Mixed flow fan and ducted fan

Abstract

The application discloses a mixed flow fan and a ducted fan, wherein the mixed flow fan comprises a volute and an impeller arranged in the volute, the impeller comprises blades, and the ratio range of the maximum height H of the blades in the direction of the impeller axis to the maximum diameter D of the impeller is 0.38-0.48. The mixed flow fan and the ducted fan effectively solve the problem of low efficiency of the mixed flow fan in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the air conditioning technical field, and in particular, relates to a mixed flow fan and a ducted air conditioner. BACKGROUND

[0002] The ducted air conditioner is a kind of air conditioner, in order to improve comfort, some ducted air conditioners adopt the mode of upper cold air and lower hot air, which can realize waterfall type refrigeration and carpet type warm air, in order to realize this air outlet mode, the air outlet of the ducted air conditioner needs to be reversible, in the existing air outlet reversible ducted air conditioner, a tubular fan or a centrifugal fan is usually used, but due to the setting mode of the fan blade, the air direction cannot be reversed after being reversed, therefore, at least two fans need to be set, one is responsible for forward air outlet, and the other is responsible for reverse air outlet, which not only makes the structure of the ducted air conditioner larger, but also increases the cost.

[0003] In order to reduce the cost, the fan needs to be reduced in size, and the mixed flow fan is a fan between the axial flow fan and the centrifugal fan, the impeller of the mixed flow fan makes the air do both centrifugal motion and axial motion, and the airflow motion in the volute is a mixture of axial flow and centrifugal motion, so it is called'mixed flow'. Moreover, the mixed flow fan can not only be reduced in size, but also can ensure the flow direction and air pressure of the airflow.

[0004] The size of the impeller of the mixed flow fan in the prior art is not reasonable, which leads to low energy efficiency of the mixed flow fan. SUMMARY

[0005] The embodiment of the present application provides a mixed flow fan and a ducted air conditioner to solve the problem of low energy efficiency of the mixed flow fan in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides a mixed flow fan, comprising: a volute;

[0007] An impeller is arranged in the volute, the impeller comprises blades, and the ratio of the maximum height H of the blades in the direction of the impeller axis to the maximum diameter D of the impeller is in the range of 0.38-0.48.

[0008] Further, an air inlet and an air outlet are arranged on the volute, the distance between the air inlet and the air outlet is A, and the ratio of H / A is in the range of 0.39-0.47.

[0009] Further, the maximum diameter of the volute is E, and the ratio of E / D is in the range of 1.1-1.25.

[0010] Further, the number of the blades is N, and the relationship between N and E is 81.54ln(N)+20≤E≤81.54ln(N)+60, wherein 2≤N≤22.

[0011] Further, the volute is a spherical-ta structure, and the maximum diameter of the volute is equal to the diameter of the spherical-ta structure.

[0012] Further, the volute is provided with an air inlet and an air outlet at two end faces of the spherical platform respectively.

[0013] Further, a line between the center of the air inlet and the center of the air outlet is collinear with the axis of the impeller.

[0014] Further, the surface of the blade has a pit and / or a protrusion.

[0015] According to another aspect of the present application, a ducted fan is provided, which comprises the mixed flow fan.

[0016] Further, the mixed flow fan is rotatably arranged in the ducted fan.

[0017] The present application improves the blade parameter which is easily ignored and neglected in the prior art, i.e. improves the ratio range of the maximum height H of the blade in the direction of the axis of the impeller to the maximum diameter D of the impeller, so that the efficiency of the impeller of the mixed flow fan is effectively improved, the efficiency loss of the impeller is reduced, and the air volume of the mixed flow fan is effectively improved. Furthermore, because the structure is optimized, the cost of the mixed flow fan is also reduced in the production of the product. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic view of the internal structure of the impeller of the mixed flow fan of the embodiment of the present application;

[0019] Figure 2 is a schematic view of the structure of the mixed flow fan of the embodiment of the present application;

[0020] Figure 3 is a schematic view of the three-dimensional structure of the impeller of the mixed flow fan of the embodiment of the present application;

[0021] Figure 4 is a schematic view of the structure of the blade of the impeller of the mixed flow fan of the embodiment of the present application. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below in combination with the drawings and specific embodiments, but is not limited to the embodiments.

[0023] The volute shape of the mixed-flow fan in the prior art is mostly a cylindrical structure, and the air duct shape is relatively fixed, so all the improvements of the mixed-flow fan in the prior art are mostly for the blade shape of the impeller or for the number of blades, so as to improve the air volume of the mixed-flow fan and achieve the purpose of improving the energy efficiency. However, through the research of the applicant on the principle of air flow and the analysis of the simulation experimental data, it is found that the conventional improvement of the blade shape and the number has a very limited effect on the air volume of the mixed-flow fan, and other data parameters of the blade and the parameters corresponding to the overall structure of the mixed-flow fan are ignored and neglected in the field, which are actually the improvement points for effectively improving the air volume of the mixed-flow fan.

