A combined structure for eliminating local thermal stress of coke oven riser jacket heat exchanger

Abstract

The present invention discloses a combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger, which relates to the field of coke oven heat exchange technology; a sealing ring is provided in the water jacket layer, and the sealing ring divides the water jacket layer into two independent spaces, namely the lower section and the upper section of the seal ring of the riser heat exchanger; the outer wall of the upper section of the water jacket layer is provided with an upper section outlet and an upper section inlet; the outer wall of the water jacket layer is provided with a lower section outlet and a lower section inlet; the lower section outlet and the lower section inlet are located below the sealing ring; the inner wall of the water jacket layer is provided with an inner steel cylinder; a heat storage layer is provided between the inner steel cylinder and the inner wall of the water jacket layer. It has a reasonable structural design, is easy to operate, and is flexible and stable; it solves the problem that the traditional riser jacket heat exchanger cannot avoid local thermal stress, and avoids the occurrence of safety accidents such as bulging and cracking.

Description

Technical Field

[0001] The invention belongs to the technical field of coke oven heat exchange, and in particular relates to a combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger. Background Art

[0002] At present, as coking plants attach great importance to resource recycling, waste heat recovery of raw gas is one of the main ways to reduce the energy consumption of coke ovens. The existing process is to pass the 650℃-850℃ high-temperature raw gas escaping from the carbonization chamber through the riser heat exchanger into the gas collecting pipe to recover the waste heat. The traditional coke oven riser jacket heat exchanger has high heat exchange efficiency, but due to the inherent structure of the riser jacket heat exchanger, local thermal stress concentration is prone to occur near the riser outlet, which causes the riser to bulge and tear at this point, seriously affecting the production safety and economic benefits of the system. Summary of the invention

[0003] In order to solve the problem that local thermal stress concentration is prone to occur near the outlet of the existing coke oven riser water jacket heat exchanger; the purpose of the present invention is to provide a combined structure for eliminating the local thermal stress of the coke oven riser jacket heat exchanger, which has a reasonable structural design, convenient operation, flexibility and stability; it solves the problem that the traditional riser jacket heat exchanger cannot avoid local thermal stress, and avoids the occurrence of safety accidents such as bulging and cracking.

[0004] The present invention provides a combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger, which comprises a water tank, a deoxygenated water pump, a deaerator, a water feed pump, a steam drum, a forced circulation water pump, a riser heat exchanger, and a pressure reducer; the riser heat exchanger comprises a water jacket layer, a sealing ring, an upper section outlet, a lower section outlet, an upper section inlet, a lower section inlet, a heat storage layer, an inner steel cylinder, an expansion joint, an outer steel cylinder, and a thermal insulation layer; a sealing ring is provided in the water jacket layer, and the sealing ring divides the water jacket layer into two independent spaces, namely, a riser heat exchanger sealing ring lower section and a sealing ring upper section; an upper section outlet and an upper section inlet are provided on the outer wall of the upper section of the water jacket layer; a lower section outlet and a lower section inlet are provided on the outer wall of the water jacket layer; The lower section outlet and the lower section inlet are located below the sealing ring; an inner steel cylinder is provided on the inner wall of the water jacket layer; a heat storage layer is provided between the inner steel cylinder and the inner wall of the water jacket layer; the outer steel cylinder is arranged on the outer wall of the water jacket layer, and an insulation layer is provided on the outer wall of the outer steel cylinder; an expansion joint is provided in the middle of the water jacket layer; the water inlet end of the forced circulation water pump is connected to the steam drum; the water outlet end of the forced circulation water pump is connected to the lower section inlet of the sealing ring of the riser heat exchanger; one line of the feed water pump is connected to the steam drum, and the other line is connected to the upper section inlet of the sealing ring of the riser heat exchanger; the upper section outlet of the sealing ring of the riser heat exchanger is connected to the pressure reducer; the pressure reducer is connected to the deaerator, and the deaerator is connected to the deaerator water tank through the deaerator water pump.

[0005] Preferably, a deoxygenated water cooling layer is provided on the upper section of the sealing ring to ensure that the inner steel cylinder at the outlet side and the flange connection is within the allowable temperature range of the material, avoiding local thermal stress caused by local high temperature, and recovering part of the heat for thermal deoxygenation.

[0006] Preferably, the sealing ring has a height of about 5 mm and a slope of not less than 10%.

[0007] Preferably, the top end of the sealing ring is located at the top end of the lower section outlet, and the bottom end of the sealing ring is located in the middle of the lower section outlet of an adjacent sealing ring.

