Outdoor unit, control method thereof and air conditioning system

Abstract

The invention provides an outdoor unit, a control method thereof and an air conditioning system. The outdoor unit comprises a shell. At least two fan blades; the diameters of any two fan blades are different. According to the outdoor unit, the control method of the outdoor unit and the air conditioning system, the at least two fan blades with different diameters are arranged, so that the outdoor unit selects different fan blades to work under the condition of different load requirements, and the driving structure for driving the fan blades can always work at the optimal rotating speed; the problems that in the prior art, a motor needs to operate at a low rotating speed, efficiency is low, and power consumption is increased are solved, the air volume of the outdoor unit can be matched with the load requirement of the outdoor unit, the energy consumption of the outdoor unit is reduced, and the working efficiency and energy saving performance of the outdoor unit are improved.

Description

Technical Field

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

[0002] In actual operation of variable frequency air conditioners, the size of the workload changes in real time, and the frequency of the compressor and the frequency of the outdoor fan need to be constantly adjusted during this period. Especially for multi-split air conditioners, most indoor units will not be fully opened in actual operation, and 80% of the operating time is running at medium and low loads. For outdoor fans, when large air volume is not required, the outdoor fan frequency needs to be lowered. However, when the outdoor fan motor is running at the minimum speed, the size of the fan blade cannot be adjusted, and the air volume at the minimum speed is still too large compared to the actual requirement. This low speed drives the large-size fan blade, which will lead to low motor efficiency and increase the power consumption of the motor. In addition, the minimum air volume of the outdoor unit still cannot match the required capacity, resulting in increased energy consumption of the air conditioner. Summary of the invention

[0003] In order to solve the technical problem in the prior art that the air volume of the outdoor unit cannot match the actual load and causes increased energy consumption, an outdoor unit and its control method and air conditioning system are provided, which use different fan blades to achieve different air volumes to ensure the normal operation of the motor and reduce energy consumption.

[0004] An outdoor unit, comprising:

[0005] A housing, wherein an air outlet is provided on the housing;

[0006] At least two fan blades, all of which are arranged in the housing, and the air outlet direction of each fan blade points to the air outlet;

[0007] The diameters of any two of the fan blades are not equal.

[0008] All the fan blades are connected to the same driving shaft, and each of the fan blades is controllably connected to the driving shaft.

[0009] The outdoor unit further includes a coupling, the coupling corresponds to the fan blades one by one, and the fan blades are connected to the drive shaft through the corresponding coupling.

[0010] The coupling includes a clockwise coupling and a counterclockwise coupling. At least one of the fan blades is connected to the drive shaft via the clockwise coupling, and at least one of the fan blades is connected to the drive shaft via the counterclockwise coupling. The drive shaft can rotate clockwise or counterclockwise.

[0011] The outdoor unit further comprises a driving mechanism, which is connected to the driving shaft and can drive the driving shaft to rotate clockwise or counterclockwise.

[0012] The outdoor unit further includes a control device, which can control the corresponding fan blades to work according to the load demand of the outdoor unit.

[0013] The number of the fan blades is two, and the two fan blades include a first fan blade and a second fan blade, and the diameter of the first fan blade is greater than the diameter of the second fan blade.

[0014] The outdoor unit has a high load mode and a low load mode. When the outdoor unit is in the high load mode, the first fan blade rotates and the second fan blade stops; when the outdoor unit is in the low load mode, the first fan blade stops and the second fan blade rotates.

[0015] The relationship between the diameter L1 of the first fan blade and the diameter L2 of the second fan blade is L2<2 / 3L1.

[0016] All the fan blades are arranged in sequence in a direction away from the air outlet, and the diameters of the fan blades gradually increase in the direction away from the air outlet.

[0017] The shell comprises a guide section, all the fan blades are arranged in the guide section, and the diameter of the guide section changes with the diameter of the fan blades.

