TWI691704B - Method for quickly calculating the maximum volume airflow rate of a fan - Google Patents

Abstract

The method for quickly calculating the maximum volume airflow rate of a fan is provided and the method comprises following steps. First a testing fan is provided and the testing fan is disposed in an air volume and air pressure testing device which is referred to wind tunnel. An operating electric power which is the testing fan power is measured when the testing fan is operating. A statics pressure relative to the atmospheric pressure is got when the testing fan is operating. An operation coefficient which is based on the electric power is provided. A formula is provided as following .

Substituting all coefficient into the formula. The Q _maxis the calculated maximum volume airflow rate. The PWR is the operating electric power. The Coef is the operation coefficient. After finish calculating the maximum volume airflow rate, the wind tunnel is adjusted to let the value of the volume airflow rate which past through the wind tunnel reach the calculated maximum volume airflow rate. Then, keep adjusting the wind tunnel to scan the near value of the calculated maximum volume airflow rate in order to find the true maximum volume airflow rate of the test fan.

Description

Method for quickly calculating maximum air volume of fan

The invention refers to a method for calculating the maximum air volume of a fan, in particular to a method for quickly calculating the maximum air volume of a fan.

At present, fans are required to make PQ curves when performing performance tests, which are used as criteria for judging the performance of the fans. Please refer to FIG. 1, which is a typical PQ curve obtained when a fan is tested. The so-called PQ curve is the curve of the static air pressure (P) and air flow (Q) after the fan performs work on the air. During the test, the air flow of the wind tunnel is mainly controlled for measurement. Two important points are when the air flow (Q) is zero and the static air pressure (P) is maximum (P _max ), and the static air pressure (P) is When the air flow rate (Q) is zero and the maximum (Q _max ) is above two points, the most difficult data to obtain is the data point of the maximum air flow rate (Q _max ). Each fan many different maximum air flow (Q _max) are different, the influence of the maximum air flow rate (Q _max) factors such as the form of the fan (Fan type), the size of the fan (Fan size), the number of blades (Blade number ) And angle of attack (Angle of attack) and other factors have an impact. Therefore, when measuring, the measurement is usually started from position 1 or position 2. If the measurement is started from position 1, the wind tunnel choke device must be fully opened and slowly closed to reduce the air flow (Q) until the static air pressure is measured (P) The data of the maximum air flow (Q _max ) of the fan can be determined only when it starts to increase. However, most of this test method has spent a lot of time on the part of the unused section before the maximum air flow (Q _max ) is really found. If the number of fans to be tested increases, it will take a lot of time to complete all fan tests. Therefore, how to quickly find the value of the maximum air flow (Q) to reduce the time required to complete the test and improve the test efficiency is worthy of consideration by those with ordinary knowledge in the art.

將所取得之該運作電功率、該相對大氣靜壓差及該運算係數，並帶入該計算公式，其中，Q _max為該測試風扇的一計算最大風量，PWR為該運作電功率，P _s為該相對大氣靜壓差， Coef為該運算係數。最後，將上述係數帶入式中後即可算出該計算最大風量Q _max，根據該計算最大風量Q _max，調整流過該風量風壓量測裝置的空氣流量到該計算最大風量後，於該計算最大風量附近繼續調整該風量風壓量測裝置的空氣流量，以找到該測試風扇真正的最大風量。 上述之快速計算風扇最大風量的方法，當該運作電功率為1000瓦以上，其中該運算係數 Coef的值為2.0到3.0之間。 上述之快速計算風扇最大風量的方法，當該運作電功率為6瓦以上1000瓦以下，其中該運算係數 Coef的值為1.5到1.9之間。 上述之快速計算風扇最大風量的方法，當該運作電功率為3瓦以上6瓦以下，其中該運算係數 Coef的值為1.0到1.4之間。 上述之快速計算風扇最大風量的方法，當該運作電功率為3瓦以下，其中該運算係數 Coef的值為0.1到0.9之間。 上述之快速計算風扇最大風量的方法，該運作電功率為該測試風扇在該相對大氣靜壓差最大時運作所測得的數據。 The purpose of the present invention is to provide a method that can quickly calculate the maximum air volume of the fan. The method for quickly calculating the maximum air volume of a fan of the present invention includes providing a test fan, installing the test fan on an air volume and air pressure measurement device, and starting the test fan. Next, an operating electric power is obtained. The operating electric power refers to: measuring the electric power consumed by the test fan when the test fan is operating. Next, a relative atmospheric static pressure difference is obtained. The relative atmospheric static pressure difference is the static pressure difference measured in the wind tunnel where the test fan is located and outside the wind tunnel when the test fan is operating. Then, provide an operation coefficient, obtain the appropriate operation coefficient according to the operating electric power, and provide a calculation formula as

