Cross-flow wind wheel blade structure, heat pump air conditioner indoor unit and heat pump air conditioner

Abstract

The invention discloses a cross-flow wind wheel blade structure, a heat pump air conditioner indoor unit and a heat pump air conditioner, and relates to the field of wind wheel structures. According to the cross-flow wind wheel blade structure, a wind wheel blade is provided with an asymmetrical wing-shaped front edge and a gradually-shrunk wave-shaped rear edge, a drainage protrusion is arranged on the back face of the blade, and a concave part is arranged between the tail end of the wind wheel blade and the drainage protrusion. After the cross-flow wind wheel blade structure is applied, the air volume of the heat pump air conditioner during operation can be increased, the operation noise is reduced, and the experience feeling of customers is improved.

Description

Technical Field

[0001] The invention relates to the field of wind wheel structures, and in particular to a crossflow wind wheel blade structure, a heat pump air conditioner indoor unit and a heat pump air conditioner. Background Art

[0002] A heat pump air conditioner is an air conditioning system that achieves two-way regulation of cooling and heating through a heat pump cycle. It drives the refrigerant cycle through a compressor, absorbs or releases ambient heat to transfer energy, and thus regulates the indoor temperature. A heat pump air conditioner usually includes an outdoor unit, an indoor unit, and connecting pipes. With the improvement of urbanization, noise and air volume have become intuitive indicators that customers pay attention to when the heat pump air conditioner is running, and the crossflow impeller blade structure located in the indoor unit of the heat pump air conditioner has a great influence on the noise and air volume of the heat pump air conditioner.

[0003] Existing crossflow impeller blades are generally straight blades with equal cross-sections or simple curved blades, which have the following problems: airflow separation is easily generated at the trailing edge of the blade, resulting in reduced efficiency; blade tail vortex shedding causes medium and high frequency noise; stress concentration is achieved at the root of the blade, which is prone to breakage after long-term use.

[0004] Therefore, in order to improve customer experience, increase the air volume of the heat pump air conditioner during operation, and reduce operating noise, it is necessary to improve the crossflow impeller blade structure. Summary of the invention

[0005] In order to solve the above problems, the present application provides a crossflow fan blade structure, a heat pump air conditioner indoor unit and a heat pump air conditioner The present application provides a cross-flow impeller blade structure, a heat pump air conditioner indoor unit and a heat pump air conditioner adopt the following technical solutions: On the first aspect, the present application provides a cross-flow impeller blade structure, the impeller blade has an asymmetric airfoil leading edge and a tapered wavy trailing edge, a drainage protrusion is arranged on the back side of the blade, and a recess is arranged between the end of the impeller blade and the drainage protrusion.

[0006] By adopting the above technical solution, the asymmetric airfoil leading edge can effectively guide the airflow into the blade channel, reduce the occurrence of airflow separation, thereby reducing flow losses and increasing air volume. The tapered wavy trailing edge design can optimize the process of airflow leaving the blade, reduce the medium and high frequency noise caused by the shedding of the tail vortex, and avoid the turbulence effect that is easily generated by the trailing edge of traditional blades. The diversion protrusions set on the back of the blade and the recessed part between it and the end of the blade can further adjust the direction of the airflow, reduce the formation of local low-pressure areas, and prevent the airflow from generating unnecessary vortices and noise on the blade surface. Overall, this structure significantly improves the working efficiency of the crossflow impeller, enhances the airflow guidance capability, and greatly reduces the noise level during operation.

[0007] Optionally, a plurality of drainage protrusions are provided, and the plurality of drainage protrusions extend intermittently along the length direction of the wind wheel blade, and the recessed portion is provided between adjacent drainage protrusions.

[0008] By adopting the above technical solution, the guide protrusion can effectively divide and guide the airflow, dispersing the airflow in the air intake area and the air outlet area to the concave part between the blade and the guide protrusion, thereby reducing the occurrence of airflow separation, improving the airflow efficiency, and enhancing the uniformity of air volume output; at the same time, it reduces the mid-high frequency noise caused by vortex shedding, achieving the dual effects of noise reduction and pressure increase.

