Gas barrier driven shaft in exhaust steam turbine

Abstract

The application discloses an air resistance pushing in-shaft exhaust steam turbine, which comprises a base and a cylinder fixed on the base, the cylinder is divided into a high-pressure area and a low-pressure area by an air seal, a multifunctional transmission shaft is rotatably connected in the cylinder, an air inlet is arranged on the cylinder and communicated with the high-pressure area, an air resistance wheel is fixed on the shaft body of the multifunctional transmission shaft in the high-pressure area, an air flow channel is formed from the air inlet, through the air resistance wheel, the shaft body air port and the low-pressure area, the air resistance wheel is driven to rotate by the air flow during the air flow movement, and the transmission structure for converting heat energy into mechanical energy is formed. The application has the effects that: the air resistance wheel is used to form resistance to the high-temperature and high-pressure air flow, the air flow is circularly moved to push the air resistance wheel to rotate, the heat energy is converted into mechanical energy, the problem of the axial thrust of the traditional air turbine is eliminated, the problems of the conversion energy loss, the air leakage of the partition plate and the moving blade top of the traditional air turbine are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power devices, in particular to a steam turbine, and more particularly to an air resistance driven shaft-in exhaust steam turbine. BACKGROUND

[0002] The energy conversion part of the traditional steam turbine is mainly composed of a stationary blade nozzle grid and a moving blade grid, and a multi-stage blade grid structure is adopted. In the energy conversion process, the steam with certain pressure and temperature in the stage is first expanded and accelerated in the nozzle grid channel to convert the thermal energy of the steam into the kinetic energy of the high-speed airflow, and then enters the moving blade channel to change the direction or change the direction while expanding and accelerating to push the impeller to rotate and convert the kinetic energy of the high-speed airflow into rotating mechanical energy.

[0003] With the large-scale of the steam turbine, the steam flow through the last stage of the steam turbine also increases. In order to efficiently convert the thermal energy of the steam flow into mechanical work, longer last stage blades are needed. The limit of the length of the last stage blades should consider the increase of centrifugal force, the increase of steam flow rate, the reduction of natural frequency and other limiting factors, and more advanced technologies are needed to support the centrifugal stress intensity and vibration characteristics. It leads to great difficulty in manufacturing steam turbine blades. At present, the manufacturing of steam turbine blades in China is basically organized in small batches. This production mode has problems such as large amount of design repetitive labor, long production cycle and high production cost in the production process. Especially for short blade stages with low aspect ratio, it is difficult to consider blade upgrading alone, which is not conducive to the upgrading of steam turbine. The traditional steam turbine generally has the problems of air leakage of the diaphragm and the moving blade top and the axial thrust of the steam turbine, which cannot be solved by simply upgrading the blades. SUMMARY

[0004] The present application solves the above-mentioned problems existing in the prior art and provides an air resistance driven shaft-in exhaust steam turbine to solve the problems of air leakage of the diaphragm and the moving blade top of the current traditional steam turbine, axial thrust of the steam turbine and meet the needs of reducing manufacturing cost.

[0005] The technical scheme that the application adopts to solve the technical problems is: the air resistance driven shaft exhaust steam turbine comprises a base, a cylinder is arranged on the base, the cylinder is divided into a high pressure area and a low pressure area by a gas seal, a multifunctional transmission shaft is rotatably connected in the cylinder, one end of the multifunctional transmission shaft is located in the low pressure area, the other end of the multifunctional transmission shaft penetrates through the high pressure area and is exposed outside the cylinder to form an output end, an air inlet is arranged on the cylinder and communicates with the high pressure area, an air resistance wheel driven by delaying airflow is fixed on the shaft body of the multifunctional transmission shaft located in the high pressure area, the multifunctional transmission shaft is hollow and communicates with the inside of the low pressure area at one end, a shaft gas port is arranged on the multifunctional transmission shaft and communicates with the inside, an airflow channel is formed from the air inlet, the airflow flows around the circumference of the multifunctional transmission shaft in the air resistance wheel, and then passes through the inside of the multifunctional transmission shaft through the shaft gas port and finally reaches the low pressure area, in the process of airflow movement, the air resistance wheel is driven to rotate by the transmission structure converting heat energy into mechanical energy due to the airflow obtaining thrust. After the steam enters the high pressure area from the air inlet, the airflow enters the air resistance wheel and is discharged to the low pressure area through the inside of the multifunctional transmission shaft from the shaft gas port, the airflow passes through the airflow channel from the air inlet, flows around the circumference of the multifunctional transmission shaft in the air resistance wheel, and then passes through the inside of the multifunctional transmission shaft through the shaft gas port and finally reaches the low pressure area, the air resistance wheel can delay airflow and make the airflow flow around the circumference of the multifunctional transmission shaft in the air resistance wheel, so that the airflow does work on the circumference of the air resistance wheel and drives the air resistance wheel to rotate, finally forming the transmission structure converting heat energy into mechanical energy to drive the multifunctional transmission shaft to rotate, the whole structure does not have a multi-stage blade structure, solves a series of problems caused by the traditional blade structure, the energy conversion is more efficient, and the use effect is better.