[0018] The outdoor unit further comprises a heat exchanger, wherein the heat exchanger is arranged in the shell, and all the fan blades are arranged between the heat exchanger and the air outlet.

[0019] A control method for the outdoor unit as described above includes:

[0020] Obtain the load demand of the outdoor unit;

[0021] The corresponding fan blades are controlled to work according to the load demand of the outdoor unit.

[0022] The number of the fan blades is two, the two fan blades include a first fan blade and a second fan blade, the diameter of the first fan blade is greater than the diameter of the second fan blade, the outdoor unit has a high load mode and a low load mode, and when the corresponding fan blade is controlled to work according to the target load of the outdoor unit, it also includes:

[0023] If the outdoor unit is in the high load mode, the first fan blade is controlled to work and the second fan blade is controlled to stop;

[0024] If the outdoor unit is in the low load mode, the second fan blade is controlled to operate, and the first fan blade is controlled to stop.

[0025] The outdoor unit shown has a cooling mode, and the control method further includes:

[0026] When the outdoor unit is in cooling mode;

[0027] Obtain the saturation temperature Td corresponding to the condensing pressure of the outdoor unit, and compare Td with the ambient temperature Tenv and the first set temperature T1;

[0028] If Td≤Tenv+K1 and Td≤T1, it is determined that the outdoor unit is in low load mode;

[0029] If Td>Tenv+K1 and / or Td>T1, it is determined that the outdoor unit is in high load mode;

[0030] K1 is the correction value.

[0031] The value range of K1 is 2°C to 5°C; and / or the value range of T1 is 38°C to 40°C.

[0032] The outdoor unit shown has a heating mode, and the control method further includes:

[0033] When the outdoor unit is in heating mode;

[0034] Obtain the saturation temperature Ts corresponding to the evaporation pressure of the outdoor unit, and compare Ts with the ambient temperature Tenv and the second set temperature T2;

[0035] If Ts≤Tenv-K2 and Ts≤T2, it is determined that the outdoor unit is in high load mode;

[0036] If Ts>Tenv-K2 and / or Ts>T2, it is determined that the outdoor unit is in low load mode.

[0037] The value range of K2 is 5°C to 10°C; and / or the value range of T2 is -30°C to -35°C.

[0038] Also includes:

[0039] If the ratio of the actual operating total capacity of the outdoor unit to the preset total capacity of the outdoor unit is ≥ a, it is determined that the outdoor unit is in a high load mode;

[0040] If the ratio of the actual operating total capacity of the outdoor unit to the preset total capacity of the outdoor unit is less than a, it is determined that the outdoor unit is in the low load mode.

[0041] The value of a ranges from 65% to 80%.

[0042] An air conditioning system comprises the outdoor unit mentioned above or a control method using the outdoor unit mentioned above.

[0043] The outdoor unit and its control method, as well as the air-conditioning system provided by the present invention, are equipped with at least two fan blades with different diameters, so that the outdoor unit can select different fan blades to work under different load requirements, and the driving structure for driving the fan blades can always maintain operation at the optimal speed, thereby avoiding the problem of low efficiency and increased power consumption caused by the need for the motor to run at a low speed in the prior art, and can also match the air volume of the outdoor unit with the load requirement of the outdoor unit, thereby reducing the energy consumption of the outdoor unit and improving the working efficiency and energy saving of the outdoor unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the structure of an outdoor unit provided by an embodiment of the present invention;

[0045] Figure 2 A control flow chart of an outdoor unit provided by an embodiment of the present invention;

[0046] Figure 3 Another control flow chart of an outdoor unit provided by an embodiment of the present invention;

[0047] In the figure:

[0048] 1. Shell; 11. Air outlet; 2. Drive shaft; 31. Clockwise coupling; 32. Counterclockwise coupling; 4. Drive mechanism; 51. First fan blade; 52. Second fan blade; 12. Guide section; 6. Heat exchanger. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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.

