Air conditioning system, top air outlet air conditioning outdoor unit and defrosting method of top air outlet air conditioning outdoor unit

Abstract

The invention provides an air-conditioning system, a top air-out air-conditioning outdoor unit and a defrosting method thereof, and the defrosting method of the top air-out air-conditioning outdoor unit comprises the following steps: starting a defrosting mode of the air-conditioning system, and controlling a high-temperature refrigerant discharged by a compressor to enter an outdoor heat exchanger; temperature parameters of multiple positions of the outdoor heat exchanger are detected; after any temperature parameter reaches a preset temperature T0, an axial flow fan of the outdoor unit of the top-air-out air conditioner is controlled to operate reversely; and after the defrosting condition is achieved, the defrosting mode is quitted. The invention provides a defrosting scheme capable of improving the defrosting effect of the outdoor unit of the top-air-out air conditioner.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an air conditioning system, a top-outlet air conditioning outdoor unit and a defrosting method thereof. Background Art

[0002] The air conditioning system is a system that can achieve indoor temperature control. The air conditioning outdoor unit is an indispensable component of the air conditioning system, which can exchange heat with the outdoor air. The air conditioning outdoor unit of the air conditioning system is divided into two types according to the air outlet method. The most common ones are side outlet and top outlet. When the top outlet method is adopted, an axial flow fan is generally installed on the top of the outdoor unit box.

[0003] In the cold winter, air conditioning systems are usually used in homes for heating. While the indoor unit outputs hot air, due to the low outdoor ambient temperature, frost is easily generated in the outdoor unit, resulting in reduced equipment efficiency, thus generating a need for defrosting.

[0004] The functional components of the top-outlet air conditioner outdoor unit (outdoor heat exchanger, compressor, gas-liquid separator, etc.) are usually installed on the chassis inside the outdoor unit. Since the air flow direction inside the top-outlet air conditioner outdoor unit is from bottom to top, and the bottom airflow is blocked by the functional components, the defrosting effect in the bottom space of the top-outlet air conditioner outdoor unit is often poor during defrosting. Moreover, during defrosting, the water produced by the melting of the frost above the outdoor heat exchanger will also flow through and accumulate at the bottom. Affected by the tension of the water, the condensed water will be adsorbed between the bottom structures of the top-outlet air conditioner outdoor unit, resulting in a vicious cycle of incomplete defrosting and subsequent ice spread. Summary of the invention

[0005] The present invention provides an air conditioning system, a top-outlet air conditioning outdoor unit and a defrosting method thereof, so as to solve the defect that the defrosting effect of the top-outlet air conditioning outdoor unit in the prior art is not ideal, and realize a defrosting scheme capable of improving the defrosting effect of the top-outlet air conditioning outdoor unit.

[0006] The present invention provides a defrosting method for an outdoor unit of a top-outlet air-conditioning system, comprising: starting a defrost mode of an air-conditioning system, controlling a high-temperature refrigerant discharged from a compressor to enter an outdoor heat exchanger; detecting temperature parameters at multiple positions of the outdoor heat exchanger; after any of the temperature parameters reaches a preset temperature T0, controlling an axial flow fan of the outdoor unit of the top-outlet air-conditioning system to run in reverse; and exiting the defrost mode after the defrost conditions are met.

[0007] According to a defrosting method for a top-outlet air-conditioning outdoor unit provided by the present invention, the multiple temperature parameters include at least an upper half temperature value T1 and a lower half temperature value T2; the upper half temperature value T1 is a temperature parameter detected at the top of the outdoor heat exchanger close to the top of the top-outlet air-conditioning outdoor unit; the lower half temperature value T2 is a temperature parameter detected at the bottom of the outdoor heat exchanger close to the top-outlet air-conditioning outdoor unit.

[0008] According to a defrosting method for a top-outlet air-conditioning outdoor unit provided by the present invention, the outdoor heat exchanger includes an upper heat exchanger and a lower heat exchanger connected in parallel to each other. In the top-outlet air-conditioning outdoor unit, the installation position of the upper heat exchanger is located above the lower heat exchanger; the upper temperature value T1 is the lowest temperature value of the upper heat exchanger; and the lower temperature value T2 is the lowest temperature value of the lower heat exchanger.

