300MW secondary reheating side exhaust air turbine low-pressure module

Abstract

The invention discloses a 300MW secondary reheat side exhaust air turbine low-pressure module, and relates to the technical field of steam turbines. The problems that in the operation process of a low-pressure module of a traditional secondary reheat turbine, thrust balance is difficult, a large amount of energy is consumed when a low-pressure cylinder operates, consequently, unit energy consumption is high, and the development trend of the energy conservation and emission reduction industry is not met are solved. Compared with an exhaust mode of a traditional air turbine low-pressure cylinder, the problems that vortexes are generated in the exhaust process of airflow, the remaining velocity loss is too large and the like are easily caused by a path of the traditional exhaust mode, the side exhaust structure optimizes the air flowing track, reduces airflow disturbance and resistance, reduces energy loss in the exhaust process, improves the inner efficiency of the low-pressure cylinder, and improves the exhaust efficiency of the low-pressure cylinder. And therefore, the power generation efficiency of the whole air turbine unit is enhanced, and the development trend of the energy-saving and emission-reducing industry is met. The invention is suitable for the technical field of secondary reheat turbines.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steam turbines, in particular to a 300MW secondary reheat side exhaust air turbine low-pressure module. BACKGROUND

[0002] At present, the air turbine is a key equipment of the compressed air energy storage system, and high efficiency and high stability are the core performance indicators of the air turbine. The low-pressure module of the traditional secondary reheat turbine is mostly designed as a shaft exhaust cylinder or a lower exhaust cylinder. The shaft exhaust cylinder is usually arranged in a downstream flow, the last-stage blade is long, the design is difficult, and the thrust balance is difficult. In addition, the bearing box is located in the exhaust cylinder, and the bearing elevation is easily affected by temperature changes, thereby affecting the shaft stability. The lower exhaust cylinder needs more bottom reserved space, the unit arrangement is difficult, the civil cost is increased, the maintenance space is small, and the maintenance and repair also increase the workload and time cost.

[0003] In summary, the low-pressure module of the traditional secondary reheat turbine has the problems of difficult thrust balance in the running process, resulting in a large amount of energy loss during the operation of the low-pressure cylinder, thereby causing high energy consumption of the unit, which does not meet the development trend of the energy-saving and emission-reduction industry. SUMMARY

[0004] The present application is to solve the problems of the low-pressure module of the traditional secondary reheat turbine, such as difficult thrust balance in the running process, resulting in a large amount of energy loss during the operation of the low-pressure cylinder, thereby causing high energy consumption of the unit, which does not meet the development trend of the energy-saving and emission-reduction industry, and proposes a 300MW secondary reheat side exhaust air turbine low-pressure module.

[0005] The 300MW secondary reheat side exhaust air turbine low-pressure module of the present application comprises a first bearing box 1, an end gas seal 2, a corrugated section 3, a conical guide plate 4, a low-pressure inner cylinder 5, a low-pressure outer cylinder 6, a second bearing box 7, a guide ring 8, a dynamic balance adjuster 9, an outer cylinder guide plate 10, an air inlet pipe 11, and a low-pressure air inlet corrugated section 12.

[0006] The inside of the low-pressure outer cylinder 6 is provided with a low-pressure inner cylinder 5, the output port of the low-pressure inner cylinder 5 is provided with a flow guide ring 8, the central part of the two sides of the low-pressure outer cylinder 6 is respectively provided with a through hole, one end of the input port of the low-pressure inner cylinder 5 is in communication with the through hole on one side of the low-pressure outer cylinder 6, the other end of the input port of the low-pressure inner cylinder 5 is in communication with the through hole on the other side of the low-pressure outer cylinder 6, the through hole on one side of the low-pressure outer cylinder 6 is fixedly connected with the output end of the first bearing box 1, the through hole on the other side of the low-pressure outer cylinder 6 is fixedly connected with the output end of the second bearing box 7, the through hole on the side of the low-pressure outer cylinder 6 is provided with a tapered flow guide plate 4 at the connection position of the input port of the low-pressure inner cylinder 5, the end of the tapered flow guide plate 4 is provided with an outer cylinder flow guide plate 10 in the circumferential direction, the connection position of the outer cylinder flow guide plate 10 and the end of the tapered flow guide plate 4 is provided with a corrugated section 3, the through hole on the side of the low-pressure outer cylinder 6 and the output end of the bearing box are uniformly provided with an end gas seal 2 and a low-pressure inlet corrugated section 12 in the circumferential direction, the end face of the end gas seal 2 is provided with a dynamic balance adjuster 9, the top end of the end gas seal 2 is fixedly connected with the end of the corresponding corrugated section 3, and the input end of the low-pressure inner cylinder 5 is provided with an inlet pipe 11.

