Deoxidizing water supply system for dry quenching coke boiler

Abstract

This utility model provides a deaeration water supply system for a dry quenching coke boiler, including a desalination feedwater device, a deaerator, a dry quenching coke boiler, a boiler feedwater pump, and a frame. The deaerator and the desalination feedwater device are connected for deoxygenating the feedwater from the desalination feedwater device. The boiler feedwater pump is connected to both the deaerator and the dry quenching coke boiler, for transporting the deaerated feedwater to the dry quenching coke boiler. Both the dry quenching coke boiler and the deaerator are mounted on the frame, with the deaerator installed above ground level at a height of h1, and the boiler feedwater pump installed at a height of h2. The height difference H between the deaerator and the boiler feedwater pump is h1-h2, where H ≥ 8m. This system reduces the overall footprint of the dry quenching coke boiler deaeration water supply system, facilitating modifications for dry quenching. Furthermore, it increases the inlet static head of the boiler feedwater pump, better meeting the required net positive suction head (NPSH) and reducing the risk of cavitation damage to the pump body.

Description

Technical Field

[0001] This utility model relates to the field of dry quenching technology, and in particular to a deaeration water supply system for a dry quenching boiler. Background Technology

[0002] The conventional operation process of a deaeration water supply system for a traditional dry quenching coke boiler is as follows: 1. Water Source Inflow: Makeup water from the plant's demineralized water network and condensate returned from the turbine power station first enter the demineralized water tank in a separately set deaeration feedwater pump station. 2. Pressurization and Preheating: After being pressurized by the deaeration feedwater pump, the above-mentioned water source is transported to a heat pipe heat exchanger for preheating treatment. 3. Deaeration Treatment: The preheated water enters the deaerator to complete the heating and deaeration process. After this process, the boiler feedwater can reach the standard of 104℃ and oxygen content ≤0.007mg / L. 4. Delivery to Boiler: The treated boiler feedwater is pressurized by the boiler feedwater pump and finally delivered to the dry quenching coke boiler.

[0003] Currently, most coking plants operate multiple dry quenching systems simultaneously. To achieve a fully dry quenching production mode and save costs, it is necessary to dismantle the original wet quenching system and build a new backup dry quenching system. However, in this process, setting up a separate deaerator feedwater pump station would require a large amount of space, and the existing plant area has limited space, making it difficult to renovate the backup dry quenching system. In addition, in the case of a separate deaerator feedwater pump station, the deaerator feedwater pump station usually cannot adequately meet the required net positive suction head (NPSHr) of the boiler feedwater pump, resulting in a significant increase in the risk of cavitation damage to the boiler feedwater pump body. Utility Model Content

[0004] The purpose of this utility model embodiment is to provide a deaeration water supply system for a dry quenching boiler, reducing its overall footprint to facilitate the renovation of dry quenching boilers. The specific technical solution is as follows:

[0005] A deaerator water supply system for a dry quenching coke boiler includes:

[0006] Demineralization water supply system;

[0007] A deaerator, connected to the desalination water supply device, is used to deoxygenate the water supply from the desalination water supply device.

[0008] Dry quenching coke boiler;

[0009] A boiler feedwater pump is connected to the deaerator and the dry quenching boiler respectively, and is used to transport the feedwater after deoxygenation by the deaerator to the dry quenching boiler.

[0010] Frame; among which,

[0011] Both the dry quenching boiler and the deaerator are installed on the frame, with the deaerator installed above the ground at a height of h1, and the boiler feed water pump installed at a height of h2. The height difference H between the deaerator and the boiler feed water pump is h1-h2, and H≥8m.

[0012] In some embodiments, H≤12m; the inlet static head of the boiler feedwater pump is P, P≥0.1MPa.

[0013] In some embodiments, the demineralized water supply device includes: a demineralized water tank, a deoxygenated water supply pump, a heat pipe heat exchanger, a demineralized water tank outlet pipe, a deoxygenated water supply pipe, and a deoxygenated water return pipe; wherein, the demineralized water tank outlet pipe is connected to the demineralized water tank and the deoxygenated water supply pump respectively, the deoxygenated water supply pipe is connected to the deoxygenated water pump and the heat pipe heat exchanger respectively, and the deoxygenated water return pipe is connected to the heat pipe heat exchanger and the deaerator respectively; a deoxygenated water pipe connects the deaerator and the boiler feed water pump; and a deoxygenated water recirculation pipe connects to the deoxygenated water pipe and the deoxygenated water supply pipe respectively.

