Energy-saving durable single-machine double-impeller tunnel ventilator

Abstract

The utility model discloses an energy-saving durable single-machine double-impeller tunnel ventilator, and relates to the technical field of tunnel ventilators. The double-shaft-extension motor is arranged in the machine shell assembly, and an annular flow guide channel is defined between the outer circumferential wall of a machine shell of the double-shaft-extension motor and the inner circumferential wall of the machine shell assembly. The first-stage impeller and the second-stage impeller are correspondingly mounted at the two ends of a rotating shaft of the double-shaft-extension motor; the first-stage guide vane is arranged in the annular flow guide channel; one end of the first-stage guide vane is close to the first-stage impeller and is bent into an arc shape to correspond to the air outlet direction of the first-stage impeller, and the other end axially extends along the parallel annular flow guide channel to be close to the second-stage impeller; the air inlet silencer is connected with a barrel opening in one end of the machine shell assembly; the air outlet silencer is connected with a barrel opening in the other end of the machine shell assembly; and the second-stage guide vane is arranged in the air outlet silencer. The air flow path can be optimized, the efficiency of the fan is improved, the energy consumption is reduced, the operation noise and vibration are reduced, and the service life is further prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of tunnel ventilator, especially to energy -conserving durable single -machine double -impeller tunnel ventilator. BACKGROUND

[0002] Traditional single -machine single -impeller axial flow fan because of the small air flow pressure, lead to energy loss, low efficiency, not applicable to long tunnel ventilation operation demand.

[0003] The existing single -machine double -impeller fan blade and guide vane spacing is compact, guide vane leading edge rear edge radius is too small, arc length distribution is too short, will affect the air flow interference problem, will produce wind flow vortex, influence double -impeller collaborative work problem, will lead to secondary flow loss, wind flow vortex can directly influence secondary impeller collaborative operation, can weaken the air volume and pressure. Fan inlet and outlet are without flow guide cover one, horn mouth, performance can weaken, lead to the overall fan performance weak, low efficiency;Air flow is chaotic due to lack of directional guidance, mainly performance vortex, backflow and pressure gradient imbalance problem;The horn mouth and the absence of flow guide cover one lead to the air flow at the fan inlet and outlet and the surrounding air mixing, boundary layer thickening, local resistance increases, air flow direction is chaotic, influence overall flow field stability. For example, without flow guide cover one, under the action of rotating air flow separation, the high -speed air flow thrown out by the impeller is easy to form separation vortex at the edge due to lack of constraint, aggravate energy loss;Vortex and backflow lead to the actual air volume of fan reduces, pressure loss increases, axial flow fan without taper air flow channel can make efficiency reduce;The fan is insufficient due to the lack of flow, the air outlet velocity is uneven, effective wind pressure will drop;Vortex induces high -frequency noise, air flow impact guide ring or impeller can produce low -frequency vibration;Fan support leg is installed in the cylinder rather than flange place can lead to the support structure stiffness is insufficient, vibration transmission path is unreasonable, vibration energy can not be effectively dispersed, lead to the cylinder becomes vibration amplifier and aggravates vibration, long -term operation is easy to lead to structural fatigue.

[0004] Therefore, how to provide energy -conserving durable single -machine double -impeller tunnel ventilator, can optimize the air flow path, improve fan efficiency, reduce energy consumption, reduce operation noise and vibration, and further improve the service life is the problem that the person skilled in the art needs to solve. UTILITY MODEL CONTENT

[0005] Therefore, the utility model provides an energy -conserving durable single machine double -impeller tunnel ventilator, it is in order to solve the above -mentioned traditional single machine double -impeller fan because the flow guide structure design is unreasonable, airflow direction is disorderly and leads to high energy consumption, low efficiency, big noise and vibration, short service life technical problem. The utility model discloses a single motor double -shaft extension simultaneously drive two -stage impeller rotation realizes airflow superposition and energy superposition, combines pneumatic optimization and strength design, noise reduction design, makes its whole ventilation performance enhancement, improves equipment service life simultaneously, makes the fan reach energy -conserving emission reduction, cost performance is high and durable, is suitable for long big tunnel etc. High pressure, large air volume, low noise, super long standby operation scene.

[0006] In order to realize the above-mentioned purpose, the utility model adopts the following technical scheme:

[0007] The utility model provides an energy -conserving durable single machine double -impeller tunnel ventilator, including:

[0008] The shell assembly is cylindrical.

[0009] The double-shaft extension motor is coaxially arranged in the shell assembly.

[0010] The primary impeller and the secondary impeller are located in the shell assembly and are one-to-one corresponding installed at the both ends of the rotating shaft of the double-shaft extension motor.

[0011] The primary guide vane is arranged in the annular flow guide channel.

[0012] The inlet silencer is coaxially connected and communicated with one end of the shell assembly and corresponds to the primary impeller.

[0013] The secondary guide vane is installed in the outlet silencer and is arranged close to the other end of the shell assembly.

[0014] The utility model discloses an energy -conserving durable single machine double -impeller tunnel ventilator, adopts single motor double -shaft extension double -impeller, simultaneously carries double static guide vane, passes through double -impeller, double guide vane and the inlet and outlet vent silencer design promotes ventilation volume, reduces the vibration noise, optimizes double -impeller cooperation mode, can promote overall efficiency, reduces energy consumption, has strengthened the service life. Among them, the first guide vane has carried out the lengthened design, and its both ends extend close to to link the corresponding first impeller and second impeller, and the first guide vane is arc curved to smooth transition guide the airflow of first impeller output one end corresponding first impeller, reduces airflow separation through curved surface transition, and the other end of first guide vane guides airflow along annular flow channel axial and is transported to second impeller, realizes the double promotion of airflow uniformity and operating stability, and further improves the flow, reduces the wind resistance and vibration, prolongs the service life. In order to further reduce noise and vibration, the inlet and outlet vent silencer is arranged at both ends of the casing assembly, the airflow output by the second guide vane orderly enters the outlet vent silencer, which can significantly reduce noise, further reduce energy consumption and improve efficiency.

