WO1997040259A1

WO1997040259A1 - A non-blade steam turbine

Info

Publication number: WO1997040259A1
Application number: PCT/CN1997/000029
Authority: WO
Inventors: Quangui Shen
Original assignee: Quangui Shen
Priority date: 1996-04-18
Filing date: 1997-04-08
Publication date: 1997-10-30
Also published as: CN1056435C; CN1153864A; AU2502497A

Abstract

This invention relates to a non-blade steam turbine having a stator, a rotor, a driving shaft, an input and an output room, side covers, bearing, a stand and tendons. The stator is composed of inner and outer casings, that are tapered and connected to each other. There is a cooling water room between the stator and the rotor. The taper rotor is located in the inner casing at equal taper and is mounted movely. There are input and output openings, which provide an arrangement inclined to the radial and are covered by the covers, in the stator. Also, there are many hollows, number and direction of which are equal to that of the openings in the stator, arrayed equally at 2-25° on the surface of the rotor, so as to increase the power and the thermoefficiency.

Description

Bladeless steam turbine

Technical field

The present invention relates to a steam turbine, in particular to a bladeless steam turbine that converts thermal energy into a mechanical energy device.

Background technique

The vane turbine following the piston steam engine has been widely used in industrial production. There are many types of vane turbines. Although the existing back pressure type, extraction type, condensing type, intermediate reheating type, etc., but their basic structure is generally the same, all are equipped with Multi-pressure stage device composed of moving blades and stationary blades, relying on steam

(Working medium) Expansion work, effective thermal efficiency up to 22% ~ 38%.

Vane turbines mainly include intake chambers, nozzles, moving blades, stationary blades, rotors, stators, main shafts, sliding bearing exhaust chambers, bolts and heat insulation layers, etc., except for the blades, rotors and stators of the main structure. Except that the pressure angles of the two pressure stages are the same, most of the dynamic and static blades of the pressure stages are from the root (axial) 15. ~ 30. Start at blade tip (axial) 70. ~ 85. The structure of the twisted and unrolled shape from thick to thin, the geometry of all the blades is very complicated.

The purpose of the present invention is to provide a bladeless turbine that significantly improves the power and effective thermal efficiency of a power machine, which mainly works by condensing and shrinking the volume of steam (working medium).

Summary of the Invention

Bladeless steam turbine, including stator, rotor, end cover, main shaft, bearings, inlet chamber, exhaust chamber, bolts, tripods and strong ribs, the shaft and rotor use a shaft key to cooperate statically, and the two ends of the shaft are connected to the bearing to move The mating and end caps are bolted and screwed, and are characterized by: 1) the stator is made of a double-layered inner shell with a tapered sleeve, and the outer shell is a cooling water chamber; the cooling water chamber is provided with an inlet and a drainage pipe; The inner shell has a frustoconical shape, and the axial taper of the inner surface is 3 to 30 X. The circumferential direction of the inner shell is provided with air holes and exhaust holes with equal intervals of 6 to 20 levels. The holes are radially spaced at a circumferential angle of 4-30 °, and the holes are in the same direction and are 35 ° to 65 ° from the radial center perpendicular. The inclination angle H¾ is perpendicular to the axial centerline. Each exhaust hole is connected to the next-stage intake hole, while the first-stage intake hole is connected to the intake chamber, and the last-stage exhaust hole is connected to the exhaust hole. The chambers are connected, each pair of adjacent intakes There are steam hole covers on the holes and exhaust holes. There is an air inlet in the steam inlet chamber and a steam exhaust port in the exhaust chamber.

2) The rotor also has a frustoconical shape and is sleeved in the stator inner shell. The rotor and the stator have a dynamic fit with a taper, that is, the axial inclination angle outside the rotor cone is the same as the axial inclination angle of the tapered inner surface of the stator inner shell. The number of inlet and exhaust steam stages set in the axial direction of the rotor is the same as the number of steam holes in the stator. The cavities distributed around the rotor are evenly spaced in the radial direction, and the interval angle of the cavities is 2. ~ 25. The radial directions of the cavities are all the same and are consistent with the direction of the steam holes of the stator. ~ 15 °, the backward inclination angle of the rear steam cavity surface in the radial direction is 20. -45 °, the two parallel axial spacers of the cavities are perpendicular to the central axis. The invention has the following advantages compared with the vane type steam turbine:

1) The rotor and the stator use the same taper, and self-phase running-in can be achieved after finishing. High concentricity can be achieved. The axial movement can be adjusted to compensate the gap caused by the thermal expansion of the metal. Adjusted to the critical gap, because the above gap is small, the fluid on the rotor surface forms a vapor film seal, because the gap seal between the stator and the rotor can improve the efficiency of the machine by 3%-5%.

