CN205190327U - Centrifugal fan impeller of adjustable splitterr vanes - Google Patents

Abstract

The utility model discloses an impeller of a centrifugal fan with adjustable splitter vanes. In the use of existing fan products, the working conditions usually do not match the rated working conditions, resulting in low efficiency of the fan and narrowing the efficient operation range of the fan. The guide ring and the wheel disc of the utility model constitute a turnover pair; the total fixed frame is fixed on the wheel disc, and is provided with a guide ring fixing device; the guide ring is connected with n splitter blade ring fixing devices; the splitter blade and The wheel cover is connected with the fixing device on the wheel cover of the splitter blade, and connected with the disc through the fixing device on the splitter vane wheel disc; the fixing device on the ring of each splitter vane is connected with the corresponding fixing device on the splitter vane wheel disc through the splitter blade adjustment piece . The utility model adjusts the angle of the splitter blade by rotating the guide ring to make the splitter blade adjusting part swing, and obtains the highest operating efficiency for different working conditions, and ensures that the centrifugal fan can also obtain the highest operation under the rated working condition under the non-rated working condition efficiency.

Description

Centrifugal fan impeller with adjustable splitter vanes

technical field

The utility model belongs to the field of fan equipment and relates to a centrifugal fan, in particular to a centrifugal fan impeller with adjustable splitter blades.

Background technique

Energy is an important material basis for economic and social development and improvement of people's living standards. The energy issue is a crucial issue for a country. Since the 1990s, the contradiction between my country's energy supply and demand has been increasing, and the problem of energy shortage has emerged. According to the survey, wind turbines account for about 10% of the country's electricity consumption. The country requires that the efficiency of the fan should not be lower than 70%, but the average operating efficiency of the existing fan is only 40%-60%. It can be seen that the energy-saving potential of the fan is very considerable. Optimizing the performance of the fan, improving the operating efficiency, and enhancing the stability of the fan operation Sex matters.

Fans can usually be divided into three categories: centrifugal fans, axial fans and mixed flow fans. Among them, centrifugal fans are used the most. Therefore, whether centrifugal fans can operate safely, reliably and efficiently has been in recent years for fan design, manufacturing, scientific research, And use the common concerns of various departments. Due to the existence of rotating parts, the large curvature of the impeller channel structure, and the influence of the viscosity of the airflow, etc., the inside of the centrifugal fan presents a very complex three-dimensional unsteady flow. The flow phenomena that often occur mainly include separation, vortex, shedding, wake, etc., and secondary flow often occurs inevitably. These unsteady and complex flows exist throughout the entire operating condition, and they are the root cause of the energy loss and noise increase of the centrifugal fan.

Fans are widely used, such as in construction projects, underground projects, ventilation and drafting of boilers, exhaust and delivery of high-temperature corrosive gases in chemical plants, air conditioning and ventilation, etc. However, both process industry and ordinary civil fans have the problem of mismatch between operating conditions and design conditions. Although some fan products have high operating efficiency under rated working conditions, the general working conditions do not match the rated working conditions in actual use. This not only results in low efficiency of the fan, but also narrows the range of efficient operation of the fan, which in turn causes stability problems in the operation of the fan. However, the requirements of the places where fans are used are very diverse. It is difficult to achieve mass production if the corresponding fans are designed according to the rated working conditions of the flow requirements of the places where the fans are used. A large number of design studies have confirmed that the use of splitter blades in the inlet section will reduce blade blockage and improve the flow capacity of the impeller. Reasonably setting the splitter blades will shift the maximum efficiency point of the centrifugal fan to the high flow or low flow conditions without reducing the maximum efficiency, and even slightly increasing the maximum efficiency.

Contents of the invention

The purpose of this utility model is to address the deficiencies of the prior art, to provide a centrifugal fan impeller with adjustable splitter blades, the use of splitter blades in the inlet section will reduce the blockage of the blades, improve the flow capacity of the impeller, and the splitter blade adjustment device The angle of the splitter vanes can be adjusted.