[0024] Based on the above reasons, the embodiment of the present application provides a mixed-flow fan, as shown in Figures 1 to 4 The mixed-flow fan includes a volute 10 and an impeller 20, the impeller 20 is arranged inside the volute 10, the impeller 20 includes blades 21, and the ratio range of the maximum height H of the blades 21 in the axial direction of the impeller 20 to the maximum diameter D of the impeller 20 is 0.38-0.48. The value of H / D will affect the basic layout of the whole fan, when the value of H / D is too small, the H height of the impeller is insufficient, and an effective pressure-increasing channel cannot be formed, the impeller cannot expand the pressure of the gas enough, which will cause the insufficient pressure-carrying capacity of the fan, and the blade shape will be more inclined to axial flow; when the value of H / D is too large, a great radial space will be wasted to meet the rotation requirement, which will affect the basic size of other parts of the fan. The simulation test is conducted on the mixed-flow fan of the example, the value of H / D of the fan is changed, and the simulation results are as follows:

[0025] H / D RPM Computing the air volume (m 3 / h) Impeller head (Pa) Impeller efficiency (%) 0.38 2200 501 114.3 78.3 0.40 2200 510 126.8 87.1 0.48 2200 503 118.3 80.2 0.50 2200 497 111.9 74.6

[0026] The present application improves the blade parameters that are easily ignored and neglected in the field, that is, improves the ratio range of the maximum height H of the blades in the axial direction of the impeller to the maximum diameter D of the impeller, so that the efficiency of the impeller of the mixed-flow fan is effectively improved, the efficiency loss of the impeller is reduced, and the air volume of the mixed-flow fan is effectively improved. The adjustment of the ratio range of H / D is not only theoretically explained, but also has strong data support on the simulation test data, which shows that it is indeed an effective improvement method. Moreover, because the optimal structure is obtained, the cost of the mixed-flow fan can be reduced in product production.

[0027] Preferably, the volute 10 is provided with an air inlet 11 and an air outlet 12, the distance between the air inlet 11 and the air outlet 12 is A, and the ratio range of H / A is 0.39-0.47. The distance A can also be understood as the length of the volute 10, Figure 2 The length of the volute 10 in the vertical direction is A. The simulation test is conducted on the mixed-flow fan of the example, the value of H / A of the fan is changed, and the simulation results are as follows:

[0028] H / A RPM Computing the air flow (m 3 / h) Impeller head (Pa) Diffuser loss (Pa) 0.35 2200 482 104.3 41.3 0.39 2200 507 121.7 38.6 0.41 2200 510 126.8 36.2 0.47 2200 497 122.4 57.4 0.48 2200 493 121.9 62.1

[0029] When the H / A value is too small, the impeller working area is insufficient, which can cause insufficient pressure-carrying capacity of the fan and excessive pressure expansion loss. When the H / A value is too large, the fan is difficult to effectively convert the high dynamic pressure generated by the impeller into static pressure, and the pressure-carrying capacity of the fan can be insufficient. Overall, a suitable H / A value can help the various performances of the fan to be in an optimal range, thereby minimizing the pressure expansion loss.

[0030] Since the mixed-flow fan in the embodiment is arranged in the ducted air conditioner, the size and shape of the volute 10 of the mixed-flow fan have process requirements and structure matching requirements. Therefore, the volute 10 of the mixed-flow fan is further improved to maximize the air volume of the mixed-flow fan while meeting the above requirements of the ducted air conditioner. In the embodiment, the maximum diameter of the volute 10 is E, and the ratio of E / D is in the range of 1.1-1.25. As shown in FIG. 8, the maximum diameter E of the volute 10 directly determines the shape of the volute of the mixed-flow fan, and the value of the maximum diameter E also has a corresponding relationship with the impeller 20, that is, the gap between the impeller 20 and the volute in the radial direction is controlled within a certain range, which can improve the air volume of the mixed-flow fan. Simulation tests are performed on the mixed-flow fan in the embodiment, and the values of E / D are changed. The simulation results are as follows: Figure 1

[0031] E / D RPM Computing the air flow (m 3 / h) Impeller head (Pa) Diffuser loss (Pa) 1.04 2200 496 123.4 58.4 1.10 2200 501 124.7 47.3 1.19 2200 510 126.8 36.2 1.25 2200 503 122.1 46.5

[0032] The airflow is subjected to work by the impeller and starts to have high dynamic pressure. The dynamic pressure needs sufficient space to be released and part of the dynamic pressure is converted into static pressure to continue to flow. When the value of E / D is too small, the pressure release space is insufficient, which can cause the proportion of the dynamic pressure converted into the static pressure to be too small, the pressure expansion loss of the fan to be too large, and the overall air volume of the fan to be too low. When the value of E / D is too large, the overall size of the fan is further expanded, which can compress the basic size of the remaining components and is not conducive to the improvement of the performance of the fan.

[0033] The number of the blades 21 in the mixed-flow fan is N, and the formula relationship between N and E is: 81.54ln(N)+20≤E≤81.54ln(N)+60, wherein 2≤N≤22.