[0050] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0053] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In actual operation of variable frequency air conditioners, the size of the workload changes in real time, and the frequency of the compressor and the frequency of the outdoor fan need to be constantly adjusted. Especially for multi-split air conditioners, most indoor units are not fully opened in actual operation, and 80% of the operating time is running at medium and low loads. For the outdoor fan, when a large air volume is not needed, the outdoor fan frequency needs to be lowered. However, when the outdoor fan motor is running at the minimum speed, the size of the fan blades cannot be adjusted, and the air volume at the minimum speed is still too large compared to the actual requirement. This low speed drives the large-size fan blades, resulting in low motor efficiency and increased power consumption of the motor. In addition, the minimum air volume of the outdoor unit still cannot match the capacity requirements, resulting in increased energy consumption of the air conditioner. To this end, the present application provides a method such as Figures 1 to 3The outdoor unit shown comprises: a housing 1, on which an air outlet 11 is arranged; at least two fan blades, all of which are arranged in the housing 1, and the air outlet direction of each of the fan blades points to the air outlet 11; the diameters of any two of the fan blades are different. By setting at least two fan blades with different diameters, the outdoor unit can select different fan blades to work under different load requirements, and the driving structure for driving the fan blades can always maintain the optimal speed to work, avoiding the problem of low efficiency and increased power consumption caused by the motor needing to run at a low speed in the prior art, and can also make the air volume of the outdoor unit match the load requirement of the outdoor unit, reduce the energy consumption of the outdoor unit, and improve the working efficiency and energy saving of the outdoor unit.

[0055] As an implementation mode, all the fan blades are connected to the same drive shaft 2, and each of the fan blades is controllably connected to the drive shaft 2. All the fan blades are driven by the same drive shaft 2, which effectively reduces the space occupied by the drive shaft 2 and the drive mechanism in the shell 1 and reduces the volume of the outdoor unit.

[0056] Preferably, all the fan blades are coaxially arranged to reduce the space occupied by the fan blades in the shell 1, and also facilitate the arrangement of a driving structure for driving all the fan blades, thereby reducing the number of driving structures and further reducing the volume of the outdoor unit.

[0057] The outdoor unit also includes a coupling, which corresponds to the fan blades one by one, and the fan blades are connected to the drive shaft 2 through the corresponding coupling. When different fan blades are working, it is only necessary to control the corresponding coupling to contact the drive shaft 2, and the couplings corresponding to other fan blades are disengaged from the drive shaft 2, so that the drive shaft 2 can drive the corresponding fan blades, thereby ensuring the working reliability of the outdoor unit.

[0058] Optionally, the coupling includes a clockwise coupling 31 and a counterclockwise coupling 32, at least one of the fan blades is connected to the drive shaft 2 through the clockwise coupling 31, and at least one of the fan blades is connected to the drive shaft 2 through the counterclockwise coupling 32, and the drive shaft 2 can rotate clockwise or counterclockwise. When the drive shaft 2 rotates clockwise, the clockwise coupling 31 rotates with the rotation of the drive shaft 2, while the counterclockwise coupling 32 remains stationary. At this time, the clockwise coupling 31 can drive the corresponding fan blade to rotate, while the counterclockwise coupling 32 The fan blades corresponding to the clockwise coupling 32 remain stationary; similarly, when the drive shaft 2 rotates counterclockwise, the counterclockwise coupling 32 will rotate with the rotation of the drive shaft 2, while the clockwise coupling 31 remains stationary. At this time, the counterclockwise coupling 32 can drive the corresponding fan blades to rotate, while the fan blades corresponding to the clockwise coupling 31 remain stationary. That is, the working state of the fan blades can be controlled by controlling the rotation direction of the drive shaft 2 (clockwise rotation or counterclockwise rotation), thereby reducing the number of components of the outdoor unit and improving the working reliability and production cost of the outdoor unit.

