CN208024581U - Centrifugal blower and roof machine - Google Patents

Abstract

The utility model provides a kind of centrifugal blower and roof machine, wherein centrifugal blower includes：Spiral case, spiral case is interior to be equipped with air-out passage, and the port of air-out passage is air outlet；Impeller is arranged in spiral case；With at least one windshied part, at least a side of air outlet is covered, and extend to the center position of air outlet.The utility model at the air outlet of spiral case by being arranged at least one windshied part, the side of air outlet is blocked by windshied part and is extended to the central area of air outlet, the large scale of air-flow in air-out passage can be vortexed and be destroyed, reduce eddy size, reduce voorticity, so that air-flow is when reaching air outlet position, will not suddenly it increase because of the sectional area of air-flow, vortex center changes, and the air-flow for the vortex of different scale occur the phenomenon that mutually colliding, reduce the pressure loss, effectively eliminate surge phenomenon, improve the total head and efficiency of wind turbine, reduce noise.

Description

Centrifugal blower and roof machine

Technical field

The utility model is related to ventilation equipment technical fields, in particular to a kind of centrifugal blower and a kind of roof machine.

Background technology

Currently, centrifugal blower on the market, as shown in Figure 1, including spiral case, impeller and the air outlet being opened on spiral case, Easily there is surge phenomenon in centrifugal blower, and especially when the static pressure of centrifugal blower is in 0Pa~100Pa, air-flow static pressure can be each The static pressure point of setting fluctuates up and down, and flow is fluctuated, causes complete machine to send out the grand sound that rumbles, and easily wind turbine is caused to damage It is bad.

Utility model content

The utility model aims to solve at least one of technical problems existing in the prior art or related technologies.

For this purpose, the one side of the utility model proposes a kind of centrifugal blower.

The other side of the utility model proposes a kind of roof machine.

In view of this, one side according to the present utility model, provides a kind of centrifugal blower, including：Spiral case, in spiral case Equipped with air-out passage, the port of air-out passage is air outlet；Impeller is arranged in spiral case；With at least one windshied part, cover out At least a side in air port, and extend to the center position of air outlet.

The utility model covers outlet air by the way that at least one windshied part is arranged at the air outlet of spiral case by windshied part The side of mouth simultaneously extends to the central area of air outlet.On the one hand the large scale of air-flow in air-out passage can be vortexed and is destroyed Fall, that is, stops that the flowing inside spiral case in the air-flow of most peripheral, reduces eddy size, reduces voorticity, effectively reduce energy Loss improves the total head and efficiency of wind turbine, reduces noise；On the other hand air-flow can be avoided to reach at the air outlet of spiral case, by It accumulates in flow area and increases suddenly, eddy size increases, and vortex center position changes, and caused different directions are not synchronized The fluid of degree mutually blend and caused by the pressure loss, static pressure fluctuation can be reduced, effectively eliminate surge phenomenon, avoid centrifugation wind Machine is damaged because of surge, extends the service life of centrifugal blower.In addition, passing through windshied part shield portions air outlet, additionally it is possible to anti- Only airflow reflux further avoids surge phenomenon occur.

In addition, each windshied part can only cover a side of air outlet, multiple sides of air outlet can be also covered simultaneously. It, can be by multiple windshied parts for the position of multiple sides of air outlet when each windshied part only covers a side of air outlet It is configured, improves the precision of assembly；When each windshied part can cover multiple sides of air outlet, such as when windshied part is in When L-type or hollow, windshied part can cover simultaneously air outlet two sides or four sides so that primary assembly can will be kept off Wind portion is arranged in place.

In addition, according to the centrifugal blower in above-mentioned technical proposal provided by the utility model, can also have following additional Technical characteristic：

In any of the above-described technical solution, it is preferable that at least one windshied part, one of windshied part is covered in outlet air At the outer side edges of mouth, the outer side edges of air outlet are the side of the center line far from impeller.

In the technical scheme, the number of windshied part can be for one or multiple, and at least there is a windshied part It is covered at the outer side edges of separate impeller of air outlet.Due to the air-flow vortex flowing in spiral case, and further away from the side of impeller The scale of vortex is bigger, and then when air-flow reaches at the air outlet of spiral case, increases suddenly since flow area accumulates, eddy size Increase, vortex center position changes, and the air-flow of caused different directions friction speed mutually blends, and causes greatly to press Power is lost, and surge occurs.And the utility model can effectively destroy spiral case by the way that windshied part is arranged at the outer side edges of air outlet Interior large scale is vortexed, and reduces eddy size, reduces voorticity, reduces static pressure fluctuation, avoids the generation of surge, and reduce energy Amount loss, improves blower press and efficiency, reduces rotational noise.