[0006] As a further improvement of the application, the air resistance wheel comprises a hollow shell fixed on the multifunctional transmission shaft, the shell is provided with an opening for airflow to pass through, and a set of barrier layers are filled and stacked around the circumference of the transmission shaft from the opening position in the shell, the barrier layers are uniformly provided with a set of through holes, the front and rear adjacent through holes are staggered and arranged to form air holes with partially overlapped through holes, and the front and rear air hole combinations form a circumferential air duct structure extending around the circumference of the multifunctional transmission shaft. A reserved space is left between the shell and the end barrier layer, and the reserved space is communicated with the shaft air port through the connecting through hole. The high-pressure area airflow enters from the shell opening, and since the inside of the shell is filled with barrier layers, it can only enter from the through hole position, and the front and rear adjacent through holes are staggered and need to pass through the air hole with overlapped through holes. In this process, the airflow will impact on the exposed end face of the barrier layer, and the airflow impact condition is repeated during the airflow flow process until the airflow enters the reserved space and is discharged from the shaft air port. Since the air duct composed of air holes is a circumferential structure around the shaft, the airflow flow process will drive the air resistance wheel to rotate and drive the transmission shaft to move, realizing the transmission shaft operation effect. According to the use requirement, the size of the through hole and the size of the air hole with overlapped through holes are adjusted to adjust the work done by the airflow on the air resistance wheel, meeting various use requirements. The reserved space is mainly to ensure that the airflow can quickly pass through the shaft air port at the tail end, so that the airflow flows more smoothly.

[0007] As a further improvement of the application, the outlet end of the multifunctional transmission shaft is fixed with an airflow boost device, the airflow boost device is composed of an inner wheel and an outer wheel, the inner wheel is sealingly connected to the outlet end of the multifunctional transmission shaft, the inner wheel is provided with at least one nozzle communicated with the outlet of the multifunctional transmission shaft, the outer wheel is a ring-shaped static blade structure, the nozzle is directed towards the surface of the static blade of the outer wheel, and the outer wheel is composed of upper and lower parts. The upper and lower parts of the outer wheel are fixed on the cylinder body. The airflow enters the multifunctional transmission shaft and is discharged at the end into the inner wheel, and then is discharged from the nozzle towards the outer wheel. The inner wheel is fixedly connected to the end of the transmission shaft, so that the inner wheel drives the transmission shaft to rotate under the action of the airflow, the tail airflow is used to boost the transmission shaft, the airflow is fully utilized, and the energy utilization efficiency is improved.

[0008] As a further improvement of the application, the barrier layer is a block structure with a fan ring cross section, and the front and rear barrier layers are stacked to form a fan ring sealing structure that only passes through the air hole between the opening and the reserved space in the shell. The fan ring block structure of the barrier layer facilitates circumferential stacking and filling to form a closed structure, ensures that the airflow can only pass through the through hole of the barrier layer, greatly improves the thrust of the airflow on the air resistance wheel, and effectively improves the effect of the airflow on the air resistance wheel.

