Casting system for steam turbine cylinder

Abstract

The utility model provides a casting system of a steam turbine cylinder, which comprises a cylinder main body, and an open riser is arranged on the top junction surface of the cylinder main body; a plurality of blind risers are arranged in the cylinder, and an anti-cracking cutting rib is arranged at the thick and thin connection position of a cylinder body in the cylinder; the two sides of each blind riser are each provided with an anti-cracking cutting rib. In the casting system, the anti-cracking cutting ribs are arranged at the positions with great thickness differences in the inner cavity of the air cylinder, and the blind risers not only can feed the inner wall of the air cylinder, but also can feed the anti-cracking cutting ribs, so that the anti-cracking cutting ribs can play a better anti-cracking role. The connecting channels are arranged between the open risers and the blind risers, so that the temperature difference of molten steel in the adjacent open risers and blind risers is as small as possible, and the cooling process of the cylinder main body is more uniform. Molten steel enters the air cylinder body through the main pouring gate, the bottom pouring gate and the vertical pouring gate, it is guaranteed that impurities in the molten steel can fully float upwards, and the air cylinder body has better internal quality.

Description

Technical Field

[0001] The invention belongs to the technical field of steam turbine cylinder casting, and in particular relates to a casting system for a steam turbine cylinder. Background Art

[0002] The cylinder is the outer shell of the steam turbine. Its function is to separate the flow part of the steam turbine from the atmosphere, forming a closed steam chamber to ensure that the steam completes the energy conversion process inside the steam turbine. The cylinder is equipped with nozzle chambers, partitions, partition sleeves and other components; the outside of the cylinder is connected to the steam inlet, exhaust, extraction and other pipelines. The high and medium pressure sections of the cylinder generally adopt alloy steel or carbon steel casting structure, and the low pressure section can adopt casting structure or welding structure of simple castings, steel and steel plates according to capacity and structural requirements.

[0003] The cylinder of a steam turbine is relatively large and often needs to be divided into two halves for casting separately. During casting, cracks are easily generated due to the large difference in thickness of the cylinder cavity, making it difficult to ensure the internal quality of the cylinder.

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0005] The object of the present invention is to provide a casting system for a steam turbine cylinder to at least solve the above-mentioned problems existing in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A casting system for a steam turbine cylinder, the casting system comprising a cylinder body, and an open riser is arranged on the top joint surface of the cylinder body;

[0008] A plurality of blind risers are arranged inside the cylinder, and anti-crack cutting ribs are arranged at the junction of the thick and thin parts of the cylinder body inside the cylinder;

[0009] An anti-cracking cutting rib is arranged on both sides of each blind riser.

[0010] In the casting system for the steam turbine cylinder as described above, preferably, adjacent open risers and blind risers are connected via a connecting channel.

[0011] In the casting system for the steam turbine cylinder as described above, preferably, one blind riser and two exposed risers are located at the same radial surface of the cylinder, the two exposed risers are at the same height, and the two exposed risers are higher than the blind riser;

[0012] The connecting channel comprises a transverse channel, and the transverse channel is connected between two open risers.

[0013] In the casting system for the steam turbine cylinder as described above, preferably, a vertical channel is connected between the blind riser at the lower part of the transverse channel and the transverse channel.

[0014] In the casting system for the steam turbine cylinder as described above, preferably, the vertical channel is located on the center line of the blind riser, and the vertical channel is located between the two visible risers.

[0015] In the casting system for the steam turbine cylinder as described above, preferably, the cross section of the open riser is circular or oblong.

[0016] The casting system for the steam turbine cylinder as described above, preferably, the casting system further comprises a buffered step casting unit, the buffered step casting unit comprises a main runner and a bottom runner, the main runner is connected to the bottom runner;

[0017] The bottom runner is located below the cylinder body, and the bottom runner fits the bottom shape of the cylinder body. A plurality of vertical runners are arranged between the bottom runner and the cylinder body.

[0018] In the casting system for the steam turbine cylinder as described above, preferably, the bottom runner includes a transverse section and an inclined section.

[0019] Beneficial effects:

[0020] In the casting system, anti-crack cutting ribs are arranged at places with a large difference in thickness in the cylinder cavity, and the blind riser can not only compensate for the shrinkage of the cylinder inner wall, but also compensate for the shrinkage of the anti-crack cutting ribs, so that the anti-crack cutting ribs can better play their anti-crack role.

[0021] By providing a connecting channel between the open riser and the blind riser, the temperature difference of the molten steel in the adjacent open risers and the blind riser is ensured to be as small as possible, thereby ensuring a more uniform cooling process of the cylinder body.