In any of the above-described technical solution, it is preferable that the number of windshied part is two, and other in which windshied part is covered in At the inner side edge of air outlet, the outer side edges of air outlet are the side of the center line far from impeller.

In the technical scheme, preferably the number of windshied part is two.When the number of windshied part is two, it is covered each by The inner side edge and outer side edges of air outlet, and then the large scale that can destroy spiral case interior air-flow is vortexed and microvortex rotation, reduces whirlpool Revolve intensity so that air-flow will not suddenly increase when reaching air outlet position because of the sectional area of air-flow, and vortex center occurs Variation, and the phenomenon that the air-flow for the vortex of different scale occur mutually collides, reduce the pressure loss, reduces static pressure fluctuation, to Surge is effectively eliminated, fan efficiency is improved.Certainly, the number that may also set up windshied part is four, is covered each by the four of air outlet A side can circumferentially destroy the vortex of spiral case interior air-flow, voorticity be reduced, to reduce pressure of the air-flow at air outlet Loss reduces static pressure fluctuation, avoids the occurrence of surge.

In any of the above-described technical solution, it is preferable that the number of windshied part is two, is covered each by the upper side edge of air outlet And at lower side, the upper side edge of air outlet is when the center line of impeller is vertically extending, and the side of air outlet being located above goes out The lower side in air port is the underlying side of air outlet when the center line of impeller is vertically extending.

In the technical scheme, two windshied parts can be also respectively overlay in the upper and lower side edge of air outlet, and then each Windshied part can relatively evenly destroy multiple dimensioned vortex, reduce voorticity, reduce energy loss, reduce static pressure fluctuation, effectively Eliminate surge phenomenon.

In any of the above-described technical solution, it is preferable that the side edge of air outlet of the windshied part where it is to air outlet The length that center position extends is length of keeping out the wind, and whole windshied parts on the side and another side on the other side are arranged It keeps out the wind the sum of length, accounts for the 2% to 6% of the length perpendicular to the side directions of air outlet.

In the technical scheme, when windshied part is arranged in a side of air outlet, and when the setting of another windshied part exists When in a side corresponding with the side, the sum of length of keeping out the wind of two windshied parts account for the 2% of the spacing of the two sides to 6%；And when windshied part is arranged in a side of air outlet, and when a side on the other side is not covered with windshied part, cover The length of keeping out the wind of the windshied part of lid side just accounts for the 2% to 6% of the spacing of two sides.By limiting any along air outlet The extending direction of side, when being blocked there are windshied part, the sum of length of keeping out the wind of whole windshied parts accounts for the 2% of the length of the side To 6%, the length that on the one hand windshied part can be avoided to stretch into inside air outlet is long and seriously affects air output, another aspect energy Surge is enough effectively eliminated, the eddy airstream to circulate along the side is destroyed, voorticity is reduced, to reduce air-flow at air outlet The pressure loss, reduce static pressure fluctuation, improve the operational efficiency of wind turbine.For example, when two windshied parts are covered each by air outlet Outer side edges and inner side edge and when extending to the center position of air outlet, the sum of length of keeping out the wind of two windshied parts accounts for the width of air outlet The 2% to 6% of degree；And when a windshied part covers the upper side edge of air outlet and extends to the center position of air outlet, and go out When being covered without windshied part on the lower side in air port, the length of keeping out the wind of a windshied part accounts for the 2% to 6% of the height of air outlet.

In any of the above-described technical solution, it is preferable that windshied part is soft weather strip or hard wind shield.

In the technical scheme, windshied part can be for soft weather strip, also can easily be the wind shield of hard, soft gear Wind item and hard wind shield are also different to the destructive power of the air-flow of vortex, can suitably be selected as needed.Preferably, Windshied part is the plastics gusset of hard.

In any of the above-described technical solution, it is preferable that windshied part to the center position of air outlet extend a side be in Linear or waveform or zigzag.

In the technical scheme, a side of windshied part extended to the center position of air outlet, both can be linear, Can undulate or zigzag, different shapes is also different to the destructive power of the vortex of air-flow, can according to actual needs, example Such as the diameter of impeller, air force etc. selects the windshied part of appropriate configuration.In addition, institute of the windshied part from side where it It is extending to the center position of air outlet away from windshied part with the side in the length that position extends to the center position of air outlet The distance between a side subject to, when a side of windshied part extended to the center position of air outlet is waveform or sawtooth When shape, length that windshied part side position where it extends to the center position of air outlet means being averaged between the two Length.

