Guided fan axial blower system with one rotor fan with curved blades

Abstract

A guide vane axial fan system has one axis of rotation and comprises a rotor fan with a hub, a rotor inlet, a rotor outlet, and rotor blades. Each rotor blade has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end and a tip width between the trailing edge and the leading edge at the tip end. The tip width is greater than the hub width. The trailing edge of each rotor blade comprises a concave section and a convex section, forming an S-shape.

Description

TECHNICAL AREA

[0001] The disclosure relates generally to a guide vane axial fan system with a rotor fan with curved blades. BACKGROUND OF THE INVENTION

[0002] Blowers are commonly used in heating, ventilation, and air conditioning (HVAC) systems to circulate room air. In a conventional blower, air is drawn into the room air recirculation system and then forced through an outlet into the interior. Conventional blowers incorporate an impeller or fan to propel the air through the outlet into the interior. The efficiency of a blower in moving high-pressure air can be increased by using a guide vane axial fan, which improves the axial movement of air out of the outlet via guide vanes.

[0003] Axial fans can experience flow separation when the static pressure rise across the fan blades reaches the limit of the fan's static operating pressure. This causes the airflow velocity through the fan to decrease beyond a point where it first drops to zero and then reverses. When the airflow reverses, air detaches from the fan blades, creating air turbulence as the detached airflow strikes the blades. This aerodynamic instability induces stresses within the blades, which can lead to mechanical failure of the fan motor. The fan blades would otherwise require balancing for efficient operation. To mitigate flow separation, axial fans are conventionally oversized relative to the specifications required for a given application, which is not economical.

[0004] Therefore, there is a need in engineering for guide vane axial fan systems that can improve laminar flow, improve the static pressure profile of the fan and reduce turbulence of the fan blades. SHORT DESCRIPTION

[0005] In one aspect, a guide vane axial fan system has a single axis of rotation and comprises a rotor fan and a stator. The rotor fan includes a hub, a rotor inlet, a rotor outlet, and rotor blades. Each rotor blade has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. The stator includes a stator inlet, a stator outlet, and stator blades. The stator blades are positioned downstream of the rotor blades. Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end and a tip width between the trailing edge and the leading edge at the tip end. The tip width is greater than the hub width.The trailing edge of each rotor blade comprises a concave section and a convex section, forming an S-shape. The concave section extends from the tip end to the convex section. The convex section extends from the concave section to the hub end.

[0006] In another aspect, a rotor fan for a guide vane axial fan system has an axis of rotation and comprises a hub, a rotor inlet, a rotor outlet, and rotor blades. Each rotor blade has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end and a tip width between the trailing edge and the leading edge at the tip end. The tip width is greater than the hub width. The trailing edge of each rotor blade comprises a concave section and a convex section, forming an S-shape. The concave section extends from the tip end to the convex section. The convex section extends from the concave section to the hub end.

[0007] In another aspect, a method for assembling a guide vane axial fan system with a rotating axis includes coupling a rotor fan to a stator such that the stator is positioned downstream of the rotor fan. The rotor fan comprises a hub, a rotor inlet, a rotor outlet, and rotor blades. The method also includes positioning the rotor blades around the hub so that the rotor fan rotates about the axis of rotation and directs an airflow toward the stator blades. Each rotor blade has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end.Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end. The tip width is greater than the hub width. The trailing edge of each rotor blade comprises a concave section and a convex section, forming an S-shape. The concave section extends from the tip end to the convex section, and the convex section extends from the concave section to the hub end.

[0008] These and other aspects and features of the present revelation will be easier to understand when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a side view of an example of a guide vane axial fan system, wherein the guide vane axial fan system comprises a rotor fan and a stator; Fig. 2 is an end view of the in Fig. 1 guide vane axial fan system shown; Fig. Figure 3 is a perspective view of the rotor fan of the [unclear text]. Fig. 1 guide vane axial fan system shown; Fig. 4 is another perspective view of the in Fig. 3 shown rotor fans; Fig. 5 is a perspective view of the stator of the in Fig. 1 guide vane axial fan system shown; Fig. 6 is an end view of the in Fig. 5 stators shown; Fig. Figure 7 is a perspective view of an example of a rotor blade of the in Fig. 3 and Fig. 4 rotor fans shown; Fig. 8 is an end view of the in Fig. 7 of the rotor blade shown, which represents a tip end of the rotor blade; Fig. 9 is an end view of the in Fig. 7 of the rotor blade shown, which represents a trailing edge of the rotor blade; Fig. 10 is an end view of the in Fig. 7 of the rotor blade shown, which represents a leading edge of the rotor blade; Fig. 11 is an end view of the in Fig. 7 of the rotor blade shown, which represents a hub end of the rotor blade; Fig. Figure 12 is a perspective view of an example stator blade of the [product name] in Fig. 5 and Fig. 6 stators shown; Fig. 13 is an end view of the in Fig. 12 stator blade shown, which represents a tip end of the stator blade; Fig. 14 is an end view of the in Fig. 12 stator blade shown, which represents a hub end of the stator blade; Fig. Figure 15 is a perspective view of an alternative embodiment of a rotor blade for use with the in Fig. 1 guide vane axial fan system shown; Fig. 16A and Fig. Figure 16B shows schematic representations of the rotor blade and stator blade angles of an exemplary guide vane axial fan blade; Fig. 17 is a table with examples of rotor blade angles at various points along the rotor blade span; Fig. Figure 18 is a table with examples of rotor blade chord lengths at various points along the rotor blade span; and Fig. Figure 19 is a schematic diagram of a representative leaf illustrating the definitions of angles of attack for leaves.