[0014] In some embodiments, the boiler feedwater pump is located at the bottom of the dry quenching boiler.

[0015] In some embodiments, h2 = 0m.

[0016] In some embodiments, the bottom of the dry quenching boiler is provided with a tight-fitting enclosed structure, and the boiler feedwater pump is located inside the tight-fitting enclosed structure.

[0017] In some embodiments, the outer wall of the tight-fitting enclosed structure includes a double-layer insulated steel plate and rock wool disposed between the double-layer insulated steel plates, wherein the thickness of the rock wool is d, and d≥50mm.

[0018] In some embodiments, the frame is an integral steel structure frame.

[0019] In some embodiments, the steel structure frame is provided with a support platform higher than the ground, and the deaerator is disposed on the support platform.

[0020] In some embodiments, the deaerator is located on one side of the dry quenching boiler.

[0021] The dry quenching coke boiler deaeration water supply system provided in this embodiment includes a desalination feedwater device, a deaerator, a dry quenching coke boiler, a boiler feedwater pump, and a frame. The deaerator is connected to the desalination feedwater device and is used to deaerate the feedwater from the desalination feedwater device. The boiler feedwater pump is connected to both the deaerator and the dry quenching coke boiler and is used to transport the deaerated feedwater to the dry quenching coke boiler. Both the dry quenching coke boiler and the deaerator are mounted on the frame, with the deaerator installed above ground level at a height of h1, and the boiler feedwater pump installed at a height of h2. The height difference H between the deaerator and the boiler feedwater pump is h1-h2, and H≥8m. In this embodiment, on the one hand, both the dry quenching boiler and the deaerator are housed within the frame, allowing them to share a single frame. Compared to a separate deaerator feedwater pump station, this reduces the overall footprint of the dry quenching boiler deaerator water supply system, facilitating retrofitting of the dry quenching process. On the other hand, the height difference H between the deaerator and the boiler feedwater pump is ≥8m. Because the deaerator is positioned higher than the boiler feedwater pump, it can provide a higher water pressure to the boiler feedwater pump under gravity, increasing the inlet static head and thus better meeting the necessary net positive suction head (NPSH) of the boiler feedwater pump, reducing the risk of cavitation damage to the pump body.

[0022] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0024] Figure 1 A schematic diagram of the pipeline connection of a deaerator water supply system for a dry quenching coke boiler provided in this application embodiment;

[0025] Figure 2 This is a schematic diagram of a deaeration water supply system for a dry quenching coke boiler, provided as an embodiment of this application.

[0026] The attached figures are labeled as follows:

[0027] Demineralized water supply device 10, demineralized water tank 11, deoxygenated water supply pump 12, heat pipe heat exchanger 13, demineralized water tank outlet pipe 14, deoxygenated water supply pipe 15, deoxygenated water return pipe 16, deaerator 20, dry quenching boiler 30, economizer 31, steam drum 32, boiler feed water pump 40, frame 50, support platform 51, deoxygenated water pipe 60, deoxygenated water recirculation pipe 70, main feed water pipe 80. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art based on this application are within the protection scope of the present utility model.

[0029] In related technologies, the conventional design of deaerator feedwater pump stations often suffers from insufficient deaerator height, resulting in at least the following drawbacks: 1. Defective equipment layout: The water supply from the deaerator to the boiler feedwater pumps is insufficient to meet the required net positive suction head (NPSHr), significantly increasing the risk of pump damage due to cavitation. In actual operation, the inlet pressure of the boiler feedwater pumps may be more than 0.3 MPa lower than the saturated steam pressure. 2. High operation and maintenance costs: In some coking plant cases, the annual maintenance cost of boiler feedwater pumps due to cavitation exceeds 500,000 yuan. 3. Severe energy efficiency loss: The design of deaerator feedwater pump stations leads to additional construction costs and pipeline heat loss, with winter heat loss reaching 5-8%. 4. Low space utilization: Traditional layouts require the construction of a separate pump station building, resulting in high civil engineering investment.