[0059] The outdoor unit further includes a driving mechanism 4, which is connected to the driving shaft 2 and can drive the driving shaft 2 to rotate clockwise or counterclockwise. The rotation direction of the driving shaft 2 can be adjusted by controlling the driving mechanism 4, and when adjusting the driving mechanism 4, it can be directly controlled by an electrical signal or by setting a transmission mechanism, so as to facilitate the adjustment of the outdoor unit.

[0060] The outdoor unit also includes a control device, which can control the corresponding fan blades to work according to the load demand of the outdoor unit. The outdoor unit pre-stores the correspondence between the high load state and the working fan blades and the correspondence between the low load state and the working fan blades. The load demand of the outdoor unit is judged, and it is determined whether the outdoor unit is in a high load state or a low load state at this time, and then the corresponding fan blades are controlled to work.

[0061] like Figure 1 As shown, the number of the blades is two, and the two blades include a first blade 51 and a second blade 52, and the diameter of the first blade 51 is larger than the diameter of the second blade 52. The outdoor unit has a high load mode and a low load mode. When the outdoor unit is in the high load mode, the first blade 51 rotates and the second blade 52 stops. At this time, the first blade 51 with a larger diameter works. When the driving mechanism 4 rotates at an optimal speed, the first blade 51 can generate a larger air volume. At this time, the outdoor unit generates a larger air volume to adapt to the high load, ensuring that the outdoor unit works normally.

[0062] When the outdoor unit is in the low load mode, the first fan blade 51 stops and the second fan blade 52 rotates. At this time, the second fan blade 52 with a smaller diameter works. When the driving mechanism 4 rotates at an optimal speed, the second fan blade 52 can generate a smaller air volume. At this time, the outdoor unit generates a smaller air volume to adapt to the low load, thereby ensuring the normal operation of the outdoor unit.

[0063] Preferably, the relationship between the diameter L1 of the first fan blade 51 and the diameter L2 of the second fan blade 52 is L2<2 / 3L1. When the diameter L1 of the first fan blade 51 is too large, the size of the housing 1 corresponding to the first fan blade 51 is large, so that the size of the second fan blade 52 corresponding to this position of the housing 1 is small, and the driving ability of the second fan blade 52 in the housing 1 becomes weaker. Similarly, when the diameter L2 of the second fan blade 52 is too small, the driving ability of the second fan blade 52 in the housing 1 will also become weaker, affecting the working efficiency of the outdoor unit. When the diameter L1 of the first fan blade 51 is too small or the diameter L2 of the second fan blade 52 is too large, the air volume of the first fan blade 51 and the air volume of the second fan blade 52 are not much different, and the effect of reducing the energy consumption of the outdoor unit is poor. Only when L2<2 / 3L1 can it be ensured that the first fan blade 51 can match the high load while the second fan blade 52 can match the low load, reduce the energy consumption of the outdoor unit, and improve the working efficiency and energy saving of the outdoor unit.

[0064] All the fan blades are arranged in sequence in the direction away from the air outlet 11, and the diameter of the fan blades gradually increases in the direction away from the air outlet 11. The fan blades with smaller diameters are placed as close to the air outlet 11 as possible to ensure that all the fan blades can reliably drive the gas and ensure the working reliability of the outdoor unit. In order to further improve the gas flow capacity in the shell 1, the shell 1 includes a guide section 12, and all the fan blades are arranged in the guide section 12, and the diameter of the guide section 12 changes with the diameter of the fan blade. The guide section 12 is used to guide the gas, and the diameter of the guide section 12 will change with the diameter of the fan blade. The spacing between each inner wall of the guide section 12 and the rotating body formed by the corresponding fan blade is basically equal, so that each part on the guide section 12 can reliably guide the corresponding fan blade, further improving the working efficiency of the outdoor unit.

[0065] The outdoor unit further comprises a heat exchanger 6, which is arranged in the housing 1, and all the fan blades are arranged between the heat exchanger 6 and the air outlet 11. Each fan blade can make the gas flow smoothly through the heat exchanger 6 during operation, thereby ensuring the working reliability of the outdoor unit.