[0015] As a further improvement of the above technical solution, it further comprises an inlet horn and an outlet horn; the outlet end of the inlet horn is coaxially connected and communicated with the inlet end of the inlet silencer; the inlet end of the outlet horn is coaxially connected and communicated with the outlet end of the outlet silencer.

[0016] The beneficial effects of the above technical solution are: through the gradually expanding structure of the inlet horn and the outlet horn, the airflow can be transitioned in a streamline manner, reducing the turbulence intensity of the input and output airflow.

[0017] As a further improvement of the above technical solution, the outlet silencer comprises a silencer cylinder, a porous mesh cylinder, silencer cotton and a flow guide cover; the inlet end of the silencer cylinder is coaxially connected and communicated with the other end of the casing assembly; the porous mesh cylinder is coaxially installed on the inner wall of the silencer cylinder, the silencer cotton is filled between the outer wall of the porous mesh cylinder and the inner wall of the silencer cylinder; the flow guide cover is coaxially arranged in the porous mesh cylinder, and the second guide vane is installed between the outer wall of the flow guide cover and the inner wall of the silencer cylinder and close to the second impeller.

[0018] The inlet silencer comprises a silencer cylinder, a porous mesh cylinder, silencer cotton and a flow guide cover; the outlet end of the silencer cylinder is coaxially connected and communicated with the one end of the casing assembly; the porous mesh cylinder is coaxially installed on the inner wall of the silencer cylinder, the silencer cotton is filled between the outer wall of the porous mesh cylinder and the inner wall of the silencer cylinder; the flow guide cover is coaxially arranged in the porous mesh cylinder and close to the first impeller.

[0019] The beneficial effects of the above technical solutions are: the flow guide cover two can guide the airflow to be distributed along the axial direction, reduce the edge vortex, reduce the local resistance coefficient by smoothing the airflow direction, and guide the airflow into the working area of the first-stage impeller, thereby improving the overall efficiency; the turbulent flow pressed against the inner wall of the sound attenuation cylinder two can enter the sound attenuation cotton two through the porous mesh cylinder two and be absorbed, thereby reducing the turbulent noise at the air inlet end. The cooperation of the flow guide cover one, the porous mesh cylinder one and the sound attenuation cotton one can effectively absorb the turbulent energy and reduce the vibration noise at the air outlet end. The second-stage guide vane orderly guides the high-speed airflow output by the second-stage impeller, so as to reduce the impact on the air outlet silencer.

[0020] As a further improvement of the above technical solutions, the flow guide cover one and the flow guide cover two are both internally provided with sound attenuation cotton.

[0021] The beneficial effects of the above technical solutions are: by installing sound attenuation cotton in the flow guide cover one and the flow guide cover two, the noise is further reduced.

[0022] As a further improvement of the above technical solutions, the machine shell assembly comprises a cylindrical main machine shell, a first-stage cylinder and a second-stage cylinder; the first-stage cylinder and the second-stage cylinder are coaxially and symmetrically installed at both ends of the main machine shell through a flange assembly;

[0023] The first-stage impeller is located in the cylinder cavity of the first-stage cylinder, and the outer peripheral side of the first-stage impeller has a preset interval one from the inner peripheral wall of the first-stage cylinder;

[0024] The second-stage impeller is located in the cylinder cavity of the second-stage cylinder, and the outer peripheral side of the first-stage impeller has a preset interval two from the inner peripheral wall of the second-stage cylinder;

[0025] The outlet end of the air inlet silencer is coaxially connected and communicated with the cylinder opening of the first-stage cylinder away from the main machine shell and corresponds to the first-stage impeller; the inlet end of the air outlet silencer is coaxially connected and communicated with the cylinder opening of the second-stage cylinder away from the main machine shell and corresponds to the second-stage impeller.

[0026] The beneficial effects of the above technical solutions are: by designing the machine shell assembly as a split structure, the separately provided first-stage cylinder and second-stage cylinder facilitate high-precision machining and manufacturing; by controlling the assembly precision of the first-stage cylinder and the second-stage cylinder through the flange assembly, the installation precision of the first-stage impeller and the second-stage impeller can be effectively controlled, so that the preset interval one and the preset interval two meet the gap design requirements, thereby improving the overall performance and operation stability of the fan.

[0027] As a further improvement of the above technical solutions, one end of the machine shell of the double-shaft extension motor is fixedly connected to the corresponding one end of the main machine shell through a connecting plate; the other end of the machine shell of the double-shaft extension motor is fixedly connected to the other end of the corresponding main machine shell through the first-stage guide vane.

[0028] The beneficial effects of the above technical solution are that the flange assembly can improve the rigidity of the end of the main shell; the fixed positions of the two ends of the double-shaft extension motor correspond to the two ends of the main shell, thereby realizing stable installation of the double-shaft extension motor and effectively reducing the vibration of the main shell.

[0029] As a further improvement of the above technical solution, the main shell, the primary cylinder and the secondary cylinder are all provided with reinforcing ribs.

[0030] The beneficial effects of the above technical solution are that the reinforcing ribs further improve the structural rigidity and reduce the vibration amplitude.

[0031] As a further improvement of the above technical solution, a support base is further included, and the support base supports the two ends of the main shell.

[0032] The beneficial effects of the above technical solution are that the support positions of the support base are designed at the positions corresponding to the flange assemblies at the two ends of the main shell, which can improve the support stability and structural rigidity and inhibit the vibration transmission.

[0033] As a further improvement of the above technical solution, a protective mesh cover is further included, and the protective mesh cover is adapted to cover the inlet end of the air inlet silencer.

[0034] The beneficial effects of the above technical solution are that the protective mesh cover effectively protects the primary impeller and the secondary impeller and can avoid large foreign matters from being sucked into the fan.

[0035] As a further improvement of the above technical solution, the outer peripheral wall of the motor shell of the double-shaft extension motor is provided with a heat dissipation opening.

[0036] The beneficial effects of the above technical solution are that the outer peripheral wall of the motor shell of the double-shaft extension motor is provided with a heat dissipation opening, which can effectively utilize the self air duct of the fan for perfect heat dissipation.