[0009] According to a defrosting method for a top-outlet air-conditioning outdoor unit provided by the present invention, when the upper temperature value T1 reaches a preset temperature T0, the compressor is controlled to stop supplying high-temperature refrigerant to the upper heat exchanger and continue to supply high-temperature refrigerant to the lower heat exchanger.

[0010] According to a defrosting method for a top-outlet air conditioner outdoor unit provided by the present invention, the defrosting conditions include that all the temperature parameters reach the preset temperature T0; and / or the total duration of the defrost mode operation reaches the preset duration S0.

[0011] According to the present invention, a defrosting method for a top-outlet air-conditioning outdoor unit is provided, comprising: obtaining the outdoor real-time temperature when starting the defrost mode; setting the preset time length S0 in this defrost mode according to the outdoor real-time temperature; the length of the preset time length S0 is inversely proportional to the temperature value of the outdoor real-time temperature.

[0012] According to a defrosting method for a top-outlet air-conditioning outdoor unit provided by the present invention, the axial flow fan stops running before any of the temperature parameters reaches a preset temperature T0.

[0013] According to a defrosting method for a top-outlet air-conditioning outdoor unit provided by the present invention, after any of the temperature parameters reaches a preset temperature T0, the axial flow fan operates intermittently; wherein each reverse operation duration of the axial flow fan is a second, and the stop time between each two reverse operations is b seconds.

[0014] The present invention also provides a top-outlet air-conditioning outdoor unit, comprising an axial flow fan capable of changing direction and a control device; the control device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and when the processor executes the program, the defrosting method for the top-outlet air-conditioning outdoor unit described in any one of the above is implemented.

[0015] The present invention further provides an air conditioning system, comprising an air conditioning indoor unit and the top-outlet air conditioning outdoor unit as described above.

[0016] The present invention provides a defrosting method for a top-outlet air conditioner outdoor unit, which uses the high-temperature refrigerant discharged from the compressor to heat and defrost the outdoor heat exchanger, and controls the axial flow fan of the top-outlet air conditioner outdoor unit to run in reverse after the temperature meets the conditions, thereby driving the air flow direction in the top-outlet air conditioner outdoor unit from top to bottom, and then the floating hot air can be blown to the bottom of the top-outlet air conditioner outdoor unit, accelerating the melting of the frost at the bottom, and blowing the melted water to the outside of the top-outlet air conditioner outdoor unit. Therefore, the defrosting method for a top-outlet air conditioner outdoor unit according to the present invention can improve the defrosting effect of the top-outlet air conditioner outdoor unit.

[0017] A top-outlet air-conditioning outdoor unit and an air-conditioning system having the top-outlet air-conditioning outdoor unit can improve the defrosting effect and enhance the performance of the equipment by executing the defrosting process through the defrosting method of the top-outlet air-conditioning outdoor unit during defrosting operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic flow chart of a defrosting method for a top-outlet air conditioner outdoor unit provided by the present invention;

[0020] Figure 2 It is a schematic diagram of the air flow direction of the top-outlet air-conditioning outdoor unit provided by the present invention when the axial flow fan is in normal operating state;

[0021] Figure 3 Schematic diagram of air flow direction of the top-outlet air conditioner outdoor unit provided by the present invention when the axial flow fan is in reverse operation

[0022] Figure 4 The present invention provides a schematic diagram of the refrigerant pipeline in the outdoor unit of the top-discharge air conditioner.

[0023] Reference numerals:

[0024] Upper heat exchanger 10; upper temperature sensor 11; upper electronic expansion valve 12; lower heat exchanger 20; lower temperature sensor 21; lower electronic expansion valve 22. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The outdoor heat exchanger of the top-outlet air-conditioning outdoor unit is usually located directly on the chassis at the same height as the compressor, gas-liquid separator and other large main components. During heating and defrosting, the bottom of the outdoor unit heat exchanger is often not defrosted cleanly. With long-term operation, it will gradually freeze from the bottom and finally spread to the entire outdoor heat exchanger, resulting in poor heat exchange effect of the entire outdoor heat exchanger, shortened defrost cycle, increased defrost time, and affected user experience.

[0027] The present invention improves the problem of difficult defrosting at the bottom of the heat exchanger at a relatively low cost by combining the control of an axial flow fan with less impact on the original structure of the outdoor unit of the top-outlet air-conditioning system, thereby reducing system energy loss, extending the defrost cycle, and improving the overall energy efficiency of the air-conditioning system.