[0007] Further, the low-pressure inner cylinder 5 and the flow guide ring 8 are integrally casted.

[0008] Further, the low-pressure outer cylinder 6 comprises a low-pressure outer cylinder upper part and a low-pressure outer cylinder lower part, the outer surface of the low-pressure outer cylinder upper part is uniformly provided with transverse ribs and longitudinal ribs, and the transverse ribs and the longitudinal ribs are arranged perpendicular to each other, and the low-pressure outer cylinder upper part and the low-pressure outer cylinder lower part are fixed by welding.

[0009] Further, one end of the upper surface of the low-pressure outer cylinder upper part is uniformly processed with two manholes 6-1 in the width direction.

[0010] Further, one side of the low-pressure outer cylinder upper part is provided with an exhaust port 6-2.

[0011] Further, the top corners of the low-pressure outer cylinder lower part are respectively provided with a base frame 6-3.

[0012] Further, one side of the low-pressure outer cylinder lower part is provided with an air inlet 6-4.

[0013] Further, the bottom surface of the low-pressure outer cylinder lower part is provided with a bottom support plate 6-5.

[0014] Further, the end gas seal 2, the corrugated section 3 and the dynamic balance adjuster 9 are integrally arranged, and the end gas seal 2 is a comb structure.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] The present application overcomes the shortcomings of the prior art, the low-pressure inner cylinder in the air turbine is designed as a large cavity body, the gas passes through the blade through-flow from the low-pressure inlet chamber, then enters the exhaust chamber for full flow and mixing, and finally is discharged from the outlet surface of one side of the exhaust chamber, the aerodynamic performance of the low-pressure exhaust chamber mainly investigates the performance parameters such as the flow difference between the inlet and outlet, the overall isentropic efficiency of the chamber and the total pressure loss, etc. The airflow of the low-pressure inner cylinder inlet chamber flows from the inlet into the inlet pipe, is converted from tangential to axial in the inlet volute, and flows into the turbine stage, the airflow basically flows along the volute flow passage, the flow condition is good, and the streamline is relatively smooth, and no obvious vortex flow occurs in the volute. The overall flow in the low-pressure exhaust chamber is relatively complex, the airflow is mixed with each other in the exhaust chamber, and most of the airflow forms vortex motion after contacting the volute wall; in order to more clearly and intuitively observe the flow condition and pressure loss condition of the low-pressure exhaust chamber, the YZ section, the XZ section and the XY section of the low-pressure exhaust chamber are taken for specific analysis. As can be seen from the YZ plane streamline diagram, the flow field distribution is relatively uniform, and the airflow produces vortex at the lower part of the exhaust chamber near the outlet due to the mutual mixing; as can be seen from the YZ plane total pressure distribution cloud diagram and the static entropy distribution cloud diagram, the airflow flow is relatively uniform. Through numerical simulation calculation, the total pressure loss of the low-pressure exhaust chamber is 1.40%. According to the data level analysis, the overall performance of the low-pressure exhaust chamber is good. Therefore, compared with the exhaust mode of the low-pressure cylinder of the conventional air turbine, the traditional exhaust mode path is easy to cause vortex flow and excessive residual velocity loss during the discharge process, etc., the side discharge structure optimizes the air flow trajectory, reduces the airflow disturbance and resistance, reduces the energy loss in the exhaust process, improves the internal efficiency of the low-pressure cylinder, and further enhances the power generation efficiency of the entire air turbine unit, which meets the development trend of the energy saving and emission reduction industry. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a side sectional view of a 300MW secondary reheat side discharge air turbine low-pressure module according to the present application;

[0018] Figure 2 is a three-dimensional structure schematic diagram of a 300MW secondary reheat side discharge air turbine low-pressure module according to the present application;

[0019] Figure 3 is a three-dimensional structure schematic diagram of a low-pressure inner cylinder in a 300MW secondary reheat side discharge air turbine low-pressure module according to the present application;

[0020] Figure 4 is a side sectional view of the output end of a low-pressure inner cylinder in a 300MW secondary reheat side discharge air turbine low-pressure module according to the present application;

[0021] Figure 5 is a bottom sectional view of a low-pressure inner cylinder in a 300MW secondary reheat side discharge air turbine low-pressure module according to the present application;

