Circulating water pipe cooling system and construction method during in-situ reconstruction of a new unit

Abstract

The present invention relates to a circulating water pipe cooling system and a construction method in the in-situ reconstruction of a new unit. The circulating water pipe cooling system is used to assist in the construction of the circulating water pipes of the in-situ reconstructed unit. It is characterized in that it includes a condenser, a cooling device, and a modified water pipe connecting the condenser and the cooling device. The modified water pipe is used for the cooling cycle of the original unit and includes a connecting pipe section and a first pipe section, a second pipe section, and a third pipe section connected in sequence. The pipe top elevations of the first pipe section and the third pipe section are both lower than the ground, and the pipe bottom elevation of the second pipe section is higher than the ground. Two connecting pipe sections are provided at both ends of the second pipe section respectively for connecting the first pipe section and the third pipe section. During construction, the cross-section of the circulating water pipe is first turned up from underground to the ground to form the second pipe section. Compared with the prior art, the present invention has the advantages of improving the reconstruction efficiency of the new unit, etc.

Description

Technical Field

[0001] The present invention relates to the field of reconstruction of thermal power plants, and particularly to a circulating water pipe cooling system and a construction method in the reconstruction of a new unit at the original site. Background Art

[0002] The circulating water pipes of thermal power plants are used to transport cooling water to the condensers in the main plant building and transport the drained water after heat exchange to the cooling facilities. Due to the large diameter of the circulating water pipes and the requirement of the circulating water supply pressure, the original circulating water pipes 7 of the thermal power plants are all underground buried pipes, and the pipe top elevation is below the ground 8, as Figure 1 shown.

[0003] Currently, small units in thermal power plants are gradually facing retirement, and there are many projects of replacing small units with large ones in power plants. The reconstruction of new units at the original site requires construction first and then shutdown, that is, before the new unit is put into operation, the old unit cannot be shut down. Therefore, during the construction of the new unit, the circulating water system should maintain the water supply to the old unit. The construction of the circulating water pipe trench is the first step in the construction of the power plant. If the circulating water pipes of the new and old units cross in elevation, it is impossible to arrange and construct the circulating water pipes of the new unit at the crossing position, which will prolong the construction period of the new unit and reduce the reconstruction efficiency of the thermal power plant. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a circulating water pipe cooling system and a construction method in the reconstruction of a new unit at the original site that improve the reconstruction efficiency.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A circulating water pipe cooling system in the reconstruction of a new unit at the original site, which is used to assist in the construction of the circulating water pipes of the unit reconstructed at the original site. It is characterized in that it includes a condenser, a cooling device, and a reformed water pipe connecting the condenser and the cooling device. The reformed water pipe is used for the cooling cycle of the original unit and includes a connecting pipe section and a first pipe section, a second pipe section, and a third pipe section connected in sequence. The pipe top elevations of the first pipe section and the third pipe section are both lower than the ground, and the pipe bottom elevation of the second pipe section is higher than the ground. Two connecting pipe sections are provided, which are respectively arranged at both ends of the second pipe section and are used to connect the first pipe section and the third pipe section.

[0007] Further, the area directly below the ground corresponding to the second pipe section is the crossing area in elevation between the circulating water pipes of the reconstructed unit and the original unit's circulating water pipes.

[0008] Further preferably, the distance between the pipe bottom of the second pipe section and the ground is 11 cm.

[0009] Further, the first pipe section, the second pipe section, and the third pipe section are all straight pipe sections.

[0010] Further, the second pipe section is obtained by intercepting from the original unit's circulating water pipe, and the intercepted pipe section is the pipe section where the elevation of the original unit's circulating water pipe intersects with the reconstructed unit's circulating water pipe.

[0011] Further, the connecting pipe section includes a saddle connection pipe and a right-angle elbow that are connected to each other. The saddle connection pipes at both ends of the connecting pipe section are respectively connected to the first pipe section and the third pipe section, and the right-angle elbows at both ends of the connecting pipe section are respectively connected to both ends of the second pipe section.

[0012] Further, a valve assembly is also provided on the second pipe section, and the valve assembly is used to control the supply pressure of the circulating water.

[0013] Even further, the valve assembly is arranged in the middle of the second pipe section and includes an exhaust valve, a manual butterfly valve, and a ball valve that are arranged in sequence from top to bottom.

[0014] Even more preferably, the exhaust valve has a specification of DN200 and PN = 1.0 MPa, the manual butterfly valve has a specification of DN200, and the ball valve has a specification of DN50.