2) The pressure of the steam in the cavities of the rotor towards the peripheral wall is equal. The steam in the cavities moves forward synchronously with the rotor and turns to the exhaust hole. The steam then flows to the next nozzle. This overcomes the vane turbine (axial) The high resistance loss caused by the impact of high-speed fluid and high-speed blades on each other can also increase the efficiency of the unit by 6% ~ 8%.

3) The steam flow turns 180 in the small steam cavity. Work by the angle, which can effectively increase the impact force of the steam flow energy and the counter-impact force, which can improve the efficiency by 7%-9%.

4) Steam flows between the inlet and exhaust steam holes of the stator and the channel of the steam guide joint. The loss of flow resistance due to pressure reduction is very small, so that its kinetic energy is converted into heat and absorbed by cooling water and brought back to the boiler for recycling. Therefore, the overall thermal efficiency loss is not large. At the same time, it overcomes the low-grade heat generated by the pressure reduction and expansion work of the existing vane turbine, that is, the waste heat cannot be recycled. The vaneless turbine of the present invention can make the entire waste heat recovery rate as high as 30% ~ 40% recyclable.

In summary, the present invention can improve the effective thermal efficiency by about 20% to 38% compared with the existing bladed steam turbine. Of course, due to the different number of stages and the rated power of the bladeless steam turbine of the present invention, the above-mentioned thermal efficiency improvement radius is different. However, in contrast, the general trend of improving the thermal efficiency of the steam turbine of the present invention is no doubt. Overview of the drawings

1 is a radial sectional view of a vaneless steam turbine according to the present invention;

2 is an axial half-section view of a vaneless steam turbine according to the present invention;

3 is a schematic diagram of a radial working principle of a vaneless steam turbine according to the present invention;

Figure 4 is the axial working principle diagram of the vaneless turbine of the present invention.

Best Mode of the Invention

1 and 2 show an embodiment of a vaneless steam turbine according to the present invention, which includes a stator

(1), rotor (10), end cover (13, 18), main shaft (12), bearing (16), inlet chamber (2), exhaust chamber (8), fastening bolts (15, 17), 4. Tripods (24), stiffeners (26), etc.

The stator (1) is formed by nesting an inner shell (5) and an outer shell (6). The inner shell (5) is frusto-conical to form a double-layered tapered stator (1). The inner layer and the outer layer are The cooling water chamber (23), the cooling water flows from the water inlet pipe (21) into the cooling water chamber (23), and flows out from the drainage pipe (22). The inner shell is provided with a 12-stage radial deflection angle 45. The steam inlet holes (3) and steam exhaust holes (4) are evenly spaced symmetrically, and the circumference angle of the space is 10. The 12-stage steam holes are evenly spaced along the axis to form 36 groups of holes spaced in and out in the circumferential direction. Each steam hole is perpendicular to the axis in the axial direction, and the radial angle of the steam holes is uniformly eccentrically inclined. Angle 45. The exhaust hole of the upper stage is connected with the intake hole of the next stage, the steam inlet of the first stage is connected with the steam inlet chamber (2), and the exhaust pipe of the last stage is connected with the exhaust chamber (8). The steam inlet of the steam chamber (2) is provided with a steam inlet flange (19), and the steam outlet of the exhaust chamber (8) is provided with a steam exhaust flange (20). Each group of steam inlets on the outer circumferential surface of the inner shell A steam hole cover (7) is provided on the hole and the steam exhaust hole.

The rotor (10) also has a truncated cone and is sleeved on the inner shell of the stator to form the same taper dynamic fit of the rotor and the stator. The axial inclination angle of the outer surface of the rotor periphery is consistent with the inclination of the inner surface of the stator shell, and its inclination design Into 3 ~ 30. And a 12-stage small cavities (9) are set on the rotor, and the circumferential angle of the radial interval between the cavities is 8. , The radial direction in the small steam cavity is the same and is consistent with the stator steam hole direction, and the rear inclination angle of the rear steam cavity surface (subject to the rotor's turning) is 35. The backward tilt angle of the front steam cavity surface is 5 °, and the axial direction of the small steam cavity is parallel to the vertical center axis of the two surfaces.

The main shaft (12) and the rotor (10) are statically fitted with a shaft chain (11). The sliding or rolling bearing (16) is placed at the center of 18), and the bearing cover (14) is fastened to the two ends of the stator with bolts (15) during assembly. The foot frame (24) is provided with ground screw holes ( 25).

In actual use, additional auxiliary devices such as axial seals, couplings, centrifugal automatic governors, steam control valves and steam control levers, and related systems are added to the heat insulation layer and related systems to form a complete set of Blade turbine equipment.