[0030] The purpose of this solution is to provide a deaeration water supply system for a dry quenching boiler, reducing its overall footprint to facilitate the renovation of dry quenching boilers.

[0031] Therefore, this application proposes a deaeration water supply system for a dry quenching coke boiler.

[0032] Figure 1 This is a schematic diagram of the pipeline connection of a deaerator water supply system for a dry quenching coke boiler, provided in an embodiment of this application. Figure 2 This is a schematic diagram of a deaerator water supply system for a dry quenching coke boiler, provided as an embodiment of this application. Figure 1 and Figure 2As shown, a deaeration water supply system for a dry quenching coke boiler includes: a desalination feedwater device 10, a deaerator 20, a dry quenching coke boiler 30, a boiler feedwater pump 40, and a frame 50. The deaerator 20 is connected to the desalination feedwater device 10 and is used to deaerate the feedwater from the desalination feedwater device 10. The boiler feedwater pump 40 is connected to both the deaerator 20 and the dry quenching coke boiler 30, and is used to transport the deaerated feedwater from the deaerator 20 to the dry quenching coke boiler 30. Both the dry quenching coke boiler 30 and the deaerator 20 are mounted on the frame 50, with the deaerator 20 positioned above ground level at a height of h1, and the boiler feedwater pump 40 positioned at a height of h2. The height difference H between the deaerator 20 and the boiler feedwater pump 40 is h1-h2, and H ≥ 8m. For example, H can be 8m, 9m, 10m, 11m, 12m, 13m, 14m, or any value between the two values ​​mentioned above, but is not limited to these.

[0033] In an embodiment of this scheme, both the dry quenching boiler 30 and the deaerator 20 are mounted on the frame 50, so that the dry quenching boiler 30 and the deaerator 20 share a frame 50. Compared with the scheme of setting up a separate deaerator water supply station, the overall footprint of the dry quenching boiler deaerator water supply system is reduced, which facilitates the reconstruction of the dry quenching boiler.

[0034] On the other hand, the required net positive suction head (NPSH) is a performance parameter of the boiler feed pump 40 itself. Once the boiler feed pump 40 is manufactured, the value of the required NPSH is also determined. It is independent of the piping system and installation conditions, as well as the properties of the liquid. Physically, it represents the pressure drop of the liquid at the pump inlet (from the pump inlet to the lowest pressure point on the impeller). The value of the required NPSH indicates how much pressure or energy is required on the pump suction side to prevent cavitation. The smaller the required NPSH value, the better the cavitation resistance of the boiler feed pump 40. A smaller pressure drop in the boiler feed pump 40 requires a smaller required NPSH from the deaerator 20. In this embodiment of the solution, the height difference H between the deaerator 20 and the boiler feedwater pump 40 is ≥8m. Because the deaerator 20 is positioned higher than the boiler feedwater pump 40, under gravity, it can provide a greater water pressure to the boiler feedwater pump 40. This increases the inlet static head (static head, also known as pressure head, is the static pressure energy per unit weight of fluid), thus better meeting the required net positive suction head (NPSH) of the boiler feedwater pump 40 and reducing the risk of cavitation damage to the pump body. Alternatively, because a boiler feedwater pump 40 with better cavitation resistance is more expensive, this embodiment of the solution, with the deaerator 20 positioned higher than the boiler feedwater pump 40, allows for a greater water pressure to the boiler feedwater pump 40 under gravity, increasing the inlet static head and thus facilitating a reduction in the cavitation resistance requirements of the boiler feedwater pump 40, thereby reducing its procurement cost.

[0035] The height difference between the deaerator 20 and the boiler feed pump 40 is a vertical height difference from the ground. In some embodiments, H≤12m. The inlet static pressure head of the boiler feed pump 40 is P, P≥0.1MPa, which is far greater than the critical net positive suction head (NPSH) of the boiler feed pump 40. This makes it easy to meet the required NPSH of the boiler feed pump 40 and reduce the risk of cavitation damage to the pump body of the boiler feed pump 40.