[0009] The reference symbols used in the drawings and their meanings are summarized in the list of reference symbols. Generally, identical parts in the illustrations are marked with the same reference symbols. DETAILED DESCRIPTION

[0010] The following description and claims refer to a number of terms which are defined as follows.

[0011] As used herein, the spatial terms “upper”, “lower”, “above”, and “below” in this disclosure are intended to denote a component or element of a component that is located upstream or downstream relative to other components and elements of components, unless the context clearly indicates otherwise. The term “upper” or “above” is intended to denote a downstream component or element of a component, and the term “lower” or “below” is intended to denote an upstream component or element of a component. If a component has a top and a bottom, the top is parallel to the bottom. Such relative spatial terms are used only for the convenience of description and are not to be understood as restrictive.

[0012] The embodiments described here relate to a guide vane axial fan system. More precisely, the embodiments relate to a guide vane axial fan system with a rotor fan and a stator with blades that improve laminar flow, enhance the static pressure profile of the fan, and reduce turbulence of the fan blades. For example, the shape of the fan blades is optimized. In particular, the shape and geometry of each blade, as well as the spacing between the blades, can influence the static pressure profile of the axial fan and thus reduce flow separation. Further embodiments may include a retrofit system package and reduced noise emissions.

[0013] The Fig. 1 and Fig. Figure 2 shows an embodiment of a guide vane axial fan system 100. The guide vane axial fan system 100 comprises a rotor 102 and a stator 104, which is arranged downstream of the rotor 102, as defined by the direction of the airflow 106 that passes through the guide vane axial fan system 100. At least in part due to the configurations of the rotor 102 and the stator 104, the guide vane axial fan system 100 offers improved performance compared to conventional systems. For example, in a wind tunnel performance evaluation, the guide vane axial fan system 100 delivers a static pressure of 2.3 inches of water column at a flow rate of 1500 cubic feet per minute, a rotational speed of 2400 revolutions per minute, a power consumption of 967 watts, and a noise level of less than 55 decibels.

[0014] In some embodiments, the guide vane axial fan system 100 further comprises a motor (not shown) coupled to the rotor 102. The motor may, for example, comprise a motor housing and a motor shaft extending therefrom. In some embodiments, the motor is coupled within the guide vane axial fan system 100 by attaching the motor housing to the stator 104. The motor shaft extends from the motor housing to be coupled to the rotor 102. Thus, the rotation of the rotor 102 is enabled by actuating the motor and the resulting rotation of the motor shaft. For example, the rotor 102 rotates in a direction of rotation R1, as shown in Fig. 2 shown. In further embodiments, the rotor 102 is set in motion in any suitable way.

[0015] As in the Fig. As shown in Figures 1-4, the rotor 102 comprises a rotor fan 108 and a rotor cover 114 extending around the rotor fan 108. The rotor fan 108 includes a rotor hub 112 and a plurality of rotor blades 116 arranged circumferentially around the rotor hub 112 and extending between the rotor hub 112 and the rotor cover 114. In some embodiments, the rotor fan 108 comprises seven to nine rotor blades 116. The rotor fan 108 has an inner diameter ranging from 8.5 to 9.5 inches and an outer diameter ranging from 15 to 16 inches. In alternative embodiments, the rotor fan 108 comprises any number of rotor blades 116 and is of any suitable size.

[0016] The rotor 102 comprises a rotor inlet 118 and a rotor outlet 120, which are at least partially defined by the rotor cover 114. The rotor inlet 118 is positioned downstream of the inlet of the blower system in communication with it. The rotor cover 114 can be shaped to facilitate the airflow 106 into the rotor inlet 118. For example, the rotor cover 114 comprises a first rim 122 that defines the rotor inlet 118. The rotor cover 114 further comprises a flared inlet section 124 extending from the first rim 122 and a main body section 126 extending from the flared inlet section 124. In the example shown, the flared inlet section 124 has a frustoconical shape, such that the first rim 122 has a larger diameter than the main body section 126.

