Ducted air conditioner protection structure, air conditioning system and refrigerant leakage detection method

Abstract

The invention provides a duct type air conditioner protection structure, an air conditioning system and a refrigerant leakage detection method.The duct type air conditioner protection structure comprises an evaporator, a shell and a main control module, the evaporator and the main control module are both located in the shell, a water pump assembly is further arranged in the shell and arranged at the position, close to the main control module, of one end of the evaporator, and the water pump assembly is connected with the evaporator. The water pump assembly comprises a water pump and a water pump support for fixing the water pump, and a refrigerant detector is arranged below the water pump support and used for detecting whether refrigerant leakage exists in the duct type air conditioner or not. The refrigerant detector is installed on the lower portion of the water pump support, so that the internal space of the duct type air conditioner can be effectively saved, the size of the duct type air conditioner is reduced, the weight is reduced, the cost is reduced, and whether R32 refrigerant leaks or not can be accurately and rapidly detected; and the position is closer to the main control module, so that the wiring of the refrigerant detector is convenient, the wiring of the refrigerant detector is simple and convenient without disorder, and the assembly difficulty and the assembly efficiency of workers are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a duct machine protection structure, an air conditioning system and a refrigerant leakage detection method. Background Art

[0002] In the field of air conditioning, R32 is a commonly used and effective refrigerant. R32 is a flammable and explosive gas. If the refrigerant leaks, it may explode, endangering people's lives and property. For duct air conditioners, the internal space is small. How to install a refrigerant detector to effectively detect the refrigerant concentration is an urgent problem to be solved in this field. In the prior art, the refrigerant detector inside the duct air conditioner is mostly installed on the side panel of the evaporator, such as Figure 7 In the second installation position shown, since the refrigerant detector is at the air outlet of the duct machine, the wind pressure here is very large, and it can only detect the air passing through the evaporator. The R32 concentration of the air at this time is much different from the actual concentration. The accuracy of the R32 refrigerant detector here is poor, and this place is far away from the main control board, making wiring difficult. As a result, the wiring inside the duct machine is messy and difficult to sort out, and even wiring errors and missing wiring occur, making the product unable to work normally and requiring rework, which greatly increases the assembly difficulty and efficiency of workers. Summary of the invention

[0003] In view of this, the present invention aims to propose a duct air conditioner protection structure, an air conditioning system and a refrigerant leakage detection method to solve the problems of poor accuracy and difficult wiring of refrigerant detectors in the prior art.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A duct air conditioner protection structure includes an evaporator, a shell and a main control module, wherein the evaporator and the main control module are both located inside the shell. A water pump assembly is also provided inside the shell, and the water pump assembly is provided at one end of the evaporator and close to the main control module. The water pump assembly includes a water pump and a water pump bracket for fixing the water pump. A refrigerant detector is provided below the water pump bracket for detecting whether there is refrigerant leakage inside the duct air conditioner. Installing the refrigerant detector at the bottom of the water pump bracket can effectively save the internal space of the duct machine, reduce the size of the duct machine, reduce weight and cost; this installation position is close to the evaporator refrigerant pipeline of the duct machine, where the corresponding evaporator refrigerant pipeline is the largest and is the elbow welding point, which is most prone to refrigerant leakage, and this position is far away from the fan, and the air delivered from the fan from the outside has little effect on this place, and it can accurately and quickly detect whether the R32 refrigerant is leaking; this position is close to the main control module, which is convenient for the wiring of the refrigerant detector, making the wiring of the refrigerant detector simple and not messy, reducing the assembly difficulty and efficiency of workers; in addition, the installation here can be connected to the water pump valve plate as a whole. If the refrigerant detector fails, the water pump valve plate can be directly opened for maintenance. The convenient disassembly method can effectively improve the maintenance efficiency and facilitate the replacement of the refrigerant detector, greatly reducing the difficulty of after-sales maintenance and reducing labor costs.