[0034] Since the number of the blades 21 is matched with the shape of the impeller, as described above, the mixed-flow fan arranged in the ducted air conditioner has a definite limit on the shape and size. Therefore, the size of the impeller and the blades cannot be infinitely increased to improve the air volume according to the prior art, but the balance relationship needs to be considered to maximize the air volume and energy efficiency in the limited size.

[0035] ​At certain size, the optimal number of blades can not be one. When the overall size of the fan is small, too many blades will increase the overall performance of the fan, but at the same time, it will also increase the channel resistance of the fan, and how to balance the two is the key to the performance improvement of the fan. When the overall size of the fan is large, too few blades will obviously restrict the further improvement of the overall performance of the fan, and there is also a balance point. The simulation test of the mixed flow fan in the embodiment is carried out by changing the number of blades N, and the simulation results are as follows:

[0036] N E (mm) RPM Computing the air volume (m 3 / h) Calculated head (Pa) 5 200 2200 502 82.7 6 200 2200 510 90.4 7 200 2200 514 91.5 8 200 2200 512 90.6

[0037] When E is 200mm size, it is obviously beyond the corresponding size range (151-191mm) of 5 blades, so from the above table, it can be seen that the calculated pressure head of the fan with 5 blades is low at the same speed, and the air volume decreases obviously, which is because the insufficient number of blades leads to low work capacity in the case of large size; when the number of blades of the impeller is 6, 7 and 8, it can be known from the data that the E value of 200mm is in the optimal size range, so the capacity of the three blades is similar, including the work capacity and the air volume of the fan. When the size of the fan is certain, the number of blades can be determined in advance by the above formula, and the performance of the blade will be more excellent.

[0038] Further preferably, the volute 10 of the mixed flow fan in the embodiment is a spherical platform structure, and the maximum diameter of the volute 10 is equal to the diameter of the spherical platform structure. The volute 10 is provided with an air inlet 11 and an air outlet 12 at two end faces of the spherical platform.

[0039] The line between the center of the air inlet 11 and the center of the air outlet 12 is collinear with the axis of the impeller 20.

[0040] The surface of the blade 21 has a pit and / or a protrusion. The pit and the protrusion can improve the airflow and increase the air volume.

[0041] The application also provides an embodiment of a ducted fan, which comprises the mixed flow fan of the above embodiment, and the mixed flow fan is rotatably arranged in the ducted fan. The mixed flow fan is between the axial flow fan and the centrifugal fan, the impeller of the mixed flow fan makes the air do both centrifugal motion and axial motion, and the airflow in the volute is mixed with the axial flow and centrifugal motion, so it is called "mixed flow". Since the mixed flow fan can not only be small in size, but also can ensure the flow direction and air pressure of the airflow, the mixed flow fan is installed in the ducted fan, the airflow direction is reversed by rotating the mixed flow fan, and the air outlet direction is changed, that is, the air outlet is on the side in the cooling mode.

[0042] It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0043] Of course, the above is the preferred embodiment of the present application. It should be pointed out that for those skilled in the art, several improvements and refinements can be made without departing from the essential principles of the present application, and these improvements and refinements are also considered within the scope of protection of the present application.

Claims

1. A mixed flow fan characterized by, The application relates to a mixed-flow fan, comprising: a volute (10); a impeller (20) arranged inside the volute (10), the impeller (20) comprising blades (21), the ratio of the maximum height H of the blades (21) in the axial direction of the impeller (20) to the maximum diameter D of the impeller (20) being in the range of 0.38-0.

48.

2. The mixed-flow fan according to claim 1, wherein: the volute (10) is provided with an air inlet (11) and an air outlet (12); the distance between the air inlet (11) and the air outlet (12) is A, and the ratio of H / A is in the range of 0.39-0.

47.

3. The mixed-flow fan according to claim 2, wherein: the maximum diameter of the volute (10) is E, and the ratio of E / D is in the range of 1.1-1.

25.

4. The mixed flow fan of claim 3, wherein the number of the blades (21) is N, and the relationship between N and E is 81.54ln(N)+20<=E<=81.54ln(N)+60, wherein 2<=N<=22.

5. The mixed-flow fan according to claim 3, wherein: the volute (10) is in the form of a spherical platform, and the maximum diameter of the volute (10) is equal to the diameter of the spherical platform.

6. The mixed-flow fan according to claim 5, wherein: the air inlet (11) and the air outlet (12) are arranged at the two end faces of the spherical platform, respectively.

7. The mixed flow fan of claim 2, wherein the line connecting the center of the air inlet (11) and the center of the air outlet (12) is collinear with the axis of the impeller (20).

8. The mixed flow fan of claim 1, wherein the surface of the blades (21) is provided with pits and / or protrusions.

9. A ducted fan machine characterised in that, The mixed-flow fan according to any one of claims 1-8.

10. The ducted fan machine according to claim 9, wherein, The mixed-flow fan is rotatably arranged in the ducted fan.

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