[0017] In some embodiments, the guide vane axial fan system 100 comprises an inlet airflow guide (not shown) coupled to the rotor 102 and positioned upstream of the rotor inlet 118. In at least some embodiments, the guide vane axial fan system 100 is positioned within an airflow system that may have a square, circular, or other suitable geometric cross-sectional shape. For example, the inlet airflow guide is shaped to direct the airflow 106, guided through a duct, into the rotor inlet 118 of the guide vane axial fan system 100.

[0018] The rotor hub 112 comprises an inner cap 128, an outer ring 130, and an annular wall 132 extending radially between the inner cap 128 and the outer ring 130. A plurality of spokes 134 extend axially from the annular wall 132 and radially between the inner cap 128 and the outer ring 130 to support the rotor 102. In this example, a cone 136 is coupled to the rotor hub 112 and extends radially from the rotor hub 112 on the inlet side. The cone 136 facilitates the airflow 106 entering the rotor fan 108 through the rotor inlet 118 and the duct leading to the rotor blades 116. In alternative embodiments, the rotor fan 108 comprises any rotor hub 112, enabling the rotor fan 108 to operate as described herein.

[0019] As in the Fig. 5 and Fig. As shown in Figure 6, the stator 104 comprises a stator hub 138, a stator casing 140, a plurality of stator blades 142 extending between them, a stator inlet 144, and a stator outlet 146. In the exemplary embodiment, the stator casing 140 defines at least partially the stator inlet 144 and the stator outlet 146. The stator inlet 144 is arranged downstream of the rotor outlet 120 in communication with it. The stator outlet 146 is arranged such that the airflow 106 can exit the stator 104.

[0020] In this example, the stator hub 138 comprises an inner ring 148, an outer ring 150, and an annular wall 152 extending radially between the inner ring 148 and the outer ring 150. A plurality of spokes 154 extend axially from the annular wall 152 and radially between the inner ring 148 and the outer ring 150. The inner ring 148 can be used as a mounting point for a motor (not shown). For example, a motor (either as a complete unit or using the stator hub 138 as a housing) can be pressed into the stator hub 138, so that the stator hub 138 acts as a heat sink exposed to the convection of the airflow directed through the stator 104. In this example, a cone 156 is coupled to the stator hub 138 and extends axially outwards from the stator hub 138 on the outlet side. The cone 156 facilitates the airflow out of the stator outlet 146.In alternative embodiments, the stator 104 comprises each stator hub 138 which enables the stator 104 to operate as described herein.

[0021] With reference to the Fig. 1-6 During operation, the rotor 102 rotates under the power of a motor, while the stator 104 remains stationary. The airflow 106 enters the guide vane axial fan system 100 via an inlet of the fan system and flows towards the rotor 102. The airflow 106 enters the rotor 102 from a hemispherical area in front of the rotor inlet 118. The airflow 106 enters the rotor cover 114 through the rotor inlet 118, flows through the rotor cover 114, interacts with the rotor blades 116, and is then expelled from the rotor 102 through the rotor outlet 120 towards the stator 104. The rotor blades 116 divide the airflow 106 into two streams (intake and pressure) while the rotor 102 accelerates to the required speed, and recombine the streams at the trailing edge 164 of the rotor blades 116.The rotor blades 116 have an angle of attack chosen to generate an airflow through the rotor 102. The airflow accelerates to a desired speed as it flows over the surface of the rotor blade 116. The rotor blades 116 are oriented such that the airflow exiting the rotor 102 has a directional component that is generally non-linear relative to a centerline.

[0022] A boundary layer forms at the leading edge 162 of the rotor blade 116, extending radially outwards from the rotor hub 112 and from the leading edge 162 to the trailing edge 164. The air adheres to the rotor blade 116 as long as the parameters of velocity, viscosity, and friction are in equilibrium. If the velocity is too high, the boundary layer detaches from the surface and begins to turbulence, indicating the onset of flow separation and adversely affecting overall performance. The designed geometries (angles and dimensions) along the rotor blades 116 contribute to a uniform airflow along the blades 116 from the leading edge 162 to the trailing edge 164 and from the rotor hub 112 to the blade tip. This geometry is selected to optimize pressure, flow rate, noise generation, and power consumption.

[0023] The airflow 106 enters the stator 104 via the stator inlet 144 and flows through the stator 104 towards a blower system outlet. The stator blades 142 are aligned to straighten the airflow 106 flowing from the rotor 102 to the stator 104 and to expel the airflow 106 from the stator 104, which is generally aligned longitudinally with a center line. The airflow 106 is expelled from the stator 104 through the stator outlet 146.