[0009] Optionally, in a cross section of the wind rotor blade, the front end point of the wind rotor blade is A, the rear end point is B, and the length of a line AB connecting the front end point A and the rear end point B is defined as a chord length L; The distance from the maximum thickness of the wind rotor blade to the connecting line AB is H 1 The distances from the leading edge of the blade to the leading edge of the blade to the connecting line AB are H 2 , H 3 ...H n ; Then: H 1 >H 2 >H 3 ...>H n .

[0010] By adopting the above technical solution, the height of the drainage protrusion is gradually reduced, optimizing the flow state of the airflow on the blade surface. By setting the distance, it is ensured that the airflow can transition more smoothly on the blade surface, thereby increasing the air volume and reducing noise. At the same time, this design can disperse the impact of the airflow, further enhancing the overall structural strength and service life of the blade.

[0011] Optionally, the leading edge curvature radius of the wind rotor blade is R 1 , the trailing edge thickness is set to t 1 , then: 0.08L≤R 1 ≤0.1L; 0.03L≤t 1 ≤0.05L.

[0012] By adopting the above technical solution, the flow loss in the blade passage is proportional to the square of the relative speed at the blade inlet, which is closely related to the curvature radius of the leading edge of the blade and the curvature radius of the lower edge close to the front disk. By controlling the curvature radius of the leading edge, the airflow can smoothly transition when entering the blade, reducing the flow loss; the control of the trailing edge thickness can reduce the medium and high frequency noise caused by the vortex shedding while ensuring the structural strength, and further optimize the stability of the airflow discharge process.

[0013] Optionally, the center of the crossflow impeller is point O, and the front end point A and the rear end point B are respectively connected to point O, and the formed ∠AOB is the angle θ, then: 10°<θ<13°.

[0014] By adopting the above technical solution, the spatial layout of the blades is effectively optimized, making the angles of the airflow entering and exiting the blades more reasonable, reducing the separation phenomenon caused by airflow impact, and increasing the uniformity of the air output. At the same time, the range of the angle θ can reduce turbulence and reduce operating noise.

[0015] Optionally, the leading edge curvature radius of the wind rotor blade is 15-17 mm, the curvature radius of the lower edge close to the front disk of the crossflow wind rotor is 18-20 mm, and the curvature radius of the lower edge away from the front disk of the crossflow wind rotor is 24-27 mm.

[0016] By adopting the above technical solution and precisely controlling the curvature radius of different parts, the purpose of improving aerodynamic performance, reducing noise and increasing efficiency is achieved. The unequal structure of the curvature radius at different positions of the lower edge breaks the cyclic disturbance pattern that may be formed by the airflow, further reducing the noise level.

[0017] Optionally, the outer diameter of the crossflow impeller is 100-110 mm, and the line connecting the front end point A and the point O is the inlet diameter d of the impeller blade. 1 The line connecting the rear end point B and point O is the outlet diameter d of the wind rotor blade. 2 , then: d 1 50-53mm, d 2 It is 40-42mm.

[0018] By adopting the above technical solution, the outer diameter of the crossflow impeller is set so that the size of the entire impeller is moderate, and the design of the air flow channel is optimized in a limited space. 1 d 2 The setting ensures that the velocity distribution of the airflow when entering and leaving the crossflow impeller is more reasonable.

[0019] Optionally, the blade thickness of the wind wheel blade is 1.0-1.7 mm, and the maximum blade thickness reaches 1.62-1.7 mm.

[0020] By adopting the above technical solution, blade thickness is one of the core parameters that determine the structural strength. The blade thickness of the crossflow impeller of the present application is relatively large, and the moment of inertia of the blade cross section is significantly increased, thereby reducing bending stress, improving bending strength, and increasing structural strength.

[0021] In the second aspect, the present application discloses a heat pump air conditioner indoor unit, including a crossflow fan, the crossflow fan includes an evaporator, a panel, a volute, a volute tongue and a crossflow wind wheel, the volute tongue and the volute cover are arranged on the outside of the crossflow wind wheel, the evaporator is arranged on the air inlet side of the crossflow wind wheel, and the crossflow wind wheel includes any one of the crossflow wind wheel blade structures described above.