[0037] According to the above technical solution, compared with the prior art, the energy-saving and durable single-motor double-impeller tunnel fan has the following advantages and beneficial effects:

[0038] 1. The single-motor double-shaft extension double-impeller is adopted, and the double-static guide vanes are simultaneously carried, the aerodynamic core link is optimized, the double-impeller and the double-guide vane are matched to reduce the wind resistance, the impeller spacing and the airflow interference problem are solved; the "blade + guide vane + inlet and outlet flow cover horn mouth layout + main machine two-end silencer" design improves the air volume, reduces the vibration noise, optimizes the double-impeller cooperative working mode; improves the overall efficiency, meets the energy efficiency standard, the primary and secondary flow guide covers optimize the airflow path, improve the fan efficiency, reduce the energy consumption, and enhance the service life.

[0039] 2. The utility model discloses a single machine double impeller, not only breaks through the traditional single machine air pressure insufficient bottleneck, simplifies the complex operation of independent link power supply and synchronous start-stop of counter-rotating fan, and one-key start-stop can be completed by single line control, and the failure rate is greatly reduced, the first guide vane blade shape of having single machine double impeller is optimized, and the motor strength and support, fan support are optimized, the overall aerodynamic performance is improved, and the service life is prolonged. Support is quickly deployed in long and big tunnel construction section, and is suitable for different ventilation demand. Through the design of inlet and outlet air port horn mouth and flow guide cover, the airflow is evenly diffused through the gradually expanding section, vortex is reduced, the guide vane chord length distribution is designed according to logarithmic spiral, the rotating kinetic energy of the moving vane outlet can be converted into pressure energy, secondary flow loss is reduced, and turbulent noise is reduced.

[0040] 3. The utility model discloses a double impeller collaborative work, enhance the fan efficiency, not only can produce the bigger wind power pressure than the same power fan, can save energy consumption more, relative to the same power reduction when running noise, the overall performance is improved, and the weight is reduced, simple structure, the overall structure lets the user worry-free use, reaches the real product of good quality and low price. DRAWINGS

[0041] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, below will be to the embodiment or prior art description needed to use the drawing briefly introduced, obviously, the drawing in the following description only is the embodiment of the utility model, for the ordinary skilled person in the art comes, under the premise of not paying the creative labor, can also obtain other drawings according to the provided drawing.

[0042] Figure 1 The utility model energy-saving durable single machine double impeller tunnel ventilator overall structure schematic diagram;

[0043] In the drawing: 1, the casing assembly;101, main casing;102, the first barrel;103, the second barrel;2, double shaft extension motor;3, the first impeller;4, the second impeller;5, the first guide vane;51, straight blade segment;52, arc blade segment;6, inlet air port muffler;61, muffling cylinder two;62, porous mesh cylinder two;63, muffling cotton two;64, flow guide cover two;7, outlet air port muffler;71, muffling cylinder one;72, porous mesh cylinder one;73, muffling cotton one;74, flow guide cover one;8, the second guide vane;9, inlet air port horn mouth;10, outlet air port horn mouth;11, flange assembly;111, annular flange;12, connecting plate;13, reinforcing rib;14, support base;141, fan leg bottom plate;142, fan L-shaped assembly leg;15, protective net cover;16, heat dissipation port;17, air duct clamp;18, junction box;19, hoisting hole. DETAILED DESCRIPTION

[0044] The embodiments of the present application are described below in detail, examples of the embodiments are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0045] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0046] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0047] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] According to the embodiment of the present application, as shown in Figure 1 The energy-saving durable single-machine double-impeller tunnel ventilator comprises a shell assembly 1, a double-shaft extension motor 2, a primary impeller 3, a secondary impeller 4, a primary guide vane 5, an air inlet silencer 6, an air outlet silencer 7 and a secondary guide vane 8.

[0049] The shell assembly 1 is cylindrical; the double-shaft extension motor 2 is coaxially arranged in the shell assembly 1; an annular flow guide channel is defined between the outer peripheral wall of the shell of the double-shaft extension motor 2 and the inner peripheral wall of the shell assembly 1; the primary impeller 3 and the secondary impeller 4 are both located in the shell assembly 1 and are one-to-one correspondingly installed at both ends of the rotating shaft of the double-shaft extension motor 2.

[0050] The first guide vane 5 is arranged in the annular guide channel; one end of the first guide vane 5 in the length direction extends close to the first impeller 3 and is curved into an arc shape to correspond to the air outlet direction of the first impeller 3 to smoothly guide the airflow; the other end of the first guide vane 5 in the length direction extends close to the second impeller 4 along the axial direction of the annular guide channel to guide the airflow.

[0051] The outlet end of the air inlet muffler 6 is coaxially connected and communicated with one end of the shell assembly 1 and corresponds to the first impeller 3; the inlet end of the air outlet muffler 7 is coaxially connected and communicated with the other end of the shell assembly 1 and corresponds to the second impeller 4; the second guide vane 8 is installed in the air outlet muffler 7 and arranged close to the other end of the shell assembly 1.

[0052] The energy-saving long-service-life single-machine double-impeller tunnel ventilator of the embodiment adopts a single motor double-shaft double-impeller, simultaneously carries double static guide vanes, improves the ventilation volume through the design of the double-impeller, double-guide-vane and air inlet and outlet mufflers, reduces the vibration noise, optimizes the double-impeller cooperative working mode, can improve the overall efficiency, reduce the energy consumption, and enhance the service life. The first guide vane 5 is designed to be lengthened, and the two ends thereof extend close to the corresponding first impeller 3 and second impeller 4 to connect the first impeller 3 and the second impeller 4; the one end of the first guide vane 5 corresponding to the first impeller 3 is curved into an arc shape to smoothly transition and guide the airflow output by the first impeller 3, and the airflow separation is reduced through the curved surface transition; the other end of the first guide vane 5 guides the airflow along the axial direction of the annular guide channel and delivers the airflow to the second impeller 4, realizes the double improvement of the airflow uniformity and the operation stability, and further improves the flow rate, reduces the wind resistance and vibration, and prolongs the service life. In order to further reduce the noise and vibration, the air inlet muffler 6 and the air outlet muffler 7 are arranged at the two ends of the shell assembly 1; the airflow output by the second impeller 4 orderly enters the air outlet muffler 7 through the second guide vane 8, which can significantly reduce the noise, further reduce the energy consumption, and improve the efficiency.