[0066] A control method for the outdoor unit as described above includes:

[0067] Obtain the load demand of the outdoor unit;

[0068] The corresponding fan blades are controlled to work according to the load demand of the outdoor unit. The outdoor unit has pre-stored correspondence between the high load state and the working fan blades and the low load state and the working fan blades. The load demand of the outdoor unit is judged to determine whether the outdoor unit is in a high load state or a low load state at this time, and then the corresponding fan blades are controlled to work.

[0069] The number of the fan blades is two, the two fan blades include a first fan blade 51 and a second fan blade 52, the diameter of the first fan blade 51 is greater than the diameter of the second fan blade 52, the outdoor unit has a high load mode and a low load mode, and when the corresponding fan blade is controlled to work according to the target load of the outdoor unit, it also includes:

[0070] If the outdoor unit is in the high load mode, the first fan blade 51 is controlled to work, and the second fan blade 52 is controlled to stop. At this time, the first fan blade 51 with a larger diameter works. When the driving mechanism 4 rotates at an optimal speed, the first fan blade 51 can generate a larger air volume. At this time, the outdoor unit generates a larger air volume to adapt to the high load, thereby ensuring that the outdoor unit works normally.

[0071] If the outdoor unit is in the low load mode, the second fan blade 52 is controlled to work and the first fan blade 51 is controlled to stop. At this time, the second fan blade 52 with a smaller diameter works. When the driving mechanism 4 rotates at the optimal speed, the second fan blade 52 can generate a smaller air volume. At this time, the outdoor unit generates a smaller air volume to adapt to the low load, thereby ensuring the normal operation of the outdoor unit.

[0072] The outdoor unit shown has a cooling mode, and the control method further includes:

[0073] When the outdoor unit is in cooling mode, the function of the fan blades of the outdoor unit is to accelerate the condensation of the high-temperature refrigerant in the outdoor unit heat exchanger 6 and dissipate the heat to the outdoor air. The greater the condensation pressure, the greater the heat exchange temperature difference between the outdoor unit heat exchanger 6 and the outdoor environment. However, the high pressure will increase the power consumption of the compressor, and too high pressure will lead to poor system reliability (pressure bearing capacity of pipelines and components, compression ratio of the compressor exceeding the range, etc.). Therefore, the fan blades of the outdoor unit are required to strengthen the heat exchange and dissipate the temperature of the heat exchanger 6 to the outdoor air in time. After the refrigerant in the heat exchanger 6 dissipates the heat, the temperature and pressure will decrease, that is, the condensation pressure decreases, but it cannot be reduced too low, otherwise the temperature difference is not enough and the heat dissipation effect is not good. Therefore, the condensation pressure needs to be controlled within a certain range, which cannot be too high or too low. The ambient temperature is directly related to the condensation pressure. If the air conditioning system is in a shutdown state, the heat in the ambient air will also conduct heat to the refrigerant in the outdoor unit heat exchanger 6. Generally, if it is left for a long time, the higher the ambient temperature is, the higher the temperature of the refrigerant in the unit will be, and the saturation temperature corresponding to its condensation pressure is basically equivalent to the ambient temperature. Therefore, the condensing pressure should also be judged in combination with the outdoor ambient temperature;

[0074] Specifically, the saturation temperature Td corresponding to the condensing pressure of the outdoor unit is obtained, and Td is compared with the ambient temperature Tenv and the first set temperature T1;

[0075] If Td≤Tenv+K1 and Td≤T1, it indicates that the saturation temperature Td corresponding to the condensing pressure of the outdoor unit is much lower than the ambient temperature and also lower than the first set temperature. At this time, the heat exchanger 6 of the outdoor unit has a strong ability to dissipate heat to the environment. It is determined that the outdoor unit is in low load mode, and only a fan with a smaller diameter needs to be turned on to ensure the heat exchange effect of the outdoor unit. At the same time, it can also avoid the condensing pressure being too low to affect the heat exchange efficiency of the outdoor unit, thereby ensuring the working reliability of the indoor unit.

