Full ducted gas turbine
By designing a full-flow pneumatic turbine, the energy is efficiently converted using compressed air, solving the problems of drainage and gas emission in coal mining roadways and achieving the dual effects of high efficiency, safety, and explosion-proof.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG SUJIE VALVE TECH CO LTD
- Filing Date
- 2026-03-25
- Publication Date
- 2026-08-04
AI Technical Summary
In the existing technology, the drainage needs in the coal mining roadways are difficult to meet, and the electric water pumps are inefficient. The heat generated when the motor is working pushes up the temperature, which poses a risk of electric sparks and makes it difficult to meet safety requirements.
It adopts a full-flow pneumatic turbine, which uses a series axial full-flow layout with a multi-stage impeller and seat ring structure to drive the turbine with compressed air, achieves efficient energy conversion in stages, outputs rotational mechanical energy, reduces exhaust gas temperature, and meets explosion-proof requirements.
It achieves efficient conversion of compressed air energy, with an overall efficiency of 89.8%, meets the explosion-proof requirements of underground coal mines, and has advantages in safety, energy saving and environmental protection, while also having gas emission and cooling effects.
Smart Images
Figure CN121897415B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pneumatic turbine technology, specifically to a full-flow pneumatic turbine. Background Technology
[0002] Underground coal seams contain abundant methane gas and water, which are released during coal mining operations. To ensure safety during mining, a sufficient amount of compressed air from the surface layer outside the mine needs to be piped to the working roadways of the coal seam to expel the methane gas from the roadways using the displacement effect; at the same time, seepage water from the coal seam needs to be forcibly pumped out of the working roadways.
[0003] Because coal seams are mostly located hundreds to thousands of meters underground and often exhibit a long and narrow coal belt distribution, mining operations are typically conducted in narrow, semi-enclosed spaces with high internal temperatures, generally above 30 degrees Celsius, resulting in a harsh working environment. Furthermore, due to the continuous release of methane gas from the coal seam, the electric water pumps used for drainage in the working roadways must meet strict explosion-proof requirements. The heat generated by the motors further increases the temperature within the roadways. Currently, compressed air diaphragm pumps are commonly used in coal mining roadways, but their low efficiency often means that the air supply is insufficient to meet actual drainage needs.
[0004] Therefore, developing a full-flow pneumatic turbine to drive a water pump for drainage can meet the drainage requirements of most coal mining operations. The cooled exhaust gas generated by the pneumatic turbine after it performs work can be directly discharged into the coal mining roadway, which can both enhance gas emission and reduce the ambient temperature inside the roadway. The water pump driven by the turbine can be switched on when drainage is needed and switched off when not needed, thus better meeting the safety requirements in the coal mining process.
[0005] Using a full-flow pneumatic turbine to drive a forced-draft fan can achieve a dual effect of forced exhaust and extraction of methane gas in coal mining roadways. Furthermore, using this turbine to drive anchor drilling rigs in coal mining roadways, replacing existing electrically driven equipment, offers high efficiency, safety, and explosion-proof characteristics. Summary of the Invention
[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a full-flow pneumatic turbine.
[0007] The objective of this invention can be achieved through the following technical solution: a full-flow pneumatic turbine, comprising: The guide section includes a volute and at least two stages of seat rings arranged sequentially along the axial direction; the volute is provided with an inlet channel extending radially or circumferentially and an outlet channel extending axially. The working section includes at least two stages of rotating wheels that are staggered with the at least two stages of seat rings and coaxially mounted on the same main shaft; The support section includes at least two bearing assemblies for supporting the rotation of the spindle, the bearing assemblies being axially distributed and located on the front and rear sides of the spindle; The outlet flow channel of the volute, the nozzle flow channels of each stage of the seat ring, the blade flow channels of each stage of the impeller, and the exhaust channel located at the downstream end are sequentially sealed and connected along the axial direction to form a continuous full flow channel from the inlet flow channel to the exhaust channel.
[0008] During operation, compressed air enters through the inlet channel, flows sequentially through the volute, the nozzle channels of each stage of the seat rings, and the blade channels of each stage of the impellers, driving the impellers to rotate the main shaft. This converts the energy of the compressed air into rotational mechanical energy, which is then discharged through the exhaust channel. The main shaft is used to connect to external machines.
[0009] This solution achieves highly efficient cascaded energy conversion of compressed air through an axial full-channel series layout and a multi-stage impeller and stage-by-stage seat ring structure, with an overall efficiency of 89.8%, significantly higher than traditional diaphragm pumps. Simultaneously, the low-temperature exhaust gas after expansion can be directly discharged into the working roadway, serving the dual purpose of reducing ambient temperature and enhancing gas emission. Its all-pneumatic drive fundamentally eliminates the risk of electrical sparks, fully meeting underground explosion-proof requirements. Furthermore, its standardized and modular cascade design allows for flexible adjustment of the number of stages based on air source parameters, providing excellent adaptability to operating conditions and ease of maintenance. It offers significant safety, energy-saving, and environmental advantages in coal mine drainage, ventilation, and drilling / anchoring applications.
[0010] Furthermore, the outlet flow channel of the volute is a circular annular flow channel coaxial with the main shaft; the nozzle flow channels of each stage of the seat ring and the blade flow channels of each stage of the impeller are designed with their central flow surfaces located on a reference cylindrical surface of the same diameter coaxial with the main shaft, so as to form a smooth airflow passage of a continuous circular annular flow channel.
[0011] This design employs an axially tandem, fully sealed flow channel structure, ensuring that the central flow surfaces of all channels are located on the same cylindrical surface throughout the entire flow of compressed air from the volute inlet to the final exhaust channel. This creates a continuous and smooth axial flow path, significantly reducing flow separation and eddy current losses, thereby dramatically increasing the overall energy conversion efficiency to 89.8%, more than three times higher than traditional mining diaphragm pumps. Simultaneously, the alternating arrangement of multi-stage impellers and seat rings with three-dimensional twisted airfoil guide vanes achieves tiered and thorough extraction and conversion of compressed air energy, ensuring stable and reliable main shaft output power. Furthermore, this device uses compressed air as its sole power source, fundamentally eliminating the risk of electrical sparks and meeting the stringent explosion-proof safety requirements of underground coal mines. The air, after performing work, expands and its temperature drops significantly; when discharged into the roadway, it enhances gas emission and effectively reduces the ambient temperature, providing both power output and auxiliary cooling capabilities.