[0006] Furthermore, the refrigerant detector includes a fixing base and a sensor, wherein the sensor is located inside the fixing base, and a first opening is provided on the fixing base, through which air outside the fixing base enters the fixing base. When refrigerant leaks, the refrigerant concentration inside the duct unit increases significantly, and the air containing the refrigerant enters the fixing base through the first opening and is detected by the sensor.

[0007] Furthermore, a fixing foot is provided on the edge of the fixing seat, and the fixing seat is fixedly installed below the water pump bracket through the fixing foot.

[0008] Furthermore, a through hole is provided on the top of the fixing seat, and a signal line connected to the sensor extends outward through the through hole and is connected to the main control module, so as to facilitate the connection between the signal line and the main control module.

[0009] Furthermore, the fixing base includes a lower cover and an upper cover, the lower cover and the upper cover are connected by a snap-fit, and a first opening is provided at a connecting portion of the lower cover and the upper cover, and the first opening corresponds to a position of the sensor inside.

[0010] Furthermore, support feet and positioning columns are arranged inside the upper cover, the support feet are arranged near the four corners inside the upper cover, and the positioning column is arranged near the middle inside the upper cover, which plays a role in positioning and fixing the PCB board. The positioning column and the support feet at the four corners can realize accurate installation of the PCB board.

[0011] Furthermore, an adjustment hole is provided on the water pump bracket, and the refrigerant detector is installed at the lower part of the adjustment hole. The installation angle of the refrigerant detector is adjusted based on the center of the adjustment hole. The angle between the sensor of the refrigerant detector and the end face of the evaporator is -30° to 30°.

[0012] Furthermore, a volute fixing plate is provided between the water pump assembly and the main control module, and a wiring hole is provided on the volute fixing plate. The signal line of the refrigerant detector passes through the wiring hole on the volute fixing plate and is connected to the main control module.

[0013] Compared with the prior art, the duct air conditioner protection structure of the present invention has the following advantages:

[0014] Installing the refrigerant detector at the bottom of the water pump bracket can effectively save the internal space of the duct machine, reduce the size of the duct machine, reduce weight and cost; this installation position is close to the evaporator refrigerant pipeline of the duct machine, where the corresponding evaporator refrigerant pipeline is the largest and is the elbow welding point, which is most prone to refrigerant leakage, and this position is far away from the fan, and the air delivered from the fan from the outside has little effect on this place, and it can accurately and quickly detect whether the R32 refrigerant is leaking; this position is close to the main control module, which is convenient for the wiring of the refrigerant detector, making the wiring of the refrigerant detector simple and not messy, reducing the assembly difficulty and efficiency of workers; in addition, the installation here can be connected to the water pump valve plate as a whole. If the refrigerant detector fails, the water pump valve plate can be directly opened for maintenance. The convenient disassembly method can effectively improve the maintenance efficiency and facilitate the replacement of the refrigerant detector, greatly reducing the difficulty of after-sales maintenance and reducing labor costs.

[0015] The present invention also provides an air conditioning system, comprising the above-mentioned duct air conditioner protection structure and an external unit, wherein the duct air conditioner protection structure is connected to the external unit via a refrigerant pipeline.

[0016] The advantages of the air conditioning system and the above-mentioned duct air conditioner protection structure over the prior art are the same, which will not be repeated here.

[0017] The present invention also provides a refrigerant leakage detection method, the detection method adopts the above-mentioned air conditioning system, and the detection method comprises:

[0018] Get the refrigerant concentration inside the duct unit;

[0019] When the refrigerant concentration exceeds the threshold, the main control module will issue an alarm prompt and send a signal to the outdoor unit to interrupt the refrigerant supply to the indoor unit;

[0020] The outdoor unit contracts its abdomen, and the refrigerant in the evaporator of the duct unit is emptied into the outdoor unit. This process lasts for a first preset time, and then the expansion valve of the air inlet pipe of the outdoor unit is closed;