[0008] Preferably, the number of the lower section outlets is 2 to 4, and they are evenly arranged on the outer wall of the water jacket layer 1 .

[0009] Preferably, the outlet diameter of the lower section outlet is 65-120 mm, the number of lower section outlets is large, the distribution is even, and the diameter is large, which fully ensures that the steam-water mixture can be quickly and smoothly discharged from the lower section of the riser heat exchanger sealing ring, avoiding separation and stagnation of steam and saturated water of the steam-water mixture.

[0010] Preferably, a temperature measuring device is provided at the outlet of the upper section to obtain the inner wall temperature of the heat storage layer in real time.

[0011] Preferably, an electric valve is provided at the entrance of the upper section, and the opening size can be adjusted.

[0012] The principle of the present invention is as follows: by setting multiple outlets and sealing rings, the water jacket layer of the riser is divided into two independent spaces. The sealing ring has a large slope, which plays a great role in smoothly discharging steam and avoiding steam stagnation dead corners. The upper part of the sealing ring is cooled with deoxygenated water to ensure that the inner steel cylinder at the connection between the outlet side and the flange is within the allowable temperature range of the material, avoiding local thermal stress caused by local high temperature, and at the same time recovering part of the heat for thermal deoxygenation. Through the above scheme, the problem that the traditional riser jacket heat exchanger cannot avoid local thermal stress is solved, and the occurrence of safety accidents such as bulging and cracking is avoided.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. Set up multiple evenly arranged lower section outlets to ensure that the steam-water mixture can be discharged quickly, and at the same time ensure that there is no dead corner of steam stagnation, so as to avoid local high temperature caused by local inability to cool due to steam stagnation, and thus avoid accidents such as tube expansion due to local thermal stress concentration;

[0015] Second, the sealing ring has a large slope, which plays a great role in smoothly discharging steam and avoiding steam stagnation dead corners; the upper part of the sealing ring is cooled by deoxygenated water to ensure that the inner steel cylinder at the outlet side and the flange connection is within the allowable temperature range of the material, avoiding local thermal stress caused by local high temperature, and at the same time recovering part of the heat for thermal deoxidation;

[0016] 3. It solves the problem of local thermal stress that cannot be avoided in traditional riser jacketed heat exchangers, and avoids the occurrence of safety accidents such as bulging and cracking. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For ease of explanation, the present invention is described in detail with reference to the following specific implementations and the accompanying drawings.

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 for Figure 1 A top view of

[0020] Figure 3 is a side view of the sealing ring structure of the present invention;

[0021] Figure 4 Another structural stereogram of the sealing ring in the present invention;

[0022] Figure 5 A diagram of the invented operating system;

[0023] In the figure: water jacket layer 1, sealing ring 2, upper section outlet 3, lower section outlet 4, upper section inlet 5, lower section inlet 6, heat storage layer 7, inner steel cylinder 8, expansion joint 9, outer steel cylinder 10, insulation layer 11; deaerated water tank 13, deaerated water pump 14, deaerator 15, feed water pump 16, steam drum 17, forced circulation water pump 18, riser heat exchanger 19, pressure reducer 20. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0025] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0026] like Figure 1 to Figure 5As shown, this specific embodiment adopts the following technical scheme: it comprises a water tank 13, a deoxygenated water pump 14, a deaerator 15, a feed water pump 16, a steam drum 17, a forced circulation water pump 18, a riser heat exchanger 19, and a pressure reducer 20; the riser heat exchanger 19 comprises a water jacket layer 1, a sealing ring 2, an upper section outlet 3, a lower section outlet 4, an upper section inlet 5, a lower section inlet 6, a heat storage layer 7, an inner steel cylinder 8, an expansion joint 9, an outer steel cylinder 10, and an insulation layer 11; a sealing ring 2 is provided in the water jacket layer 1, and the sealing ring 2 divides the water jacket layer into two independent spaces, namely the lower section and the upper section of the sealing ring of the riser heat exchanger; the outer wall of the upper section of the water jacket layer 1 is provided with an upper section outlet 3 and an upper section inlet 5; the outer wall of the water jacket layer 1 is provided with a lower section outlet 4 and a lower section inlet 6; the lower section outlet 4, The lower section inlet 6 is located below the sealing ring 2; an inner steel cylinder 8 is provided on the inner wall of the water jacket layer 1; a heat storage layer 7 is provided between the inner steel cylinder 8 and the inner wall of the water jacket layer 1; the outer steel cylinder 10 is arranged on the outer wall of the water jacket layer 1, and the outer wall of the outer steel cylinder 10 is provided with a thermal insulation layer 11; an expansion joint 9 is provided in the middle of the water jacket layer 1; the water inlet end of the forced circulation water pump 18 is connected to the steam drum 17; the water outlet end of the forced circulation water pump 18 is connected to the lower section inlet 6 of the sealing ring of the riser heat exchanger; one path of the feed water pump 16 is connected to the steam drum 17, and the other path is connected to the upper section inlet 5 of the sealing ring of the riser heat exchanger; the upper section outlet 3 of the sealing ring of the riser heat exchanger is connected to the pressure reducer 20; the pressure reducer 20 is connected to the deaerator 15, and the deaerator 15 is connected to the deaerator water tank 13 through the deaerator water pump 14.