[0076] If Td>Tenv+K1 and / or Td>T1, the saturation temperature Td corresponding to the condensation pressure of the outdoor unit is higher than the ambient temperature, or the saturation temperature Td corresponding to the condensation pressure is higher than the first set temperature. When one of the two conditions is met, the heat exchanger 6 of the outdoor unit has a weak ability to dissipate heat to the environment. It is determined that the outdoor unit is in high-load mode, and a fan with a larger diameter needs to be turned on to ensure the heat exchange effect of the outdoor unit and the working reliability of the indoor unit.

[0077] K1 is a correction value. By setting the K1 value, the heat dissipation effect between the heat exchanger 6 and the environment can be guaranteed. When Td is higher than Tenv+K1, the heat dissipation effect between the heat exchanger 6 and the environment can be guaranteed to be better. When K1 is not set, the temperature difference between the heat exchanger 6 and the environment is small and the heat dissipation effect is poor.

[0078] Preferably, the value range of K1 is 2°C to 5°C, preferably 5°C. When the saturation temperature Td corresponding to the condensing pressure is higher than the ambient temperature by more than 5°C, the heat dissipation effect is better. When the saturation temperature Td corresponding to the condensing pressure is lower than the ambient temperature by 5°C, the heat dissipation is poor due to the small temperature difference.

[0079] The value range of T1 is 38℃ to 40℃.

[0080] The outdoor unit shown has a heating mode, and the control method further includes:

[0081] When the outdoor unit is in heating mode, the heat exchanger 6 of the outdoor unit is on the low-pressure side, absorbing heat from the air for evaporation of the refrigerant in the heat exchanger 6. The function of the fan blades of the outdoor unit is also to enhance heat exchange, and enhance the absorption of heat from the outdoor air to heat the refrigerant in the heat exchanger 6. The better the evaporation effect, the greater the evaporation pressure. Conversely, the worse the evaporation effect, the smaller the evaporation pressure. The refrigerant in the heat exchanger 6 needs to have a certain temperature difference with the outdoor ambient temperature to better exchange heat. Generally, the heat exchange is better when the saturation temperature corresponding to the evaporation pressure is lower than the outdoor ambient temperature. The higher the evaporation pressure, the more heat the heat exchanger 6 absorbs from the environment, and the better the heating effect. Conversely, the lower the evaporation pressure, the less heat the refrigerant in the outdoor heat exchanger 6 absorbs for evaporation, and the less gaseous refrigerant. If the evaporation pressure is too low, the compressor cannot absorb the gaseous refrigerant, and there is a risk of damage and wear. Therefore, the evaporation pressure needs to be controlled within a certain range, and it cannot be too high or too low.

[0082] Specifically, the saturation temperature Ts corresponding to the evaporation pressure of the outdoor unit is obtained, and Ts is compared with the ambient temperature Tenv and the second set temperature T2;

[0083] If Ts≤Tenv-K2 and Ts≤T2, it indicates that the saturation temperature Ts corresponding to the evaporation pressure of the outdoor unit is much lower than the ambient temperature and also lower than the second set temperature. At this time, the ability of the heat exchanger 6 of the outdoor unit to absorb heat from the environment is weak, and it is determined that the outdoor unit is in high-load mode, and a fan with a larger diameter needs to be turned on to ensure the heat exchange effect of the outdoor unit and the working reliability of the indoor unit.