[0021] The fan of the duct unit will be turned off after running for a second preset time, the refrigerant remaining in the duct unit will be emptied, and the entire air conditioning system will be turned off. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of a duct machine according to an embodiment of the present invention;

[0023] Figure 2 This is a front view of the air duct machine according to an embodiment of the present invention;

[0024] Figure 3 A side view of the duct machine according to an embodiment of the present invention;

[0025] Figure 4 for Figure 2 Middle CC section view;

[0026] Figure 5 for Figure 1 Middle BB plane section view;

[0027] Figure 6 for Figure 1 Middle EE section view;

[0028] Figure 7 This is a schematic diagram of the arrangement of refrigerant detection sensors for a ducted air conditioner according to an embodiment of the present invention;

[0029] Figure 8 for Figure 7 Middle BB plane section view;

[0030] Fig. 9 for Figure 7 Sectional view of the middle AA plane;

[0031] Fig.10 for Figure 7 Middle CC section view;

[0032] Fig.11 for Figure 1 Middle DD section view;

[0033] Fig.12 This is an axial view of the air duct machine protection structure according to an embodiment of the present invention;

[0034] Fig.13 An exploded view of the duct machine protection structure according to an embodiment of the present invention;

[0035] Fig.14 This is a schematic diagram of the assembly of the refrigerant detector according to an embodiment of the present invention;

[0036] Fig.15 This is a schematic diagram of the angle adjustment of the refrigerant detector according to an embodiment of the present invention;

[0037] Fig.16 This is a view of the assembly structure of the refrigerant detector and the water pump shaft according to an embodiment of the present invention;

[0038] Fig.17 An exploded view of the assembly structure of the refrigerant detector according to an embodiment of the present invention;

[0039] Fig.18 This is a schematic diagram of the structure of the fixing base and the sensor according to an embodiment of the present invention;

[0040] Fig.18a A top view of a fixing base and a sensor according to an embodiment of the present invention;

[0041] Fig.18b A bottom view of the fixing base and the sensor according to an embodiment of the present invention;

[0042] Fig.18c for Fig.18 Middle AA section view;

[0043] Fig.19 This is a schematic diagram of the upper cover of the fixing base according to an embodiment of the present invention;

[0044] Fig. 20 This is a schematic diagram of the lower cover of the fixing base according to an embodiment of the present invention;

[0045] Fig.21 This is a schematic diagram of the structure of the fixing base according to an embodiment of the present invention;

[0046] Fig.21a for Fig.21 Middle BB section view;

[0047] Figure 21b for Fig.21 Middle AA section view.

[0048] Description of reference numerals:

[0049] 100-refrigerant detector, 1-fixed seat, 11-lower cover, 111-first connecting ear, 12-upper cover, 13-sensor, 14-first opening, 15-buckle, 16-connecting part, 121-positioning column, 122-support foot, 123-second connecting ear, 17-fixed foot, 20-signal line, 21-through hole, 101-first installation position, 102-second installation position, 103-third installation position, 200-evaporator, 21-refrigerant pipeline, 22-evaporator end face, 300-housing, 31-water pump valve plate, 32-water pump bracket, 33-water pump, 34-volute fixing plate, 35-wiring hole, 36-adjustment hole, 37-air outlet, 400-main control module DETAILED DESCRIPTION

[0050] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In addition, the directions involved in the following specific embodiments are briefly described: the directions or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "top", "bottom" and the like mentioned in the embodiments refer to the directions or positional relationships shown in the accompanying drawings, and the term "on..." refers to being directly or indirectly supported by... elements.

[0051] like Figure 8 As shown, in the prior art duct machine, the refrigerant detector 100 is installed on the evaporator side panel, close to the duct machine outlet, where the wind pressure is relatively high, and the sensor is located here and can only detect the air passing through the evaporator. The R32 concentration in the air passing through the evaporator is much different from the actual concentration, resulting in poor detection accuracy. In addition, the refrigerant detector is installed on the evaporator side panel, far away from the main control module, resulting in complex wiring of the connection line between the sensor and the main control module, affecting the internal structure of the duct machine.