[0024] The stator blades 142 are shaped such that the air, as it leaves the trailing edge 208 of the rotor blades 116, adheres to the stator blades 142 with minimal turbulence. The stator blades 142 are configured to straighten any swirling airflow from the rotor 102 and convert the air velocity into pressure by reducing its speed. The geometry is therefore chosen to reduce the occurrence of air separation and to minimize the noise generated by the conversion of air velocity into pressure.

[0025] The geometry (angle and contour) of the blades 116, 142 at the respective hubs 112, 138 contributes not only to the mechanical strength of the blades 116, 142, but also to the angle of attack. The choice of geometry can limit the extent of change in the contour of the blades 116, 142. Since the chords of the blades 116, 142 move away from the respective hubs 112, 138, the blades 116, 142 are contoured to provide optimal performance within the limits of the aforementioned requirements, provided that the boundary layer does not detach and the blades 116, 142 can be manufactured using the chosen manufacturing process, such as casting, machining, and the like.

[0026] At the tip of the rotor blade 116, the selected geometry is optimized for the same requirements, additionally taking into account the air flowing radially from the tip of the rotor blade 116. By varying the design angles and contours of the tip, techniques can be employed to minimize these tip effects. Noise generation can play an important role in the selection of these parameters. The stator 104 has the same requirements as the rotor 102, except that in some examples, the tips of the stator blades 142 are attached to the stator shroud 140, which provides structural support to the stator blades 142. The contour along the chord and span of the blades 116, 142 between the respective hubs 112, 138 and tips can be selected within the limits of manufacturability to optimize the flow acting on the blades 116, 142.In addition, the trailing edge 164 of the rotor blades 116 is axially spaced from the leading edge 162 of the stator blades 142 by an optimized distance based on the radial distance from the axis of rotation.

[0027] In the exemplary embodiment, the cross-sections of the rotor blades 116 and the stator blades 142 are essentially constant in thickness. Alternatively, the rotor blades 116 and the stator blades 142 can define an airfoil shape with a thickness that varies between the trailing and leading edges.

[0028] In this example, the angles of the rotor blades 116 and the stator blades 142 are optimized for minimal flow separation along the blade span under most operating conditions. Such minimal flow separation increases the efficiency and reduces the noise emission of the guide vane axial fan system 100. Additionally, the number of rotor blades 116 and stator blades 142 is optimized based on at least one design criterion, such as the desired airflow (CFM), static pressure, and efficiency. In the exemplary embodiment, the rotor 102 comprises nine rotor blades 116 and the stator 104 comprises twenty-one stator blades 142. Alternatively, the rotor 102 and the stator 104 can comprise any number of blades that facilitate the operation of the guide vane axial fan system 100 described herein. The cross-sections of the rotor blades 116 and the stator blades 142 are essentially of constant thickness.Alternatively, the rotor blades 116 and the stator blades 142 can define an airfoil shape with a thickness that changes between the trailing edges and the leading edges.

[0029] The Fig. Figures 7-15 illustrate the geometry of the rotor blades 116 and stator blades 142 of the guide vane axial fan system 100. As shown in the Fig. As shown in Figures 7-11, each rotor blade 116 in the example embodiment comprises a hub end 158 which is connected to the rotor hub 112 (shown in Figure 7-11). Fig. 3) is coupled, a tip end 160 opposite the hub end 158, a leading edge 162 located on the rotor inlet side 118 of the rotor blade 116, and a trailing edge 164 located on the rotor outlet side 120 of the rotor blade. The leading edge 162 and the trailing edge 164 each extend between the hub end 158 and the tip end 160.

[0030] In this example, the trailing edge 164 of each rotor blade 116 is curved. For instance, the trailing edge 164 of each rotor blade 116 comprises a concave section 166 and a convex section 168, forming an S-shape. Concave refers to an edge or surface that curves inward toward the interior of the blade 116 to define a shell shape. Convex refers to an edge or surface that curves outward from the interior of the blade 116 to define a bulge. The concave section 166 of the trailing edge 164 extends from the tip end 160 of the rotor blade 116 to the convex section 168 of the trailing edge 164. The convex section 168 of the trailing edge 164 extends from the concave section 166 of the trailing edge 164 to the hub end 158 of the rotor blade 116. Accordingly, the trailing edge 164 is curved along its entire extent.In this example, the concave section 166 and the convex section 168 each extend along approximately half the extent of the rotor blade 116.

[0031] Furthermore, the concave section 166 has a first radius and the convex section 168 has a second radius. The first radius differs from the second radius. For example, the first radius is larger than the second radius. Additionally, in this example, the first radius of the concave section 166 varies between the tip end 160 of the rotor blade 116 and the convex section 168 of the trailing edge 164. Furthermore, the second radius of the convex section 168 varies between the concave section 166 of the trailing edge 164 and the hub end 158 of the rotor blade 116.