The purpose of this utility model is achieved by the following technical solutions:

The utility model comprises a wheel disc, a wheel cover, a main blade, a splitter blade and a splitter blade adjustment device; n pieces of main blades uniformly distributed along the circumference are fixedly arranged between the wheel disc and the wheel cover, and n≥8; A splitter vane is arranged between the main blades; the splitter vane adjusting device includes a total fixed frame, a guide ring, a fixing device on the splitter vane ring, a splitter vane regulator, a fixing device on the splitter vane wheel cover and a splitter vane wheel Fixing device on the disc; the guide ring and the roulette form an epicyclic pair with the central axis of the roulette as the rotation axis; the total fixing frame is fixed on the roulette, and is provided with a guide ring fixing device; The ring is connected with fixing devices on n splitter blade rings evenly distributed along the circumference; the splitter blades are connected with the wheel cover through the fixing device on the splitter blade wheel cover, and connected with the wheel disc through the fixing device on the splitter blade wheel disc; each The fixing device on the ring of the splitter vane is connected with the corresponding fixing device on the wheel disk of the splitter vane through the adjusting part of the splitter vane.

The length of the splitter blade is shorter than that of the main blade; the thickness of the splitter blade gradually decreases from the leading edge to the trailing edge.

The guide ring fixing device is a clamping groove; the guide ring is embedded in the clamping groove, and the clamping groove is provided with bolts for clamping the guide ring.

The fixing device on the splitter blade wheel cover and the fixing device on the splitter blade wheel disc are both nuts and countersunk bolts to cooperate with fasteners; In the countersunk hole of the countersunk bolt of the fixing device. The fixing device on the splitter vane ring is a nut and a bolt cooperating with a fastener. The splitter blade adjusting part is an adjustment rod; one end of the adjustment rod is fixed on the bolt rod of the countersunk bolt in the fixing device on the splitter blade wheel, and the adjustment groove opened at the other end is sleeved on the splitter blade ring and fixed on the bolt shank of the device.

The groove length of the regulating groove is twice the diameter of the bolt rod of the fixing device on the splitter vane ring.

Compared with the prior art, the utility model has the following advantages:

1. The utility model can effectively improve the "jet-wake" structure of the impeller outlet by setting the splitter vanes in the centrifugal fan, thereby improving the flow field, reducing energy consumption, increasing the stability and reliability of operation, and can also be used in To a certain extent, achieve the effect of noise reduction; improve the performance of the centrifugal fan to meet people's growing demand for energy saving and comfort of the fan; the adjustment device corresponding to the splitter blade can effectively and flexibly adjust the splitter blade according to the needs of different working conditions angle to ensure that the centrifugal fan can obtain the highest operating efficiency under rated working conditions under non-rated working conditions; for small centrifugal fans, the structure of long and short blades can significantly improve its manufacturability, and casting instead of welding can Improve the stiffness and strength of the impeller.

2. A reasonable circumferential position of the splitter blade can delay the formation and development of the lateral secondary flow, reduce the degree of pressure diffusion on the suction surface of the blade, and reduce the intensity and scope of the impeller outlet wake.

3. The blockage at the inlet of the blade is reduced; the expansion angle of the blade path is reduced to reduce the separation loss; the slip coefficient is reduced to improve the working ability.

4. The splitter blade can effectively reduce the load of a single blade of the impeller, effectively improve the secondary flow phenomenon inside the impeller, and make more low stagnation pressure fluid flow tend to be normal.

5. Avoid impeller inlet blockage caused by too many long blades and backflow and vortex in the impeller flow channel.

6. The addition of small blades in the part of the wheel channel where deflow and boundary layer separation are prone to occur will add work to the fluid near the outlet of the suction surface, and effectively prevent the occurrence and development of deflow.