[0015] A construction method for a circulating water pipe cooling system in the reconstruction of a new unit at the original site as described above includes the following steps:

[0016] S1: Select the intersection area in elevation between the reconstructed unit's circulating water pipe and the original unit's circulating water pipe;

[0017] S2: Intercept the circulating water pipe of the original unit in the intersection area to obtain the second pipe section, and the remaining parts of the original unit's circulating water pipe are respectively used as the first pipe section and the third pipe section;

[0018] S3: Install the two connecting pipe sections at the open ends of the first pipe section and the third pipe section respectively, and the other ends of the two connecting pipe sections extend out of the ground and face each other;

[0019] S4: Modify the length of the second pipe section according to the distance between the two connecting pipe sections, and install the second pipe section between the two connecting pipe sections;

[0020] S5: Construct the circulating water pipe of the reconstructed unit in the area directly below the second pipe section facing the ground.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1) In the present invention, a part of the middle of the circulating water pipe is turned up from underground to the ground and connected to the original underground circulating water pipe through a connecting pipe section to continue to supply cooling water to the old unit, which can ensure that the old unit cannot be shut down. At the same time, layout space is reserved for the construction of the circulating water pipe of the new unit, effectively reducing the construction period of the new unit and improving the reconstruction efficiency of the thermal power plant;

[0023] 2) In the present invention, the intersection section of the elevation layout of the circulating water pipe of the old unit and the circulating water pipe of the new unit is intercepted, and the second pipe section turned up to the ground directly uses the original circulating water pipe, and only the connecting pipe section needs to be added. The reconstruction construction process is simple, fast and convenient, and the on-site weld joint docking is convenient, accurately reserving layout space for the circulating water pipe of the new project, ensuring that during the construction of the new unit, the circulating water pipe of the original unit can supply water normally to maintain the normal operation of the unit;

[0024] 3) In the present invention, a valve assembly is arranged in the second pipe section to control the supply pressure of the circulating water, ensuring that cooling water in the normal working state can still be provided to the original unit even when the elevation of the second pipe section is higher than the ground. It has high reliability and can provide a reference reconstruction method for the intersection construction of the circulating water pipe in the equal-capacity replacement project. Description of the Drawings

[0025] Figure 1 Schematic diagram of the cooling circulating water pipe for the original unit;

[0026] Figure 2 Schematic diagram of the cooling circulating water pipe of the present invention.

[0027] Among them, 1. First pipe section, 2. Second pipe section, 3. Third pipe section, 4. Connecting pipe section, 41. Saddle connection pipe, 42. Right-angle elbow, 5. Valve assembly, 51. Exhaust valve, 52. Manual butterfly valve, 53. Ball valve, 6. Circulating water pipe of the reconstructed unit, 7. Circulating water pipe of the original unit, 8. Ground, 9. Intersection area. Detailed Embodiment

[0028] The present invention will be described in detail below with reference to the drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0029] Embodiment

[0030] As Figure 2 shown, the present invention provides a circulating water pipe cooling system in the reconstruction of a new unit at the original site, which is used to assist in the construction of the circulating water pipe 6 of the reconstructed unit at the original site, including a condenser, a cooling device, and a modified water pipe connecting the condenser and the cooling device. The modified water pipe is used for the cooling circulation of the original unit.

[0031] There is an intersection in the elevation layout of the circulating water pipes of the new and old units. Therefore, in the early stage of the present invention, the intersecting section of the circulating water pipes is turned up from underground to the ground 8, and a saddle connection + 90° elbow + straight pipe section is adopted. It is turned up to the ground 8, and the center elevation of the pipe changes from the original underground to above the ground 8. The turning-up span is determined according to the actual intersection position. Specifically, the modified water pipe includes a connecting pipe section 4 and a first pipe section 1, a second pipe section 2, and a third pipe section 3 connected in sequence. The top elevations of the first pipe section 1 and the third pipe section 3 are both lower than the ground 8, and the bottom elevation of the second pipe section 2 is higher than the ground 8. Two connecting pipe sections 4 are provided, respectively arranged at both ends of the second pipe section 2 for connecting the first pipe section 1 and the third pipe section 3. Right below the ground 8 facing the second pipe section 2 is the intersection area 9 in elevation between the circulating water pipe 6 of the rebuilt unit and the circulating water pipe 7 of the original unit.

[0032] In this embodiment, the distance between the bottom of the second pipe section 2 and the ground 8 is 11 cm. The first pipe section 1, the second pipe section 2, and the third pipe section 3 are all straight pipe sections. The second pipe section 2 is obtained by intercepting the circulating water pipe of the original unit. The intercepted pipe section is the pipe section where the elevation of the circulating water pipe of the original unit intersects with the circulating water pipe 6 of the rebuilt unit, that is, the pipe section originally in the intersection area 9. The connecting pipe section 4 includes a saddle connection pipe 41 and a right-angle elbow 42 connected to each other. The saddle connection pipes 41 of the two ends of the connecting pipe section 4 are respectively connected to the first pipe section 1 and the third pipe section 3, and the right-angle elbows 42 of the two ends of the connecting pipe section 4 are respectively connected to both ends of the second pipe section 2. The pipe sections are connected by welding.

[0033] As Figure 2 shown, a valve assembly 5 is also provided on the second pipe section 2 in this embodiment for controlling the supply pressure of the circulating water. The valve assembly 5 is arranged in the middle of the second pipe section 2 and includes an exhaust valve 51, a manual butterfly valve 52, and a ball valve 53 arranged in sequence from top to bottom. Among them, the exhaust valve 51 has a specification of DN200 and PN = 1.0 MPa, the manual butterfly valve 52 has a specification of DN200, and the ball valve 53 has a specification of DN50.