[0052] like Figure 1-21bAs shown, the present invention provides a duct machine protection structure, including an evaporator 200, a shell 300 and a main control module 400. The evaporator 200 and the main control module 400 are both located inside the shell 300. A water pump assembly is also provided in the shell 300. The water pump assembly is provided at one end of the evaporator 200 and close to the main control module 400. The water pump assembly includes a water pump 33 and a water pump bracket 32 ​​for fixing the water pump 33. A refrigerant detector 100 is provided below the water pump bracket 32 ​​for detecting whether there is refrigerant leakage inside the duct machine. Installing the refrigerant detector at the bottom of the water pump bracket can effectively save the internal space of the duct machine, reduce the volume of the duct machine, reduce weight and cost; the main reason for R32 refrigerant leakage is the evaporator elbow welding. Improper welding operation, excessive pressure of the internal refrigerant, internal corrosion and other reasons may cause the elbow welding to break, resulting in refrigerant leakage. This installation position is close to the evaporator refrigerant pipeline of the duct machine. The corresponding evaporator refrigerant pipeline 21 is the most and is the elbow welding point, which is most prone to refrigerant leakage. In addition, this position is far away from the fan, and the fan is The air delivered from the outside has little effect on this point, and it can accurately and quickly detect whether the R32 refrigerant is leaking; and this position is close to the main control module, which is convenient for the wiring of the refrigerant detector, making the wiring of the refrigerant detector simple and uncluttered, reducing the difficulty and efficiency of assembly for workers; in addition, the installation here can be connected to the water pump valve plate as a whole. If the refrigerant detector fails, the water pump valve plate can be directly opened for maintenance. The convenient disassembly method can effectively improve the maintenance efficiency and facilitate the replacement of the refrigerant detector, greatly reducing the difficulty of after-sales maintenance and reducing labor costs.

[0053] The refrigerant detector 100 includes a fixing base 1 and a sensor 13. The sensor 13 is located inside the fixing base 1. A first opening 14 is provided on the fixing base 1. The air outside the fixing base 1 enters the fixing base 1 through the first opening 14. When the refrigerant leaks, the refrigerant concentration inside the duct unit is significantly increased. The air containing the refrigerant enters the fixing base through the first opening and is detected by the sensor 13. The greater the concentration of the R32 refrigerant gas, the greater the current generated inside the detector, and the R32 refrigerant leakage signal will be sent to the main control module 400, thereby causing an alarm. Furthermore, the first opening 14 is set as an internal expansion hole, so that the refrigerant leaking inside the duct unit can be detected more quickly and accurately.

[0054] Preferably, a waterproof layer is wrapped around the outside of the refrigerant detector 100 to prevent the refrigerant detector from generating condensed water and causing an internal short circuit on the PCB board, thereby ensuring the normal operation of the refrigerant detector. More preferably, the waterproof layer is configured as a sponge layer that is breathable and absorbent, so that the refrigerant gas can be normally detected by the sensor and condensed water is prevented from entering the interior of the fixing seat.

[0055] Further, such as Fig.16As shown, a fixing foot 17 is provided at the edge of the fixing base 1, and the fixing base 1 is fixedly mounted below the water pump bracket 32 ​​through the fixing foot 17. Preferably, two fixing feet 17 are provided, which are respectively located on both sides of the fixing base 1. A through hole 21 is also provided at the top of the fixing base 1, and a signal line 20 connected to the sensor 13 extends outward through the through hole 21 and is connected to the main control module 400.