[0028] like Figure 2 As shown, when the outdoor unit of the top-outlet air conditioner is operating under normal conditions, the axial flow fan blows air upward, driving the outside air through the outdoor heat exchanger and into the interior of the outdoor unit. It is understandable that the closer to the axial flow fan, the greater the air volume, so the air volume around the upper part of the outdoor heat exchanger is larger. However, since the fins in the lower part of the outdoor heat exchanger are far away from the axial flow fan and are blocked by the main components such as the chassis, compressor and gas-liquid separator, the air volume passing through the fins is relatively small, and the heat exchange effect is poor. In a relatively cold environment, frost is more likely to form between the structures near the bottom of the outdoor heat exchanger, and heat tends to float up every time defrosting occurs. The melted water gathers downward under the action of gravity, causing ice to gradually form from the bottom, affecting the operating state of the equipment.

[0029] like Figure 4 As shown, according to a preferred embodiment of the present invention, the outdoor heat exchanger is divided into two parts, an upper heat exchanger 10 and a lower heat exchanger 20. The upper heat exchanger 10 and the lower heat exchanger 20 are respectively provided with an upper temperature sensor 11 and a lower temperature sensor 21, which are respectively used to detect the surface temperature or the internal refrigerant temperature of the upper heat exchanger 10 and the lower heat exchanger 20. The upper heat exchanger 10 and the lower heat exchanger 20 are preferably also provided with an upper electronic expansion valve 12 and a lower electronic expansion valve 22 on the refrigerant pipeline, respectively, to control the refrigerant flow in the upper heat exchanger 10 and the lower heat exchanger 20.

[0030] like Figure 1As shown, during the defrosting process, the working mode of the outdoor unit is switched to refrigeration operation, that is, the high-temperature refrigerant discharged from the compressor is introduced into the outdoor heat exchanger to start heating and defrosting. At this time, the axial flow fan is preferably stopped to prevent accelerated heat loss. The detection values ​​of the upper temperature sensor 11 and the lower temperature sensor 21 are continuously obtained. When the preset temperature T0 is reached, it means that this part of the heat exchanger has met the defrosting temperature condition. Taking into account the user comfort issue, the defrosting stage is preferably limited to a preset duration S0. Even if the detection values ​​of the upper temperature sensor 11 and the lower temperature sensor 21 do not reach the preset temperature T0, the device will exit the defrosting mode and continue indoor heating to ensure the indoor temperature control effect of the air-conditioning system.

[0031] During the above defrosting process, when the detection value of the upper temperature sensor 11 reaches the preset temperature T0, the upper electronic expansion valve 12 is preferably controlled to close, thereby stopping the supply of high-temperature refrigerant to the upper heat exchanger 10, so that all the refrigerant passes through the lower heat exchanger 20, accelerating the melting of the bottom frost. Figure 3 As shown, the axial flow fan is controlled to run in reverse to blow air downward, taking away the heat and blowing away the floating ice and melt water at the bottom. Preferably, the axial flow fan stops after running in reverse for a seconds, waits for b seconds, and then continues to run until the detection value of the lower half temperature sensor 21 reaches the preset temperature T0 or the total defrosting time reaches the preset time S0, the entire defrosting process is completed, and the outdoor unit exits the defrosting mode.

[0032] In order to better understand the above technical solution, Figure 1-Figure 4 Various specific implementations of the air conditioning system, the top-outlet air conditioning outdoor unit and the defrosting method thereof of the present invention are described.

[0033] According to the present invention, a defrosting method for an outdoor unit of a top-outlet air conditioner is provided. Figure 1 As shown, it includes: starting the defrost mode of the air-conditioning system, controlling the high-temperature refrigerant discharged from the compressor to enter the outdoor heat exchanger; detecting the temperature parameters of multiple positions of the outdoor heat exchanger; after any temperature parameter reaches the preset temperature T0, controlling the axial flow fan of the top-outlet air-conditioning outdoor unit to run in reverse; after the defrost conditions are met, exiting the defrost mode.