[0012] The central flow surface is the curved surface formed by the midpoint of the flow channel in the radial direction. Specifically, the central flow surfaces of the volute outlet flow channel, the nozzle flow channels of each stage of the bearing ring, the blade flow channels of each stage of the impeller, and the exhaust channel are designed and arranged on or infinitely close to a theoretical reference cylindrical surface coaxial with the main shaft and having the same diameter. This ensures that the average radial position of the central flow surfaces of each flow channel remains consistent along the axial direction. This ensures that the airflow core can smoothly and continuously pass through all stages along the axial direction, which is the core structural feature constituting efficient full-channel energy conversion.
[0013] Furthermore, the seat ring includes a primary seat ring, a secondary seat ring, a tertiary seat ring, and a quaternary seat ring arranged sequentially along the axial direction; the rotating wheel includes a primary rotating wheel, a secondary rotating wheel, a tertiary rotating wheel, and a quaternary rotating wheel arranged alternately with the primary seat ring, the secondary seat ring, the tertiary seat ring, and the quaternary seat ring.
[0014] Furthermore, the nozzle flow channel of the first-stage seat ring is a conical annular structure with a gradually decreasing cross-sectional area along the airflow direction, and the nozzle flow channel of the first-stage seat ring is provided with first-stage guide vanes evenly distributed along its circumference.
[0015] The tapered nozzle channel of the first-stage seat ring efficiently converts the pressure energy of compressed air from the volute into kinetic energy through organized and controllable acceleration, and uniformly guides it into the runner with optimized direction and velocity. Simultaneously, this structure effectively avoids localized supersonic airflow and shock wave generation, reducing energy loss and operating noise, and ensuring smooth matching with subsequent flow channels, laying a crucial foundation for the high-efficiency, stable, and low-noise operation of the entire machine. Without the guidance and constraint of the tapered channel and the first-stage guide vanes, the high-pressure airflow entering the runner chamber from the volute may experience a sudden expansion or flow separation, resulting in a drastic and disordered increase in local velocity, easily reaching or exceeding the speed of sound at the blade leading edge or the throat of the flow channel, forming shock waves. Shock waves not only lead to huge energy losses and significantly reduce efficiency, but also cause violent fluctuations and instability in the flow field. The nozzle channel of the first-stage seat ring is a conical annular tapered channel with a large inlet thickness and a small outlet thickness, with a tapering ratio between 0.006 and 0.009. The first-stage seat ring has a disc-shaped cross-section and features an inner and outer hollow conical annular structure. The nozzle flow channel lies between these two structures. First-stage guide vanes, evenly distributed along the circumference of the nozzle flow channel, form a complete unit. The diameter of the inlet end of the nozzle flow channel of the first-stage seat ring is the same as the diameter of the outlet end of the outlet flow channel of the volute. The diameter of the outlet end of the nozzle flow channel of the first-stage seat ring is the same as the diameter of the inlet end of the impeller flow channel of the first-stage runner.
[0016] Furthermore, the nozzle flow channels of the secondary, tertiary, and quaternary seat rings are conical annular structures with gradually expanding cross-sectional areas along the airflow direction or cylindrical annular structures with equal cross-sectional areas. The nozzle flow channel of the secondary seat ring is provided with secondary guide vanes evenly distributed along its circumference, the nozzle flow channel of the tertiary seat ring is provided with tertiary guide vanes evenly distributed along its circumference, and the nozzle flow channel of the quaternary seat ring is provided with quaternary guide vanes evenly distributed along its circumference.
[0017] The second-stage, third-stage, and fourth-stage seat rings have the same or similar shapes, and the nozzle flow channel diffusion ratio of the second-stage, third-stage, and fourth-stage seat rings is between 0.05 and 0.08. Alternatively, the nozzle flow channels of the second-stage, third-stage, and fourth-stage seat rings can be straight cylinders with a diffusion ratio of 0. The nozzle flow channel thickness of the second-stage seat ring increases sequentially, as do that of the third-stage and fourth-stage seat rings. The diameter of the inlet end of the nozzle flow channel of the second-stage seat ring is the same as the diameter of the outlet end of the blade flow channel of the first-stage runner, and the diameter of the outlet end of the nozzle flow channel of the second-stage seat ring is the same as the diameter of the inlet end of the blade flow channel of the second-stage runner, and so on.
[0018] Furthermore, it also includes four enclosures, namely a first-level enclosure, a second-level enclosure, a third-level enclosure, and a fourth-level enclosure. Each level of enclosure is arranged alternately with each level of seat ring, and each level of enclosure, together with the adjacent seat ring, forms a wheel chamber for accommodating each level of wheel.
[0019] Furthermore, the volute housing has a seat ring cavity, and the primary seat ring is fixedly disposed within the seat ring cavity. The volute housing, primary cover, secondary seat ring, secondary cover, tertiary seat ring, tertiary cover, quaternary seat ring, and quaternary cover are arranged sequentially along the axial direction and fixed by fasteners. Sealing elements are provided between the volute housing and the primary cover, as well as between the other cover levels and the seat rings at each level. The cover and each seat ring are integrally formed or separately formed.
[0020] Furthermore, it also includes a bearing support end cover, which is located at the outer end of the fourth-stage rotor and is sealed and fixedly connected to the fourth-stage enclosure. The exhaust channel is located on the bearing support end cover, and a bearing assembly is fixedly installed inside the bearing support end cover.