[0053] Specifically, the first guide vane 5 is divided into a straight blade segment 51 and an arc blade segment 52 from the end close to the second impeller 4 to the end close to the first impeller 3; the length direction of the straight blade segment 51 is arranged along the axial direction of the shell assembly 1, and the width direction of the straight blade segment 51 is arranged along the radial direction of the shell assembly 1; the end of the arc blade segment 52 away from the straight blade segment 51 is arranged approximately along the air outlet direction of the first impeller 3, so that the airflow output by the first impeller 3 naturally transitions to the arc blade segment 52, reduces the airflow resistance, and makes the airflow travel along the axial direction of the annular guide channel under the gradual guidance of the arc blade segment 52. The first guide vane 5 can be made by arc bending one end of a straight strip-shaped metal plate.

[0054] Specifically, the first guide vane 5 is a plurality of, and the plurality of first guide vanes 5 are evenly distributed around the outer peripheral wall of the shell of the double-shaft motor 2 to evenly divide the annular guide channel into a plurality of guide channels in the circumferential direction.

[0055] Specifically, the secondary guide vanes 8 are arc-shaped vanes and are multiple; the multiple secondary guide vanes 8 are uniformly distributed around the inner wall of the air outlet muffler 7 and are close to and correspond to the secondary impeller 4, so as to orderly lead the airflow output by the secondary impeller 4 in the axial direction and improve the conveying efficiency.

[0056] In some embodiments, the air inlet horn 9 and the air outlet horn 10 are further included; the outlet end of the air inlet horn 9 is coaxially connected and communicated with the inlet end of the air inlet muffler 6; the inlet end of the air outlet horn 10 is coaxially connected and communicated with the outlet end of the air outlet muffler 7.

[0057] Through the divergent structure of the air inlet horn 9 and the air outlet horn 10, the airflow can be transitioned in a streamline manner, and the turbulence intensity of the input and output airflow can be reduced.

[0058] Specifically, the ends of the air inlet horn 9 and the air outlet horn 10 away from each other are large-aperture ends.

[0059] In some embodiments, the large-aperture end of the air outlet horn 10 is welded and fixed with a wind pipe clamp 17; the wind pipe clamp 17 is used to facilitate the user to bundle the wind pipe.

[0060] In some embodiments, the air outlet muffler 7 includes a muffling cylinder 71, a porous mesh cylinder 72, muffling cotton 73, and a flow guide cover 74; the inlet end of the muffling cylinder 71 is coaxially connected and communicated with the other end cylinder port of the machine shell assembly 1; the porous mesh cylinder 72 is coaxially installed on the inner wall of the muffling cylinder 71, the muffling cotton 73 is filled between the outer wall of the porous mesh cylinder 72 and the inner wall of the muffling cylinder 71, and the flow guide cover 74 is coaxially arranged in the porous mesh cylinder 72; the secondary guide vanes 8 are installed between the outer wall of the flow guide cover 74 and the inner wall of the muffling cylinder 71 and close to the secondary impeller 4.

[0061] The air inlet muffler 6 includes a muffling cylinder 61, a porous mesh cylinder 62, muffling cotton 63, and a flow guide cover 64; the outlet end of the muffling cylinder 61 is coaxially connected and communicated with the one end cylinder port of the machine shell assembly 1; the porous mesh cylinder 62 is coaxially installed on the inner wall of the muffling cylinder 61, the muffling cotton 63 is filled between the outer wall of the porous mesh cylinder 62 and the inner wall of the muffling cylinder 61, and the flow guide cover 64 is coaxially arranged in the porous mesh cylinder 72 and close to the primary impeller 3.

[0062] The flow guide cover two 64 can guide the airflow to be distributed in the axial direction, reduce the edge vortex, reduce the local drag coefficient by smoothing the airflow direction, and guide the airflow into the working area of the first-stage impeller 3, thereby improving the overall efficiency; the turbulent flow pressed against the inner wall of the sound attenuation cylinder two 61 can enter the sound attenuation cotton two 63 through the porous mesh cylinder two 62 and be absorbed, thereby reducing the turbulent noise at the air inlet end. The cooperation of the flow guide cover one 74, the porous mesh cylinder one 72 and the sound attenuation cotton one 73 can effectively absorb the turbulent energy and simultaneously reduce the vibration noise at the air outlet end. The second-stage guide vane 8 orderly guides the high-speed airflow output by the second-stage impeller 4, so as to reduce the impact on the air outlet sound attenuator 7.

[0063] Specifically, the porous mesh cylinder one 72 and the porous mesh cylinder two 62 are both formed by splicing a plurality of arc-shaped porous mesh plates; the porous mesh plates are fixed to the inner wall of the sound attenuation cylinder one 71 or the sound attenuation cylinder two 61 by bolts or welding; the sound attenuation cotton two 63 filled between the outer peripheral wall of the porous mesh cylinder two 62 and the inner peripheral wall of the sound attenuation cylinder two 61 is a cylindrical sound attenuation cotton layer, and the thickness of the cylindrical wall of the cylindrical sound attenuation cotton layer is 10 cm.

[0064] In some embodiments, the flow guide cover one 74 and the flow guide cover two 64 are both provided with sound attenuation cotton.

[0065] By installing sound attenuation cotton in the flow guide cover one 74 and the flow guide cover two 64, the noise is further reduced.

[0066] Specifically, the flow guide cover one 74 and the flow guide cover two 64 are both conical flow guide covers; the tip of the flow guide cover one 74 corresponds to the inlet end of the sound attenuation cylinder one 71; the tip of the flow guide cover two 64 corresponds to the outlet end of the sound attenuation cylinder two 61. A plurality of second-stage guide vanes 8 are uniformly distributed around the outer peripheral wall of the flow guide cover one 74, and the two ends of the second-stage guide vanes 8 in the width direction are respectively welded and fixed to the outer peripheral wall of the flow guide cover one 74 and the inner peripheral wall of the sound attenuation cylinder one 71, thereby supporting and fixing the flow guide cover one 74. The flow guide cover two 64 is welded and fixed to the inner peripheral wall of the sound attenuation cylinder two 61 by a connecting plate.