[0084] If Ts>Tenv-K2 and / or Ts>T2, the saturation temperature Ts corresponding to the evaporation pressure of the outdoor unit is higher than the ambient temperature, or the saturation temperature Ts corresponding to the condensation pressure is higher than the second set temperature. When one of the two conditions is met, the heat exchanger 6 of the outdoor unit has a strong ability to absorb heat from the environment, and the outdoor unit is determined to be in low load mode. It is only necessary to turn on a fan with a smaller diameter to ensure the heat exchange effect of the outdoor unit. At the same time, it can also avoid the evaporation pressure being too high to affect the heat exchange efficiency of the outdoor unit, thereby ensuring the working reliability of the indoor unit.

[0085] K2 is a correction value. By setting the K2 value, the heat dissipation effect between the heat exchanger 6 and the environment can be guaranteed. When Ts is lower than Tenv-K2, it can ensure that the heat exchanger 6 has a better heat absorption effect from the environment. When K2 is not set, the temperature difference between the heat exchanger 6 and the environment is small and the heat absorption effect is poor.

[0086] The value range of K2 is 5℃ to 10℃. When the saturation temperature corresponding to the evaporation pressure is more than 10℃ lower than the ambient temperature, it means that the heat absorption is insufficient.

[0087] The value range of T2 is -30℃ to -35℃. When Ts is lower than T2, the evaporation pressure is too low and the compressor cannot absorb the gaseous refrigerant, which poses a risk of damage and wear.

[0088] As another implementation, it also includes:

[0089] If the ratio of the actual operating total capacity of the outdoor unit to the preset total capacity of the outdoor unit is ≥ a, it is determined that the outdoor unit is in a high load mode;

[0090] If the ratio of the actual operating total capacity of the outdoor unit to the preset total capacity of the outdoor unit is less than a, it is determined that the outdoor unit is in a low load mode;

[0091] That is, by directly comparing the actual operating total capacity with the preset total capacity and distinguishing between high load and low load according to the preset ratio, the outdoor unit can be controlled in the same way to ensure the reliable operation of the outdoor unit.

[0092] The value range of a is 65% to 80%, and the preferred value of a is 75%.

[0093] An air conditioning system comprises the outdoor unit mentioned above or a control method using the outdoor unit mentioned above.

[0094] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An outdoor unit, characterized in that: include: A housing (1), wherein the housing (1) is provided with an air outlet (11); at least two fan blades, all of which are arranged in the housing (1), and the air outlet direction of each fan blade points to the air outlet (11); The diameters of any two of the fan blades are not equal.

2. The outdoor unit according to claim 1, characterized in that: All the fan blades are connected to the same drive shaft (2), and each fan blade is controllably connected to the drive shaft (2).

3. The outdoor unit according to claim 2, characterized in that: The outdoor unit also includes a coupling, the coupling corresponds to the fan blades one by one, and the fan blades are connected to the drive shaft (2) through the corresponding coupling.

4. The outdoor unit according to claim 3, characterized in that: The coupling comprises a clockwise coupling (31) and a counterclockwise coupling (32); at least one of the fan blades is connected to the drive shaft (2) via the clockwise coupling (31); at least one of the fan blades is connected to the drive shaft (2) via the counterclockwise coupling (32); and the drive shaft (2) can rotate clockwise or counterclockwise.

5. The outdoor unit according to claim 4, characterized in that: The outdoor unit further comprises a driving mechanism (4), wherein the driving mechanism (4) is connected to the driving shaft (2), and the driving mechanism (4) can drive the driving shaft (2) to rotate clockwise or counterclockwise.

6. The outdoor unit according to claim 1, characterized in that: The outdoor unit further includes a control device, which can control the corresponding fan blades to work according to the load demand of the outdoor unit.

7. The outdoor unit according to claim 1, characterized in that: The number of the fan blades is two, and the two fan blades include a first fan blade (51) and a second fan blade (52), and the diameter of the first fan blade (51) is greater than the diameter of the second fan blade (52).

8. The outdoor unit according to claim 7, characterized in that: The outdoor unit has a high load mode and a low load mode. When the outdoor unit is in the high load mode, the first fan blade (51) rotates and the second fan blade (52) stops; when the outdoor unit is in the low load mode, the first fan blade (51) stops and the second fan blade (52) rotates.