[0022] Figure 6 is a main sectional view of a 300MW secondary reheat side exhaust air turbine low pressure module middle end gas seal, corrugated section and dynamic balance regulator connection state according to the present application;

[0023] Figure 7 is a main sectional view of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure inner cylinder, low pressure outer cylinder, inlet pipe and low pressure inlet corrugated section connection state according to the present application;

[0024] Figure 8 is an equivalent stress nephogram of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure inner cylinder according to the present application;

[0025] Figure 9 is a middle section contact stress nephogram of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure inner cylinder according to the present application;

[0026] Figure 10 is a temperature field distribution of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure outer cylinder according to the present application;

[0027] Figure 11 is a middle section contact stress nephogram of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure outer cylinder according to the present application;

[0028] Figure 12 is a 3D streamline diagram of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure inner cylinder exhaust cavity according to the present application;

[0029] Figure 13 is a 3D streamline diagram of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure inner cylinder exhaust cavity according to the present application;

[0030] Figure 14 is a low pressure exhaust cavity YZ plane total pressure distribution nephogram of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure inner cylinder according to the present application;

[0031] Figure 15 is a low pressure exhaust cavity YZ plane static entropy distribution nephogram of a 300MW secondary reheat side exhaust air turbine low pressure module middle low pressure inner cylinder according to the present application. DETAILED DESCRIPTION

[0032] DETAILED DESCRIPTION Figures 1 to 15The 300MW secondary reheat side exhaust air turbine low pressure module comprises a first bearing box 1, an end gas seal 2, a corrugated section 3, a conical guide plate 4, a low pressure inner cylinder 5, a low pressure outer cylinder 6, a second bearing box 7, a guide ring 8, a dynamic balance adjuster 9, an outer cylinder guide plate 10, an air inlet pipe 11 and a low pressure air inlet corrugated section 12;

[0033] The low pressure outer cylinder 6 is internally provided with the low pressure inner cylinder 5, the output port of the low pressure inner cylinder 5 is provided with the guide ring 8, the two sides of the low pressure outer cylinder 6 are respectively provided with a through hole, one end of the input port of the low pressure inner cylinder 5 is in communication with the through hole on one side of the low pressure outer cylinder 6, the other end of the input port of the low pressure inner cylinder 5 is in communication with the through hole on the other side of the low pressure outer cylinder 6, the through hole on one side of the low pressure outer cylinder 6 is fixedly connected with the output end of the first bearing box 1, the through hole on the other side of the low pressure outer cylinder 6 is fixedly connected with the output end of the second bearing box 7, the through hole on the side of the low pressure outer cylinder 6 is provided with the conical guide plate 4 at the connection position of the input port of the low pressure inner cylinder 5, the end of the conical guide plate 4 is provided with the outer cylinder guide plate 10 in the circumferential direction, the connection position of the outer cylinder guide plate 10 and the end of the conical guide plate 4 is provided with the corrugated section 3, the through hole on the side of the low pressure outer cylinder 6 is uniformly provided with the end gas seal 2 and the low pressure air inlet corrugated section 12 in the circumferential direction at the connection position of the output end of the bearing box, the end face of the end gas seal 2 is provided with the dynamic balance adjuster 9, the top end of the end gas seal 2 is fixedly connected with the end of the corresponding corrugated section 3, and the input end of the low pressure inner cylinder 5 is provided with the air inlet pipe 11.

[0034] In the specific embodiment, the low pressure outer cylinder 6 and the low pressure inner cylinder 5 are connected through the low pressure air inlet corrugated section 12, so that the expansion and vibration can be absorbed.

[0035] Specific embodiment two: in combination Figures 1 to 15 The 300MW secondary reheat side exhaust air turbine low pressure module is further limited to the low pressure module in the specific embodiment one, and the low pressure inner cylinder 5 and the guide ring 8 are integrally casted.

[0036] In the specific embodiment, the low pressure inner cylinder is casted by cast iron material and is formed into two parts, the nodular cast iron has high strength and excellent processing performance, and the middle part is connected by a flange sealing structure through bolts.

[0037] The low pressure inner cylinder air inlet area adopts a volute air inlet channel, the air inlet adopts tangential volute air inlet, the air inlet mode can make the flow field in the volute uniform, can obviously overcome the air flow excitation problem caused by non-steady effect, can ensure the safe and stable operation of the unit, can shorten the turbine length, can improve the through-flow efficiency, can start quickly, has excellent variable working condition performance, can reduce the flow loss of the inlet part, can allow to increase the air flow rate, has extremely high air kinetic energy conversion efficiency, can reduce the manufacturing cost and improve the economy of the unit.