In Figure 1, the working medium (steam) enters the steam inlet chamber (2) in the upper part of the stator (1) in the direction of arrow A, so that all the nozzles (steam inlets) of the entire first pressure stage have uniform pressure, and high-pressure steam is in the first stage nozzle. (3) is accelerated in the channel to generate kinetic energy, that is, the impact energy of steam, high-speed steam impacts the small steam cavity in the rotor (10), and the generated kinetic energy is transmitted to the shaft to perform external work. Enter the small steam cavity (9) The steam in the first pressure stage moves radially with the rotor (10) forward (see Figure 1), and flows out through the steam outlet (4) of the first pressure stage. The steam enters the first pressure stage, Once the first kinetic energy transfer is completed, the first work is performed.

The steam discharged from the first pressure stage flows axially along the steam hole cover (7) and enters the second pressure stage nozzle (3) to accelerate and impact the small steam cavity again. In the second small steam cavity of the rotor (10), The steam enters and exits for the second time, and the kinetic energy generated by the second pressure stage is transmitted again through the shaft to perform work. The steam flows from the high pressure to the low pressure in this order and works repeatedly, and the pressure drops gradually, and the steam The final work is performed through the nozzle (3) of the last stage (twelfth stage), and the exhaust chambers of the exhaust holes (4) of the last stage are merged and then exhausted.

Figure 3 is a schematic diagram of the rotational torque force due to the centrifugal pressure of the steam. The rotational torque force is generated by the eccentric inertial impact caused by the high-speed steam flowing out of the mouth of the mouth.

Because the stator inner shell (5) is processed in the circumferential direction of the nozzle (3) and the exhaust (4), the same method of inclined eccentric hole machining is used. The inclined eccentric angle of the hole is formed with the center vertical line of the stator (1). 35. -65. The inclination and eccentricity are directly proportional to the magnitude of the torque force.

As shown in Figure 3 and Figure 4, steam enters and exits at 180 in the small steam cavity. Turning and completing, the steam produced 180. The reciprocation of the angle (the impact of the intake air and the recoil of the exhaust steam), and the way of working effectively improves the optimal angle selection of the working medium to transfer the kinetic energy.

The steam in the passage of the steam hole cover of the stator (1) produces a stepwise decompression and acceleration axial movement, and the expansion of the steam hole cover (7) produces the function of storing energy, so that the next pressure stage has sufficient quality improvement. High steam transfer energy (mass is proportional to energy in motion). Increasing the mass of working medium step by step is another special option for this structure.

The present invention mainly uses condensing steam to reduce the pressure of the steam flow and accelerate the volume to reduce the pressure. It is completely opposite to the working principle of the expansion expansion and drag reduction and acceleration of the vane steam turbine, which chooses to shrink the working medium. The working principle of non-expansion can effectively recover the waste heat of the steam and play a regeneration cycle. The stator (1) uses an inner shell (5) and an outer shell (6). The sleeve structure sealing device uses cooling water (23) as a coolant. It plays two roles, one is to cool the high-temperature steam to reduce the volume and generate a pressure drop, so as to reduce the flow resistance and accelerate the fluid. The second is that the high-temperature steam passes through the inner shell (5) and the steam hole cover (7). The large-area heat conduction and radiation of metal produce heat exchange, so that the waste heat of steam can be recycled and the utilization rate can be increased by 30% to 40%.

The torque generated by the device is the sum of the eccentric pressure of the steam from all the inclined eccentric holes of the device, and the power generated by the rotor is the sum of the energy chapters of the high-velocity impact and reaction kinetic energy generated by the high pressure of steam.

Obviously, the inner surface of the inner shell (5) of the stator (1) is consistent with the outer surface of the rotor (10), and is processed into a conical structure with the same taper. The function of the same taper is that the taper can be adjusted to optimize the seal after a single match. Clearance to eliminate misalignment errors caused by machining and assembly tolerances. Inclined taper is conducive to adjusting sealing clearance and improving sealing performance. Due to the multi-stage (6-20) structure, the utilization of the exhaust steam excess speed energy is fully improved Therefore, the output (rated power) is increased. The porous structure of the stator is required to increase the eccentric pressure and capacity. Without affecting the welding hole cover, the circumferential distribution angle of the inlet and exhaust holes should be 3-30. The (axial) centerline of the steam holes of each pressure stage on the outer circumferential surface of the stator inner shell is consistent. The nozzle steam holes and the central vertical line form an inclined slope of 35. ~ 65. Eccentric angle (see Figure 3).