[0027] Among them, the upper section of the sealing ring 2 is provided with a deoxygenated water cooling layer to ensure that the inner steel cylinder at the outlet side and the flange connection is within the allowable temperature range of the material, avoiding local thermal stress caused by local high temperature, and at the same time recovering part of the heat for thermal deoxygenation. The height of the sealing ring 2 is about 5mm, and the slope is not less than 10%. The top of the sealing ring 2 is located at the top of the lower section outlet 4, and the bottom of the sealing ring 2 is located in the middle of the adjacent lower section outlet of the sealing ring. The number of the lower section outlets 4 is 2 to 4, and they are evenly arranged on the outer wall of the water jacket layer 1. The outlet diameter of the lower section outlet 4 is 65 to 120mm. The number of the lower section outlets 4 is large, the distribution is uniform, and the diameter is large, which fully ensures that the steam-water mixture can be quickly and smoothly discharged from the lower section of the riser heat exchanger sealing ring, avoiding the separation and stagnation of the steam and saturated water of the steam-water mixture.

[0028] In addition, a temperature measuring device is provided at the upper section outlet 3, which can obtain the inner wall temperature of the heat storage layer 7 in real time; an electric valve is provided at the upper section inlet 5, which can adjust the opening size.

[0029] In specific implementation, the number of outlets in the lower section of the riser heat exchanger is 2 to 4, which are evenly arranged in the radial direction, and the outlet diameter is 65 to 120 mm. The number of outlets in the lower section is large, the distribution is even, and the diameter is large, which fully ensures that the steam-water mixture can be quickly and smoothly discharged from the lower section of the riser heat exchanger sealing ring, avoiding the separation and stagnation of the steam and saturated water of the steam-water mixture.

[0030] In addition, the top of the sealing ring is located at the top of the outlet of the lower section of the riser heat exchanger, and the bottom is located in the middle of the outlet of the lower section of the adjacent sealing ring. The height of the 7 sealing rings is 5mm, and the slope of the 7 sealing rings is 10%. The sealing ring is a conical surface with the cone top eliminated. The orthographic latitude ring just fits in with the annular space of the jacket of the riser for flowing condensed water to form a seal, thereby ensuring that the steam-water mixture can be discharged quickly. Because the top part of the riser is relatively short, the circulating water inside has limited heat absorption and will not form steam; ensure that there is no dead corner of steam stagnation, avoid local high temperature caused by local inability to cool due to steam stagnation, and cause accidents such as tube expansion due to local thermal stress concentration.

[0031] Furthermore, a temperature measuring device is provided at the upper section outlet, which can obtain the inner wall temperature of the heat storage layer in real time, and control the opening of the upper section inlet valve by the temperature signal, thereby ensuring that the inner wall temperature of the heat storage layer is stable at about 500 degrees Celsius.

[0032] Furthermore, the water at the outlet of the upper section enters the deaerator after being depressurized, and the desalted water is thermally deoxygenated.