[0067] In some embodiments, the shell assembly 1 includes a cylindrical main shell 101, a first-stage cylinder 102 and a second-stage cylinder 103; the first-stage cylinder 102 and the second-stage cylinder 103 are coaxially and symmetrically installed at the two ends of the main shell 101 through a flange assembly 11;

[0068] The first-stage impeller 3 is located in the cylinder cavity of the first-stage cylinder 102, and the outer peripheral side of the first-stage impeller 3 has a preset interval one from the inner peripheral wall of the first-stage cylinder 102;

[0069] The second-stage impeller 4 is located in the cylinder cavity of the second-stage cylinder 103, and the outer peripheral side of the first-stage impeller 3 has a preset interval two from the inner peripheral wall of the second-stage cylinder 103;

[0070] The outlet end of the air inlet muffler 6 is coaxially connected and communicated with the cylinder port of the first-stage cylinder 102 away from the main casing 101 and corresponds to the first-stage impeller 3; the inlet end of the air outlet muffler 7 is coaxially connected and communicated with the cylinder port of the second-stage cylinder 103 away from the main casing 101 and corresponds to the second-stage impeller 4.

[0071] By designing the casing assembly 1 as a split structure, the separately arranged first-stage cylinder 102 and second-stage cylinder 103 facilitate high-precision machining; by controlling the assembly precision of the first-stage cylinder 102 and second-stage cylinder 103 through the flange assembly 11, the installation precision of the first-stage impeller 3 and second-stage impeller 4 can be effectively controlled, so that the preset interval one and preset interval two meet the gap design requirements, thereby improving the overall performance and operation stability of the fan.

[0072] Specifically, the flange assembly 11 includes a plurality of annular flanges 111 and annular rubber pads. The main casing 101, the first-stage cylinder 102, the second-stage cylinder 103, the air inlet muffler 6, and the air outlet muffler 7 are all adapted to be fixed with annular flanges 111 at both ends of the cylinder port. The main casing 101 and the first-stage cylinder 102, the main casing 101 and the second-stage cylinder 103, the air inlet muffler 6 and the first-stage cylinder 102, and the air outlet muffler 7 and the second-stage cylinder 103 are all connected and communicated through the annular flanges 111 and fastened by bolts, and the annular rubber pads are arranged between any two annular flanges 111 for sealing communication.

[0073] Specifically, the small-diameter end of the air inlet horn 9 and the air outlet horn 10 is coaxially adapted to be fixed with an annular flange 111; the small-diameter end of the air inlet horn 9 and the corresponding end of the air inlet muffler 6 are adapted to be connected and communicated through the annular flange 111 and fastened by bolts; the small-diameter end of the air outlet horn 10 and the corresponding end of the air outlet muffler 7 are adapted to be connected and communicated through the annular flange 111 and fastened by bolts. The air inlet horn 9 and the air outlet horn 10 are convenient to disassemble and maintain.

[0074] Specifically, since the first-stage cylinder 102, the second-stage cylinder 103, and the main casing 101 are all connected through flanges, the first-stage cylinder 102 and the second-stage cylinder 103 can be machined by precision machine tools, which can better control the gap (i.e., the preset interval one and the preset interval two) between the blades of the first-stage impeller 3 and the second-stage impeller 4 and the corresponding first-stage cylinder 102 or second-stage cylinder 103 to be ≤3mm, thereby improving the overall performance of the fan.

[0075] In some embodiments, one end of the casing of the double-shaft extension motor 2 is fixedly connected to one end of the corresponding main casing 101 through a connecting plate 12; the other end of the casing of the double-shaft extension motor 2 is fixedly connected to the other end of the corresponding main casing 101 through the first-stage guide vane 5.

[0076] The flange assembly 11 can play a role in improving the end stiffness of the main shell 101; the fixed positions of the two ends of the double-shaft extension motor 2 correspond to the two ends of the main shell 101, thereby realizing stable installation of the double-shaft extension motor 2 and effectively reducing the vibration of the main shell 101. By ingeniously using the first guide vane 5 to replace the connecting plate to fix the other end of the motor shell of the double-shaft extension motor 2, the motor support structure is reduced, thereby reducing the ventilation resistance.

[0077] In some embodiments, the main shell 101, the first cylinder 102 and the second cylinder 103 are all provided with reinforcing ribs 13.

[0078] The reinforcing ribs 13 further play a role in strengthening the structural stiffness and reducing the vibration amplitude.

[0079] In some embodiments, lifting holes 19 are formed in the reinforcing ribs 13.

[0080] In some embodiments, a support base 14 is further included, which supports and fixes the two ends of the main shell 101 at the top end.

[0081] The support position of the support base 14 is designed at the positions corresponding to the flange assemblies 11 at the two ends of the main shell 101, which can improve the support stability and structural stiffness and suppress vibration transmission.

[0082] Specifically, the support base 14 includes a fan leg bottom plate 141 and a plurality of fan L-shaped assembly legs 142 welded and fixed at the upper end of the fan leg bottom plate 141; the plurality of fan L-shaped assembly legs 142 are one-to-one correspondingly welded and fixed at the annular flanges 111 at the two ends of the main shell 101 and the annular flanges 111 at the ends of the first cylinder 102 and the second cylinder 103 away from the main shell 101.

[0083] In contrast, the fan leg of the traditional single-machine double-impeller fan is installed at the cylinder rather than the flange, which can cause excessive vibration, mainly related to insufficient support structural stiffness, unreasonable vibration transmission path and installation process defects. As a main force component, if the leg is not connected through the flange rigid structure, the vibration energy cannot be effectively dispersed, resulting in the cylinder becoming a vibration amplifier. If the natural frequency of the cylinder leg system coincides with the fan speed (such as 1500 rpm corresponding to 25 Hz), resonance is easily induced, and the amplitude can be amplified by 3-5 times. The plurality of fan L-shaped assembly legs 142 of the present embodiment are one-to-one correspondingly supported and fixed at the annular flanges 111, which greatly improves the connection and support stiffness, effectively reduces the vibration and improves the stability of the fan operation.