[0021] Furthermore, each stage of the impeller includes a hub, an outer ring coaxially fitted around the outside of the hub, and multiple airfoil blades connected between the hub and the outer ring and evenly distributed along the circumference. A sub-channel extending along the airflow direction is formed between two adjacent airfoil blades. The airflow direction at the inlet of the sub-channel is configured to be close to the tangential direction of the central flow surface, and the airflow direction at the outlet of the sub-channel is configured to be close to the axial direction of the central flow surface.
[0022] Furthermore, blade flow channels are formed between the outer circumferential surface of each stage hub and the inner circumferential surface of each stage runner outer ring. The diameter at the inlet of each stage blade flow channel is the same as the diameter at the outlet of the nozzle flow channel in the adjacent upper stage seat ring, and the diameter at the outlet of each stage blade flow channel is the same as the diameter at the inlet of the nozzle flow channel in the adjacent lower stage seat ring.
[0023] Compared with the prior art, the technical effects of the present invention are as follows: First, the compressed air-driven full-flow pneumatic turbine efficiently converts the internal energy of compressed air into rotational mechanical energy, which is output through the main shaft, replacing the drive motor of other rotating equipment, thus having energy-saving and emission-reduction functions; the exhaust gas discharged after the compressed air has completed its work expands in volume and decreases in temperature, which can be used in coal mining roadways to reduce the ambient temperature of the coal mining roadways; and the use of a compressed air prime mover to replace the electric motor in coal mining roadways has explosion-proof function.
[0024] Second, the full-flow pneumatic turbine of the present invention adopts a design method of high speed, optimal reaction degree and axial annular outflow mode of volute, which reduces the external size of the full-flow pneumatic turbine, realizes the efficient conversion of compressed air internal energy, and meets the requirements of miniaturization and micro-miniaturization.
[0025] Third, the full-flow pneumatic turbine of the present invention adopts a standardized design of four-stage drive. The shape and size of the seat ring and impeller are the same or nearly the same. The number of stages can be adjusted according to the compressed air source parameters and working environment parameters, which can efficiently recover the internal energy of compressed air and has a wide range of applications.
[0026] IV. The full-flow pneumatic turbine-driven drainage pump of the present invention is used for the discharge of seepage water in coal mining roadways. Its efficiency is more than three times that of the currently widely used diaphragm pump, and it has broad application prospects and promotion value.
[0027] Fifth, the full-flow pneumatic turbine of the present invention is driven by compressed air commonly used in coal mines, which drives a forced exhaust fan, replacing the forced exhaust operation of gas in coal mining roadways driven by electric motors, and can achieve the dual emission effect of forced exhaust and suction of gas.
[0028] VI. The full-flow pneumatic turbine of this invention uses compressed air, which is commonly used in coal mines, to drive the anchor drilling rig. It can realize drilling operations in coal mining roadways without the safety hazards of motor drive, and has the characteristics of high efficiency, safety and explosion-proof. Attached Figure Description
[0029] Figure 1 This is a cross-sectional view of the entire machine of the present invention.
[0030] Figure 2 This is a half-sectional perspective view of the volute casing of the present invention.
[0031] Figure 3This is a cross-sectional view of the primary seat ring of the present invention.
[0032] Figure 4 This is a cross-sectional view of the secondary seat ring, tertiary seat ring, and quaternary seat ring of the present invention.
[0033] Figure 5 This is a cross-sectional view of the first-stage, second-stage, third-stage, and fourth-stage rotating wheels of the present invention.
[0034] Figure 6 This is a schematic diagram of the guide vanes and impellers of each stage of the present invention.
[0035] Figure number markings: 1. Volute; 101. Inlet flow channel; 102. Outlet flow channel; 103. Seat ring cavity; 104. Inlet cavity; 2. First-stage seat ring; 201. First-stage guide vane; 3. Second-stage seat ring; 301. Second-stage guide vane; 4. Third-stage seat ring; 401. Third-stage guide vane; 5. Fourth-stage seat ring; 501. Fourth-stage guide vane; 6. First-stage impeller; 601. First-stage blade; 7. Second-stage impeller; 701. Second-stage blade; 8. Third-stage impeller; 801. Third-stage blade; 9. Fourth-stage impeller Wheel; 901, fourth-stage propeller blade; 10, bearing assembly; 11, first-stage enclosure; 12, second-stage enclosure; 13, third-stage enclosure; 14, fourth-stage enclosure; 15, runner chamber; 16, bearing support end cover; 1601, exhaust channel; 17, fastener; 18, sealing element; 19, first sealing groove; 20, first sealing positioning end; 21, second sealing groove; 22, second sealing positioning end; 23, flow channel groove; 24, flow channel protrusion ring; 25, gland; 26, main shaft. Detailed Implementation
[0036] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.
[0037] according to Figures 1 to 6As shown: A full-flow pneumatic turbine includes: a guide section, which includes a volute 1 and at least two stages of seat rings arranged sequentially along the axial direction; the volute 1 has an inlet flow channel 101 extending radially or circumferentially and an outlet flow channel 102 extending axially; a power section, which includes at least two stages of impellers arranged alternately with the at least two stages of seat rings and coaxially mounted on the same main shaft 26; a support section, which includes at least two bearing assemblies 10 for supporting the rotation of the main shaft 26, the bearing assemblies 10 being distributed axially and located on the front and rear sides of the main shaft 26; wherein, the outlet flow channel 102 of the volute 1, the nozzle flow channels of each stage of seat rings, the blade flow channels of each stage of impellers, and the exhaust channel 1601 located at the downstream end are sequentially and sealed together along the axial direction to form a continuous full-flow channel from the inlet flow channel 101 to the exhaust channel 1601. The outlet flow channel 102 of the volute 1 is an annular flow channel coaxial with the main shaft 26. The nozzle flow channels of each stage of the seat rings and the blade flow channels of each stage of the impeller are designed with their central flow surfaces located on a reference cylindrical surface of the same diameter as the outlet flow channel 102 of the volute 1, coaxial with the main shaft 26, to form a smooth airflow path for a continuous annular flow channel. The central flow surfaces of the outlet flow channel 102 of the volute 1, the nozzle flow channels of each stage of the seat rings, the blade flow channels of each stage of the impeller, and the exhaust channel 1601 are designed and arranged on or infinitely close to a theoretical reference cylindrical surface coaxial with the main shaft 26 and of the same diameter. This ensures that the average radial position of the central flow surfaces of each flow channel remains consistent along the axial direction. This ensures that the airflow core can smoothly and continuously pass through all stages along the axial direction, which is the core structural feature constituting efficient full-flow channel energy conversion.