[0033] When the present specific embodiment is in operation, the saturated water from the forced circulation water pump 18 enters the lower section inlet 6 of the sealing ring of the riser heat exchanger, absorbs heat and becomes a steam-water mixture and flows out from the lower section outlet 4 of the sealing ring of the riser heat exchanger; the deoxygenated water from the feed water pump 16 enters the steam drum 17 in one way and enters the upper section inlet 5 of the sealing ring of the riser heat exchanger in the other way, absorbs heat and flows out from the upper section outlet 3 of the sealing ring of the riser heat exchanger, ensuring that the inner steel cylinder 8 at the connection between the outlet side of the riser heat exchanger and the flange is within the allowable temperature range of the material to avoid local thermal stress caused by local high temperature; the water flowing out from the upper section outlet 3 of the sealing ring of the riser heat exchanger enters the deaerator 15 after passing through the pressure reducer 20, and the desalted water from the water tank 13 is thermally deoxygenated, fully saving energy.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0035] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger, characterized in that: It comprises a water tank (13), a deoxygenated water pump (14), a deaerator (15), a feed water pump (16), a steam drum (17), a forced circulation water pump (18), a riser heat exchanger (19), and a pressure reducer (20); the riser heat exchanger (19) comprises a water jacket layer (1), a sealing ring (2), an upper section outlet (3), a lower section outlet (4), an upper section inlet (5), a lower section inlet (6), a heat storage layer (7), an inner steel cylinder (8), an expansion joint (9), An outer steel cylinder (10) and an insulation layer (11); a sealing ring (2) is provided in the water jacket layer (1), and the sealing ring (2) divides the water jacket layer into two independent spaces, namely, a lower section of the sealing ring of the riser heat exchanger and an upper section of the sealing ring; an upper section outlet (3) and an upper section inlet (5) are provided on the outer wall of the upper section of the water jacket layer (1); a lower section outlet (4) and a lower section inlet (6) are provided on the outer wall of the water jacket layer (1); the lower section outlet (4) and the lower section inlet (6) are provided ) is located below the sealing ring (2); an inner steel cylinder (8) is provided on the inner wall of the water jacket layer (1); a heat storage layer (7) is provided between the inner steel cylinder (8) and the inner wall of the water jacket layer (1); the outer steel cylinder (10) is arranged on the outer wall of the water jacket layer (1), and the outer wall of the outer steel cylinder (10) is provided with a heat insulation layer (11); an expansion joint (9) is provided in the middle of the water jacket layer (1); the water inlet end of the forced circulation water pump (18) is connected to the steam drum (17) The water outlet of the forced circulation water pump (18) is connected to the lower inlet (6) of the sealing ring of the riser heat exchanger; one line of the feed water pump (16) is connected to the steam drum (17), and the other line is connected to the upper inlet (5) of the sealing ring of the riser heat exchanger; the upper outlet (3) of the sealing ring of the riser heat exchanger is connected to the pressure reducer (20); the pressure reducer (20) is connected to the deaerator (15), and the deaerator (15) is connected to the deaerator water tank (13) through the deaerator water pump (14).

2. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: The upper section of the sealing ring (2) is provided with a deoxygenated water cooling layer.

3. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: The sealing ring (2) has a height of about 5 mm and a slope of not less than 10%.

4. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: The top end of the sealing ring (2) is located at the top end of the lower section outlet (4), and the bottom end of the sealing ring (2) is located in the middle of the lower section outlets of adjacent sealing rings.

5. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: The number of the lower section outlets (4) is 2 to 4, and they are evenly arranged on the outer wall of the water jacket layer (1).

6. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: The outlet diameter of the lower section outlet (4) is 65 to 120 mm.

7. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: A temperature measuring device is provided at the upper section outlet (3).

8. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: An electric valve is provided at the upper section inlet (5).

9. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 1, characterized in that: When the combined structure is in operation, saturated water from the forced circulation water pump (18) enters the lower section inlet (6) of the sealing ring of the riser heat exchanger, absorbs heat and becomes a steam-water mixture before flowing out from the lower section outlet (4) of the sealing ring of the riser heat exchanger; deoxygenated water from the feed water pump (16) enters the steam drum (17) in one way and enters the upper section inlet (5) of the sealing ring of the riser heat exchanger in the other way, absorbs heat and flows out from the upper section outlet (3) of the sealing ring of the riser heat exchanger, ensuring that the inner steel cylinder (8) at the connection between the outlet side of the riser heat exchanger and the flange is within the allowable temperature range of the material, thereby avoiding local thermal stress caused by local high temperature; the water flowing out from the upper section outlet (3) of the sealing ring of the riser heat exchanger enters the deaerator (15) after being decompressed by the pressure reducer (20), and thermally deoxygenates the desalted water from the water tank (13).

10. The combined structure for eliminating local thermal stress of a coke oven riser jacket heat exchanger according to claim 3, characterized in that: The riser heat exchanger (19) is provided with a plurality of outlets and a sealing ring to separate the water jacket layer of the riser into two independent spaces. The sealing ring has a slope, which plays a great role in smoothly discharging steam and avoiding steam stagnation dead corners. The upper part of the sealing ring is cooled by deoxygenated water to ensure that the inner steel cylinder at the outlet side and the flange connection is within the allowable temperature range of the material, avoiding local thermal stress caused by local high temperature, and at the same time recovering part of the heat for thermal deoxygenation.

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