TW200419076A - High efficiency ceiling fan - Google Patents

Abstract

Ceiling fan energy consumption efficiency is enhanced with fan blades that have an angle attack that decreases from root end to tip end at higher rates of decrease nearer their tip ends than at their root ends. Air flow distribution is enhanced with at least a portion of the blades having a dihedral that continuously increases. Efficiency on downdraft is also achieved with the blades having concave top and bottom surfaces.

Description

200419076 发明 Description of the invention: [Technical field to which the invention belongs] The serial number of this case is the green application filed on July 30, 2002. The invention relates to ceiling fans, in particular electric ceiling fans and their efficiency. [Prior art] For many years, ceiling fans driven by electric motors have been used for air circulation. They usually have a motor located in the hood and mounted to a straight rod, so that the fan blade ^ rotates on the axis of the straight rod. The traditional fan blades are flat and have an oblique side: or the inclination provides an angle of attack of the air when rotating, so that the air flows downward. When a fan blade extending radially from its axis of rotation rotates, 'the movement path of the blade tip is at any time the path of the great secretion end, so the blade tip moves much faster than the root end. In order to balance the wind resistance load along the airflow generated by the blades and their movements, the fan blades are designed with a reduced angle of attack towards the tip. This design feature is common in the design of other rotating blades, such as boat propeller blades and aircraft propeller blades.

Flonda Solar Energy Center carried out a study on the efficiency of commercially available ceiling fans in mid-1997. This test report was published in the U.S. M39,54m Financial Specialist's owner found that the design of fan blades can be increased. Efficiency, which is the air flow rate (cfM) per power consumption (waUs), the blade gradually bends at the root end and narrows down evenly to a smaller bend or an angle of attack, such as a 20 inch blade (Including the narrowed string-shaped part) The root has 26.7. Zhi-qu has 69 at the tip. Of the bend. Another-The long-standing problem with ceiling fans related to JL is the distribution of airflow. blade

87191.DOC 200419076 has an angle of attack, but the blades of most ceiling fans are rotated in a horizontal plane. This forces the chi gas downward and provides airflow under the fan. Because the airflow does not flow directly from the fan, the surrounding airflow insufficient. Because the fan blades are hyperbolic, this can reduce the impact of this problem, but it needs to consider the lack of airflow under the fan. [Summary of the Invention] We know that reducing the angle of attack or twisting angle at a uniform rate is not the most efficient for ceiling fans. The circumference of a two-foot blade or the tip of a propeller blade is 2 Π (2), so the distance of one-foot midpoint or half of the length is 2 Π (1). This linear relationship is consistent with the aircraft propeller blade system. When it does, the path of its orbit usually falls in a plane perpendicular to the flight path. However, the orbital path of the ceiling fan is parallel and located below the airflow, so the blades do not hit the air uniformly, which is different from the aircraft. The reason for this phenomenon is that the tip of the ceiling fan blade, and the benefit of air exchange is greater than the inside of the blade tip. The air near the axis of rotation must move from the surrounding environment through the space between the ceiling surface and the fan blades to the end of the i-section. Due to the above matters, we have realized that blades with angle of attack can increase the efficiency of ceiling fans. The angle of attack increases non-uniformly from the root end to the tip, especially the rate of change of the angle of attack or slope at the tip of the blade is greater than the rate of change at the root. This can force the fan blades below the ceiling to displace air inward, so the moxa gas near the root end of the blade is easier to replace. But whether this theory is correct or not, it has made clear the improvement in efficiency. Since the change in the angle of attack at the blade tip is greater than the change in the angle of attack at the root, it means that the fan efficiency will be significantly improved. Ceiling fan blades with upward curves can also improve airflow distribution.

87191.DOC 200419076

The result is not only an increase in efficiency. The result is not only an increase in efficiency, but also a better air distribution. Into a progressive hyperbola, which extends from the root end to the tip, and can be matched with the non-uniform reduction of the angle of attack or twist

The degree is less than about 25% of the thickness along both sides. [Embodiment] The fan blade technology is disclosed in U.S. Patent No. 6,039,541, which assumes that the air flowing into the fan blades comes from a direction perpendicular to the plane of rotation of the blades. In addition, when applied to aircraft propeller blade theory, it assumes that airflow flows from the blade root to the tip at a fixed speed. Based on this assumption, the blade has a certain twisting speed from the root to the tip. The twisting of the blade is to optimize the relative angle of attack with respect to the direction of the airflow relative to the blade surface. This ensures that the blade operates from the root to the tip at the optimal angle of attack. The angle of attack changes to match the speed at which the blade tip moves faster than the speed at which the blade root moves'. The increase in this speed changes the direction of the blade upwind. This assumption is invalid for ceiling fans. Ceiling fan is an air circulation device. It does not move air like the propeller blade of an airplane. The air does not move at the same vector or speed from the blade root to the tip. Figure 1 shows a conventional ceiling fan, except for the outline of its blades. The fan is installed under the ceiling by a straight down bar, which extends from the ceiling to the electric motor and the outer frame of the switch box, and the fan has a light device at the bottom end. Electricity is supplied to the motor conductor driving blades through which the conductor extends