9. The outdoor unit according to claim 8, characterized in that: The relationship between the diameter L1 of the first fan blade (51) and the diameter L2 of the second fan blade (52) is L2<2 / 3L1.

10. The outdoor unit according to claim 1, characterized in that: All the fan blades are arranged in sequence in a direction away from the air outlet (11), and the diameters of the fan blades gradually increase in the direction away from the air outlet (11).

11. The outdoor unit according to claim 10, characterized in that: The housing (1) comprises a flow guide section (12), all the fan blades are arranged in the flow guide section (12), and the diameter of the flow guide section (12) changes with the diameter of the fan blades.

12. The outdoor unit according to claim 1, characterized in that: The outdoor unit further comprises a heat exchanger (6), wherein the heat exchanger (6) is arranged in the housing (1), and all the fan blades are arranged between the heat exchanger (6) and the air outlet (11).

13. A control method for an outdoor unit according to any one of claims 1 to 12, characterized in that: include: Obtain the load demand of the outdoor unit; The corresponding fan blades are controlled to work according to the load demand of the outdoor unit.

14. The control method of the outdoor unit according to claim 13, characterized in that: The number of the fan blades is two, the two fan blades include a first fan blade (51) and a second fan blade (52), the diameter of the first fan blade (51) is greater than the diameter of the second fan blade (52), the outdoor unit has a high load mode and a low load mode, and when the corresponding fan blade is controlled to work according to the target load of the outdoor unit, it also includes: If the outdoor unit is in the high load mode, the first fan blade (51) is controlled to operate, and the second fan blade (52) is controlled to stop; If the outdoor unit is in the low load mode, the second fan blade (52) is controlled to operate, and the first fan blade (51) is controlled to stop.

15. The control method of the outdoor unit according to claim 14, characterized in that: The outdoor unit shown has a cooling mode, and the control method further includes: When the outdoor unit is in cooling mode; Obtain the saturation temperature Td corresponding to the condensing pressure of the outdoor unit, and compare Td with the ambient temperature Tenv and the first set temperature T1; If Td≤Tenv+K1 and Td≤T1, it is determined that the outdoor unit is in low load mode; If Td>Tenv+K1 and / or Td>T1, it is determined that the outdoor unit is in high load mode; K1 is the correction value.

16. The control method of the outdoor unit according to claim 15, characterized in that: The value range of K1 is 2°C to 5°C; and / or the value range of T1 is 38°C to 40°C.

17. The control method of the outdoor unit according to claim 14, characterized in that: The outdoor unit shown has a heating mode, and the control method further includes: When the outdoor unit is in heating mode; Obtain the saturation temperature Ts corresponding to the evaporation pressure of the outdoor unit, and compare Ts with the ambient temperature Tenv and the second set temperature T2; If Ts≤Tenv-K2 and Ts≤T2, it is determined that the outdoor unit is in high load mode; If Ts>Tenv-K2 and / or Ts>T2, it is determined that the outdoor unit is in low load mode.

18. The control method of the outdoor unit according to claim 17, characterized in that: The value range of K2 is 5°C to 10°C; and / or the value range of T2 is -30°C to -35°C.

19. The control method of the outdoor unit according to claim 14, characterized in that: Also includes: If the ratio of the actual operating total capacity of the outdoor unit to the preset total capacity of the outdoor unit is ≥ a, it is determined that the outdoor unit is in a high load mode; If the ratio of the actual operating total capacity of the outdoor unit to the preset total capacity of the outdoor unit is less than a, it is determined that the outdoor unit is in the low load mode.

20. The control method of the outdoor unit according to claim 19, characterized in that: The value of a ranges from 65% to 80%.

21. An air conditioning system, characterized in that: A control method comprising the outdoor unit according to any one of claims 1 to 12 or applying the outdoor unit according to any one of claims 13 to 20.

Images