The obtained operating electric power, the relative atmospheric static pressure difference and the calculation coefficient are brought into the calculation formula, where Q _max is a calculated maximum air volume of the test fan, PWR is the operating electric power, and P _{s is} the Relative to the atmospheric static pressure difference, Coef is the calculation coefficient. Finally, after the above coefficients are brought into the formula, the calculated maximum air volume Q _max can be calculated. According to the calculated maximum air volume Q _max , the air flow through the air volume and air pressure measurement device is adjusted to the calculated maximum air volume. Calculate the air flow of the air volume and air pressure measurement device near the maximum air volume to find the true maximum air volume of the test fan. The above method for quickly calculating the maximum air volume of the fan, when the operating electric power is more than 1000 watts, wherein the value of the calculation coefficient Coef is between 2.0 and 3.0. The above method for quickly calculating the maximum air volume of the fan, when the operating electric power is more than 6 watts and less than 1000 watts, wherein the value of the calculation coefficient Coef is between 1.5 and 1.9. The above method for quickly calculating the maximum air volume of the fan, when the operating electric power is more than 3 watts but less than 6 watts, wherein the value of the calculation coefficient Coef is between 1.0 and 1.4. The above method for quickly calculating the maximum air volume of the fan, when the operating electric power is less than 3 watts, wherein the calculation coefficient Coef is between 0.1 and 0.9. In the above method for quickly calculating the maximum air volume of the fan, the operating electric power is the data measured when the test fan is operated when the relative atmospheric static pressure difference is maximum.

(1) 式1中，PWR為測試風扇的運作電功率，P _s為該相對大氣靜壓差， Coef為所得之運算係數，將三個係數值帶入式1中計算後得出該測試風扇的計算最大風量Q' _max。請參閱圖4，圖4所繪示為本實施例風扇測試時會得出的典型PQ曲線，最後實施步驟S250，調整風量控制裝置320使風洞的空氣流量到達計算最大風量Q' _max後，雖然計算最大風量Q' _max有可能位於比真正的最大風量Q _max還大的位置3或是有可能位於比真正的最大風量Q _max還小的位置4，不是完全準確但只要繼續調整風量控制裝置320控制風洞的空氣流量在該計算最大風量Q' _max附近掃描就能找到該測試風扇真正的最大風量Q _max。 請參閱圖5，圖5所繪示為另一種測試風扇最大風量風洞設施400示意圖，其與測試風扇最大風量風洞設施300的差異在於：空氣流動方向相反。另外，須說明的是圖3與圖4中所繪示之風量風壓量測裝置皆僅為粗略表達，在本領域具有通常知識者皆知真正的風量風壓量測裝置之設施外觀與形狀並非如此，但此非講述之重點，故不加以繪示與說明。 綜上所述，可知本發明之快速計算風扇最大風量的方法，在測試一開始就能得出待測試風扇的計算最大風量，可以迅速地找到待測試風扇真正的最大風量並開始製作PQ曲線圖，大幅減少完成風扇測試所需的時間並提升風扇測試的效率。雖然本發明已以較佳實施例揭露如上，然其並非用以限定本發明，任何所屬技術領域中具有通常知識者，在不脫離本發明之精神和範圍內，當可作些許之更動與潤飾，因此本發明之保護範圍當視後附之申請專利範圍所界定者為準。 Please refer to FIGS. 2 and 3. FIG. 2 is a schematic diagram of an implementation step of a method for quickly calculating the maximum air volume of a fan. FIG. 3 is a schematic diagram of an air volume and pressure measurement device 300, hereinafter referred to as a wind tunnel, where arrow 12 is The air flows. First, implement step S210, provide a test fan 10, set it in a wind tunnel and start it. Next, step S220 is implemented. When the test fan 10 is started, the operating power of the test fan 10 is measured by the electric power sensor 310, and the air pressure sensor 330 measures the relative atmospheric static pressure difference between the inside and outside of the wind tunnel passing through the test fan. In other embodiments, the measurement of the operating electric power may also be performed when the air volume control device 320 closes the wind tunnel so that the air flow rate is zero. Next, step S230 is implemented to obtain a suitable calculation coefficient according to the measured operating power of the test fan. In this embodiment, if the operating electric power is higher than 1000 watts, the value of the calculation coefficient is between 2.0 and 3.0; if the operating electric power is between 6 watts and 1000 watts, the value of the calculation coefficient is 1.5 To 1.9; if the operating electrical power is between 3 watts and 6 watts, the value of the calculation coefficient is between 1.0 and 1.4; if the operating electrical power is less than 3 watts, the value of the calculation coefficient is 0.1 To 0.9. After that, step S240 is implemented, and the measured operating electric power, relative atmospheric static pressure difference and calculation coefficient are brought into the following formula:

(1) In Equation 1, PWR is the operating electric power of the test fan, P _{s is} the relative atmospheric static pressure difference, Coef is the calculation coefficient obtained, and the three coefficient values are calculated into Equation 1 to calculate the test fan’s Calculate the maximum air volume _Q'max . Please refer to FIG. 4. FIG. 4 illustrates a typical PQ curve obtained during the fan test of this embodiment. Finally, step S250 is implemented to adjust the air volume control device 320 so that the air flow of the wind tunnel reaches the calculated maximum air volume Q′ _max , although calculating the maximum wind amount Q _'max likely located _max larger than the actual maximum wind amount Q position 3 or there may be in Q _max is smaller than the actual maximum volume position 4, is not entirely accurate as long as continue to adjust the air volume control means 320 controlling the air flow in the wind tunnel of calculating the maximum flow rate Q _'max to find a real scanning near maximum air volume of the test fan Q _max. Please refer to FIG. 5. FIG. 5 is a schematic diagram of another test fan maximum air volume wind tunnel facility 400. The difference from the test fan maximum air volume wind tunnel facility 300 is that the air flow direction is opposite. In addition, it should be noted that the air volume and air pressure measurement devices shown in FIGS. 3 and 4 are only rough expressions, and those with ordinary knowledge in the art know the appearance and shape of the real air volume and air pressure measurement devices. This is not the case, but this is not the focus of the description, so it is not shown and explained. In summary, it can be seen that the method for quickly calculating the maximum air flow of the fan of the present invention can obtain the calculated maximum air flow of the fan to be tested at the beginning of the test, and can quickly find the true maximum air flow of the fan to be tested and start to make a PQ curve chart , Significantly reduce the time required to complete the fan test and improve the efficiency of the fan test. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone who has ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be deemed as defined by the appended patent application scope.

1: Position 1

2: Position 2

3: position 3

4: Position 4

10: Test the fan

12: Arrow

300: Test the maximum air volume of the wind tunnel facility

310: electric power sensor

320: Air volume control device

330: Barometric pressure sensor

400: Test the maximum wind volume of the fan wind tunnel facility

S210~S250: flow chart steps

Figure 1 shows a typical PQ curve obtained during a fan test. FIG. 2 is a diagram illustrating an implementation step of a method for quickly calculating the maximum air volume of a fan. FIG. 3 is a schematic diagram of an air volume and pressure measurement device 300. FIG. 4 illustrates a typical PQ curve obtained during the fan test of this embodiment. FIG. 5 is a schematic diagram of another wind tunnel facility 400 for testing the maximum air volume of the fan.

S210~S250: flow chart steps

Claims (6)

A method for quickly calculating the maximum air volume of a fan includes: providing a test fan, installing the test fan on an air volume and air pressure measurement device and starting the test fan; obtaining an operating electrical power, the operating electrical power refers to: When the test fan is operating, measure the electrical power consumed by the test fan during operation; obtain a relative atmospheric static pressure difference, which refers to the difference between the inside and outside of the wind tunnel where the test fan is located when the test fan is operating Static pressure difference; provide an operation coefficient, obtain the appropriate operation coefficient according to the operating electric power, and provide a calculation formula as

The obtained operating electric power, the relative atmospheric static pressure difference and the calculation coefficient are brought into the calculation formula, where Q _max is a calculated maximum air volume of the test fan; PWR is the operating electric power; P _{s is} the Relative atmospheric static pressure difference; Coef is the calculation coefficient; According to the calculated maximum air volume Q _max , after adjusting the air flow through the air volume wind pressure measurement device to the calculated maximum air volume, continue to adjust the air volume near the calculated maximum air volume The air flow of the air pressure measurement device to find the true maximum air volume of the test fan. According to the method for quickly calculating the maximum air volume of a fan as described in item 1 of the patent application range, when the operating electric power is more than 1000 watts, the value of the calculation coefficient Coef is between 2.0 and 3.0. According to the method for quickly calculating the maximum air volume of a fan as described in item 1 of the patent application scope, when the operating electric power is above 6 watts and below 1000 watts, the value of the calculation coefficient Coef is between 1.5 and 1.9. According to the method for quickly calculating the maximum air volume of a fan as described in item 1 of the patent application scope, when the operating electric power is more than 3 watts but less than 6 watts, the value of the calculation coefficient Coef is between 1.0 and 1.4. According to the method for quickly calculating the maximum air volume of a fan as described in item 1 of the patent application scope, when the operating electric power is less than 3 watts, the calculation coefficient Coef is between 0.1 and 0.9. According to the method for quickly calculating the maximum air volume of a fan as described in item 1 of the patent application scope, the operating electric power is the data measured by the test fan operating at the maximum relative atmospheric static pressure difference.

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