87191.DOC 200419076 to a local power source. Spiral fan blades are superior to flat fan blades and have a progressive hyperboloid. The airflow reaching and leaving the fan blades is shown with multiple arrow lines, so that you can understand why the fan blades do not impact the moxa like the propeller blades of an aircraft, and the space defined above the blades changes the vector of the airflow entering the fan. in contrast. As shown in Fig. 2, the fan blade narrows with its width and chord. It narrows from the bottom or root to the tip, so the tip size is smaller. In addition, the blades all have the hyperboloid shown in FIG. 1, but they are not the advantages of the present invention. The hyperboloid provides a larger air distribution under the fan. Referring to Figs. 2 and 3, although the blade has a single structure, the figure shows that the blade has three parts. A blade with a length of 24 inches has three parts of the same length, namely 8 inches, which are all twisted in the form of β, but the rate of rotation from the root to the tip is different. The twist angle or angle of attack is reduced from the root end to 10 of the tip. , As shown in Figure 丨 'This reduction at three different rates into the first 8-inch leaf adjacent to the root end-the rate of change in the twist in the site is 0/40, the rate of the middle part is 0. 7. The change rate of torsion in the third part adjacent to the tip is i.O. / 料 ^ # 然 ’There is a slight conversion between adjacent parts. Therefore, the difference in the angle of attack from the outer side to the other side in FIG. 3 is ⑼. / 英 忖 X8H) 'The difference in the middle part is about 6. , The inner part is about 3 °. 〃 Figures 5 to 7 show the blade 10 of the fan i in detail. The root end u is mounted to the fan and the rotor. Rotate 'the clearest line with the center of the leaf green

87191.DOC 200419076 shows that the blade has 0 at the root end U. The hyperbola has a continuous arc or curve between the two ends of the fan blade at the tip 13 and ioc. The hyperbola has a continuous change between the two ends. As shown in the line ㈤, the airflow is distributed directly below the fan and in the surrounding space. In contrast, the fans of the previous technology mainly guided the air below it, so the air flow in the surrounding space was indirect and weak. Although fan blades inclined with a fixed hyperboloid along the length can solve this problem, they need to consider the fan; weaker airflow. The blade hyperbola can be continuously changed between the two ends, but it is fixed near the root end and / or the tip, and the rest is arc or curved. In fact, see the design of Zhuan Niao ’, the most efficient design is that the hyperboloid from the root to the middle of the tip is G. After that, it continues to increase to 1 (). . In a preferred embodiment, the root end of the blade has G. The hyperboloid has 10 at the tip. Hyperboloid, but the hyperboloid at the root can be less than or greater than 0. The tip hyperboloid can be smaller or larger than the core fan size, power, height, and application = considerations for selecting a particular hyperboloid. The ceiling fan can be operated in the traditional reverse direction, as shown in Figure 8A. When viewed from below, the blades rotate clockwise. In this direction and its angle of attack, the blades make the air upward in the direction shown by the arrow. A common example is to pull down the hot air above the fan. As shown in Figure 8β, the blades can also rotate counterclockwise, which blows air to people to cool them in a hot environment. I have found that blades of different thicknesses can increase efficiency, which is shown in Figure 8C, where the blades narrow from the side to the side. The top of the blade 1 Q is slightly depressed like the bottom, so the hollow depression is located between its root and tip. Which produces the best efficiency

87191.DOC -9- 200419076 The thickness of the blade along the center is less than about 25% of the thickness on both sides, and the top and bottom surfaces should have the same profile. I do not yet understand why this is better than a flat surface, reduced angle of attack, and hyperbolic variation. For ease of illustration and clarification, FIG. 8C shows only the fan blades along plane 8-8. When the blade is rotated in the manner shown in FIG. 8B to form a downward airflow, the change in thickness between the sides of the blade increases the efficiency by 3% to 4%. If it is rotated in the direction of FIG. 8A, the efficiency change is not obvious. The reason for this, especially when only one surface is recessed, the efficiency improvement is small. The fan is tested in the Hunter Fan Company's laboratory and it is certified by the Environmental Protection Agency to perform the Energy Star CompHance test. Except that the air speed detector is still installed above and near the top of the blade, the fan is tested according to the Energy Star test regulations, which measures the air speed near the fan blade. During the test, different air velocities were measured at different positions from the root to the tip of the blade. Figure 4 shows the test parameters. The actual test results are shown in Table 1. Detector Average Speed Air Speed FPM FPS 0 283 4.7 1 303 5.1 2 320 5.3 3 325 5.4 4 320 5.3 5 313 5.2 31.4