[0022] By adopting the above-mentioned technical solution, after the indoor unit of the heat pump air conditioner applies the crossflow impeller blade structure of the present application, the air volume and noise generated at the same gear during operation are significantly better than the existing ones, and the air outlet is more uniform than the existing ones, avoiding the circulation of gas in the volute of the heat pump air conditioner, and at the same time avoiding gas reflux.

[0023] In a third aspect, the present application discloses a heat pump air conditioner, comprising a heat pump air conditioner outdoor unit, the above-mentioned heat pump air conditioner indoor unit and connecting pipelines.

[0024] By adopting the above technical solution and referencing the crossflow impeller blade structure of the present application, the heat pump air conditioner has higher air supply efficiency, lower noise and more stable long-term operating performance.

[0025] In summary, the present application has at least one of the following beneficial effects: 1. The asymmetric airfoil leading edge and the tapered wavy trailing edge design effectively suppress airflow separation and reduce the formation of low-speed vortex areas, greatly improving the airflow guidance efficiency and optimizing the uniformity of the airflow. 2. The diversion bulge is combined with specific geometric parameters to reduce the formation of local low-pressure areas, reduce turbulence, and significantly reduce the frequency of vortex shedding and medium and high-frequency noise energy; 3. The blade thickness of the crossflow impeller is relatively large, and the moment of inertia of the blade cross section is significantly increased, thereby reducing bending stress, improving bending strength, and increasing structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the wind wheel blade of the present application; Figure 2 This is a schematic diagram of the distance between the wind rotor blades and the end points of the present application; Figure 3 It is a schematic diagram of the structure of the wind wheel blade of the present application; Figure 4 is a cross-sectional schematic diagram of the crossflow impeller of the present application; Figure 5 It is a thickness fitting curve diagram of the wind wheel blade of the present application and the comparative blade; Figure 6 It is a cross-sectional schematic diagram of the indoor unit of the heat pump air conditioner of the present application; Figure 7 It is a comparison chart of air volume data between the indoor unit of the heat pump air conditioner of the present application and the indoor unit of the comparative heat pump air conditioner; Figure 8 It is a noise data comparison chart of the heat pump air conditioner indoor unit of the present application and the comparison heat pump air conditioner indoor unit.

[0027] Description of reference numerals: 11. Condenser; 12. Electric heating; 13. Front panel; 14. Crossflow impeller; 15. Impeller blades. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1-8 This application is described in further detail.

[0029] The embodiments of the present application disclose a crossflow impeller blade structure, a heat pump air conditioner indoor unit and a heat pump air conditioner.

[0030] Reference Figure 1 and Figure 2 A crossflow wind rotor blade structure, the wind rotor blade includes an asymmetric airfoil leading edge and a tapered wavy trailing edge, the asymmetric leading edge airfoil adopts an almond-shaped curved surface, and the curved surface is spliced ​​by two smoothly transitioned arcs, one of which is a main curve with a smaller radius, and the other is an auxiliary curve with a larger radius. The tapered wavy trailing edge is composed of a series of gradually shrinking wave crests and troughs arranged alternately. The wind rotor blade is provided with a drainage protrusion on the back of the blade, and the drainage protrusion is provided in plurality and extends intermittently along the length direction of the wind rotor blade, and a recess is provided between the end of the wind rotor blade and the drainage protrusion, that is, between two adjacent drainage protrusions.

[0031] The asymmetric airfoil leading edge of the wind rotor blade can effectively guide the airflow into the blade channel, reduce the occurrence of airflow separation, thereby reducing flow losses and increasing air volume. The tapered wavy trailing edge design can optimize the process of airflow leaving the blade, reduce the mid- and high-frequency noise caused by the shedding of the tail vortex, and avoid the turbulence effect that is easily generated by the trailing edge of traditional blades. The drainage protrusion can effectively guide the airflow and disperse the airflow to the concave part for a smoother flow, which not only greatly increases the air volume of the crossflow fan, but also significantly reduces the operating noise, achieving a dual improvement in performance and comfort.