[0034] The defrosting method of the top-discharge air conditioner outdoor unit utilizes the high-temperature refrigerant discharged from the compressor to heat the outdoor heat exchanger for defrosting, and controls the axial flow fan of the top-discharge air conditioner outdoor unit to run in reverse after the temperature meets the conditions, thereby driving the air flow direction in the top-discharge air conditioner outdoor unit to be from top to bottom, and then the rising hot air can be blown to the bottom of the top-discharge air conditioner outdoor unit, accelerating the melting of frost at the bottom, and the melted water can be blown to the outside of the top-discharge air conditioner outdoor unit, thereby improving the defrosting effect of the top-discharge air conditioner outdoor unit.

[0035] According to a defrosting method for a top-outlet air-conditioning outdoor unit provided by the present invention, multiple temperature parameters can be obtained at different height positions of the outdoor heat exchanger, so as to more comprehensively monitor the progress of heating and defrosting. The multiple temperature parameters preferably include at least an upper temperature value T1 and a lower temperature value T2. Among them, the upper temperature value T1 is a temperature parameter for detecting the top of the outdoor heat exchanger near the top-outlet air-conditioning outdoor unit; the lower temperature value T2 is a temperature parameter for detecting the bottom of the outdoor heat exchanger near the top-outlet air-conditioning outdoor unit. Since heat easily floats up with the air, when the outdoor heater releases heat, the rising speed of the upper temperature value T1 is usually higher than that of the lower temperature T2. By comparing the upper temperature value T1 and the lower temperature value T2 with the preset temperature T0, the heating and defrosting progress of the upper and lower parts of the outdoor heat exchanger can be judged respectively.

[0036] Preferably Figure 4 As shown, the outdoor heat exchanger includes an upper heat exchanger 10 and a lower heat exchanger 20 connected in parallel. In the top-outlet air-conditioning outdoor unit, the upper heat exchanger 10 is installed above the lower heat exchanger 20. When the top-outlet air-conditioning outdoor unit is in use, the refrigerant supply of the upper heat exchanger 10 and the lower heat exchanger 20 can be connected at the same time, or only one of them can be connected, according to the working or defrosting requirements.

[0037] According to a defrosting method for a top-outlet air conditioner outdoor unit provided by the present invention, the upper temperature value T1 is preferably the lowest temperature value of the upper heat exchanger 10; the lower temperature value T2 is preferably the lowest temperature value of the lower heat exchanger 20. When the upper temperature value T1 is increased to a preset temperature T0, the frost on the upper heat exchanger 10 is basically completed by absorbing heat and melting, and it can be determined that the upper heat exchanger 10 has been defrosted. Similarly, when the lower temperature value T2 is increased to a preset temperature T0, the frost on the lower heat exchanger 20 is basically completed by absorbing heat and melting, and it can be determined that the lower heat exchanger 20 has been defrosted.

[0038] According to a defrosting method for a top-outlet air conditioner outdoor unit provided by the present invention, when the upper half temperature value T1 reaches a preset temperature T0, the compressor is controlled to stop supplying high-temperature refrigerant to the upper half heat exchanger 10, and continue to supply high-temperature refrigerant to the lower half heat exchanger 20. When the upper half temperature value T1 reaches the preset temperature T0, it can be understood that the purpose of heating and defrosting the upper half heat exchanger 10 is basically achieved. At this time, the supply of high-temperature refrigerant to the upper half heat exchanger 10 can be stopped, and the refrigerant can be concentratedly supplied to the lower half heat exchanger 20 that has not completed defrosting, thereby improving the defrosting efficiency of the plate heat exchanger 20 and reducing energy waste during the defrosting process.

[0039] Furthermore, preferably during the defrosting process, Figure 4The upper electronic expansion valve 12 and the lower electronic expansion valve 22 shown control the change of the refrigerant flow in the upper heat exchanger 10 and the lower heat exchanger 20 respectively. For example, when the compressor supplies high-temperature refrigerant to the upper heat exchanger 10 and the lower heat exchanger 20 at the same time, the upper electronic expansion valve 12 and the lower electronic expansion valve 22 are both in the open state. When the parallel flow path is connected, the pressure in the refrigerant flow path can be balanced by adjusting the opening of the upper electronic expansion valve 12 and the lower electronic expansion valve 22; after the upper electronic expansion valve 12 is closed, the opening of the lower electronic expansion valve 22 can be increased. Preferably, during the closing process of the upper electronic expansion valve 12, the opening gradually decreases over a period of time until it is completely closed, and at the same time, the opening of the lower electronic expansion valve 22 gradually increases to a suitable opening size, so as to reduce the impact on the pipeline during the change of the refrigerant flow path and improve the safety performance of the equipment.