Synthetic composition angle / speed angle 23.2 11.7 24.9 11.7 0.07 26.7- 11.5 0.16 28.4 11.0 0.54 30.1 10.2 0.79 31.8 9.4 0.76 ^ 87191.DOC -10- 200419076 6 308 5.1 33.1 33.5 · 8.8 0.63 7 305 5.1 34.9 35.3 8.3 0.51 8 290 4.8 36.6 37.0 7.5 0.77 9 275 4.6 38.4 38.7 6.8 0.71 10 262 4.4 40.1 40.4 6.2 0.60 11 235 3.9 41.9 42.0 5.3 0.87 12 174 2.9 43.6 43.7 3.8 1.54 13 132 2.2 45.4 45.5 2.8 1.03 Comparative test results are shown in Table 2 Among them, the blade 1 has the aforementioned 10 ° fixed hyperboloid, the blade 2 is a Hampton Bay Gossomer Wind / Windward blade of the design shown in the 6,039,541 patent, and the blade 3 has 15. Flat blade with fixed angle of attack. As defined earlier, the table lists improvements in energy efficiency. Table 2 Blade motors with cylinders are better than Hampton Bay, better than standard modified, no cylinder is better than Hampton Bay, modified 4 feet outside, improved 1 172 X 18 AM 12,878 21% 29% 37,327 24% 27% 2 188X15 10,639 NA 6% 30,034 NA NA 3 172X 18 AM 10,018 -6% NA 28,000 -7% -7% 87191.DOC -11-200419076 ^ The ceiling fan's enhanced airflow distribution shown here makes energy efficiency better than previous technologies: Of course, fans It can also be applied to other corrections such as table tops. Although the specific embodiments of the present invention are disclosed herein, other changes, improvements, or deletions are within the spirit and scope of the scope of patent application of the present invention. [Brief description of the drawings] FIG. 1 is a side view of a ceiling fan, which is a preferred embodiment of the present invention. FIG. 2 is the outline of the fan blade of FIG. 1, which is illustrated by a hypothetical plane. Figure 3 is the outline of the blade of Figure 2, showing the spiral of the blade at different locations along its length. Figure 4 is a graph of airflow test parameters. 5 is a side view of a blade of the fan of FIG. 1. 6 is a top view of a fan blade of FIG. 1. FIG. 7 is an end view of a blade of the fan of FIG. 1. FIG. Figs. 8A and 8B are other side views of a fan blade of Fig. 1, which are shown in section. Fig. 8C is a sectional view of the blade along plane 8-8. [Illustration of Symbols] 10 11 12 13 15 Blade Root End Soft Tip Center Line

87191.DOC

Claims (1)

200419076 The scope of patent application: 1. A type of "ceiling fan of a plurality of fan blades, which are installed to rotate with the vertical axis of the fan rotating blades, and the two extended side parts of each fan blade are located outside the extended central part And the thickness of each fan blade < Wei central part is smaller than the thickness of the two side parts. 2. Minus patents_ ceiling fan of item 1, wherein the thickness of each blade along its centerline is less than about 25% of the maximum thickness of the side portion. 3. The ceiling fan according to the scope of the patent application, wherein the two edge portions and the central portion of each blade extend approximately from the root end to the tip of each blade. 4. According to the ceiling fan of the scope of patent application, each blade has a concave top surface and a bottom surface. 5. The ceiling fan according to item 1 of the scope of the patent application, wherein each of the fan blades is curved upward toward its tip to have a continuous progressive hyperbola. 6. The ceiling fan according to item 5 of the patent application, wherein the hyperbola at the root end of each blade is approximately zero. , The hyperbola at the tip is about 10. . 7. According to the patent application of the ceiling fan, the angle of attack of each blade near the axis is greater than the angle of attack at the end of the axis of the fan, and the change rate of the angle = angle is inconsistent. 8. The ceiling fan according to item 7 of the scope of patent application, wherein the hyperbola of each blade at the tip is about 10. , The angle of attack is about 10. . 9. The ceiling fan according to item 5 of the patent, wherein the angle of attack of each blade near the axis of the fan is greater than the angle of attack at the end of the axis of the fan, and the rate of change of the angle of attack is inconsistent. 10 of the blades at the root end of the blade. According to the ceiling fan of item 9 of the patent application scope, its 87191.DOC 200419076 hyperboloid is about 0. , The hyperbola at the tip is about 10. . 11. 12. 13. 14. 15.-A ceiling fan having a plurality of fan blades, the blades of which have recessed top surfaces and spreading surfaces, are mounted to rotate in two directions with the vertical fan axis of the blade rotation. The ceiling fan according to item 11 of the patent application, wherein the top and bottom surfaces of the blade have the same contour. A ceiling fan according to item 12 of the patent application, wherein each blade is curved upward toward its pointed end to have a continuous progressive hyperboloid. According to the ceiling fan of claim 12, wherein the angle of attack of each blade near the axis of the fan is greater than the angle of attack at the end of the axis of the fan 'and the rate of change of the angle of attack is inconsistent. According to the ceiling fan of the patent application No. 13, the angle of attack of each blade near the axis of the fan is greater than the angle of attack at the end of the axis of the fan, and the rate of change of the angle of attack is inconsistent. 87191.DOC