[0056] Specifically, Figures 16 to 21 As shown, the fixing base 1 includes a lower cover 11 and an upper cover 12, and the lower cover 11 and the upper cover 12 are connected by a buckle 15. A first opening 14 is provided at the connection portion between the lower cover 11 and the upper cover 12, and the first opening 14 corresponds to the position of the internal sensor 13. The first opening 14 is provided at the connection portion between the upper cover and the lower cover to facilitate the installation of the sensor. Further, there are multiple buckles 15, and the buckles 15 include a snap ring and a block. The snap ring is provided at the edge of the lower cover 11 or the upper cover 12, and the block is provided at the edge of the upper cover 12 or the lower cover 11, thereby realizing the pre-positioning assembly of the lower cover 11 and the upper cover 12. Furthermore, a through hole 21 is provided at the top of the upper cover 12, and the signal line 20 connected to the sensor 13 extends outward through the through hole 21.

[0057] Furthermore, a connecting portion 16 is provided at the joint of the lower cover 11 and the upper cover 12, and the upper cover and the lower cover are further fixedly connected together by screws or other connecting members passing through the connecting portion 16. Preferably, two screws or other connecting members are provided, and the two connecting members are respectively located on the left and right sides or the front and rear sides of the fixing base 1.

[0058] Specifically, a first connecting ear 111 is further provided on the edge of the lower cover 11, and a second connecting ear 123 is correspondingly provided on the edge of the upper cover 12. The first connecting ear 111 and the second connecting ear 123 are butted together to form a connecting portion. The top edge of the middle portion of the upper cover 12 is lower than the top edge of the second connecting ear 123, so that a gap is formed between the top of the upper cover 12 and the water pump bracket 32, which is convenient for the signal line to pass through.

[0059] Support feet 122 are arranged inside the upper cover 12. The support feet 122 are arranged near the four corners inside the upper cover 12. The support feet 122 are used to fix and install the PCB board. Furthermore, a positioning column 121 is arranged inside the upper cover 12. The positioning column 121 is located near the middle of the upper cover 12 and plays a role in positioning and fixing the PCB board. The positioning column and the support feet at the four corners can achieve accurate installation of the PCB board.

[0060] As part of the embodiments of the present invention, Fig.15As shown, an adjustment hole 36 is also provided on the water pump bracket 32, and the refrigerant detector 100 is installed at the lower part of the adjustment hole 36. The installation angle of the refrigerant detector is adjusted based on the center of the adjustment hole, thereby adjusting the angle between the refrigerant detector and the end face of the evaporator. Furthermore, the angle between the sensor of the refrigerant detector and the end face of the evaporator is -30° to 30°, wherein the end face of the evaporator is parallel to the water pump valve plate 31. Specifically, as Fig.10 As shown, at this time, the angle between the installation direction 104 of the refrigerant detector and the evaporator end face 22 is 0°. When the refrigerant detector rotates clockwise, the angle formed by the evaporator end face of the refrigerant detector is a positive value, and when the refrigerant detector rotates counterclockwise, it is a negative value. The refrigerant detector is most accurate when the angle is -30° to 30°.

[0061] The water pump assembly also includes a water pump valve plate 31, which is perpendicular to the water pump bracket 32 ​​and is arranged on the outside of the water pump bracket 32, thereby protecting the water pump and the refrigerant detector. At the same time, it is convenient to open the water pump valve plate to repair and replace the refrigerant detector. The convenient disassembly method can effectively improve the maintenance efficiency, greatly reduce the difficulty of after-sales maintenance, and reduce labor costs.

[0062] Furthermore, a volute fixing plate 34 is provided between the water pump assembly and the main control module 400 , and a wiring hole 35 is provided on the volute fixing plate 34 . The signal line 20 of the refrigerant detector 100 passes through the wiring hole 35 on the volute fixing plate 34 and is connected to the main control module 400 .

[0063] As part of an embodiment of the present invention, an air conditioning system is also provided, and the air conditioning system includes the above-mentioned air duct air conditioner protection structure.

[0064] As part of an embodiment of the present invention, a refrigerant leakage detection method is also provided. The detection method adopts the air conditioning system described above, and the detection method includes:

[0065] S1. Obtain the refrigerant concentration inside the duct unit;

[0066] The refrigerant detector continuously detects the refrigerant concentration inside the duct unit. When it is detected that the refrigerant concentration exceeds the threshold, a signal indicating that the refrigerant concentration is too high is sent to the main control module.