[0032] Furthermore, in this example, the leading edge 162 is curved. For example, the leading edge 162 is concave. Additionally, the leading edge 162 has a radius that changes along its length. For example, the radius of the leading edge 162 decreases from the hub end 158 to the tip end 160, so that the leading edge 162 has a more pronounced curvature towards the tip end 160.

[0033] The curvatures of the trailing edge 164 and the leading edge 162 give the rotor blade 116 certain properties and improve its performance. For example, the trailing edge 164 and the leading edge 162 curve away from each other as they approach the tip 160 to achieve a greater width and higher load at the tip 160.

[0034] For example, each rotor blade 116 has a hub width HW between the trailing edge 164 and the leading edge 162 of the rotor blade 116 at the hub end 158, and a tip width TW between the trailing edge 164 and the leading edge 162 of the rotor blade 116 at the tip end 160. The hub width HW and the tip width TW are measured in a direction parallel to the axis of rotation of the rotor blade 116. In this example, the tip width TW is greater than the hub width HW. As a result, the rotor blades 116 have an increased load near the tip end 160 and a reduced load near the hub end 158, which can be a region of high losses. Therefore, the rotor blades 116 improve the overall efficiency of the rotor fan 108 and reduce the broadband noise generated by the system in the lower range.

[0035] Furthermore, in this example, the tip 160 of the rotor blade 116 includes a tip edge 170 that extends from the leading edge 162 to the trailing edge 164. In this example, the tip edge 170 is curved and has a radius. For example, the radius of the tip edge 170 changes along its length. The tip edge 170 can be concave, convex, or a combination thereof. In this example, the tip edge 170 is convex along its entire length.

[0036] Furthermore, in this example, a blade height is a distance measured from the leading edge 162 to the trailing edge 164 in a direction perpendicular to the axis of rotation of the rotor blade 116. For example, the rotor blade 116 has a blade height 165 (shown in Fig. 11) at the hub end 158 in a range of 1.7 in. to 1.9 in. and a blade height 167 (shown in Fig. 8) at the tip end 160 in a range of 1.7 inches to 1.8 inches.

[0037] As in the Fig. As shown in Figures 12-14, each stator blade 142 comprises a hub end 172 coupled to the stator hub 138, a fairing end 174 coupled to the stator fairing 140, a leading edge 176 located on the side of the stator inlet 144 of the stator blade 142, and a trailing edge 178 located on the side of the stator outlet 146 of the stator blade 142. The leading edge 176 and the trailing edge 178 each extend between the hub end 172 and the fairing end 174.

[0038] In this example, the hub end 172 and the casing end 174 of the stator blade 142 are curved and not parallel to each other. For example, the hub end 172 and the casing end 174 of the stator blade 142 each have a radius that changes along their lengths.

[0039] Furthermore, in this example, the leading edge 176 and the trailing edge 178 of the stator blade 142 are curved and not parallel to each other. For example, the leading edge 176 and the trailing edge 178 of the stator blade 142 each have a radius that changes along their extent.

[0040] Fig. Figure 15 is a perspective view of an example of a rotor blade 200 for use with a rotor fan 108 (shown in Fig. 1) The rotor blade 200 comprises a hub end 202, a tip end 204 opposite the hub end 202, a leading edge 206 and a trailing edge 208. The leading edge 206 and the trailing edge 208 each extend between the hub end 202 and the tip end 204.

[0041] In this example, the trailing edge 208 of the rotor blade 200 comprises a concave section 210 and a convex section 212, forming an S-shape. Furthermore, the leading edge 206 is concavely curved along its entire extent. Additionally, the rotor blade 200 has an increased width from its center point to the tip end 204, as the leading edge 206 and the trailing edge 208 are curved away from each other towards the tip end 204. This results in an increased load near the tip end 204 and a reduced load near the hub end 202, which can be a region of high losses. Therefore, the rotor blade 200 improves the overall efficiency of the rotor fan 108 (shown in Figure 1). Fig. 1) and reduces the broadband noise generated by the system in the lower range.

[0042] The rotor blade 200 has a pronounced load at the tip end 204. For example, the ratio of the tip width to the hub width for the rotor blade 200 is at least two. Furthermore, the curves of the leading edge 206, the trailing edge 208, the hub end 202, and the tip end 204 provide a profile for the rotor blade 200 that facilitates flow adhesion to the rotor blade 200. In addition, the rotor blade 200 includes surfaces (e.g., a suction surface and a pressure surface) 214 that extend between the edges and have curves that follow or complement the curves of the edges and facilitate the interaction of the rotor blade 200 with the airflow. In this example, the surfaces 214 are smooth and free of any features (e.g., holes, protrusions, depressions, ribs, etc.).