[0038] The outlet flow channel 102 of the volute 1 has an annular cross-section. The volute 1 contains a seat ring cavity 103 for accommodating the first-stage seat ring 2. The seat ring cavity 103 is an axially open annular cavity. The outlet flow channel 102 is axially aligned with and directly connected to the seat ring cavity 103, allowing the gas flowing out of the outlet flow channel 102 to enter the first-stage seat ring 2 in the seat ring cavity 103 without any detours. The volute 1 is the first intake channel for compressed air directly connected to the outside. To ensure a more stable and uniform flow of compressed air into the outlet flow channel 102 and ultimately into the first-stage seat ring 2, the rationality of its flow channel design directly affects the energy conversion efficiency of subsequent seat rings and the impeller. By optimizing the flow channel shape and outlet structure of the volute 1, efficient and stable conversion of the compressed air's internal energy into kinetic energy is achieved, providing uniform and stable airflow conditions for subsequent multi-stage work. The central flow surface of the outlet flow channel 102 and the central flow surface of the first-stage seat ring 2 are located on the same cylindrical surface. The volute 1 also includes an intake chamber 104, which connects the inlet flow channel 101 and the outlet flow channel 102. The longitudinal section of the intake chamber 104 is a fully elliptical cross-section. The structure of the volute 1 allows the airflow to turn from the circumferential inlet to the axial outlet without turning or abrupt changes in cross-section, avoiding turbulence and separation losses. At the same time, it ensures that the airflow is evenly distributed in the circumferential direction and naturally connects to subsequent multi-stage flow channels along the axial direction, providing streamlined and aligned flow channel conditions for multi-stage continuous energy conversion, thereby maximizing energy extraction efficiency.
[0039] The central flow surface is the curved surface formed by the midpoint of the flow channel in the radial direction. Specifically, the central flow surfaces of the outlet flow channel 102 of the volute 1, the nozzle flow channels of each stage of the seat ring, the blade flow channels of each stage of the impeller, and the exhaust channel 1601 are designed and arranged on or infinitely close to a theoretical reference cylindrical surface coaxial with the main shaft 26 and having the same diameter. This ensures that the average radial position of the central flow surfaces of each flow channel remains consistent along the axial direction. This ensures that the airflow core can smoothly and continuously pass through all stages along the axial direction, which is the core structural feature constituting efficient full-channel energy conversion.
[0040] The preferred seat ring includes a first-stage seat ring 2, a second-stage seat ring 3, a third-stage seat ring 4, and a fourth-stage seat ring 5 arranged sequentially along the axial direction; the rotating wheel includes a first-stage rotating wheel 6, a second-stage rotating wheel 7, a third-stage rotating wheel 8, and a fourth-stage rotating wheel 9 arranged alternately with the first-stage seat ring 2, the second-stage seat ring 3, the third-stage seat ring 4, and the fourth-stage seat ring 5.
[0041] The nozzle flow channel of the first-stage seat ring 2 is a conical annular structure with a gradually decreasing cross-sectional area along the airflow direction. The nozzle flow channel of the first-stage seat ring 2 is provided with first-stage guide vanes 201 evenly distributed along its circumference. The first-stage seat ring 2 is fixedly installed in the seat ring cavity 103.
[0042] The nozzle flow channel of the first-stage seat ring 2 is a conical annular tapered flow channel with a large inlet thickness and a small outlet thickness, with a flow channel tapering ratio of 0.007 to 0.009, preferably 0.008 to 0.009, and more preferably 0.0082, 0.0083, 0.0084, or 0.0085.
[0043] The first-stage guide vane 201 is a three-dimensional twisted airfoil structure. The outer side of the airfoil has a relative thickness of 10.02%, a relative camber of 1.76%, an inlet installation angle of 21.95 degrees, and an outlet installation angle of 13.12 degrees. The leading edge of the outer side is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 6.16 mm. The trailing edge of the outer side is a circle with a diameter of 2 mm. The inner side has a relative thickness of 10.09%, a relative camber of 2.09%, an inlet installation angle of 19.77 degrees, and an outlet installation angle of 11.62 degrees. The leading edge of the inner side is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5.36 mm. The trailing edge of the inner side is a circle with a diameter of 2 mm.
[0044] The nozzle channels of the second-stage seat ring 3, the third-stage seat ring 4, and the fourth-stage seat ring 5 are conical rings or cylindrical rings with a gradually expanding cross-sectional area along the airflow direction. The nozzle channel of the second-stage seat ring 3 is provided with second-stage guide vanes 301 evenly distributed along its circumference. The nozzle channel of the third-stage seat ring 4 is provided with third-stage guide vanes 401 evenly distributed along its circumference. The nozzle channel of the fourth-stage seat ring 5 is provided with fourth-stage guide vanes 501 evenly distributed along its circumference.
[0045] Secondary seat ring 3, tertiary seat ring 4, and quaternary seat ring 5 have the same or similar shapes, and the nozzle flow channel diffusion ratio of secondary seat ring 3, tertiary seat ring 4, and quaternary seat ring 5 is between 0.05 and 0.08. Alternatively, the nozzle flow channel of secondary seat ring 3, tertiary seat ring 4, and quaternary seat ring 5 can be a straight cylinder with a diffusion ratio of 0.
[0046] The second-stage guide vane 301, the third-stage guide vane 401, and the fourth-stage guide vane 501 are three-dimensional twisted airfoil structures. The relative thickness of the outer side of each airfoil is 13% to 15%, the relative camber of the outer side is 16% to 19%, the inlet installation angle of the outer side is 90 degrees, and the outlet installation angle of the outer side is 12 to 14 degrees. The relative thickness of the inner side is 11% to 13%, the relative camber of the inner side is 19% to 21%, the inlet installation angle of the inner side is 90 degrees, and the outlet installation angle of the inner side is 10 to 13 degrees. The leading edge of the airfoil is elliptical, and the trailing edge is circular.