[0009] As a further improvement of the present application, the barrier layer is provided with a fixed through hole, and the front and rear through holes are connected to form a pressure relief air passage of the annular straight-through shaft body air port. The straight-through shaft body air port is connected to the front and rear through holes, which can make the gas flow quickly pass through to achieve the purpose of pressure relief, avoid the situation that the gas flow through the air resistance wheel is too slow to cause the high pressure area to have too high pressure, and ensure that the high pressure area does not have too high pressure, which is safer to use.

[0010] As a further improvement of the present application, the opening of the shell is located on the radial surface of the transmission shaft, and the air resistance wheel is at least arranged in pairs, and the openings of the shell of the air resistance wheels arranged in pairs are staggered by 180 degrees. The design of the opening of the shell located on the radial surface of the transmission shaft can make the air inlet direction perpendicular to the direction of the barrier layer to achieve the purpose of efficient and rapid passage of the gas flow, and reduce the situation that the air flow speed decreases due to the opening in other directions. However, this opening design will result in an irregular overall structure of the air resistance wheel, which is easy to cause the transmission shaft to be unbalanced during high-speed operation. Therefore, it is necessary to ensure that the air resistance wheel is at least arranged in pairs and the openings of the shell are staggered by 180 degrees, so that the transmission shaft meets the requirement of dynamic balance and the transmission shaft operates more stably and smoothly.

[0011] As a further improvement of the present application, a condenser pipe fixed to the cylinder body is arranged in the low pressure area, and the condenser pipe is located close to the exhaust port of the gas flow boosting device. The condenser pipe can cool and depressurize the overheated steam discharged by the gas flow boosting device, effectively ensure that the low pressure area is maintained in a stable region, and improve the gas flow efficiency of the exhaust circulation system.

[0012] As a further improvement of the present application, the output end of the multifunctional transmission shaft and the shaft body part connected with the air resistance wheel and the gas flow boosting device are all tooth shaft structures. After such arrangement, the fixed connection structure on the multifunctional transmission shaft is more stable and the transmission efficiency is higher due to the meshing connection of the tooth shaft structure, which can meet higher design and use requirements.

[0013] The present application has the advantages of reasonable and compact structure, efficient energy conversion by using the air resistance wheel, improved work efficiency of the steam turbine, and the specific effects include:

[0014] 1. The circumferential air inlet of the air resistance wheel makes the gas flow move around the transmission shaft, eliminating the axial thrust problem of traditional gas turbines;

[0015] 2. The air resistance wheel forms resistance to high temperature and high pressure gas flow, making the gas flow move in a circular direction to push the air resistance wheel to rotate, converting heat energy into mechanical energy, solving the problems of energy conversion loss, and air leakage of the separator and moving blades of traditional gas turbines;

[0016] 3. No traditional static and dynamic blade cascade energy conversion is needed, eliminating the unstable factors such as bending deformation and fracture of the last stage blades of traditional gas turbines;

[0017] 4. The air resistance wheel can realize the regulation of the resistance, torque and rotating speed by changing the material and structure inside the wheel, so that the energy of the air turbine can be used optimally.

[0018] 5. The inner wheel of the air flow boosting device sprays the air flow to the outer wheel at a high speed, so that the inner wheel gets a counter thrust, and the transmission shaft is further driven to rotate, and the energy of the air flow tail of the air turbine is effectively used. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Fig. 1 is a structural schematic diagram of the present application;

[0020] Figure 2 Fig. 2 is a structural schematic diagram of the air resistance wheel;

[0021] Figure 3 Fig. 3 is a structural schematic diagram of the inner structure of the air resistance wheel;

[0022] Figure 4 Fig. 4 is a structural schematic diagram of the barrier layer;

[0023] Figure 5 Fig. 5 is a sectional view of the air passage composed of the through holes of the barrier layer after stacking;

[0024] Figure 6 Fig. 6 is a sectional view of the pressure relief air passage composed of the through holes of the barrier layer after stacking;

[0025] Figure 7 Fig. 7 is a structural schematic diagram of the inner structure of the air flow boosting device;

[0026] Figure 8 Fig. 8 is a structural schematic diagram of the inner wheel of the air flow boosting device.