[0022] The molten steel enters the cylinder body through the main runner, the bottom runner and the vertical runner. A bottom runner that fits the shape of the cylinder body is arranged at the bottom of the cylinder body. Since the bottom runner is located below the cylinder body, the molten steel can gradually enter the cylinder body from the bottom of the cylinder body, ensuring that impurities in the molten steel can fully float up and preventing impurities in the molten steel from solidifying in the cylinder body, thereby ensuring that the cylinder body has better internal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0024] Figure 1 A top view of a casting system for a steam turbine cylinder according to an embodiment of the present invention;

[0025] Figure 2 A front view of a casting system for a steam turbine cylinder according to an embodiment of the present invention;

[0026] Figure 3 A side view of a casting system for a steam turbine cylinder according to an embodiment of the present invention.

[0027] In the figure: 1. Cylinder body; 2. Visible riser; 3. Concealed riser; 4. Horizontal channel; 5. Vertical channel; 6. Main runner; 7. Anti-crack cutting rib; 8. Bottom runner; 81. Horizontal section; 82. Inclined section; 9. Vertical runner. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0029] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0031] According to a specific embodiment of the present invention, Figure 1-3 As shown, the present invention provides a casting system for a turbine cylinder, the casting system includes a cylinder body 1, an open riser 2 is arranged on the top joint surface of the cylinder body 1; a plurality of hidden risers 3 are arranged inside the cylinder, and anti-cracking ribs 7 are arranged at the thick and thin junction of the cylinder body inside the cylinder; an anti-cracking rib 7 is arranged on both sides of each hidden riser 3.

[0032] In the casting system, anti-crack cutting ribs 7 are arranged at places where the thickness difference is large in the inner cavity of the cylinder, and the structural strength of the cylinder inner wall at the places where the thickness difference is large is strengthened by the anti-crack cutting ribs 7, so as to prevent cracks from being generated at the places where the thickness of the cylinder inner wall is uneven; and a blind riser 3 is arranged near the anti-crack cutting rib 7, so that the blind riser 3 can not only compensate for the shrinkage of the cylinder inner wall, but also compensate for the shrinkage of the anti-crack cutting rib 7, so that the anti-crack cutting rib 7 can better play its anti-cracking role.

[0033] Adjacent open risers 2 and blind risers 3 are connected through a connecting channel. In one embodiment of the present application, the blind riser 3 is completely located inside the casting mold, a portion of the open riser 2 is located inside the casting mold, and the top surface of the open riser 2 is connected to the outside world; this makes the heat dissipation speed of the open riser 2 and the blind riser 3 inconsistent; by setting a connecting channel between the open riser 2 and the blind riser 3, the molten steel in the open riser 2 and the blind riser 3 can flow through the connecting channel, which not only reduces the temperature difference between the open riser 2 and the blind riser 3, but also ensures that the temperature difference of the molten steel in the adjacent open risers 2 and the blind riser 3 is as small as possible, thereby ensuring that the cooling process of the cylinder body 1 is more uniform.

[0034] A blind riser 3 and two exposed risers 2 are located at the same radial plane position of the cylinder, the two exposed risers 2 are at the same height, and the two exposed risers 2 are higher than the blind riser 3; the connecting channel includes a transverse channel 4, and the transverse channel 4 is connected between the two exposed risers 2.

[0035] In one embodiment of the present application, the open risers 2 at the same height and at the same radial surface position of the cylinder are connected by a transverse channel 4, so that the molten steel in the two open risers 2 flows through the transverse channel 4, thereby reducing the temperature difference between the two open risers 2 as much as possible, so that the cooling speed on both sides of the cylinder is as consistent as possible, avoiding uneven cooling of symmetrical parts of the cylinder, and causing deformation, cracks, etc.; thereby, the cylinder body 1 has a more uniform cooling process, ensuring that the cylinder body 1 has better product quality.

[0036] A vertical channel 5 is connected between the blind riser 3 at the bottom of the transverse channel 4 and the transverse channel 4. The two exposed risers 2 and the blind riser 3 are connected to each other through the transverse channel 4 and the vertical channel 5. The vertical channel 5 is located on the center line of the blind riser 3, and the vertical channel 5 is located between the two exposed risers 2. The transverse channel 4 and the vertical channel 5 can ensure that the molten steel has better fluidity in the casting system of the cylinder during the casting process, thereby ensuring that the cylinder body has better internal quality.