In any of the above-described technical solution, it is preferable that at least one windshied part is mounted on the flange at air outlet；Or extremely A few windshied part is integrally formed with spiral case.

In the technical scheme, it is provided with flange at air outlet, convenient for the air outlet of wind turbine is directed at peace with other component Dress.At least one windshied part is mounted on the flange at air outlet, is on the one hand convenient for Assembly And Disassembly, is on the other hand also allowed for straight See the length that ground control windshied part extends to the central area of air outlet.At least one windshied part can also with spiral case one at Type at this point, at least one windshied part is located at the edge of air-out passage, and bends to the central area of air outlet, is kept out the wind with being formed Portion to control the length that windshied part after bending extends to the central area of air outlet, is not necessarily to by the length of reserved windshied part Additional configuration windshied part uses manpower and material resources sparingly without additional assembly windshied part.

The another aspect of the utility model proposes a kind of roof machine, including：As any one of above-mentioned technical proposal from Heart wind turbine.

The utility model proposes roof machine, due to the centrifugal blower with any one of above-mentioned technical proposal, and then have The advantageous effect for having any of the above-described technical solution, does not repeat one by one herein.

In the above-mentioned technical solutions, it is preferable that roof machine further includes：Shell, enclosure interior are equipped with indoor cavity and room Side inside cavity indoors is arranged in outboard chambers, centrifugal blower.

In the technical scheme, the indoor side chamber in shell can be arranged in the centrifugal blower in any of the above-described technical solution In body, naturally it is also possible to it is arranged in the cavity of outside, or is arranged simultaneously in side chamber body and outside cavity indoors, it can basis It needs to install centrifugal blower in place.In addition, roof machine further includes evaporator, condenser, compressor etc..

The additional aspect and advantage of the utility model will become apparent in following description section, or new by this practicality The practice of type is recognized.

Description of the drawings

The above-mentioned and/or additional aspect and advantage of the utility model will in the description from combination following accompanying drawings to embodiment Become apparent and is readily appreciated that, wherein：

Fig. 1 shows the structural schematic diagram of centrifugal blower in the related technology；

Fig. 2 shows the structural schematic diagrams of the centrifugal blower of one embodiment of the utility model；

Fig. 3 shows the structural schematic diagram of the windshied part of one embodiment of the utility model；

Fig. 4 shows the structural schematic diagram of the windshied part of second embodiment of the utility model；

Fig. 5 shows the structural schematic diagram of the windshied part of the third embodiment of the utility model.

Wherein, the correspondence in Fig. 1 between reference numeral and component names is：

12 ' spiral cases, 122 ' air outlets, 16 ' impellers；

Correspondence in Fig. 2 to Fig. 5 between reference numeral and component names is：

12 spiral cases, 122 air outlets, 14 windshied parts, 16 impellers, H：It keeps out the wind length.

Specific implementation mode

In order to be more clearly understood that the above objects, features, and advantages of the utility model, below in conjunction with the accompanying drawings and have The utility model is further described in detail in body embodiment.It should be noted that in the absence of conflict, this Shen The feature in embodiment and embodiment please can be combined with each other.

Many details are elaborated in the following description in order to fully understand the utility model, still, this practicality Novel to be implemented different from other modes described here using other, therefore, the scope of protection of the utility model is simultaneously It is not limited by following public specific embodiment.

Referring to Fig. 2 to Fig. 5 descriptions according to the centrifugal blower and roof machine described in the utility model some embodiments.

As shown in Fig. 2, the one side embodiment of the utility model provides a kind of centrifugal blower, including：Spiral case 12, snail Air-out passage is equipped in shell 12, the port of air-out passage is air outlet 122；Impeller 16 is arranged in spiral case 12；With it is at least one Windshied part 14 covers at least a side of air outlet 122, and extends to the center position of air outlet 122.