[0047] The preferred secondary guide vane 301 has a relative thickness of 14.86% on its outer side, a relative camber of 18.54% on its outer side, an inlet installation angle of 90 degrees on its outer side, an outlet installation angle of 13.15 degrees on its outer side, an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5.5 mm on its outer side, and a circular shape with a diameter of 2 mm on its outer side. The relative thickness of its inner side is 12.47%, a relative camber of 20.02% on its inner side, an inlet installation angle of 90 degrees on its inner side, an outlet installation angle of 11.59 degrees on its inner side, an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5 mm on its inner side, and a circular shape with a diameter of 2 mm on its inner side.
[0048] The preferred three-stage guide vane 401 has an outer relative thickness of 12.94%, an outer relative camber of 18.00%, an outer inlet installation angle of 90 degrees, an outer outlet installation angle of 13.15 degrees, an outer leading edge that is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5 mm, and an outer trailing edge that is a circle with a diameter of 2 mm; the inner relative thickness is 12.47%, the inner relative camber is 20.24%, the inner inlet installation angle is 90 degrees, the inner outlet installation angle is 11.56 degrees, the inner leading edge that is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5 mm, and an inner trailing edge that is a circle with a diameter of 2 mm.
[0049] The preferred fourth-stage guide vane 501 has an outer relative thickness of 12.95%, an outer relative camber of 18.01%, an outer inlet installation angle of 90 degrees, an outer outlet installation angle of 13.18 degrees, an outer leading edge that is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5.5 mm, and an outer trailing edge that is a circle with a diameter of 2 mm. The inner relative thickness is 12.46%, the inner relative camber is 20.23%, the inner inlet installation angle is 90 degrees, the inner outlet installation angle is 11.55 degrees, the inner leading edge that is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5 mm, and an inner trailing edge that is a circle with a diameter of 2 mm.
[0050] Relative thickness of the outer wing: The ratio of the thickness of the outer wing surface to the wing length (the straight-line distance between the inlet and outlet of the wing centerline).
[0051] Relative camber on the outer side of the wing: The ratio of the maximum distance from the centerline of the outer side of the wing to the wing length (the straight-line distance between the inlet and outlet of the wing centerline) to the wing length.
[0052] Outer wing inlet installation angle: The angle between the direction of fluid inflow on the outer wing and the opposite direction of the circumferential velocity component on the outer wing.
[0053] Outlet installation angle on the outer side of the wing: The angle between the direction of fluid outflow on the outer side of the wing and the opposite direction of the circumferential velocity component on the outer side of the wing.
[0054] The same applies to the inner side of the wing. The side closer to the main shaft 26 is the inner side, and the side farther from the main shaft 26 is the outer side. The outer side of the wing is the side away from the main shaft 26, and the inner side of the wing is the side closer to the main shaft 26.
[0055] The diameter of the inlet end of the nozzle flow channel of the second-stage seat ring 3 is the same as the diameter of the outlet end of the blade flow channel of the first-stage runner 6, and the diameter of the outlet end of the nozzle flow channel of the second-stage seat ring 3 is the same as the diameter of the inlet end of the blade flow channel of the second-stage runner 7, and so on.
[0056] Each stage of the runner includes a hub, a runner outer ring coaxially fitted around the hub, and multiple airfoil blades connected between the hub and the runner outer ring and evenly distributed along the circumference. A sub-channel extending along the airflow direction is formed between two adjacent airfoil blades. The airflow direction at the inlet of the sub-channel is configured to be close to the tangential direction of the central flow surface, and the airflow direction at the outlet of the sub-channel is configured to be close to the axial direction of the central flow surface. A blade channel is formed between the outer circumferential surface of each stage of the hub and the inner circumferential surface of each stage of the runner outer ring. The diameter at the inlet of each stage of the blade channel is the same as the diameter at the outlet of the nozzle channel in the adjacent upper stage seat ring, and the diameter at the outlet of each stage of the blade channel is the same as the diameter at the inlet of the nozzle channel in the adjacent lower stage seat ring.
[0057] The first-stage rotor 6, second-stage rotor 7, third-stage rotor 8, and fourth-stage rotor 9 are respectively equipped with a first-stage blade 601 flow channel, a second-stage blade 701 flow channel, a third-stage blade 801 flow channel, and a fourth-stage blade 901 flow channel. The configuration of each blade flow channel is a conical annular structure with a gradually expanding cross-sectional area along the airflow direction or a cylindrical annular structure with a constant cross-sectional area, and the central flow surface of each blade flow channel is coplanar with the central flow surface of the outlet flow channel 102. Within each blade flow channel, three-dimensionally twisted airfoil blades are evenly distributed along their circumference, corresponding to the first-stage blade 601, second-stage blade 701, third-stage blade 801, and fourth-stage blade 901.
[0058] The diffusion ratio of the conical annular blade channel with a gradually expanding cross-sectional area along the airflow direction is 0.005 to 0.008. Preferably, the diffusion ratio is 0.006 to 0.007. A diffusion ratio of 0.006 to 0.007, and more preferably 0.0061, 0.0062, or 0.0063, is beneficial for the smooth expansion and deceleration of the airflow within the channel, more effectively transferring the pressure and kinetic energy of the airflow to the airfoil blades and converting it into the rotational torque of the rotor.