[0040] According to a defrosting method for a top-outlet air-conditioning outdoor unit provided by the present invention, the defrosting conditions described above include that all temperature parameters reach a preset temperature T0; and / or that the total duration of the defrost mode operation reaches a preset duration S0. Among them, the defrosting progress of the outdoor heat exchanger can be more accurately judged by the change in the temperature parameters of the outdoor heat exchanger. However, the core purpose of using an air-conditioning system in a cold environment is to regulate the indoor temperature. Therefore, in order to ensure the comfort of indoor users, the total duration of the defrost mode operation can be limited to avoid the indoor temperature being unable to be regulated due to long-term defrosting, which affects the user experience. Preferably, according to the defrosting method of the present invention, if any of the above-mentioned defrosting conditions is met, the defrost mode can be exited, giving priority to ensuring the normal operation of the air-conditioning system.

[0041] The preset temperature T0 and the preset duration S0 may be pre-set fixed values ​​or variable values ​​that can be adaptively adjusted according to the actual environment. For example, the outdoor environment temperature and the atmospheric pressure in the outdoor environment may affect the value and the speed of change of the actual temperature parameter. Either of the preset temperature T0 and the preset duration S0 may be set to be adaptively adjusted according to the outdoor environment temperature or the atmospheric pressure in the outdoor environment.

[0042] According to the present invention, a defrosting method for a top-outlet air conditioner outdoor unit is provided, comprising: obtaining the outdoor real-time temperature when starting the defrost mode; setting the preset duration S0 in this defrost mode according to the outdoor real-time temperature; the length of the preset duration S0 is inversely proportional to the temperature value of the outdoor real-time temperature. The lower the outdoor real-time temperature, the greater the impact of the ambient temperature on the temperature parameter, and the preset duration S0 can be extended, thereby reducing the restriction requirements on the total duration of the defrost mode operation, so as to provide a better defrosting effect under extreme conditions.

[0043] According to a defrosting method for a top-outlet air conditioner outdoor unit provided by the present invention, the axial flow fan stops running before any temperature parameter reaches a preset temperature T0. Since the flow of air will accelerate the loss of heat from the outdoor heat exchanger, the axial flow fan is stopped during the process of heating the outdoor heat exchanger with a high-temperature refrigerant to reduce heat loss. After any temperature parameter reaches the preset temperature T0, at least a portion of the outdoor heat exchanger has reached the defrosting condition. At this time, the axial flow fan is reversed to blow the automatically floating hot air to the bottom of the equipment where defrosting is more difficult, thereby improving the defrosting efficiency of the bottom of the equipment, and can drive away frost and melt water through the air inlet of the outdoor unit through airflow to prevent melt water from accumulating at the bottom of the equipment.

[0044] Furthermore, according to a defrosting method for a top-outlet air conditioner outdoor unit provided by the present invention, after any of the above temperature parameters reaches a preset temperature T0, the axial flow fan is intermittently operated. Preferably, the axial flow fan runs in reverse for a second each time, so as to drive the hot air to blow to the bottom of the device within a second, and the stop time between each two reverse operations is b seconds, so as to avoid too much cold air from entering the interior of the device, and within b seconds, the heat of the outdoor heater can increase the air temperature in the device to maintain a better defrosting environment. Depending on the use environment, a≥b can be set in an outdoor environment with a lower degree of coldness, or a≤b can be set in an outdoor environment with a higher degree of coldness.

[0045] The present invention also provides a top-outlet air-conditioning outdoor unit, comprising an axial flow fan capable of reversing operation and a control device. Preferably, the outdoor heat exchanger of the top-outlet air-conditioning outdoor unit is divided into two parts, an upper heat exchanger 10 and a lower heat exchanger 20. The upper heat exchanger 10 and the lower heat exchanger 20 are respectively provided with an upper temperature sensor 11 and a lower temperature sensor 21, which are used to detect the surface temperature or internal refrigerant temperature of the upper heat exchanger 10 and the lower heat exchanger 20, respectively. The upper heat exchanger 10 and the lower heat exchanger 20 are preferably also provided with an upper electronic expansion valve 12 and a lower electronic expansion valve 22 on the refrigerant pipeline, respectively, to control the refrigerant flow in the upper heat exchanger 10 and the lower heat exchanger 20, respectively.