[0043] The Fig. 16A and Fig. 16B are schematic representations of a representative sheet 300, which illustrate the definitions of angles for sheets (e.g., those in the Fig. 7, Fig. 12 and Fig. The 15 sheets shown (116, 142, 200) illustrate this. Sheet 300 comprises a front edge 302, a rear edge 304, a tip 306 and a hub 308 and has a pivot point 310.

[0044] The geometry of blade 300 is optimized by selecting its angles to achieve the desired flow conditions. For example, the angles Beta (β) and Theta (θ) characterize the geometry of blade 300 at various points along its span. These angles can be defined by M-prime coordinates in an M-prime vs. Theta coordinate system. M-prime coordinates are converted from Cartesian coordinates in x, y, z format by taking a section S1 of blade 300 at a selected point along its span in three-dimensional Cartesian space, as shown in Fig. Figure 16A shows that, for example, section S1 can be taken at a 50% span of the blade 300, which is determined by rotating a mean streamline around the Z-axis and cutting the blade 300. Section S1 is transferred to a flat surface without distortion of angles or lengths, as shown in Figure 16A. Fig. Figure 16B shows how to convert Cartesian coordinates in x, y, z format to M-coordinates (m, s). In M-coordinates, "m" is the meridional position and "s" is the meridional length component. The M-coordinates are divided by a radius R to obtain M-prime coordinates (m', theta), as shown in Fig. shown in Figure 16B. The angle θ is defined as an angle measured between a vertical axis 312 and the radius R extending to a point on the section S1. The radius R and the vertical axis 312 extend through the rotation center axis 310 of the sheet 300. A positive angle θ is measured clockwise, and a negative angle θ is measured counterclockwise from the Fig. The vertical axis 312 shown in Figure 16A is measured. The section can be defined along the blade 300, for example with respect to the hub 308, the tip 306 and / or the center of the span.

[0045] As in Fig. As shown in Figure 16B, the beta angle (β) is defined as the inclination of a camber line 314 of the sheet 300 at a reference point along the sheet 300. The angle β can be measured between the M-axis and a line 316 that is tangent to the camber line 314 at the reference point along the sheet 300. For example, Figure 16B shows... Fig. 16B the angle β for the leading edge 302 of the sheet 300. A positive angle β is measured clockwise, and a negative angle β is measured counterclockwise from the in Fig. The M-prime axis shown in Figure 16B is measured. Equation Eq (1) gives the relationship between angle θ and angle β. Eq (1): β=tan−1(ds / dm)=tan−1(r∗dθ / dm)

[0046] These beta and theta angles are optimized at different spans across the blade, for example, span 0 (hub), span 0.5 (half the blade width), and span 1 (fairing or blade tip). The blade is then swept to intersect these geometries at the different spans, thus defining the blade geometry. Since the geometries at the different spans constitute the overall blade geometry, any changes to the beta and / or theta angle at each span length affect the blade's output characteristics.

[0047] The beta and theta angle configurations of the blades are optimized to achieve a specific flow rate at a given pressure. Generally, the optimization of flow rate and pressure considers parameters such as flow rate, static pressure, noise level, and energy consumption. The noise level requirement is to ensure that it does not exceed the noise level requirements of centrifugal blowers used in engineering for the specific application (e.g., in residential or commercial areas requiring low noise levels). Energy efficiency is maximized for the considered parameters. The blade geometry and angles are chosen to achieve an optimal combination of these requirements. An iterative process was used to vary these angles and determine the optimal combination.

[0048] Fig. Figure 17 is a table with example angles for rotor blades 116 at various points along the span of the rotor blade 116. In particular, it shows Fig. 17 defines a range of beta angles and theta angles for the leading edge 162 and the trailing edge 164 of rotor blades 116 at each span of 0, 0.5, and 1. For example, at the rotor hub, the beta angle for the leading edge 162 is in the range of 70 degrees to 80 degrees, and the beta angle for the trailing edge 164 is in the range of 25 degrees to 35 degrees. At the tip, the beta angle for the leading edge 162 is in the range of 80 degrees to 90 degrees, and the beta angle for the trailing edge 164 is in the range of 60 degrees to 70 degrees. At a distance equal to half the span from the hub end to the tip, the beta angle for the leading edge 162 is in the range of 70 degrees to 80 degrees, and the beta angle for the trailing edge 164 is in the range of 55 degrees to 70 degrees.