[0037] In one embodiment of the present application, the vertical channel 5 is located on the center line of the blind riser 3 and in the middle of the two visible risers 2, so that the position of the blind riser 3 to any one of the two visible risers 2 through the vertical channel 5 and the transverse channel 4 is equal, and the two visible risers 2 are interconnected with the blind riser 3, so that the molten steel in the two visible risers 2 and the blind riser 3 can circulate with each other through the transverse channel 4 and the vertical channel 5, thereby ensuring that the temperature difference between the molten steel in the two visible risers 2 and the blind riser 3 is as small as possible; and the two visible risers 2 can both provide shrinkage compensation for the blind riser 3, so that the blind riser 3 can better provide shrinkage compensation for the inner wall of the cylinder, ensuring that the cylinder body 1 has better internal quality.

[0038] The cross section of the open riser 2 is circular or oblong. In one embodiment of the present application, the cylinder body 1 is half of a complete cylinder, that is, the complete cylinder is divided into two halves and cast separately, and then the two halves of the cylinder body 1 are matched to form a complete cylinder. In this embodiment, the top of the cylinder body 1 is the joint surface of the two halves of the cylinder body 1. The multiple open risers 2 are respectively set as cylinders or oblong cylinders, so that the open risers 2 can cover the joint surface of the cylinder body 1 as much as possible, so that the joint surface of the cylinder body 1 will not have defects such as shrinkage holes and looseness, and ensure that the joint surface of the cylinder body 1 has better internal quality.

[0039] The casting system also includes a buffered stepped casting unit, which includes a main runner 6 and a bottom runner 8, and the main runner 6 is connected to the bottom runner 8; the bottom runner 8 is located below the cylinder body 1, and the bottom runner 8 fits the bottom shape of the cylinder body 1, and multiple vertical runners 9 are arranged between the bottom runner 8 and the cylinder body 1.

[0040] In one embodiment of the present application, molten steel enters the cylinder body 1 through the main runner 6, the bottom runner 8 and the vertical runner 9. A bottom runner 8 that fits the outer shape of the cylinder body 1 is provided at the bottom of the cylinder body 1, so that the molten steel can reach the cylinder body 1 through the shortest path. Moreover, since the bottom runner 8 is located below the cylinder body 1, the molten steel can gradually enter the cylinder body 1 from the bottom of the cylinder body 1, ensuring that impurities in the molten steel can fully float up, avoiding the impurities in the molten steel from solidifying in the cylinder body 1, thereby ensuring that the cylinder body 1 has better intrinsic quality.

[0041] The bottom runner 8 includes a transverse section 81 and an inclined section 82. In one embodiment of the present application, the transverse section 81 of the bottom runner 8 fits the relatively horizontal portion of the front of the cylinder body 1, and the inclined section 82 of the bottom runner 8 fits the inclined portion of the rear of the cylinder body 1, so that the shape of the bottom runner 8 fits the shape of the cylinder body 1 as much as possible, thereby making it easier for molten steel to enter the cylinder body 1.

[0042] It should be understood that the above description is merely exemplary and the embodiments of the present application do not limit this.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A casting system for a steam turbine cylinder, characterized in that: The casting system comprises a cylinder body, and an open riser is arranged on the top joint surface of the cylinder body; A plurality of blind risers are arranged inside the cylinder, and anti-cracking cutting ribs are arranged at the junction of the thick and thin parts of the cylinder body inside the cylinder; An anti-cracking cutting rib is arranged on both sides of each blind riser.

2. The casting system for a steam turbine cylinder according to claim 1, characterized in that: The adjacent exposed risers and concealed risers are communicated with each other through a connecting channel.

3. The casting system for a steam turbine cylinder according to claim 2, characterized in that: A blind riser and two exposed risers are located at the same radial plane position of the cylinder, the two exposed risers are at the same height, and the two exposed risers are higher than the blind riser; The connecting channel comprises a transverse channel, and the transverse channel is connected between two open risers.

4. The casting system for a steam turbine cylinder according to claim 3, characterized in that: A vertical channel is connected between the blind riser at the lower part of the transverse channel and the transverse channel.

5. The casting system for a steam turbine cylinder according to claim 4, characterized in that: The vertical channel is located on the center line of the blind riser, and the vertical channel is located between the two visible risers.

6. The casting system for a steam turbine cylinder according to claim 5, characterized in that: The cross section of the open riser is circular or oblong.

7. The casting system for a steam turbine cylinder according to any one of claims 1 to 6, characterized in that: The casting system further comprises a buffered step casting unit, wherein the buffered step casting unit comprises a main runner and a bottom runner, and the main runner is connected to the bottom runner; The bottom runner is located below the cylinder body, and the bottom runner fits the bottom shape of the cylinder body. A plurality of vertical runners are arranged between the bottom runner and the cylinder body.

8. The casting system for a steam turbine cylinder according to claim 7, characterized in that: The bottom runner includes a transverse section and an inclined section.

Images