[0084] In some embodiments, a protective mesh cover 15 is further included, which is adapted to cover the inlet end of the inlet silencer 6.

[0085] The protective screen cover 15 effectively protects the first-stage impeller 3 and the second-stage impeller 4, and prevents large foreign matters from being sucked into the fan.

[0086] In some embodiments, the outer peripheral wall of the housing of the double-shaft extension motor 2 is provided with a heat dissipation opening 16.

[0087] The outer peripheral wall of the housing of the double-shaft extension motor 2 is provided with a heat dissipation opening 16, which can effectively utilize the self air duct of the fan for perfect heat dissipation.

[0088] In some embodiments, a terminal box 18 is arranged outside the fan, facilitating wiring.

[0089] Specifically, the energy-saving long-lasting single-machine double-impeller tunnel fan provided by the utility model firstly passes through CFD simulation: comprehensive aerodynamic, thermodynamic and noise characteristics, and fusion of structure and cost analysis, precise prediction is realized through multi-region modeling, high-precision grid division and dynamic coupling method; performance and cost are more optimal through multidisciplinary collaborative optimization.

[0090] For the core components, the material of the first-stage impeller 3 and the second-stage impeller 4 adopts aluminum alloy die casting (ZL114A), and the dynamic balance grade is G2.5. The structure is a backward inclined blade (blade outlet angle 30°-45°), the blade is bolted to the hub, and the angle is supported to be adjusted by ±15°. The protection grade of the double-shaft extension motor 2 is IP55 (dustproof and waterproof), the insulation grade is H level, and the protective cover and the housing are designed in an integrated manner. The installation mode is direct driving (without speed reducer), the shaft end adopts double-bearing support, the double-shaft extension motor 2 has four bearings SFF / FAG, and the bearing service life is greater than or equal to 30,000 hours. The shape of the housing is a straight cylinder or a gradually expanding type, the inner wall is smooth (Ra≤3.2 μm), and the turbulent resistance is reduced; the material of the housing is Q235B steel plate welding, and the outer surface is covered with an epoxy resin anticorrosive layer (thickness≥70 μm), which is suitable for high-humidity environments.

[0091] Specifically, the first-stage guide vane 5 is used as the front end support of the motor at the same time, the traditional linear guide vane is changed into a concave arc cross section, and airflow separation is reduced through curved surface transition. The concave arc guide vane can increase suction by 18% and reduce resistance by 23%. Non-linear geometric transition (such as cubic Bezier curve) is adopted, the installation angle (α value range 26°-30°) and the twist angle of the guide vane are optimized, the lift-drag ratio and noise control are balanced, and the arc length of the first-stage and second-stage guide vanes is lengthened to be greater than or equal to 450 cm. In addition to the 450 cm curved surface of the first-stage guide vane, the straight plate in the rear half part is also lengthened by greater than or equal to 200 cm, the direct blowing property is increased by 31%, the axial velocity ratio is increased from 78% to 92%, the vibration amplitude of the blade of the first-stage guide vane is reduced from 4.8 mm / s to 1.5 mm / s, and the total pressure efficiency can be increased from 76.3% to 82.1%.

[0092] Corresponding key connection and assembly relationship, the first impeller 3 and the second impeller 4 and the transmission shaft of the double-shaft extension motor 2 are made of special 40Cr steel alloy shaft after quenching and tempering treatment, the surface is plated with hard chromium (thickness 0.05mm), and the impeller is fixed by means of flat key and locking screw (8.8 grade to prevent screw back); the shaft coupling is an elastic diaphragm coupling, which compensates for the axial / radial deviation and transmits torque ≥2000Nm. The thickness of the casing is ≥8mm, the thickness of the annular flange 111 is ≥12mm, the outer peripheral wall of the main casing 101, the first cylinder 102 and the second cylinder 103 is welded with reinforcing ribs. The thickness of the fan leg bottom plate 141 is ≥10mm, the number of L-shaped assembly legs 142 of the fan is more than 4, and the amplitude is ≤0.1mm.

[0093] The annular rubber pad connected to the inlet and outlet ends of the cylinder part adopts flexible gasket, which can withstand temperature-40℃~150℃, and the thickness is ≥10mm. The annular flange 111 adopts flange standard: HG / T20592PN16, and the center circle diameter of bolt hole is according to ISO5211 standard.

[0094] For structural details and size parameters, typical size (take Φ1400mm axial flow fan as an example), impeller diameter: 1400mm, hub ratio 0.55, blade number 9. Casing length: 5850mm (including horn mouth), width 1662mm, height 1809mm. Special structure design, anti-surge device: guide vane is arranged at both ends of the impeller, range 15°~25°, to prevent low flow surge.

[0095] For material and corrosion prevention treatment, the main body material impeller blade: aluminum alloy (ZL114A, density 2.7g / cm3) corrosion resistant. Impeller hub: Q355NH weather resistant steel (thickness 8mm), after sand blasting rust removal (Sa2.5 level), coated with epoxy zinc-rich primer (dry film thickness 80μm).

[0096] For corrosion prevention treatment of key components, bolts / nuts: dacromet treatment (zinc-chromium coating, thickness ≥10μm), suitable for high salt spray environment. Cable sheath: low smoke halogen-free flame retardant material (combustion performance GB / T19666-2019B1 level).

[0097] Optimized design for performance, including aerodynamic optimization design, C4-72 airfoil for blade airfoil, chord length distribution according to logarithmic spiral design to reduce secondary flow loss. Static guide vane: arc plate + straight plate for first-stage guide vane; arc plate for second-stage guide vane; the collaborative design of the two realizes the double promotion of airflow uniformity and operation stability, the flow is increased by 15%, the static pressure efficiency is increased by 10.9 percentage points (high pressure area), the blade passing frequency vibration amplitude is reduced from 5.0 mm / s to 1.2 mm / s, and the service life is prolonged by more than 22%. Fairing (fairing one 74 and fairing two 64): the front fairing has a cone angle of 15°, and the rear fairing has an expansion angle of 7°, which reduces turbulent noise, and the noise is ≤75 dB(A).