[0049] Fig. Figure 18 is a table with examples of the chord lengths of the rotor blade 116 at various points along the span of the rotor blade 116. In particular, it shows Fig. 18 chord lengths for rotor blades 116 at each span 1 (tip end), span 0.75, span 0.5, span 0.25 and span 0 (hub end). The chord length is measured using a straight line extending between points on the leading edge 162 and the trailing edge 164. For example, rotor blade 116 has a chord length of 5.34 in. at the tip end 160, a chord length of 4.46 in. at a span of 0.75, a chord length of 0.50 in. at a span of 0.5, a chord length of 3.97 in. at a span of 0.25, and a chord length of 3.04 at the hub end 158. Accordingly, rotor blade 116 has a greater chord length at the tip end 160, and the chord length decreases towards the hub end 158, resulting in a greater load at the tip end 160 than at the hub end 158.

[0050] Fig. Figure 19 is a schematic diagram of a representative leaf 400, which shows definitions of angles of attack for leaves (e.g., those in Fig. 7, Fig. 12 and Fig. The blade 400 is illustrated in Figure 15 (sheets 116, 142, 200). It comprises a leading edge 402, a trailing edge 404, a tip end 406, and a hub end 408. The blade 400 also has a pivot axis 410 and a section line S2 extending midway between the leading edge 402 and the trailing edge 404. An angle of attack is defined as the angle between a line perpendicular to the pivot axis 410 and a tangent to the section line S2 at a given point on the span of the blade 400. A forward angle of attack is measured counterclockwise from the perpendicular line, and a backward angle of attack is measured clockwise from the perpendicular line. For example, the blade 400 has a backward angle of attack SA1 at the tip end 406 and a forward angle of attack SA2 at the hub end 408.

[0051] Referring to Fig.For example, the blade 116 has a forward angle of attack at the tip end 160 in a range of 5° to 8° and a backward angle of attack at the hub end 158 in a range of 18° to 23°.

[0052] Other variations of the disclosed embodiments can be understood and implemented by those skilled in the art when implementing the claimed invention with reference to the drawings, the disclosure, and the accompanying claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are listed in differing dependent claims does not mean that a combination of these measures cannot be advantageously employed. Reference numerals in the claims are not to be understood as limiting the scope of the claims.

[0053] Although the invention has been presented and described in detail in the drawings and the preceding description, this presentation and description are to be considered illustrative or exemplary and not limiting. It is understood that changes and modifications can be made by those skilled in the art within the scope of the following claims. In particular, the present invention includes further embodiments with any combination of features from the various embodiments described above and below. Furthermore, the statements made herein to characterize the invention refer to one embodiment of the invention and not necessarily to all embodiments.

[0054] The terms used in the claims should be interpreted in such a way as to have the broadest possible meaningful interpretation in accordance with the foregoing description. For example, the use of the article "a" or "the" when introducing an element should not be interpreted as excluding a multitude of elements. Likewise, the phrase "or" should be interpreted as inclusive, so that the statement "A or B" does not exclude "A and B" unless it is clear from the context or the foregoing description that only one of A and B is meant.Furthermore, the phrase "at least one of A, B, and C" should be interpreted as referring to one or more elements from a group of elements consisting of A, B, and C, and not as requiring at least one of the listed elements A, B, and C, regardless of whether A, B, and C are related as categories or otherwise. Additionally, the phrase "A, B, and / or C" or "at least one of A, B, or C" should be interpreted as encompassing each individual element from the listed elements, e.g., A; each subset of the listed elements, e.g., A and B; or the entire list of elements A, B, and C.

[0055] This written description uses examples to disclose the invention, including its best embodiment, and to enable a person skilled in the art to carry out the invention, including the manufacture and use of devices or systems and the performance of methods contained therein. The patentable scope of the invention is defined by the claims and may include other examples that might occur to a person skilled in the art. Such other examples shall fall within the scope of the claims if they have structural elements that do not differ from the wording of the claims or if they contain equivalent structural elements with insignificant differences from the wording of the claims.