[0046] The control device of the top-discharge air conditioner outdoor unit comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, any of the above-mentioned defrosting methods for the top-discharge air conditioner outdoor unit is implemented.

[0047] The present invention also provides an air conditioning system, comprising an air conditioning indoor unit and the above-mentioned top-outlet air conditioning outdoor unit. The air conditioning system can be a central air conditioning system, a wall-mounted or cabinet-type household air conditioning system, a multi-split air conditioning system, etc.

[0048] According to the air conditioning system of the present invention, when performing a defrosting operation, the defrosting process is performed by using a defrosting method of a top-outlet air conditioning outdoor unit, which can improve the defrosting effect and enhance the performance of the equipment.

[0049] In addition, the logic instructions in the memory of the above-mentioned control device can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0050] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the defrosting method for the top-outlet air-conditioning outdoor unit provided by the above-mentioned methods.

[0051] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the defrosting method for the top-discharge air conditioner outdoor unit provided by the above methods.

[0052] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0053] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A defrosting method for an outdoor unit of a top-outlet air conditioner, characterized in that: include: Start the defrost mode of the air conditioning system and control the high-temperature refrigerant discharged from the compressor to enter the outdoor heat exchanger; Detecting temperature parameters at multiple locations of the outdoor heat exchanger; After any of the temperature parameters reaches the preset temperature T0, the axial flow fan of the top-outlet air conditioner outdoor unit is controlled to run in reverse; After the defrost conditions are met, exit the defrost mode.

2. The defrosting method for a top-outlet air conditioner outdoor unit according to claim 1, characterized in that: The plurality of temperature parameters at least include an upper half temperature value T1 and a lower half temperature value T2; The upper half temperature value T1 is a temperature parameter detected at the top of the outdoor heat exchanger close to the top-outlet air conditioner outdoor unit; The lower half temperature value T2 is a temperature parameter detected at the bottom of the outdoor heat exchanger close to the top-outlet air-conditioning outdoor unit.

3. The defrosting method for a top-outlet air conditioner outdoor unit according to claim 2, characterized in that: The outdoor heat exchanger comprises an upper heat exchanger (10) and a lower heat exchanger (20) connected in parallel with each other, and in the top-outlet air-conditioning outdoor unit, the installation position of the upper heat exchanger (10) is located above the lower heat exchanger (20); The upper temperature value T1 is the lowest temperature value of the upper heat exchanger (10); The lower half temperature value T2 is the lowest temperature value of the lower half heat exchanger (20).

4. The defrosting method for a top-outlet air conditioner outdoor unit according to claim 3, characterized in that: When the upper temperature value T1 reaches the preset temperature T0, the compressor is controlled to stop supplying high-temperature refrigerant to the upper heat exchanger (10) and continue to supply high-temperature refrigerant to the lower heat exchanger (20).

5. The defrosting method for a top-outlet air conditioner outdoor unit according to any one of claims 1 to 4, characterized in that: The defrosting condition includes that all the temperature parameters reach the preset temperature T0; And / or the total duration of the defrost mode operation reaches a preset duration S0.

6. The defrosting method for a top-outlet air conditioner outdoor unit according to claim 5, characterized in that: include: When the defrost mode is started, obtaining the outdoor real-time temperature; According to the outdoor real-time temperature, the preset time length S0 in this defrosting mode is set; The length of the preset time duration S0 is inversely proportional to the temperature value of the outdoor real-time temperature.

7. The defrosting method for a top-outlet air conditioner outdoor unit according to any one of claims 1 to 4, characterized in that: Before any of the temperature parameters reaches the preset temperature T0, the axial flow fan stops running.

8. The defrosting method for a top-outlet air conditioner outdoor unit according to claim 7, characterized in that: After any of the temperature parameters reaches a preset temperature T0, the axial flow fan operates intermittently; The duration of each reverse operation of the axial flow fan is a seconds, and the duration of the stop between two reverse operations is b seconds.

9. A top-outlet air conditioner outdoor unit, characterized in that: Includes axial flow fans and control equipment capable of reversing operation; The control device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the defrosting method for the top-outlet air-conditioning outdoor unit described in any one of claims 1 to 8 is implemented.

10. An air conditioning system, characterized in that: It comprises an air-conditioning indoor unit and the top-outlet air-conditioning outdoor unit as claimed in claim 9.

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