[0067] S2. When the refrigerant concentration exceeds the threshold, the main control module will give an alarm and send a signal to the outdoor unit to interrupt the refrigerant supply to the indoor unit;

[0068] When the main control module receives a signal that the refrigerant concentration is too high, the main control module sends a signal to the outdoor unit to interrupt the refrigerant supply to the indoor unit, so that the expansion valve of the outdoor unit's outlet pipe is closed and the refrigerant supply to the indoor unit is stopped.

[0069] S3, the outdoor unit contracts and empties the refrigerant in the evaporator of the duct unit into the outdoor unit. This process lasts for a first preset time, and then the expansion valve of the air inlet pipe of the outdoor unit is closed, so that all the refrigerant in the evaporator of the duct unit enters the outdoor unit.

[0070] The outdoor unit contracts to exhaust the refrigerant in the evaporator, allowing the refrigerant in the evaporator to enter the outdoor unit and continue for a first preset time to fully ensure that the refrigerant in the evaporator completely enters the outdoor unit, and then the outdoor unit intake pipe expansion valve is closed.

[0071] Further, the first preset time is set to 5 to 30 seconds. Preferably, the first preset time is set to 10 seconds.

[0072] S4. After the fan of the duct unit runs for the second preset time, the fan is turned off to evacuate the refrigerant remaining in the duct unit, and the entire air conditioning system is turned off and no longer runs.

[0073] Furthermore, the second preset time is set to 5 minutes to ensure that the refrigerant remaining in the duct unit is exhausted.

[0074] Test example

[0075] In order to fully illustrate the accuracy of refrigerant detection by the installation position of the refrigerant detector described in the present invention, the detection accuracy of the refrigerant detector at different positions is analyzed and tested below.

[0076] like Figures 7 to 11 As shown, the position where the refrigerant detector is installed at the lower part of the water pump bracket 32 ​​is defined as the first installation position 101 (the solution of the present invention), the position where the refrigerant detector is installed on the evaporator side panel in the prior art is positioned as the second installation position 102, and the position where the refrigerant detector is installed near the fan outlet 37 is defined as the third installation position 103, wherein the third installation position 103 is closer to the wind wheel outlet than the first installation position 101, and the air transported from the outside by the wind wheel has a greater impact on the third installation position 103 than the first installation position 101, and the accuracy of the R32 refrigerant detector is worse than that at the first installation position 101, that is, the third installation position 103 is the farthest from the main control board among the three solutions, and wiring is difficult.

[0077] Specifically, Figures 7 to 9 As shown, sensors are set at twelve points of the duct unit, namely, the first point A, the second point B, the third point C, the fourth point D, the fifth point E, the sixth point F, the seventh point G, the eighth point H, the ninth point I, the tenth point J, the eleventh point K, and the twelfth point L. The average value of the concentration detected at the twelve points is used as the actual concentration inside the duct unit. Then, at different concentrations, the concentrations detected by the R32 refrigerant detector at the three positions are recorded. The test results are shown in Table 1 below:

[0078] Table 1 Sensor test data at different installation positions at different concentrations

[0079]

[0080] It can be seen from the above data that the R32 refrigerant detector is in the best position when it is in the first installation position. Through experimental verification, the R32 refrigerant detector at the first installation position has the highest accuracy, followed by the third installation position. The detection accuracy of the second installation position in the prior art is the worst.

[0081] The above sensors are arranged at 12 locations in total, and then the average value is taken as the actual concentration of R32 refrigerant inside the duct unit. The angle between the R32 refrigerant sensor and the evaporator end face is adjusted at different concentrations based on the center of the circular hole on the water pump bracket. Then, the concentration detected by the R32 refrigerant detector at three locations is recorded at different angles. The test results are shown in Table 2 below:

[0082] Table 2 Sensor test data at different installation positions at different angles

[0083]

[0084]

[0085] From the above data, it can be seen that the sensor is most accurate when it is oriented at -30° to 30° to the end face of the evaporator.