The utility model passes through windshied part 14 by the way that at least one windshied part 14 is arranged at the air outlet 122 of spiral case 12 It covers the side of air outlet 122 and extends to the central area of air outlet 122.It on the one hand can be by air-flow in air-out passage Large scale vortex destroys, that is, stops that the flowing inside spiral case 12 in the air-flow of most peripheral, reduces eddy size, it is strong to reduce vortex Degree, effectively reduces energy loss, improves the total head and efficiency of wind turbine, reduces noise；On the other hand air-flow can be avoided to reach snail At the air outlet 122 of shell 12, increase suddenly since flow area accumulates, eddy size increases, and vortex center position changes, institute The fluid for the different directions friction speed brought mutually blend and caused by the pressure loss, static pressure fluctuation can be reduced, effectively disappeared Except surge phenomenon, centrifugal blower is avoided to be damaged because of surge, extends the service life of centrifugal blower.In addition, passing through windshied part 14 Shield portions air outlet 122, additionally it is possible to prevent airflow reflux, further avoid surge phenomenon occur.

In addition, each windshied part 14 can only cover a side of air outlet 122, air outlet 122 can be also covered simultaneously Multiple sides.When each windshied part 14 only covers a side of air outlet 122, multiple windshied parts 14 can be directed to air outlet The position of 122 multiple sides is configured, and improves the precision of assembly；When each windshied part 14 can cover air outlet 122 When multiple sides, such as when windshied part 14 is L-shaped or hollow, windshied part 14 can cover two sides of air outlet 122 simultaneously Side or four sides so that windshied part 14 can be arranged in place for primary assembly.

In one embodiment of the utility model, it is preferable that at least one windshied part 14, one of windshied part 14 It is covered at the outer side edges of air outlet 122, the outer side edges of air outlet 122 are the side of the center line far from impeller 16.

In this embodiment, the number of windshied part 14 can be for one or multiple, and at least there is a windshied part 14 are covered at the outer side edges of separate impeller 16 of air outlet 122.Due to the air-flow vortex flowing in spiral case 12, and further away from leaf The scale that the side of wheel 16 is vortexed is bigger, and then when air-flow reaches at the air outlet 122 of spiral case 12, since flow area product is prominent So increase, eddy size increases, and vortex center position changes, and the air-flow of caused different directions friction speed is mutually mixed It is mixed, the great pressure loss is caused, surge occurs.And the utility model is kept out the wind by being arranged at the outer side edges of air outlet 122 Portion 14, the large scale that can effectively destroy in spiral case 12 are vortexed, and reduce eddy size, reduce voorticity, reduce static pressure fluctuation, The generation of surge is avoided, and reduces energy loss, improves blower press and efficiency, reduces rotational noise.

In one embodiment of the utility model, it is preferable that the number of windshied part 14 is two, and other in which is kept out the wind Portion 14 is covered at the inner side edge of air outlet 122, and the inner side edge of air outlet 122 is close to the side of the center line of impeller 16.

In this embodiment, preferably the number of windshied part 14 is two.When the number of windshied part 14 is two, cover respectively The inner side edge and outer side edges of lid air outlet 122, and then the large scale that can destroy 12 interior air-flow of spiral case is vortexed and microvortex rotation, Reduce voorticity so that air-flow will not suddenly increase, whirlpool when reaching 122 position of air outlet because of the sectional area of air-flow The phenomenon that air-flow that rotation center changes, and the vortex of different scale occurs mutually collides reduces the pressure loss, reduces static pressure Fluctuation improves fan efficiency to effectively eliminate surge.Certainly, the number that may also set up windshied part 14 is four, is covered each by Four sides of air outlet 122 can circumferentially destroy the vortex of 12 interior air-flow of spiral case, voorticity be reduced, to reduce air-flow The pressure loss at air outlet 122 reduces static pressure fluctuation, avoids the occurrence of surge.

In one embodiment of the utility model, it is preferable that as shown in Fig. 2, the number of windshied part 14 is two, respectively At the upper side edge and lower side for covering air outlet 122, wherein the upper side edge of air outlet 122 is when the center line of impeller 16 is vertical When extension, the lower side of the side of air outlet 122 being located above, air outlet 122 is when the center line of impeller 16 is vertically extending When, the underlying side of air outlet 122.

In this embodiment, two windshied parts 14 can be also respectively overlay in the upper and lower side edge of air outlet 122, in turn Each windshied part 14 can relatively evenly destroy multiple dimensioned vortex, reduce voorticity, reduce energy loss, reduce static pressure wave It is dynamic, effectively eliminate surge phenomenon.