[0098] The core of the energy-saving durable single-machine double-impeller tunnel ventilator is a specially-made double-bearing variable-frequency permanent magnet motor, which is equipped with a double-turbine structure, adopts a new type of secondary jet pressure boosting design, optimizes the wing type design of the blade guide vane, selects aluminum blade high-pressure die casting, adds an inlet and outlet horn and a fairing design, uniformly diffuses airflow through a gradually expanding cross section, reduces vortex, and designs the chord length distribution of the guide vane according to a logarithmic spiral. The rotating kinetic energy at the outlet of the moving vane can be converted into pressure energy, the secondary flow loss is reduced, and the turbulent noise is reduced. The main motor drives a specially-made 40Cr steel alloy shaft (quenching treatment), the shaft body is integrated with a neodymium iron boron permanent magnet (NdFeB), both ends are equipped with double bearings (NU319 and 6319), and Mobil Polyrex EM polyurea-based lubricating grease special lubricating oil is added. The advanced soap-based formula and patented production technology make it have low noise characteristics, can improve the performance of the bearing, protect and prolong the service life of the motor, and make the service life of the fan increase by several times. Installation connection and support: the whole double turbine works collaboratively, the fan efficiency is enhanced to ≥85%, not only can generate greater wind pressure than the same power fan, but also can save energy consumption than the same power fan, and the noise during operation is 5-8% lower than the same power. The double bearings can prolong the service life by more than 50%, the overall performance is improved by more than 10%, the weight is reduced, the structure is simple, the overall structure makes the user worry-free use, and a truly good quality and low price product is achieved.

[0099] The energy-saving durable single-machine double-impeller tunnel ventilator has the following characteristics:

[0100] Single-machine double-impeller collaborative driving structure: single motor double shaft extension, double impeller and double static guide vane group are carried; double vortex is generated, flow separation is delayed, fan efficiency is improved, and the product is suitable for high pressure, large flow and closed space operation requirements.

[0101] Impeller, airflow optimization design: through single motor drive double impeller rotation, realize airflow shaping, improve efficiency. Blade guide vane airfoil optimization: moving blade adopts NACA series or XFOIL airfoil. Static guide vane first stage guide vane: arc plate + straight plate is adopted. Two stage guide vane: arc plate is adopted. The combination of different structures; Forced to guide the airflow direction, suppress the pressure difference disorder. Combined with CFD to optimize the airfoil leading edge and trailing edge radius, chord length distribution and thickness gradient. The chord length increases by 1%, the wind energy capture efficiency increases by 0.5%. And concave arc section: change the traditional linear guide vane to concave arc section, reduce airflow separation through curved surface transition. Concave arc guide vane can increase suction by 18% and reduce resistance by 23%. Multi-segment linear design: adopt nonlinear geometric transition (such as cubic Bezier curve), optimize guide vane installation angle (α = 26°-30°) and torsion angle, balance lift-drag ratio and noise control. Compared with traditional counter rotating blower, one group of motor noise is also relatively weakened, single machine double impeller can offset sound wave interference through two stage rotation, at the same time reduce noise.

[0102] The effect of different structures of the two guide vanes: the first stage guide vane adopts arc plate + straight plate, the operation of the arc blade segment 52 is: through the circular arc shape to guide the airflow to produce swirl, (the tangential velocity component consistent with the rotation direction of the impeller) makes the airflow enter the first stage guide vane at an angle closer to the rotation direction of the impeller, smooth airflow transition, reduce the impact loss at the inlet of the first stage guide vane, improve the energy conversion efficiency. The circular arc transition can reduce the noise when the airflow impacts the guide vane, and at the same time reduce the vibration amplitude of the guide vane itself, so that the fan runs more smoothly; Straight blade segment 51: straight plate part is used to accurately control the airflow direction, avoid the superimposed interference of the pulsating airflow at the outlet of the first stage guide vane to the second stage impeller. (Vortex airflow is changed to straight airflow) Expand the airflow channel, more suitable for the demand of two stage impeller inlet working condition. (Note: if the second stage impeller inlet is vortex, it will make the impeller and the airflow consistent, reduce the performance of the second stage of the fan, so the arc + straight plate segment guide vane is designed) The effect of the second stage guide vane adopting arc plate: the airflow enters the first stage guide vane after passing through the first stage impeller, and then enters the second stage impeller again. The airflow is pressurized again through the second stage impeller, and then enters the second stage arc guide vane. The second stage arc guide vane converts part of the rotational kinetic energy of the high-speed rotating airflow at the outlet of the second stage impeller into pressure energy, improving the overall wind pressure. The arc design of the second stage guide vane at the outlet can reduce the secondary flow loss of the airflow at the outlet of the second stage impeller, and optimize the efficiency of the impeller. Therefore, the bending + straight plate design of the first stage guide vane realizes high efficiency airflow distribution through swirl guidance and mechanical reinforcement, and the pure bending structure of the second stage guide vane focuses on the high speed energy recovery and flow stability generated by the second stage impeller. The cooperative design of the two has strong stability in improving efficiency, reducing energy consumption and adapting to complex working conditions.

[0103] Add guide structure:

[0104] Inlet / outlet air port flared mouth: The flared structure of the mouth reduces the turbulence intensity of the free flow by 40%-60% through streamlined transition. The principle is to guide the secondary flow to form a laminar boundary layer at the inlet section, reducing flow separation at the impeller inlet. The outlet air port flared mouth design (opening angle 7°-15°) optimizes air flow uniformity by changing the air flow direction, reduces air intake resistance, and increases high-pressure zone air flow by 20%-30%.

[0105] Inlet / outlet air port fairing: The elliptical conical cross-section can effectively reduce airflow separation and vortex generation. In the fan, the design of the fairing reduces the local resistance coefficient by smoothing the air flow direction, thereby improving overall efficiency. The fairing reduces the separation phenomenon after the air flow hits the guide vane, suppresses turbulence generation, and reduces turbulence noise. This method can reduce turbulence intensity by 40%.

[0106] Additional silencer:

[0107] Porous sound-absorbing material: The main machine flange support is enhanced, and the main machine air duct has no sound-absorbing device due to the enhancement of the main machine strength. Therefore, silencers are added at the inlet and outlet of the air duct to absorb turbulence energy and reduce noise without affecting the strength of the motor installation.