Claims

[1] Guide vane axial fan system with one axis of rotation, wherein the guide vane axial fan system comprises: a rotor fan comprising a hub, a rotor inlet, a rotor outlet and rotor blades, each rotor blade of the rotor blades having a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end and a trailing edge extending between the hub end and the tip end; and a stator with a stator inlet, a stator outlet and stator blades, wherein the stator blades are positioned downstream of the rotor blades, wherein each rotor blade has a hub width between the trailing edge and the leading edge at the hub end and a tip width between the trailing edge and the leading edge at the tip end, and wherein the tip width is greater than the hub width, and wherein the trailing edge of each rotor blade comprises a concave section and a convex section forming an S-shape, the concave section extending from the tip end to the convex section and the convex section extending from the concave section to the hub end. [2] Guide vane axial fan system according to claim 1, wherein the concave section has a first radius and the convex section has a second radius, wherein the first radius differs from the second radius. [3] Guide vane axial fan system according to claim 2, wherein the first radius is larger than the second radius. [4] Guide vane axial fan system according to one of claims 1 to 3, wherein the leading edge is curved and has a radius. [5] Guide vane axial fan system according to claim 4, wherein the radius changes along the extent of the leading edge. [6] Guide vane axial fan system according to claim 4 or 5, wherein the leading edge is concave. [7] Guide vane axial fan system according to any one of claims 1 to 6, wherein the tip end comprises a tip edge extending from the front edge to the rear edge, and wherein the tip edge is curved and has a radius. [8] Guide vane axial fan system according to claim 7, wherein the radius of the tip edge changes along the extent of the tip edge. [9] Guide vane axial fan system according to any one of claims 1 to 8, wherein the rotor fan comprises a rotor housing extending around the rotor blades, the rotor housing defining the rotor inlet and the rotor outlet, the stator inlet being arranged to receive the airflow ejected from the rotor outlet. [10] Guide vane axial fan system according to any one of claims 1 to 9, wherein an angle Beta is defined as the slope of a camber line at a point along a span of a first rotor blade of the rotor blades, where the angle Beta for the leading edge at the hub is in the range of 70 degrees to 80 degrees and the angle Beta for the trailing edge is in the range of 25 degrees to 35 degrees; and where at the tip end the angle Beta for the leading edge is in the range of 80 degrees to 90 degrees and the angle Beta for the trailing edge is in the range of 60 degrees to 70 degrees. [11] Guide vane axial fan system according to claim 10, wherein at a distance corresponding to half the distance from the hub end to the tip end, the angle Beta for the leading edge is in the range of 70 degrees to 80 degrees and the angle Beta for the trailing edge is in the range of 55 degrees to 70 degrees. [12] Rotor fan for a guide vane axial fan system with one axis of rotation, wherein the rotor fan comprises: a hub; a rotor inlet; a rotor outlet; and Rotor blades, each rotor blade of the rotor blades having a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end, wherein each rotor blade has a hub width between the trailing edge and the leading edge at the hub end and a tip width between the trailing edge and the leading edge at the tip end, and wherein the tip width is greater than the hub width, and wherein the trailing edge of each rotor blade comprises a concave section and a convex section forming an S-shape, the concave section extending from the tip end to the convex section and the convex section extending from the concave section to the hub end. [13] Rotor fan according to claim 12, wherein the concave section has a first radius and the convex section has a second radius, wherein the first radius differs from the second radius. [14] Rotor fan according to claim 12 or 13, wherein the leading edge has a concave curvature. [15] Rotor fan according to any one of claims 12 to 14, wherein the tip end comprises a tip edge extending from the front edge to the rear edge, and wherein the tip edge is curved and has a radius. [16] Rotor fan according to any one of claims 12 to 15, wherein an angle Beta is defined as the slope of a camber line at a point along a span of a first rotor blade of the rotor blades. where the angle Beta for the leading edge at the hub is in the range of 70 degrees to 80 degrees and the angle Beta for the trailing edge is in the range of 25 degrees to 35 degrees; and where at the tip end the angle Beta for the leading edge is in the range of 80 degrees to 90 degrees and the angle Beta for the trailing edge is in the range of 60 degrees to 70 degrees. [17] Rotor fan according to claim 16, wherein at a distance corresponding to half the distance from the hub end to the tip end, the angle Beta for the leading edge is in the range of 70 degrees to 80 degrees and the angle Beta for the trailing edge is in the range of 55 degrees to 70 degrees. [18] Rotor fan according to any one of claims 12 to 17, further comprising a rotor housing extending around the rotor fan, the rotor housing defining the rotor inlet and the rotor outlet. [19] Method for assembling a guide vane axial fan system with a rotary axis, the method comprising: Coupling a rotor fan with a stator such that the stator is positioned downstream of the rotor fan, wherein the rotor fan comprises a hub, a rotor inlet, a rotor outlet and rotor blades, Positioning the rotor blades around the hub so that the rotor fan rotates around the axis of rotation and directs the airflow towards stator blades of the stator, each rotor blade of the rotor blades having a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. wherein each rotor blade has a hub width between the trailing edge and the leading edge at the hub end and a tip width between the trailing edge and the leading edge at the tip end, and wherein the tip width is greater than the hub width, and wherein the trailing edge of each rotor blade comprises a concave section and a convex section forming an S-shape, the concave section extending from the tip end to the convex section and the convex section extending from the concave section to the hub end. [20] The method of claim 19, further comprising manufacturing a first rotor blade of the rotor blades, wherein an angle Beta is defined as the slope of a camber line at a point along a span of the first rotor blade, where the angle Beta for the leading edge at the hub is in the range of 70 degrees to 80 degrees and the angle Beta for the trailing edge is in the range of 25 degrees to 35 degrees, and where at the tip end the angle Beta for the leading edge is in the range of 80 degrees to 90 degrees and the angle Beta for the trailing edge is in the range of 60 degrees to 70 degrees.

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