[0059] The airfoil blades have a relative thickness of 10%–12% on the outer side, a relative camber of 11%–13%, an inlet angle of 55–65 degrees, and an outlet angle of 10–12 degrees. The inner side has a relative thickness of 15%–17%, a relative camber of 27%–29%, an inlet angle of -60–-55 degrees, and an outlet angle of 12–14 degrees. The leading edge of the airfoil blades is elliptical, and the trailing edge is circular. Airflow enters from the leading edge and exits from the trailing edge. The different inlet angles and relative cambers on the inner and outer sides allow the airfoil to better adapt to changes in relative velocity and direction of airflow at different radii from the rotor hub to the outer ring, ensuring that airflow across the entire blade span impacts the blades at the optimal angle, generating higher work capacity and lower drag, thus significantly improving efficiency. The inner circumferential surface near each stage of the impeller flow channel is called the inner side, and the outer circumferential surface near each stage of the impeller flow channel is called the outer side.
[0060] The preferred first-stage blade 601 has an outer relative thickness of 10.13%, an outer relative camber of 12.72%, an outer inlet installation angle of 61.39 degrees, an outer outlet installation angle of 11.47 degrees, an outer leading edge that is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5 mm, and an outer trailing edge that is a circle with a diameter of 2 mm. The inner relative thickness is 16.83%, the inner relative camber is 28.39%, the inner inlet installation angle is -59.4 degrees, the inner outlet installation angle is 13.54 degrees, the inner leading edge that is an ellipse with a major-to-minor axis ratio of 3:1 and a minor axis length of 5 mm, and an inner trailing edge that is a circle with a diameter of 2 mm.
[0061] The outer wing of the second-stage rotor blade 701 has a relative thickness of 11.00%, a relative camber of 12.95%, an inlet angle of 60.40 degrees, an outlet angle of 11.44 degrees, and an elliptical leading edge with a minor axis ratio of 3:1 and a minor axis length of 5 mm. The trailing edge of the outer wing is a circle with a diameter of 2 mm. The inner wing has a relative thickness of 16.72%, a relative camber of 28.5%, an inlet angle of -58.36 degrees, an outlet angle of 13.58 degrees, and an elliptical leading edge with a minor axis ratio of 3:1 and a minor axis length of 5 mm. The trailing edge of the inner wing is a circle with a diameter of 2 mm.
[0062] The three-stage rotor blade 801 has a relative thickness of 11.26% on the outer side, a relative camber of 12.79%, an inlet angle of 59.33 degrees, an outlet angle of 11.41 degrees, and an elliptical leading edge with a minor axis ratio of 3:1 and a minor axis length of 5 mm. The trailing edge is a circle with a diameter of 2 mm. The relative thickness of the inner side is 16.65%, a relative camber of 28.74%, an inlet angle of -57.24 degrees, an outlet angle of 13.62 degrees, and an elliptical leading edge with a minor axis ratio of 3:1 and a minor axis length of 5 mm. The trailing edge is a circle with a diameter of 2 mm.
[0063] The 901 four-stage rotor blade has a relative thickness of 11.21% on the outer side, a relative camber of 12.55%, an inlet angle of 58.16 degrees, an outlet angle of 11.37 degrees, and an elliptical leading edge with a minor axis ratio of 3:1 and a minor axis length of 5 mm. The trailing edge is a circle with a diameter of 2 mm. The relative thickness of the inner side is 16.71%, a relative camber of 28.87%, an inlet angle of -56.02 degrees, an outlet angle of 13.67 degrees, and an elliptical leading edge with a minor axis ratio of 3:1 and a minor axis length of 5 mm. The trailing edge is a circle with a diameter of 2 mm.
[0064] Compressed air enters circumferentially from the volute 1, is rectified within the volute 1, and then flows out axially from the outlet channel 102. Subsequently, the airflow sequentially passes through a four-stage series of "seat ring-rotor" combinations: in each seat ring 2, the axially flowing airflow is accelerated and adjusted to a helical direction with an outlet installation angle of approximately 13 degrees by three-dimensionally twisted guide vanes, impacting the rotor at the optimal tangential angle. In the corresponding rotor, the airflow meets the airflow over the airfoil blades with a larger inlet installation angle (e.g., the outer inlet installation angle of the first-stage rotor 6 is 61.39 degrees / the inner inlet installation angle is -59.4 degrees), converting its kinetic and pressure energy into mechanical energy, causing the rotor to rotate. The rotated airflow then flows out in a near-axial direction (approximately 11-14 degrees). After four stages of continuous expansion and work, the pressure and temperature of the airflow are significantly reduced, and it is finally discharged from the machine in a near-axial direction through the axial exhaust channel 1601, thus efficiently converting the internal energy of the compressed air into rotational mechanical energy to drive the main shaft 26.
[0065] The pneumatic turbine also includes four enclosures: a primary enclosure 11, a secondary enclosure 12, a tertiary enclosure 13, and a quaternary enclosure 14. Each enclosure and each corresponding seat ring are arranged alternately, and each enclosure, together with its adjacent seat ring, forms a runner chamber 15 to accommodate the runner at each stage. The pneumatic turbine also includes a bearing support end cover 16, located at the outer end of the quaternary runner 9 and sealed and fixedly connected to the quaternary enclosure 14. An exhaust passage 1601 is located on the bearing support end cover 16, and a bearing assembly 10 is fixedly installed inside the bearing support end cover 16. The volute 1, primary enclosure 11, secondary seat ring 3, secondary enclosure 12, tertiary seat ring 4, tertiary enclosure 13, quaternary seat ring 5, and quaternary enclosure 14 are arranged sequentially along the axial direction and fixed by fasteners 17. Sealing elements 18 are provided between the volute 1 and the primary enclosure 11, as well as between the other enclosures and seat rings at each stage. The enclosures and each seat ring are integrally formed or separately formed. A first sealing groove 19 is formed between the outer periphery of the first-stage seat ring 2 and the cavity wall of the seat ring cavity 103. A sealing element 18 is located in the first sealing groove 19. A first sealing positioning end 20 protrudes from the first enclosure near the volute 1 towards the first sealing groove 19 and is embedded within it. A second sealing groove 21 is formed by axially recessing the enclosure and other seat rings at their ends away from the volute 1. Sealing elements 18 of the same or different types are provided within the second sealing groove 21. A second sealing positioning end 22 protrudes from the enclosure and each seat ring towards the second sealing groove 21 and is embedded within it. Each stage of the rotating wheel is provided with a flow channel protrusion ring 24. The volute 1, each stage of the seat ring, and the bearing support end cap 16 are all provided with flow channel grooves 23 that mate with the flow channel protrusion ring 24. A buffer flow channel is formed between the flow channel protrusion ring 24 and the flow channel groove 23. The bearing assembly 10 mainly includes inner and outer bearing rings and balls. A pressure cap 25 is also fixedly connected to the outer end of the volute 1, and a sealing element is provided inside the pressure cap 25.
