duct extend horizontally, and a plurality of air outlets are arranged at intervals in the length direction.

6. An air conditioning unit, characterized in that, Including the air duct structure according to any one of claims 1 to 5.

7. A control method for an air conditioning unit, characterized in that, Using the air conditioning unit according to claim 6, including the steps of: Obtaining the real-time temperature T inside the chamber; When the set temperature T_set inside the chamber is less than the real-time temperature T, running the refrigeration mode, and controlling the air duct switching assembly to switch to the second state; When the set temperature T_set inside the chamber is greater than the real-time temperature T, running the heating mode, and controlling the air duct switching assembly to switch to the first state.

8. The control method of the air conditioner unit according to claim 7, characterized in that, When the air duct switching assembly performs a state switch, first execute the instruction to open the air valve in the instruction, and then execute the instruction to close the air valve.

9. The control method of the air conditioner unit according to claim 7, characterized in that, After the air conditioning unit is started, it further includes the steps of: Obtaining the oxygen content O2 detected by oxygen detectors located at different positions in the room, and calculating the average value of the oxygen content O2; Judging the preset interval where the average value of the oxygen content O2 is located, and adjusting the opening degree of the fresh air valve according to the fresh air valve adjustment logic corresponding to the preset interval.

10. The control method of the air conditioner unit according to claim 7, characterized in that, When the oxygen content O2 detected by any oxygen detector is less than or equal to the preset minimum oxygen content O2min, control the fresh air valve to be fully open.

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