[0108] Bearing and transmission system enhancement:

[0109] Bearing: Single machine double impeller group, supporting rotor rotation, more need high temperature, high strength, friction resistant bearing (special single-sided double bearing, one motor 4 bearing design, bearing combination NU319 cylindrical roller bearing and 6319 deep groove ball bearing) Different double bearing cooperation while running, enhance the radial and axial load, make the fan run more stable, the service life is enhanced.

[0110] Transmission device: Special alloy steel (45Cr steel): suitable for high load scene, surface carburizing treatment hardness reaches HRC58-62, core maintains 35-40HRC toughness. Through quenching and high temperature tempering treatment, the comprehensive mechanical properties can be improved, the fatigue life is increased by 3 times, and the tensile strength is increased by 20%MPa.

[0111] Low energy consumption and intelligent control: Combined with permanent magnet synchronous motor, multiple gas sensors, automatic intelligent variable frequency speed regulation technology, realize the intelligent dynamic optimization of fan energy efficiency, meet the needs of industrial automation and green energy.

[0112] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and integrate different embodiments or examples described in the present specification.

[0113] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. Energy saving long lasting single machine double impeller tunnel ventilator characterized in that, It includes: The casing assembly (1) is cylindrical; The double shaft extension motor (2) is coaxially arranged in the casing assembly (1); the casing outer wall of the double shaft extension motor (2) and the inner wall of the casing assembly (1) define an annular flow guide channel; The primary impeller (3) and the secondary impeller (4) are both located in the casing assembly (1) and are installed at the two ends of the rotating shaft of the double shaft extension motor (2) one by one; The primary guide vane (5) is arranged in the annular flow guide channel; one end of the primary guide vane (5) in the length direction extends close to the primary impeller (3) and is curved into an arc shape to correspond to the air outlet direction of the primary impeller (3) to smoothly guide the airflow; the other end of the primary guide vane (5) in the length direction extends close to the secondary impeller (4) along the axial direction of the annular flow guide channel to guide the airflow; The air inlet muffler (6) and the air outlet muffler (7) are coaxially connected and communicated with one end of the casing assembly (1) and correspond to the primary impeller (3); the air outlet muffler (7) is coaxially connected and communicated with the other end of the casing assembly (1) and corresponds to the secondary impeller (4); The secondary guide vane (8) is installed in the air outlet muffler (7) and arranged close to the other end of the casing assembly (1).

2. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 1, wherein, It also includes an air inlet horn (9) and an air outlet horn (10); the outlet end of the air inlet horn (9) is coaxially connected and communicated with the inlet end of the air inlet muffler (6); the inlet end of the air outlet horn (10) is coaxially connected and communicated with the outlet end of the air outlet muffler (7).

3. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 1 wherein, The air outlet muffler (7) includes a muffler cylinder (71), a porous mesh cylinder (72), a sound absorbing cotton (73), and a flow guide cover (74); the inlet end of the muffler cylinder (71) is coaxially connected and communicated with the other end of the casing assembly (1); the porous mesh cylinder (72) is coaxially installed in the inner wall of the muffler cylinder (71), the sound absorbing cotton (73) is filled between the outer wall of the porous mesh cylinder (72) and the inner wall of the muffler cylinder (71); the flow guide cover (74) is coaxially arranged in the porous mesh cylinder (72), and the secondary guide vane (8) is installed between the outer wall of the flow guide cover (74) and the inner wall of the muffler cylinder (71) and close to the secondary impeller (4); The air inlet silencer (6) comprises a silencer tube two (61), a porous mesh tube two (62), a silencer cotton two (63) and a fairing two (64); the outlet end of the silencer tube two (61) is coaxially connected and communicated with the one end tube port of the casing assembly (1); the porous mesh tube two (62) is coaxially installed on the inner wall of the silencer tube two (61), and the silencer cotton two (63) is filled between the outer wall of the porous mesh tube two (62) and the inner wall of the silencer tube two (61); the fairing two (64) is coaxially arranged in the porous mesh tube one (72) and close to the primary impeller (3).

4. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 3 wherein, The fairing one (74) and the fairing two (64) are both provided with silencer cotton.

5. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 1 wherein, The casing assembly (1) comprises a cylindrical main casing (101), a primary cylinder (102) and a secondary cylinder (103); the primary cylinder (102) and the secondary cylinder (103) are coaxially and symmetrically installed on both ends of the main casing (101) through a flange assembly (11); The primary impeller (3) is located in the cylinder cavity of the primary cylinder (102), and the outer peripheral side of the primary impeller (3) has a preset interval one from the inner wall of the primary cylinder (102); The secondary impeller (4) is located in the cylinder cavity of the secondary cylinder (103), and the outer peripheral side of the primary impeller (3) has a preset interval two from the inner wall of the secondary cylinder (103); The outlet end of the air inlet silencer (6) is coaxially connected and communicated with the tube port of the primary cylinder (102) away from the main casing (101) and corresponds to the primary impeller (3); the inlet end of the air outlet silencer (7) is coaxially connected and communicated with the tube port of the secondary cylinder (103) away from the main casing (101) and corresponds to the secondary impeller (4).

6. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 5 wherein, One end of the casing of the double-shaft extension motor (2) is fixedly connected to one end of the corresponding main casing (101) through a connecting plate (12); the other end of the casing of the double-shaft extension motor (2) is fixedly connected to the other end of the corresponding main casing (101) through the primary guide vane (5).

7. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 5 wherein, The main casing (101), the primary cylinder (102) and the secondary cylinder (103) are all provided with reinforcing ribs (13).

8. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 5 wherein, A support base (14) is further included, and the support base (14) supports and fixes the two ends of the main casing (101) at the top end.

9. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 5 wherein, A protective mesh cover (15) is further included, and the protective mesh cover (15) is adaptively covered on the inlet end of the air inlet silencer (6).

10. The energy efficient, long lasting, single motor double impeller tunnel ventilator as claimed in claim 1 wherein, The outer peripheral wall of the casing of the double-shaft extension motor (2) is provided with a heat dissipation port (16).

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