[0032] Reference Figure 2 In this application, there are three drainage protrusions on the back of the blade. In the cross section of the wind rotor blade, the front end point of the wind rotor blade is A, the rear end point is B, and the line AB connecting the front end point A and the rear end point B is the chord line of the blade. Find the maximum thickness of the wind rotor blade, and its distance to the connecting line AB is H. 1 The distances from the three drainage protrusions to the connecting line AB are H 2 , H 3 and H 4 , then H 1 >H 2 >H 3 >H 4By setting the distance of the drainage protrusions, when the crossflow impeller blades rotate, the drainage protrusions can disperse the airflow in the air inlet area and the air outlet area to the recessed parts between the drainage protrusions, which not only significantly reduces the airflow angle when the blades are inlet, but also effectively reduces the airflow separation phenomenon on the back of the blade near the trailing edge.

[0033] Reference Figure 2 and Figure 3 The basic shape of the wind rotor blade is an arc. In the cross section of the wind rotor blade, the length of the connecting line AB is defined as the chord length L, and the leading edge curvature radius of the wind rotor blade is R. 1 , the trailing edge thickness is set to t 1 , then: 0.08L≤R 1 ≤0.1L; 0.03L≤t 1 ≤0.05L.

[0034] The leading edge curvature radius of the wind wheel blade is set to 15-17 mm. In this embodiment, the specific data is 16.8 mm. According to domestic and foreign research, the flow loss in the blade channel is proportional to the square of the relative speed of the blade inlet, and the speed is closely related to the leading edge curvature radius of the blade and the lower edge curvature radius close to the front disk. By designing the size of the leading edge curvature radius of the crossflow wind wheel structure, the flow loss in the blade channel is reduced, thereby increasing the air supply.

[0035] The thickness of the trailing edge is set to 3%-5% of the chord length, which can reduce the mid- and high-frequency noise caused by tail vortex shedding while ensuring structural strength, and further optimize the smoothness of the airflow discharge process.

[0036] The crossflow wind wheel includes a front disk, a rear disk, wind wheel blades and a hub, wherein the hub and a plurality of wind wheel blades together constitute a middle-section wind blade. A crossflow wind wheel is composed of a plurality of middle-section wind blades, and the middle-section wind blades are connected by welding.

[0037] In existing crossflow impellers, in order to reduce the noise at the blade passing frequency, the angles between impeller blades are generally set according to different angle values, rather than fixed. This design will lead to inconsistent work done by the flow channels between the blades, resulting in uneven air flow, increased pressure fluctuations in the flow field, and thus greater broadband noise.

[0038] Reference Figure 4 In this application, the center of the crossflow impeller is point O, and the front end point A and the rear end point B are connected to point O, and the angle θ formed is ∠AOB, then: 10°<θ<13°. In this embodiment, the angle θ is specifically 10.9°. By setting equal angles, the angles of the airflow when entering and flowing out of the blades are more reasonable, which enhances the uniformity of the airflow and avoids the pressure fluctuation problem caused by uneven work of the flow channel.

[0039] Reference Figure 3In the wind rotor blade, the curvature radius of the lower edge close to the front disk of the crossflow wind rotor is 18-20mm, and the curvature radius of the lower edge away from the front disk of the crossflow wind rotor is 24-27mm. In this embodiment, the curvature radius of the lower edge of the blade close to the front disk is 18.1mm, while the curvature radius of the lower edge of the blade away from the front disk increases to 25.3mm. This unequal structure breaks the cyclic disturbance mode that may be formed by the airflow, further reduces the formation of turbulence and wake vortex, and further reduces the noise level.