[0038] The low-pressure inner cylinder and the flow guide ring are integrally cast, which is different from the structure that the inner cylinder and the flow guide ring are bolted together. The flow guide effect is better, and the strength is better. In addition, due to the advantage of good rigidity of the cast part, it can well reduce the air leakage loss caused by the deformation of the joint surface, and improve the flow operation efficiency; at the same time, the self-sealing type cylinder body structure technology is adopted, which ensures the good sealing performance of the low-pressure inner cylinder. The low-pressure inlet chamber of the air turbine adopts a single-inlet tangential inlet volute design, and three flow guide rib plates are added in the volute flow channel to improve the gas flow condition and effectively suppress the generation of gas flow vortex.

[0039] Specific implementation method three: in combination with Figures 1 to 15 The present embodiment is a further limitation of the low-pressure module described in the first specific implementation. The 300MW secondary reheat side exhaust air turbine low-pressure module described in the present embodiment includes a low-pressure outer cylinder upper part and a low-pressure outer cylinder lower part. The outer surface of the low-pressure outer cylinder upper part is uniformly provided with transverse ribs and longitudinal ribs, and the transverse ribs and longitudinal ribs are perpendicular to each other. The low-pressure outer cylinder upper part and the low-pressure outer cylinder lower part are fixed by welding.

[0040] In the present specific implementation, the longitudinal ribs of the low-pressure outer cylinder upper part are 60mm thick, the transverse ribs are 100mm thick, and the low-pressure outer cylinder lower part is all welded with T-shaped steel. The ribs are staggered and welded on the surface of the cylinder body, which not only effectively enhances the overall stiffness of the low-pressure outer cylinder 6 and the bending strength of the peripheral side plate, but also saves the overall installation space.

[0041] After multiple rounds of simulation test and scheme optimization, the flange thickness of the low-pressure outer cylinder 6 is increased to 250mm, and the thickness of the middle support plate is 420mm, which significantly improves the overall stiffness of the outer cylinder and the structural stability of the gas outlet flange.

[0042] Specific implementation method four: in combination with Figures 1 to 15 The present embodiment is a further limitation of the low-pressure module described in the third specific implementation. The 300MW secondary reheat side exhaust air turbine low-pressure module described in the present embodiment includes a low-pressure outer cylinder upper part, and the upper surface of the low-pressure outer cylinder upper part is uniformly provided with two manholes 6-1 along the width direction at one end.

[0043] In the present specific implementation, the upper surface of the low-pressure outer cylinder upper part is uniformly provided with two manholes 6-1 along the width direction at one end. After entering the manhole 6-1, there is a ladder on both sides, which can directly climb into the inside bottom, facilitating personnel access.

[0044] Specific implementation method five: in combination with Figures 1 to 15The embodiment is a further limitation of the low-pressure module described in Embodiment Four. The 300 MW secondary reheat side exhaust air turbine low-pressure module has an exhaust port 6-2 on one side of the upper part of the low-pressure outer cylinder.

[0045] In this embodiment, the exhaust port 6-2 is designed with six M48 bolts for connection, effectively enhancing the sealing of the exhaust side. The exhaust port 6-2 is supported by six support pipes, all of which are φ219x24 specifications, enhancing the strength of the exhaust side flange and the cylinder.

[0046] Embodiment Six: Combination Figures 1 to 15 The embodiment is a further limitation of the low-pressure module described in Embodiment Three. The 300 MW secondary reheat side exhaust air turbine low-pressure module has a base frame 6-3 at the top of the lower part of the low-pressure outer cylinder.

[0047] Embodiment Seven: Combination Figures 1 to 15 The embodiment is a further limitation of the low-pressure module described in Embodiment Six. The 300 MW secondary reheat side exhaust air turbine low-pressure module has an air inlet 6-4 on one side of the lower part of the low-pressure outer cylinder.

[0048] Embodiment Eight: Combination Figures 1 to 15 The embodiment is a further limitation of the low-pressure module described in Embodiment Seven. The 300 MW secondary reheat side exhaust air turbine low-pressure module has a bottom support plate 6-5 on the bottom surface of the lower part of the low-pressure outer cylinder.

[0049] Embodiment Nine: Combination Figures 1 to 15 The embodiment is a further limitation of the low-pressure module described in Embodiment One. The 300 MW secondary reheat side exhaust air turbine low-pressure module has an end gas seal 2, a corrugated section 3, and a dynamic balance adjuster 9 integrated, and the end gas seal 2 is a comb structure.