[0086] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A ducted air conditioner protection structure, comprising an evaporator (200), a housing (300) and a main control module (400), wherein the evaporator (200) and the main control module (400) are both located inside the housing (300), and a water pump assembly is also provided inside the housing (300), characterized in that: The water pump assembly is arranged at one end of the evaporator (200) and close to the main control module (400), and the water pump assembly includes a water pump (33) and a water pump bracket (32) for fixing the water pump (33). A refrigerant detector (100) is arranged below the water pump bracket (32) for detecting whether there is a refrigerant leak inside the duct machine.

2. The air duct machine protection structure according to claim 1, characterized in that: The refrigerant detector (100) comprises a fixing base (1) and a sensor (13), wherein the sensor (13) is located inside the fixing base (1), and a first opening (14) is provided on the fixing base (1), and air outside the fixing base (1) enters into the fixing base (1) through the first opening (14).

3. The air duct machine protection structure according to claim 2 is characterized in that: A fixing foot (17) is provided on the edge of the fixing seat (1), and the fixing seat (1) is fixedly mounted below the water pump bracket (32) via the fixing foot (17).

4. The air duct machine protection structure according to claim 2, characterized in that: A through hole (21) is also provided on the top of the fixing seat (1), and a signal line (20) connected to the sensor (13) extends outward through the through hole (21) and is connected to the main control module (400).

5. The air duct machine protection structure according to claim 2, characterized in that: The fixing base (1) comprises a lower cover (11) and an upper cover (12), wherein the lower cover (11) and the upper cover (12) are connected via a buckle (15), and a first opening (14) is provided at the connection portion between the lower cover (11) and the upper cover (12), wherein the first opening (14) corresponds to the position of the sensor (13) inside.

6. The air duct machine protection structure according to claim 5, characterized in that: Support feet (122) and positioning columns (121) are arranged inside the upper cover (12); the support feet (122) are distributed near the four corners inside the upper cover (12); and the positioning columns (121) are located near the middle inside the upper cover (12).

7. The air duct machine protection structure according to claim 1, characterized in that: An adjustment hole (36) is also provided on the water pump bracket (32), and the refrigerant detector (100) is installed at the lower part of the adjustment hole (36). The installation angle of the refrigerant detector is adjusted based on the center of the adjustment hole (36). The angle between the sensor of the refrigerant detector (100) and the end face of the evaporator is -30° to 30°.

8. The air duct machine protection structure according to claim 1, characterized in that: A volute fixing plate (34) is also provided between the water pump assembly and the main control module (400), and a wiring hole (35) is provided on the volute fixing plate (34). The signal line (20) of the refrigerant detector (100) passes through the wiring hole (35) on the volute fixing plate (34) and is connected to the main control module (400).

9. An air conditioning system, characterized in that: It comprises the duct air conditioner protection structure as claimed in any one of claims 1 to 8, and also comprises an external unit, wherein the duct air conditioner protection structure is connected to the external unit through a refrigerant pipeline.

10. A refrigerant leakage detection method, characterized in that: The detection method adopts the air conditioning system according to claim 9, and the detection method comprises: Get the refrigerant concentration inside the duct unit; When the refrigerant concentration exceeds the threshold, the main control module will issue an alarm prompt and send a signal to the outdoor unit to interrupt the refrigerant supply to the indoor unit; The outdoor unit contracts its abdomen, and the refrigerant in the evaporator of the duct unit is emptied into the outdoor unit. This process lasts for a first preset time, and then the expansion valve of the air inlet pipe of the outdoor unit is closed; The fan of the duct unit will be turned off after running for a second preset time, the refrigerant remaining in the duct unit will be emptied, and the entire air conditioning system will be turned off.

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