[0027] Fig. 1 is a structural schematic diagram of the present application; DETAILED DESCRIPTION

[0028] The present application will be further described below in combination with the drawings:

[0029] Referring to the attached drawings: This embodiment of the pneumatically driven in-shaft exhaust turbine includes a base 1 fixed to the bottom surface. A cylinder 2 is provided on the base 1. The cylinder 2 is divided into a high-pressure zone and a low-pressure zone by an air seal. A multi-functional drive shaft 3 is rotatably connected inside the cylinder 2. One end of the multi-functional drive shaft 3 is located in the low-pressure zone, while the other end passes through the high-pressure zone and is exposed outside the cylinder to form an output end. The cylinder 2 is provided with an air inlet communicating with the high-pressure zone. A pneumatic drag wheel 4 is fixed on the shaft of the multi-functional drive shaft 3 located in the high-pressure zone, which is driven by delaying the airflow. The multi-functional drive shaft 3 is hollow inside and communicates with the interior of the low-pressure zone at one end. The multi-functional drive shaft 3 is provided with a shaft air port communicating with the interior, forming an airflow channel that enters from the air inlet, flows around the circumference of the multi-functional drive shaft 3 in the pneumatic drag wheel 4, passes through the shaft air port, and finally reaches the low-pressure zone. During the airflow movement, the pneumatic drag wheel 4 gains thrust due to the airflow, forming a transmission structure that converts thermal energy into mechanical energy and drives the multi-functional drive shaft 3 to rotate.

[0030] The air resistance wheel 4 includes a hollow outer shell 5 fixed on the multi-functional drive shaft 3. The outer shell 5 has an opening for airflow to pass through. A set of barrier layers 6 are stacked around the circumference of the drive shaft starting from the opening position inside the outer shell 5. A set of through holes 7 are evenly distributed on the barrier layer 6. The front and rear adjacent through holes 7 are staggered to form an air hole formed by the partial overlap of the through holes 7. The front and rear air holes are combined to form a circumferential air passage structure extending around the circumference of the multi-functional drive shaft 3. A space is reserved between the outer shell 5 and the end barrier layer 6. The reserved space is connected to the air port of the shaft through the connecting through hole.

[0031] An airflow booster device 13 is fixed to the outlet end of the multi-functional drive shaft 3. The airflow booster device 13 consists of an inner wheel 8 and an outer wheel 9. The inner wheel 8 is sealed to the outlet end of the multi-functional drive shaft 3 and has at least one nozzle 10 communicating with the outlet of the multi-functional drive shaft 3. The outer wheel 9 has an annular stationary blade structure, with the nozzle 10 facing the surface of the stationary blade of the outer wheel 9. The outer wheel 9 consists of upper and lower parts, which are respectively fixed to the cylinder body. A gap is reserved between the inner wheel 8 and the outer wheel 9 to ensure that when the nozzle 10 sprays airflow towards the stationary blade of the outer wheel 9, most of the airflow impacts the surface of the stationary blade and is guided to the outside of the outer wheel.

[0032] The barrier layer 6 is a block structure with a fan-shaped cross-section. The front and rear barrier layers 6 are stacked to form a fan-shaped sealing structure that seals and fills the gap between the opening and the reserved space inside the outer shell 5, with only air holes passing through.

[0033] Preferably, the barrier layer 6 is provided with a fixed through hole 11, and the front and rear through holes 11 are connected to form an annular straight-through air vent for the vent of the shaft.

[0034] Preferably, the openings of the housing are located on the radial surface of the transmission shaft, the air resistance wheels are arranged at least in pairs, and the openings of the air resistance wheels in the pairs are staggered by 180°.

[0035] Since the high-pressure area and the low-pressure area are connected through the inside of the transmission shaft, the hollow structure of the multifunctional transmission shaft 3 forms a medium-pressure transition area between the high pressure and the low pressure, and the high, medium and low pressures ensure the rapid movement of the airflow in the air path.

[0036] The low-pressure area is provided with a condenser pipe 12 fixed to the cylinder block, and the condenser pipe 12 is located close to the exhaust port of the airflow boosting device.

[0037] Preferably, the output end of the multifunctional transmission shaft 3, and the shaft body parts connected with the air resistance wheels and the airflow boosting device are all toothed shaft structures.

[0038] Although the present application has been illustrated and described with reference to the preferred embodiments, it should be understood by those skilled in the art that various changes in form and details can be made within the scope of the claims.