The rotor (10) adopts multiple small cavities (9), which increases the effective force area and increases the power. The pressure stages of the small cavities (9) should be the same as the pressure stages of the stator (1). Each pressure There is no limit to the number of small cavities (single and even) in each stage. The (axial) centerline of the cavities between each stage does not have to be aligned, which can increase the distribution of torque. The diameter of the small cavities (9) in each pressure stage The distribution angle is 2-25. It is uniformly distributed in the circumferential direction. The axial two parallel planes of each small air cavity are perpendicular to the axis, and the backward inclination angle of the rear steam cavity surface in the radial direction is 20 to 45. This can reduce the eddy current loss generated when steam enters and exits the air cavity, The backward tilt angle of the front steam cavity surface in the radial direction is 5-15 °. This angle is favorable for receiving steam impact force and reducing the effect of centrifugal force generated when the rotor (10) is running.

The use of cooling water and steam convection improves the heat exchange rate and cooling effect, and increases the water temperature, reduces the steam temperature, and increases the value of waste heat utilization.

The capacity of the cross-sectional area of the steam hole cover (7) is 2 to 10 times larger than the capacity of the cross-sectional area of the inlet and exhaust holes (14), which is conducive to the accelerated flow of steam in the axial direction and the energy accumulation and storage function. It can expand the heat dissipation area and increase the cooling effect.

Both the stator (1) and the rotor (10) adopt a monolithic structure, and its role is to improve the tensile and shear strength of the metal under thermal stress and improve the mechanical properties of the metal. The stator (1) and the rotor (10) adopt non-friction Dynamic cooperation, so that the main body of the device does not wear, which is beneficial to improve the service life.

There are steam seal groups (26) between the pressure stages and at the first and last stages to improve the sealing effect on steam.

Although the present invention has been described with reference to specific embodiments, those of ordinary skill in the art should understand that, as long as the modifications to the specific embodiments do not deviate from the subject matter and advantages of the present invention, it should be understood that all these modifications are included in Within the spirit and scope of the invention as defined by the claims.

Claims

O 97/40259 claims

1. Bladeless steam turbine, including stator, rotor, end cover, main shaft, bearings, inlet chamber, exhaust chamber, bolts, stand, and stiffeners, the shaft and rotor use a static key, and both ends of the shaft are connected to the bearing It has a dynamic fit, and the two end covers are fastened with bolts, which are characterized by:

a) The stator is composed of a double-layered inner shell and outer shell. The inner and outer shells are cooling water chambers. The cooling water chambers are provided with inlet and drain pipes. The inner shell has a truncated cone shape. The axial tilt angle is 3-30. The inner shell is provided along the axial direction with uniformly spaced inlet and exhaust holes of approximately 6-20 grades, and the circumferential angle between the radial holes is 4. ~ 30. The steam holes are in the same direction and at an inclination eccentricity of 35 ° to 65 ° with the radial center perpendicular line, which is perpendicular to the axial center line. Each exhaust hole is connected to the next-stage air inlet hole, and the first-stage inlet The air holes are connected to the air intake chamber, and the last stage exhaust holes are connected to the air exhaust chamber. Each adjacent pair of air intake holes and exhaust holes is provided with a steam hole cover, and there are air inlets in the air intake chamber. There are steam outlets in the exhaust chamber.

b) The rotor also has a truncated cone shape and is sleeved in the stator inner shell. The rotor and the stator have a dynamic fit with a taper, that is, the axial inclination angle of the outer cone of the rotor is the same as the axial inclination of the inner cone of the stator. The number of inlet and exhaust steam stages set in the axial direction of the rotor is the same as the number of steam holes in the stator. The circumferentially distributed cavities are evenly spaced in the circumferential direction. The cavitation interval is 2 ° ~ 25 °. The radial direction of the cavities They are all the same and are consistent with the direction of the steam holes of the stator. -15. The rearward inclination angle of the rear steam cavity surface in the radial direction is 20. ~ 45. The two parallel axial spacers of the cavities are perpendicular to the central axis.

2. The bladeless steam turbine according to claim 1, wherein the axial inclination angle of the inner surface of the stator inner casing is eight. -12 °, there are 12-16 stages for the inlet and exhaust holes.

3. The bladeless steam turbine according to claim 1, wherein the radial separation angle of the steam holes on the stator inner shell is 5. ~ 15 °, the direction of the pores and the radial center perpendicular to the inclined eccentric angle of 45 ° ~ 50 °.

4. The bladeless steam turbine according to claim 1, wherein the small cavities on the rotor are radially spaced at an angle of 5. ~ 10. The rearward inclination angle of the rear steam cavity surface in the radial direction is 35. ~ 40 °, the backward camber angle of the front steam cavity surface is 5 °. ~ 10 °.