[0066] The working principle of this pneumatic turbine: 1. Compressed air from the outside enters the volute 1 in the circumferential direction through the air supply pipe connected to the inlet flow channel 101 of the volute 1. It moves in the volute 1 with a constant average circumferential velocity in the volute 1 with a variable cross-sectional area. It flows out axially through the annular outlet flow channel 102 of the volute 1 and flows into the nozzle flow channel of the first stage seat ring 2 in a uniform and axial manner. Second, the pressurized gas flowing into the nozzle channel of the first-stage seat ring 2 expands and accelerates in the first-stage guide vane 201 and adjusts its flow direction. It then enters the first-stage blade 601 channel of the rotating first-stage impeller 6 in a uniform and tangential manner, causing the first-stage blade 601 in the first-stage impeller 601 channel to generate lift, which drives the first-stage impeller 6 and the main shaft 26 to rotate and do work, thus converting the internal energy of the pressurized gas into rotational mechanical energy for the first time. Third, the pressurized gas flowing out of the first-stage blade 601 flow channel of the first-stage impeller 6 flows uniformly and axially into the second-stage nozzle flow channel of the second-stage seat ring 3. It expands and accelerates in the second-stage guide vane 301 and adjusts its flow direction. It then enters the second-stage blade 701 flow channel of the second-stage impeller 7 uniformly and tangentially, causing the second-stage blade 701 of the second-stage impeller 7 to generate lift, which drives the second-stage impeller 7 and the main shaft 26 to rotate and do work, thus converting the internal energy of the pressurized gas into rotational mechanical energy for the second time. Fourth, the pressurized gas flowing out of the flow channel of the second-stage blade 701 of the second-stage rotor 7 flows uniformly and axially into the flow channel of the third-stage nozzle of the third-stage seat ring 4. It expands and accelerates in the third-stage guide vane 401 and adjusts the flow direction. It then enters the flow channel of the third-stage blade 801 of the third-stage rotor 8 uniformly and tangentially, causing the third-stage blade 801 of the third-stage rotor 8 to generate lift, which drives the third-stage rotor 8 and the main shaft 26 to rotate and do work, converting the internal energy of the pressurized gas into rotational mechanical energy for the third time. Fifth, the pressurized gas flowing out of the flow channel of the third-stage blade 801 of the third-stage rotor 8 flows uniformly and axially into the flow channel of the fourth-stage nozzle of the fourth-stage seat ring 5. It expands and accelerates in the fourth-stage guide vane 501 and adjusts the flow direction. It then enters the flow channel of the fourth-stage blade 901 of the fourth-stage rotor 9 uniformly and tangentially, causing the fourth-stage blade 901 of the fourth-stage rotor 9 to generate lift, which drives the fourth-stage rotor 9 and the main shaft 26 to rotate and do work, converting the internal energy of the pressurized gas into rotational mechanical energy for the fourth time. VI. The gas flowing out from the flow channel of the fourth-stage blade 901 of the fourth-stage runner 9 flows into the support blade in the exhaust channel 1601 of the bearing support end cover 16 and then exits as exhaust gas from the high-efficiency full-flow channel pneumatic turbine to complete the power process. VII. The first-stage rotary wheel 6, the second-stage rotary wheel 7, the third-stage rotary wheel 8, and the fourth-stage rotary wheel 9 are installed on the main spindle 26 by the standard keys in their respective standard keyways and the four keyways of the main spindle 26. They are positioned by the four bushings fitted on the main spindle 26, and the work done by the four rotary wheels is transmitted to the main spindle 26 and output through the power output terminal of the main spindle 26.
[0067] Compressed air from the pipeline has high pressure and temperature, containing a large amount of pressure potential energy and internal energy. After entering the pneumatic turbine, the compressed air flows sequentially through multiple stages of nozzle and blade flow channels, which are connected in series to perform work. In the nozzle flow channel, the airflow expands and accelerates, converting some pressure energy into kinetic energy, and the temperature begins to decrease initially. In the blade flow channel, the high-speed airflow impacts the airfoil blades, driving the rotor to rotate and outputting mechanical work. In this process, the kinetic energy of the airflow and the remaining pressure energy are both converted into mechanical energy. According to the law of conservation of energy, the energy consumed to complete this part of the mechanical work ultimately comes from the reduction of the gas's own internal energy, resulting in a significant decrease in gas temperature. Each stage repeats the process of expansion and acceleration to impact work to reduction of internal energy (temperature decrease). Through multiple stages of continuous energy extraction, the gas pressure and temperature are gradually and fully reduced, from about 25°C at the inlet to about 5°C at the outlet.
[0068] The direct discharge of low-temperature exhaust gas into the coal mining roadway effectively reduces the ambient temperature within the roadway, improving working conditions for workers. This solves the problem of overheating from electric equipment exacerbating high roadway temperatures. The cooling process itself embodies efficient energy conversion, aligning with the goal of improving efficiency. Simultaneously, the introduction of low-temperature gas helps dilute and remove methane, enhancing safety. This innovative use of a single compressed air power source to simultaneously achieve both mechanical power output and environmental cooling maximizes the cascade utilization of energy and overall benefits.