[0050] In this embodiment, the end gas seal 2, the corrugated section 3, and the dynamic balance adjuster 9 are integrated, and the end gas seal 2 is a comb structure. This design effectively reduces airflow loss, absorbs position changes caused by the shaft, and has the function of adjusting dynamic balance on site. The integrated design has high integration, compact structure, and small space occupation, which can shorten the bearing span and increase the maintenance space.

Claims

1. A 300MW secondary reheat exhaust air turbine low-pressure module, characterized by: It includes a No. 1 bearing box (1), an end gas seal (2), a bellows section (3), a conical guide plate (4), a low-pressure inner cylinder (5), a low-pressure outer cylinder (6), a No. 2 bearing box (7), a guide ring (8), a dynamic balance regulator (9), an outer cylinder guide plate (10), an air intake pipe (11) and a low-pressure air intake bellows section (12); A low-pressure inner cylinder (5) is provided inside the low-pressure outer cylinder (6), and a guide ring (8) is provided at the output port of the low-pressure inner cylinder (5). A through hole is provided at the center of each side of the low-pressure outer cylinder (6), and one end of the input port of the low-pressure inner cylinder (5) is connected to the through hole on one side of the low-pressure outer cylinder (6), and the other end of the input port of the low-pressure inner cylinder (5) is connected to the through hole on the other side of the low-pressure outer cylinder (6). The through hole on one side of the low-pressure outer cylinder (6) is fixedly connected to the output end of the No. 1 bearing box (1), the through hole on the other side of the low-pressure outer cylinder (6) is fixedly connected to the output end of the No. 2 bearing box (7), and the through hole on the side of the low-pressure outer cylinder (6) is connected to the low-pressure inner cylinder (6). A conical guide plate (4) is provided at the connection of the cylinder (5) input port, an outer cylinder guide plate (10) is provided at the end of the conical guide plate (4) along the circumferential direction, a corrugated section (3) is provided at the connection between the outer cylinder guide plate (10) and the end of the conical guide plate (4), an end gas seal (2) and a low-pressure air intake corrugated section (12) are uniformly provided at the connection between the side through hole of the low-pressure outer cylinder (6) and the output end of the bearing box along the circumferential direction, a dynamic balance regulator (9) is provided at the end face of the end gas seal (2), the top end of the end gas seal (2) is fixedly connected to the end of the corresponding corrugated section (3), and an air intake pipe (11) is provided at the input end of the low-pressure inner cylinder (5).

2. A 300MW secondary reheat side exhaust air turbine low-pressure module according to claim 1, characterized in that: The low-pressure inner cylinder (5) and the guide ring (8) are integrally cast.

3. A 300MW secondary reheat exhaust air turbine low-pressure module according to claim 1, characterized in that: The low-pressure outer cylinder (6) comprises an upper portion of the low-pressure outer cylinder and a lower portion of the low-pressure outer cylinder. The outer surface of the upper portion of the low-pressure outer cylinder is evenly provided with transverse ribs and longitudinal ribs, and the transverse ribs and longitudinal ribs are arranged perpendicular to each other. The upper portion of the low-pressure outer cylinder and the lower portion of the low-pressure outer cylinder are fixed by welding.

4. A 300MW secondary reheat exhaust air turbine low-pressure module according to claim 3, characterized in that: One end of the upper surface of the upper part of the low-pressure outer cylinder is evenly processed with two manholes (6-1) along the width direction.

5. A 300MW secondary reheat side exhaust air turbine low pressure module according to claim 4, characterized in that: An exhaust port (6-2) is provided on one side of the upper portion of the low-pressure outer cylinder.

6. A 300MW secondary reheat exhaust air turbine low-pressure module according to claim 3, characterized in that: A base frame (6-3) is respectively provided at the four corners of the top end of the lower part of the low-pressure outer cylinder.

7. A 300MW secondary reheat exhaust air turbine low-pressure module according to claim 6, characterized in that: An air inlet (6-4) is provided on one side of the lower portion of the low-pressure outer cylinder.

8. A 300MW secondary reheat exhaust air turbine low-pressure module according to claim 7, characterized in that: A bottom support plate (6-5) is provided on the bottom surface of the lower part of the low-pressure outer cylinder.

9. The 300MW secondary reheat exhaust air turbine low-pressure module according to claim 1, characterized in that: The end gas seal (2), the bellows section (3) and the dynamic balance regulator (9) are integrally arranged, and the end gas seal (2) is a comb-tooth structure.

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