Table 1 shows without windshied part 14 at the air outlet 122 of wind turbine, and respectively the upper side edge of air outlet 122 and under Side be respectively provided with keep out the wind length H be 5mm windshied part 14 static pressure fluctuation situation：

Table 1：

Static pressure (Pa)	Air quantity (CFM)	Power (W)	Static pressure fluctuation range (Pa)	Air quantity/power	Remarks
						60	2385	760	45-80	3.14	Without windshied part
60	2356	751	59-61	3.14	Upper and lower both sides add windshied part

Wherein, static pressure indicates the setting static pressure of wind turbine, can intuitively be obtained by table 1, and it is keeping out the wind for 5mm that length of keeping out the wind, which is arranged, Portion 14, the influence very little to air quantity, can but be greatly lowered the fluctuation of decompression, keep air-flow static pressure relatively stable, and then effectively keep away Exempt from the appearance of surge.

In one embodiment of the utility model, it is preferable that as shown in Fig. 2, air outlet of the windshied part 14 where it The length that 122 side edge extends to the center position of air outlet 122 is the length H that keeps out the wind, and setting is in the side and in contrast Another side on whole windshied parts 14 the sum of the length H that keeps out the wind, account for the length perpendicular to the side directions of air outlet 122 2% to 6%.

In this embodiment, when windshied part 14 is arranged in a side of air outlet 122, and when another windshied part 14 is set It sets when in a side corresponding with the side, the sum of length of keeping out the wind of two windshied parts 14 accounts for the spacing of the two sides 2% to 6%；And when windshied part 14 is arranged in a side of air outlet 122, and a side on the other side is not covered with gear When wind portion 14, cover the windshied part 14 of side the length H that keeps out the wind just account for two sides spacing 2% to 6%.Pass through restriction Extending direction along any side of air outlet 122, when being blocked there are windshied part 14, the length H that keeps out the wind of whole windshied parts 14 The sum of account for the side length 2% to 6%, the length that on the one hand windshied part 14 can be avoided to stretch into inside air outlet 122 is spent It grows and seriously affects air output, on the other hand can effectively eliminate surge, destroy the eddy airstream to circulate along the side, reduce whirlpool Intensity is revolved, to reduce the pressure loss of the air-flow at air outlet 122, static pressure fluctuation is reduced, improves the operational efficiency of wind turbine.

For example, the width of the air outlet of wind turbine is 324mm, two windshied parts that length is 5mm that keep out the wind are set and are covered in out The inside and outside side edge in air port, at this point, the sum of length of keeping out the wind of two windshied parts accounts for the 3.1% of air outlet width；Certainly, also may be used Two windshied parts that length are 8mm that keep out the wind are set and are covered in the inside and outside side edge of air outlet, at this point, two windshied parts keep out the wind The sum of length accounts for the 4.9% of air outlet width.The extending direction of the width direction of air outlet and the center line of impeller is perpendicular.

In one embodiment of the utility model, it is preferable that windshied part 14 is soft weather strip or hard wind shield.

In this embodiment, windshied part 14 can be for soft weather strip, also can easily be the wind shield of hard, soft gear Wind item and hard wind shield are also different to the destructive power of the air-flow of vortex, can suitably be selected as needed.Preferably, Windshied part 14 is the plastics gusset of hard.

In one embodiment of the utility model, it is preferable that as shown in Figures 3 to 5, windshied part 14 to air outlet A side that 122 center position extends is linear or waveform or zigzag.

In this embodiment, a side of windshied part 14 extended to the center position of air outlet 122, both can be linear Shape, also can undulate or zigzag, different shapes is also different to the destructive power of the vortex of air-flow, can be according to practical need Want, for example, impeller 16 diameter, air force etc. selects the windshied part 14 of appropriate configuration.In addition, windshied part 14 is from its institute It is away from windshied part 14 with the side to outlet air in the length that the position of side extends to the center position of air outlet 122 Subject to the distance between a side that the center position of mouth 122 extends, when prolonging to the center position of air outlet 122 for windshied part 14 When a side stretched is waveform or zigzag, windshied part 14 where it side position to the center side of air outlet 122 Mean average length between the two to the length of extension.

In one embodiment of the utility model, it is preferable that at least one windshied part 14 is mounted at air outlet 122 On flange；Or at least one windshied part 14 is integrally formed with spiral case 12.

In this embodiment, it is provided with flange at air outlet 122, be convenient for the air outlet 122 of wind turbine and other component pair Quasi- installation.At least one windshied part 14 is mounted on the flange at air outlet 122, is on the one hand convenient for Assembly And Disassembly, another party Face also allows for intuitively controlling the length that windshied part 14 extends to the central area of air outlet 122.At least one windshied part 14 It can be integrally formed with spiral case 12, at this point, at least one windshied part 14 is located at the edge of air-out passage, and to air outlet 122 Central area is bent, to form windshied part 14, by the length of reserved windshied part 14, to control after bending windshied part 14 to going out The length that the central area in air port 122 extends is saved without additional configuration windshied part 14 without additional assembly windshied part 14 Manpower and materials.