[0069] The axial full-flow-channel series layout, along with the multi-stage impeller and each stage of seat ring, achieves highly efficient cascaded conversion of compressed air energy, with an overall efficiency of 89.8%, significantly higher than traditional diaphragm pumps. Simultaneously, the low-temperature exhaust gas after expansion can be directly discharged into the working roadway, serving the dual purpose of reducing ambient temperature and enhancing gas emission. Its all-pneumatic drive fundamentally eliminates the risk of electrical sparks, fully meeting underground explosion-proof requirements. Furthermore, its standardized, modular cascade design allows for flexible adjustment of the number of stages based on air source parameters, providing excellent adaptability to operating conditions and ease of maintenance. It offers significant safety, energy-saving, and environmental advantages in coal mine drainage, ventilation, and drilling / anchoring applications.
[0070] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection defined by the claims of the present invention.
Claims
1. A full-flow-path pneumatic turbine, characterized in that, include: The guide section includes a volute (1) and at least two stages of seat rings arranged sequentially along the axial direction; The volute (1) is provided with an inlet channel (101) extending circumferentially and an outlet channel (102) extending axially. The working section includes at least two stages of rotating wheels that are staggered with the at least two stages of seat rings and coaxially mounted on the same main shaft (26); The support section includes at least two bearing assemblies (10) for supporting the rotation of the main shaft (26), the bearing assemblies (10) being axially distributed and located on the front and rear sides of the main shaft (26); Among them, the outlet flow channel (102) of the volute (1), the nozzle flow channel of each stage of the seat ring, the blade flow channel of each stage of the impeller and the exhaust channel (1601) located at the downstream end are sequentially sealed and connected along the axial direction to form a continuous full flow channel from the inlet flow channel (101) to the exhaust channel (1601). The volute (1) is formed with a seat ring cavity (103), and the outlet flow channel (102) of the volute (1) is a circular annular flow channel coaxial with the main shaft (26); the gas flowing out of the outlet flow channel (102) can enter the seat ring cavity (103) without turning. The nozzle flow channels of each stage of the seat ring and the blade flow channels of each stage of the impeller are designed with their central flow surfaces located on the reference cylindrical surface of the same diameter as the central flow surface of the outlet flow channel (102) of the volute (1) on the same axis as the main shaft (26), so as to form a smooth airflow passage of a continuous annular full flow channel. The structure of the volute (1) allows the airflow to turn from the circumferential inlet to the axial outlet without any turning point or abrupt change in cross section.
2. The full-flow pneumatic turbine according to claim 1, characterized in that: The seat ring includes a first-stage seat ring (2), a second-stage seat ring (3), a third-stage seat ring (4), and a fourth-stage seat ring (5) arranged sequentially along the axial direction; the rotating wheel includes a first-stage rotating wheel (6), a second-stage rotating wheel (7), a third-stage rotating wheel (8), and a fourth-stage rotating wheel (9) arranged alternately with the first-stage seat ring (2), the second-stage seat ring (3), the third-stage seat ring (4), and the fourth-stage seat ring (5).
3. The full-flow pneumatic turbine according to claim 2, characterized in that: The nozzle flow channel of the first-stage seat ring (2) is a conical ring structure with a gradually decreasing cross-sectional area along the airflow direction, and the nozzle flow channel of the first-stage seat ring (2) is provided with first-stage guide vanes (201) evenly distributed along its circumference.
4. A full-flow-path pneumatic turbine according to claim 3, characterized in that: The nozzle channels of the secondary seat ring (3), tertiary seat ring (4) and quaternary seat ring (5) are conical rings or cylindrical rings with equal cross-sectional areas that gradually expand along the airflow direction. The nozzle channel of the secondary seat ring (3) is provided with secondary guide vanes (301) that are evenly distributed along its circumference. The nozzle channel of the tertiary seat ring (4) is provided with tertiary guide vanes (401) that are evenly distributed along its circumference. The nozzle channel of the quaternary seat ring (5) is provided with quaternary guide vanes (501) that are evenly distributed along its circumference.
5. A full-flow-path pneumatic turbine according to claim 4, characterized in that: It also includes four enclosures, namely a first-level enclosure (11), a second-level enclosure (12), a third-level enclosure (13), and a fourth-level enclosure (14). Each level of enclosure is arranged alternately with each level of seat ring, and each level of enclosure, together with the adjacent seat ring, forms a wheel chamber (15) for accommodating each level of wheel.
6. A full-flow pneumatic turbine according to claim 5, characterized in that: The volute (1) is formed with a seat ring cavity (103), and the first-level seat ring (2) is fixedly disposed in the seat ring cavity (103). The volute (1), the first-level enclosure (11), the second-level seat ring (3), the second-level enclosure (12), the third-level seat ring (4), the third-level enclosure (13), the fourth-level seat ring (5) and the fourth-level enclosure (14) are arranged in sequence along the axial direction and fixed by fasteners (17). Sealing elements (18) are provided between the volute (1), the first-level enclosure (11) and other enclosures and seat rings at each level.
7. A full-flow pneumatic turbine according to claim 6, characterized in that: It also includes a bearing support end cover (16), which is located at the outer end of the fourth stage wheel (9) and is sealed and fixedly connected to the fourth stage enclosure (14). The exhaust channel (1601) is located on the bearing support end cover (16), and a bearing assembly (10) is fixedly installed inside the bearing support end cover (16).
8. A full-flow pneumatic turbine according to claim 2, characterized in that: Each stage of the impeller includes a hub, an outer ring coaxially fitted on the outside of the hub, and multiple airfoil blades connected between the hub and the outer ring and evenly distributed along the circumference. A sub-channel is formed between two adjacent airfoil blades, extending along the airflow direction. The airflow direction at the inlet of the sub-channel is configured to be close to the tangential direction of the central flow surface, and the airflow direction at the outlet of the sub-channel is configured to be close to the axial direction of the central flow surface.
9. A full-flow pneumatic turbine according to claim 8, characterized in that: The outer circumferential surface of each stage hub and the inner circumferential surface of each stage runner outer ring form a blade flow channel. The diameter at the inlet of each stage blade flow channel is the same as the diameter at the outlet of the nozzle flow channel in the adjacent upper stage seat ring, and the diameter at the outlet of each stage blade flow channel is the same as the diameter at the inlet of the nozzle flow channel in the adjacent lower stage seat ring.