[0034] The construction method of the circulating water pipe cooling system in the reconstruction of the new unit at the original site includes the following steps:

[0035] S1: Select the intersection area 9 in elevation between the circulating water pipe 6 of the rebuilt unit and the circulating water pipe 7 of the original unit;

[0036] S2: Intercept the circulating water pipe of the original unit in the intersection area 9 to obtain the second pipe section 2, and the remaining parts of the circulating water pipe 7 of the original unit are respectively used as the first pipe section 1 and the third pipe section 3;

[0037] S3: Install the two connecting pipe sections 4 at the open ends of the first pipe section 1 and the third pipe section 3 respectively, and the other ends of the two connecting pipe sections 4 extend out of the ground 8 and face each other;

[0038] S4: Modify the length of the second pipe section 2 according to the distance between the two connecting pipe sections 4, and install the second pipe section 2 between the two connecting pipe sections 4;

[0039] S5: Construct the modified unit circulating water pipe 6 in the area directly below the second pipe section 2 facing the ground 8.

[0040] As mentioned above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any staff familiar with the technical field of the present invention can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A circulating water pipe cooling system in the reconstruction of a new unit at the original site, which is used to assist in the construction of the circulating water pipe of the unit reconstructed at the original site. Characterized in that, It includes a condenser, a cooling device, and a modified water pipe connecting the condenser and the cooling device. The modified water pipe is used for the cooling cycle of the original unit, and includes a connecting pipe section (4) and a first pipe section (1), a second pipe section (2), and a third pipe section (3) connected in sequence. The pipe top elevations of the first pipe section (1) and the third pipe section (3) are both lower than the ground (8), the pipe bottom elevation of the second pipe section (2) is higher than the ground (8), and directly below the second pipe section (2) facing the ground (8) is the cross - region (9) of the circulating water pipe of the reconstructed unit and the circulating water pipe of the original unit in terms of elevation. The second pipe section (2) is obtained by intercepting the original unit's circulating water pipe, and the intercepted pipe section is the pipe section where the elevation of the original unit's circulating water pipe intersects with the reconstructed unit's circulating water pipe. The pipe bottom elevation of the second pipe section (2) is higher than the ground (8). Two connecting pipe sections (4) are provided, which are respectively arranged at both ends of the second pipe section (2) and are used to connect the first pipe section (1) and the third pipe section (3).

2. A circulating water pipe cooling system in the reconstruction of a new unit at the original site according to claim 1, Characterized in that, The distance between the pipe bottom of the second pipe section (2) and the ground (8) is 11 cm.

3. A circulating water pipe cooling system in the reconstruction of a new unit at the original site according to claim 1, Characterized in that, The first pipe section (1), the second pipe section (2), and the third pipe section (3) are all straight pipe sections.

4. A circulating water pipe cooling system in the reconstruction of a new unit at the original site according to claim 3, Characterized in that, The connecting pipe section (4) includes a saddle - connection pipe (41) and a right - angle elbow (42) connected to each other. The saddle - connection pipes (41) of the two connecting pipe sections (4) at both ends are respectively connected to the first pipe section (1) and the third pipe section (3), and the right - angle elbows (42) of the two connecting pipe sections (4) at both ends are respectively connected to both ends of the second pipe section (2).

5. A circulating water pipe cooling system in the reconstruction of a new unit at the original site according to claim 1, Characterized in that, A valve assembly (5) is further provided on the second pipe section (2), and the valve assembly (5) is used to control the supply pressure of the circulating water.

6. A circulating water pipe cooling system in the reconstruction of a new unit at the original site according to claim 5, Characterized in that, The valve assembly (5) is arranged in the middle of the second pipe section (2) and includes an exhaust valve (51), a manual butterfly valve (52), and a ball valve (53) arranged in sequence from top to bottom.

7. A circulating water pipe cooling system in the reconstruction of a new unit at the original site according to claim 6, Characterized in that, The exhaust valve (51) has a specification of DN200, PN = 1.0 MPa, the manual butterfly valve (52) has a specification of DN200, and the ball valve (53) has a specification of DN50.

8. A construction method of a circulating water pipe cooling system in the reconstruction of a new unit at the original site as claimed in claim 1, Characterized in that, It includes the following steps: S1: Select the intersection area (9) of the circulating water pipe of the reconstructed unit and the circulating water pipe of the original unit in terms of elevation; S2: Cut off the circulating water pipe of the original unit within the intersection area (9) to obtain the second pipe section (2), and the remaining parts of the circulating water pipe of the original unit are respectively used as the first pipe section (1) and the third pipe section (3); S3: Install two connecting pipe sections (4) at the open ends of the first pipe section (1) and the third pipe section (3) respectively, and the other ends of the two connecting pipe sections (4) extend out of the ground (8) and face each other; S4: Modify the length of the second pipe section (2) according to the distance between the two connecting pipe sections (4), and install the second pipe section (2) between the two connecting pipe sections (4); S5: Construct the circulating water pipe of the reconstructed unit in the area directly below the second pipe section (2) facing the ground (8).

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