The another aspect embodiment of the utility model proposes a kind of roof machine, including：Such as any one of above-described embodiment Centrifugal blower.

The utility model proposes roof machine, due to the centrifugal blower with any one of above-described embodiment, and then have The advantageous effect of any of the above-described embodiment, does not repeat one by one herein.

In one embodiment of the utility model, it is preferable that roof machine further includes：Shell, enclosure interior are equipped with interior Side inside cavity indoors is arranged in side chamber body and outside cavity, centrifugal blower.

In this embodiment, the indoor cavity in shell can be arranged in the centrifugal blower in any of the above-described embodiment In, naturally it is also possible to it is arranged in the cavity of outside, or is arranged simultaneously in side chamber body and outside cavity indoors, it can be according to need Centrifugal blower is installed in place.In addition, roof machine further includes evaporator, condenser, compressor etc..

In the present invention, term " multiple " then refers to two or more, unless otherwise restricted clearly.Term The terms such as " installation ", " connected ", " connection ", " fixation " shall be understood in a broad sense, for example, " connection " may be a fixed connection, Can be detachably connected, or be integrally connected；" connected " can be directly connected, and can also pass through the indirect phase of intermediary Even.For the ordinary skill in the art, it can understand above-mentioned term in the present invention as the case may be Concrete meaning.

In the description of this specification, the description of term " one embodiment ", " some embodiments ", " specific embodiment " etc. Mean that particular features, structures, materials, or characteristics described in conjunction with this embodiment or example are contained at least the one of the utility model In a embodiment or example.In the present specification, schematic expression of the above terms are not necessarily referring to identical embodiment Or example.Moreover, the particular features, structures, materials, or characteristics of description can be in any one or more embodiments or example In can be combined in any suitable manner.

The above descriptions are merely preferred embodiments of the present invention, is not intended to limit the utility model, for this For the technical staff in field, various modifications and changes may be made to the present invention.It is all in the spirit and principles of the utility model Within, any modification, equivalent replacement, improvement and so on should be included within the scope of protection of this utility model.

Claims (10)

1. a kind of centrifugal blower, which is characterized in that including：

Spiral case, the spiral case is interior to be equipped with air-out passage, and the port of the air-out passage is air outlet；

Impeller is arranged in the spiral case；With

At least one windshied part covers at least a side of the air outlet, and extends to the center position of the air outlet.

2. centrifugal blower according to claim 1, which is characterized in that

In at least one windshied part, one of them described windshied part is covered at the outer side edges of the air outlet, it is described go out The outer side edges in air port are the side of the center line far from the impeller.

3. centrifugal blower according to claim 2, which is characterized in that

The number of the windshied part is two, and windshied part described in other in which is covered in the inner side edge of the air outlet Place, the inner side edge of the air outlet are the side of the center line close to the impeller.

4. centrifugal blower according to claim 1, which is characterized in that

The number of the windshied part is two, is covered each by the upper side edge and lower side of the air outlet, the air outlet Upper side edge is the side of the air outlet being located above when the center line of the impeller is vertically extending, the air outlet Lower side is the underlying side of the air outlet when the center line of the impeller is vertically extending.

5. centrifugal blower according to any one of claim 1 to 4, which is characterized in that

The length that the side edge of the air outlet of the windshied part where it extends to the center position of the air outlet is Keep out the wind length, length of keeping out the wind described in the whole windshied part being arranged on the side and another side on the other side it With account for the 2% to 6% of the length perpendicular to the side directions of the air outlet.

6. centrifugal blower according to any one of claim 1 to 4, which is characterized in that

The windshied part is soft weather strip or hard wind shield.

7. centrifugal blower according to any one of claim 1 to 4, which is characterized in that

The windshied part extend to the center position of the air outlet a side is linear or waveform or zigzag.

8. centrifugal blower according to any one of claim 1 to 4, which is characterized in that

At least one windshied part is mounted on the flange at the air outlet；Or

At least one windshied part is integrally formed with the spiral case.

9. a kind of roof machine, which is characterized in that including：

Such as centrifugal blower described in any item of the claim 1 to 8.

10. roof machine according to claim 9, which is characterized in that the roof machine further includes：

Shell, the enclosure interior are equipped with indoor cavity and outside cavity, and the centrifugal blower is arranged in the indoor Inside cavity.