7. Adding small blades between the blades of the original impeller can make the wake area at the exit of the impeller broken and smaller, so as to reduce the loss of the fan and improve the stability of the fan flow field.

Description of drawings

Fig. 1 is a perspective view of the overall structure of the utility model;

Fig. 2 is the distribution schematic diagram of main blade and splitter blade in the utility model;

Fig. 3 is the schematic diagram of the diverter blade adjusting device in the utility model;

Fig. 4 is a schematic structural view of the splitter vane in the present invention.

detailed description

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

As shown in FIGS. 1 and 2 , the centrifugal fan impeller with adjustable splitter blades includes a disc 1 , a wheel cover 2 , a main blade 3 , splitter blades 4 and a splitter blade adjustment device 5 . Between the wheel disc 1 and the wheel cover 2, n pieces of main blades 3 uniformly distributed along the circumference are fixedly arranged, n≥8; a splitter blade 4 is arranged between every two adjacent main blades 3; the splitter blade adjustment device 5 is used to adjust the splitter flow Blades 4 angles.

As shown in Figure 3, the splitter vane adjustment device 5 includes a total fixed frame 5-1, a guide ring 5-2, a fixing device 5-3 on the splitter vane ring, a splitter vane adjustment member 5-4, and a splitter vane wheel cover. The fixing device 5-5 and the fixing device 5-6 on the splitter vane disc. The guide ring 5-2 and the wheel disc 1 form an epicyclic pair with the center axis of the wheel disc as the rotation axis; the total fixed frame 5-1 is fixed on the wheel disc 1, and is provided with a guide ring fixing device. The guide ring 5-2 is connected with n splitter vane ring upper fixing devices 5-3 evenly distributed along the circumference; They are connected through the fixing device 5-6 on the splitter vane wheel; the fixing device 5-3 on each splitter vane ring is connected with the corresponding fixing device 5-6 on the splitter vane wheel through the splitter blade adjustment part 5-4.

The guide ring fixing device is a clamping groove; the guide ring 5-2 is embedded in the clamping groove, and the guide ring 5-2 can be fixed by tightening the bolts on the clamping groove.

The fixing device 5-5 on the splitter blade wheel cover and the fixing device 5-6 on the splitter blade wheel disc are both nuts and countersunk bolts to cooperate with fasteners; the two sides of the splitter blade 4 are respectively embedded in the splitter blade wheel cover. 5 and in the countersunk holes of the countersunk bolts of the fixture 5-6 on the splitter blade wheel disc. The fixing device 5-3 on the splitter vane ring is a nut and bolt cooperating fastener. The splitter blade adjustment part 5-4 is an adjustment rod; one end of the adjustment rod is fixed on the bolt rod of the countersunk bolt in the fixing device 5-6 on the splitter blade disc, and the adjustment groove opened at the other end is sleeved on the splitter blade circle. On the bolt shank of the fixing device 5-3 on the ring; the groove length of the adjusting groove is 2 times of the diameter of the bolt shank of the fixing device 5-3 on the splitter vane ring.

As shown in Figures 2 and 4, the length of the splitter blade is shorter than the length of the main blade 3; the thickness of the splitter blade gradually decreases from the leading edge to the trailing edge.

The working principle of the centrifugal fan impeller with adjustable splitter vanes is as follows:

Adjust the angle of the splitter vane according to the requirements of different working conditions of the centrifugal fan, so as to obtain the highest operating efficiency for different working conditions. The highest operating efficiency here refers to the efficiency of the centrifugal fan at the rated operating point. That is to say, the existence of the splitter blade adjustment device can ensure that the centrifugal fan can obtain the highest operating efficiency under the rated working condition even under the non-rated working condition, so as to achieve a better expansion and stability effect.