Claims

1. A gas resistance pushed shaft exhaust steam turbine, comprising a base (1) fixed on a base surface, a cylinder (2) provided on the base (1), a high pressure area and a low pressure area separated by a gas seal in the cylinder (2), a multi-functional transmission shaft (3) rotatably connected in the cylinder (2), one end of the multi-functional transmission shaft (3) located in the low pressure area and the other end penetrating through the high pressure area and exposed outside the cylinder to form an output end, characterized in that: The cylinder (2) is provided with an air inlet communicating with the high pressure area, the multifunctional transmission shaft (3) is fixed with the air resistance wheel (4) driven by delaying airflow on the shaft body in the high pressure area, the multifunctional transmission shaft (3) is hollow and communicates with the inside of the low pressure area at one end, the multifunctional transmission shaft (3) is provided with a shaft body air port communicating with the inside, forming an airflow channel from the air inlet, around the circumference of the multifunctional transmission shaft (3) in the air resistance wheel (4), then through the shaft body air port through the inside of the multifunctional transmission shaft and finally to the low pressure area. During the movement of the airflow, the air resistance wheel (4) obtains the thrust of the airflow and forms the transmission structure for converting heat energy into mechanical energy to drive the rotation of the multifunctional transmission shaft (3). ​ 2. A gas-lubricated, push-sump, axial exhaust steam turbine according to claim 1, characterized in that: The air resistance wheel (4) comprises a hollow shell (5) fixed on the multifunctional transmission shaft (3), the shell (5) is provided with an opening for the airflow to pass through, and a group of barrier layers (6) are filled and stacked around the circumference of the transmission shaft from the opening position in the shell (5), the barrier layers (6) are uniformly distributed with a group of through holes (7), the front and rear through holes (7) are staggered and arranged to form air holes formed by the partial coincidence of the through holes (7), and the front and rear air holes are combined to form a circumferential air duct structure extending around the circumference of the multifunctional transmission shaft (3). The shell (5) and the end barrier layer (6) are reserved space, and the reserved space is communicated with the shaft body air port through the connecting through hole.

3. A gas-lubricated, push-sump, axial exhaust steam turbine according to claim 1, characterized in that: The outlet end of the multifunctional transmission shaft (3) is fixed with an airflow boost device (13), the airflow boost device (13) is composed of an inner wheel (8) and an outer wheel (9), the inner wheel (8) is sealingly connected to the outlet end of the multifunctional transmission shaft (3), the inner wheel (8) is provided with at least one nozzle (10) communicating with the outlet of the multifunctional transmission shaft (3), the outer wheel (9) is a ring-shaped static blade structure, the nozzle (10) is directed to the static blade surface of the outer wheel (9), and the outer wheel (9) is composed of two parts, and the upper and lower parts of the outer wheel are fixed on the cylinder body.

4. A gas-lubricated, push-sump, axial exhaust steam turbine according to claim 2, characterized in that: The barrier layer (6) is a block structure with a fan ring cross section, and the front and rear barrier layers (6) are stacked to form a fan ring sealing structure that only passes through the air holes in the shell (5) between the opening and the reserved space.

5. A gas-lubricated, push-sump, axial exhaust steam turbine according to claim 2 or 4, characterized in that: The barrier layer (6) is provided with a fixed position through hole (11), and the front and rear through holes (11) are connected to form a ring-shaped pressure relief air duct of the shaft body air port.

6. A gas barrier propelled shaft in exhaust steam turbine in accordance with claim 2 characterized by: The opening of the shell is located on the radial surface of the transmission shaft, the air resistance wheel is arranged at least in pairs, and the openings of the shells of the air resistance wheels arranged in pairs are staggered by 180°.

7. A gas-lubricated, push-sump, axial exhaust steam turbine according to claim 3, characterized in that: The low pressure area is provided with a condenser pipe (12) fixed on the cylinder body, and the condenser pipe (12) is close to the air outlet position of the airflow boost device.

8. A gas-lubricated, push-sump, axial exhaust steam turbine according to claim 3, characterized in that: The output end of the multifunctional transmission shaft (3), the shaft body part connected with the air resistance wheel and the airflow boost device are all gear shaft structures.

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