[0040] In the crossflow impeller, the outer diameter of the crossflow impeller is 100-110mm, and the line connecting the front end point A and point O is the inlet diameter d of the impeller blade. 1 The line connecting the rear end point B and point O is the outlet diameter d of the wind rotor blade. 2 , then: d 1 50-53mm, d 2 In this embodiment, the outer diameter of the crossflow impeller is 106 mm, d 1 52mm, d 2 The diameter of the fan blade is 40.4 mm, and the outlet installation angle of the fan blade is forward. Through the specific structural parameter design, a cross-flow fan structure with good noise and air volume is obtained when the heat pump air conditioner is running, providing users with a good experience.

[0041] Reference Figure 5 In the design of crossflow wind rotor blades, blade thickness is one of the core parameters that determine the structural strength. The existing crossflow wind rotor blade thickness is mostly between 0.8 and 1.4 mm, which is insufficient in structural strength, and the stress concentration at the root of the blade is easy to break after long-term use. In this application, the blade thickness of the wind rotor blade is 1.0-1.7 mm, and the maximum blade thickness reaches 1.62-1.7 mm. The maximum blade thickness of this embodiment reaches 1.66 mm.

[0042] According to the bending theory of beams, the bending stress formula is: Where M is the bending moment, y is the distance from the neutral axis to the cross section, and I is the cross-sectional inertia moment. For the blade cross section (which can be approximated as a cantilever beam with a variable cross section), the inertia moment I∞t 3 (t is the blade thickness). In the present application, after the blade thickness of the crossflow wind wheel blade increases, I increases significantly, thereby reducing the bending stress σ 弯曲 , improving the bending strength and increasing the structural strength.

[0043] The implementation principle of a crossflow impeller blade structure in the embodiment of the present application is as follows: the crossflow impeller blade reduces the occurrence of airflow separation by setting an asymmetric airfoil leading edge, the tapered wavy trailing edge reduces the medium and high frequency noise and turbulence caused by the shedding of the tail vortex, and the drainage protrusions and recesses further reduce the noise. The overall structural strength of the blade is improved by designing the blade thickness, and the design of other dimensions enables the indoor unit of the heat pump air conditioner to have a higher air volume and lower noise during operation, thereby achieving stable long-term operation.

[0044] In a second aspect, the present application provides a heat pump air conditioner indoor unit. Figure 6 The indoor unit of the heat pump air conditioner includes a cross-flow fan, an electric heater, a condenser and a front panel.

[0045] The crossflow fan includes an evaporator, a panel, a volute, a volute tongue and a crossflow fan wheel, wherein the crossflow fan wheel is arranged in the central part of the volute, and the crossflow fan wheel is divided into an inlet area and an outlet area by the volute tongue and the volute. The evaporator often adopts a three-fold structure design, the evaporator is arranged on the air inlet side of the crossflow fan wheel, and the volute tongue is arranged on the air outlet side of the crossflow fan wheel. The crossflow fan wheel includes a plurality of middle section blades, and the crossflow fan wheel blade structure disclosed in the present application is applied.

[0046] The heat pump air conditioner indoor unit of the present invention is compared with the heat pump air conditioner indoor unit of the prior art. Figure 7 and Figure 8 , combined with the test data, the heat pump air conditioner indoor unit using the crossflow fan blade structure in this application has the following advantages: 1. Increased air volume and optimized air flow uniformity: Under the same windshield conditions, the cross-flow impeller structure of the present invention can increase the air volume of the indoor unit of the heat pump air conditioner by 10% to 15%, while improving the air outlet uniformity by about 20%, thereby avoiding the pressure fluctuation and air flow backflow problems caused by uneven work of the flow channel in the traditional design.

[0047] 2. Significant improvement in noise performance At rated speed, the overall operating noise of the present invention is reduced by 3 to 5 dB (A) compared with the traditional crossflow impeller, and the noise peak in the 1kHz to 4kHz frequency band is reduced by more than 40%, which significantly improves the noise texture and comfort perceived by users.

[0048] 3. Enhanced structural strength and reliability By optimizing the blade thickness, the maximum thickness is increased to 1.66mm, and through the synergy with the asymmetric leading edge, tapered trailing edge and other designs, the blade thickness improves the bending strength, the airfoil optimization reduces the aerodynamic load, further reduces the working stress, and enhances the structural strength. The wavy trailing edge and the drainage bulge design offset the flow loss that may be caused by the increase in blade thickness. The comparison of wind volume data shows that the increase in blade thickness does not affect its performance balance.