As shown in FIG. 3 , the angle of the splitter vane can be adjusted by rotating the guide ring 5-2 according to the working conditions of the centrifugal fan, and the splitter vane regulator 5-4 swings with the guide ring 5-2. After the angle of the splitter vanes is adjusted according to the requirements of the working conditions of the centrifugal fan, the guide ring 5-2 is first fixed by the general fixing frame 5-1, and then the corresponding splitter is divided by the nuts of the fixing device 5-3 on each splitter vane ring. The blades are fixed, and finally the corresponding splitter blades are further fixed by the nuts of the fixing device 5-5 on the splitter blade wheel cover.

Adding splitter blades 4 between adjacent main blades 3 can break and reduce the wake region at the exit of the impeller, thereby reducing fan losses and improving the stability of the fan flow field.

The splitter blade can reduce the blockage at the blade inlet; reduce the expansion angle of the blade passage to reduce the separation loss, reduce the slip coefficient and improve the working ability. For the backward impeller, under a certain number of blades, the decrease of the length of the short blades will move the highest efficiency point to the direction of small flow; the change of the relative installation angle of the short blades has a great influence on the pressure, especially when the relative installation angle is positive , the magnitude of the pressure drop is large; the relative installation angle has little effect on the efficiency, but changes the highest efficiency point, making it move to the direction of small flow. Therefore, the highest operating efficiency can be obtained according to different working conditions. The highest operating efficiency here refers to the efficiency of the centrifugal fan at the rated operating point. That is to say, the existence of the splitter blade adjustment device can ensure that the centrifugal fan can obtain the highest operating efficiency under the rated working condition even under the non-rated working condition, so as to achieve a better expansion and stability effect.

Claims (5)

1. The impeller of the centrifugal fan with adjustable splitter blades comprises a wheel disc, a wheel cover, a main blade and a splitter vane, and is characterized in that: it also includes a splitter blade adjustment device; the fixed arrangement between the wheel disc and the wheel cover is uniform along the circumference. n pieces of main blades are distributed, n≥8; a splitter blade is arranged between every two adjacent main blades; The blade regulator, the fixing device on the wheel cover of the splitter blade and the fixing device on the wheel disc of the splitter blade; the guide ring and the wheel disc constitute an epicyclic pair with the central axis of the disc as the rotation axis; the total fixing frame is fixed on On the wheel disc, there is a guide ring fixing device; the guide ring is connected with n splitter blade ring fixing devices uniformly distributed along the circumference; the splitter blade and the wheel cover are connected by the splitter vane wheel cover fixing device , and the wheel disc is connected through the fixing device on the splitter blade wheel disc; the fixing device on the ring of each splitter vane is connected with the corresponding fixing device on the splitter vane wheel disc through the splitter blade adjustment piece. 2. The centrifugal fan impeller with adjustable splitter blades according to claim 1, characterized in that: the length of the splitter blades is shorter than the length of the main blades; the thickness of the splitter blades gradually decreases from the leading edge to the trailing edge. 3. The centrifugal fan impeller with adjustable splitter blades according to claim 1, characterized in that: the guide ring fixing device is a clamping groove; the guide ring is embedded in the clamping groove, and the clamping groove is provided with There are bolts to clamp the guide ring. 4. The centrifugal fan impeller with adjustable splitter blades according to claim 1, characterized in that: the fixing device on the splitter blade wheel cover and the fixing device on the splitter blade wheel disc are both nuts and countersunk bolts. Firmware; the two sides of the splitter blade are respectively embedded in the countersunk bolt countersunk holes of the fixing device on the splitter blade wheel cover and the fixing device on the splitter blade disc; the fixing device on the splitter blade ring is a nut and bolt matching fastener; The splitter blade adjusting part is an adjustment rod; one end of the adjustment rod is fixed on the bolt rod of the countersunk bolt in the fixing device on the splitter blade wheel, and the adjustment groove opened at the other end is sleeved on the splitter blade ring and fixed on the bolt shank of the device. 5 . The centrifugal fan impeller with adjustable splitter vanes according to claim 4 , wherein the length of the adjustment groove is twice the diameter of the bolt rod of the fixing device on the splitter vane ring. 6 .