[0049] 4. Improved energy efficiency and user experience The indoor unit of the heat pump air conditioner using the crossflow wind wheel blade structure disclosed in the present application has significantly better air volume and noise at the same gear position during operation than the existing one, and can increase the indoor unit of the heat pump air conditioner using the existing crossflow wind wheel structure by 10 to 15 m under the same windshield condition. 3 At the same time, the indoor unit of the heat pump air conditioner of the present application can still maintain efficient heat exchange in the "windless" mode, and the system energy efficiency and user experience are better.

[0050] In a third aspect, the present application discloses a heat pump air conditioner, comprising a heat pump air conditioner indoor unit applying the above-mentioned crossflow wind wheel blade structure, a heat pump air conditioner outdoor unit and connecting pipelines.

[0051] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A crossflow wind wheel blade structure, characterized in that: The wind rotor blade has an asymmetric airfoil leading edge and a tapered wavy trailing edge, a drainage protrusion is arranged on the back side of the blade, and a recess is arranged between the end of the wind rotor blade and the drainage protrusion.

2. A crossflow wind wheel blade structure according to claim 1, characterized in that: A plurality of drainage protrusions are provided, and the plurality of drainage protrusions extend intermittently along the length direction of the wind wheel blade, and the recessed portion is provided between adjacent drainage protrusions.

3. The crossflow wind wheel blade structure according to claim 1, characterized in that: In the cross section of the wind rotor blade, the front end point of the wind rotor blade is A, the rear end point is B, and the length of the line AB connecting the front end point A and the rear end point B is defined as the chord length L; The distance from the maximum thickness of the wind rotor blade to the connecting line AB is H1, and the distances from the leading end of the blade to each drainage protrusion to the connecting line AB are H2, H3...H n ; Then: H1>H2>H3...>H n .

4. A crossflow wind wheel blade structure according to claim 3, characterized in that: The leading edge curvature radius of the wind rotor blade is R1, and the trailing edge thickness is set to t1, then: 08L≤R1≤0.1L; 0.03L≤t1≤0.05L.

5. A crossflow impeller blade structure according to claim 1, wherein the center of the crossflow impeller is point O, the front end point A and the rear end point B are connected to point O respectively, and the formed ∠AOB is the angle θ, then: 10°<θ<13°.

6. A crossflow wind rotor blade structure according to claim 1, wherein the leading edge curvature radius of the wind rotor blade is 15-17 mm, the curvature radius of the lower edge close to the front disk of the crossflow wind rotor is 18-20 mm, and the curvature radius of the lower edge away from the front disk of the crossflow wind rotor is 24-27 mm.

7. The crossflow wind wheel blade structure according to claim 1, characterized in that: The outer diameter of the crossflow impeller is 100-110mm, the line connecting the front end point A and point O is the inlet diameter d1 of the impeller blade, and the line connecting the rear end point B and point O is the outlet diameter d2 of the impeller blade, then: d1 is 50-53mm, d2 is 40-42mm.

8. The crossflow impeller blade structure according to claim 1, characterized in that: The thickness of the wind wheel blades is 1.0-1.7mm, and the maximum thickness reaches 1.62-1.7mm.

9. A heat pump air conditioner indoor unit, characterized in that: The invention comprises a crossflow fan, which comprises an evaporator, a panel, a volute, a volute tongue and a crossflow wind wheel. The volute tongue and the volute cover are arranged on the outside of the crossflow wind wheel. The evaporator is arranged on the air inlet side of the crossflow wind wheel. The crossflow wind wheel comprises a crossflow wind wheel blade structure as described in any one of claims 1 to 8.

10. A heat pump air conditioner, characterized in that: It comprises a heat pump air conditioner outdoor unit, a heat pump air conditioner indoor unit as claimed in claim 9 and connecting pipelines.

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