[0036] In some embodiments, the boiler feedwater pump 40 is located at the bottom of the dry quenching boiler 30 to shorten the length of the water supply pipe and supply water to the dry quenching boiler 30.

[0037] The boiler feedwater pump 40 can be positioned at an elevation of 0m at the bottom of the dry quenching boiler 30, with both the boiler feedwater pump 40 and the bottom of the dry quenching boiler 30 at ground level. That is, h2 = 0m, but it is not limited to this. It is easy to understand that the boiler feedwater pump 40 can also be positioned at an elevation greater than 0m at the bottom of the dry quenching boiler 30, as long as the height difference H between the deaerator 20 and the boiler feedwater pump 40 is ≥ 8m.

[0038] On the other hand, placing the boiler feedwater pump 40 at the bottom of the dry quenching boiler 30 also facilitates maintaining the pump's ambient temperature at a suitable level using a tightly sealed structure, ensuring normal operation in winter. In practice, the bottom of the dry quenching boiler 30 is equipped with a tightly sealed structure, and the boiler feedwater pump 40 is located within this structure. The tightly sealed structure, arranged around the dry quenching boiler 30, provides ventilation, rain protection, and heat insulation.

[0039] For example, the outer wall of the tight-fitting enclosed structure includes a double-layer thermal insulation steel plate and rock wool placed between the double-layer thermal insulation steel plates. The thickness of the rock wool is d, where d ≥ 50 mm. In some cases, this can maintain the pump body ambient temperature > 5°C, ensuring normal operation in winter.

[0040] The embodiments of this application do not limit the structure of the frame 50, and are not limited to masonry structures and steel frame structures.

[0041] Taking the steel structure frame as an example, the steel structure frame includes multiple vertical steel frames and multiple horizontal steel frames. The multiple vertical steel frames and multiple horizontal steel frames are connected as one unit, which makes the overall structure of the frame 50 relatively stable.

[0042] In some embodiments, the steel structure frame is provided with a support platform 51 above the ground, and the deaerator 20 is disposed on the support platform 51. The support platform 51 is connected to at least one vertical steel frame and at least one horizontal steel frame. The support platform 51 can be a steel plate or a metal support frame, etc., to provide stable support for the deaerator 20.

[0043] The deaerator 20 can be arranged on one side of the dry quenching coke boiler 30.

[0044] In this embodiment of the solution, the deaerator 20 is arranged on the steel structure frame of the dry quenching boiler 30, and the boiler feed water pump 40 is set at the bottom of the dry quenching boiler 30, which can effectively reduce the land occupation and investment cost of the deaerator feed water pump station.

[0045] The demineralized water supply device 10 includes: a demineralized water tank 11, a deoxygenated water supply pump 12, a heat pipe heat exchanger 13, a demineralized water tank outlet pipe 14, a deoxygenated water supply pipe 15, and a deoxygenated water return pipe 16. The demineralized water tank outlet pipe 14 connects to the demineralized water tank 11 and the deoxygenated water supply pump 12. The deoxygenated water supply pipe 15 connects to the deoxygenated water pump 12 and the heat pipe heat exchanger 13. The deoxygenated water return pipe 16 connects to the heat pipe heat exchanger 13 and the deaerator 20. A deoxygenated water pipe 60 connects the deaerator 20 and the boiler feed water pump 40. A deoxygenated water recirculation pipe 70 connects to the deoxygenated water pipe 60 and the deoxygenated water supply pipe 15.

[0046] In this application, makeup water from the plant's demineralized water network and condensate returned from the turbine power station are transported via pipeline to the demineralized water tank 11. After being pressurized by the deaerator feedwater pump 12, the condensate in the demineralized water tank 11 is transported to the heat pipe heat exchanger 13 for preheating, and then enters the deaerator 20 for heating and deaeration treatment. The boiler feedwater treated by the deaerator 20 can reach a temperature of 104℃ and an oxygen content ≤0.007mg / L. Finally, it is pressurized by the boiler feedwater pump 40 and transported to the dry quenching boiler 30. Specifically, the boiler feedwater treated by the deaerator 20 first enters the economizer 31 of the dry quenching boiler 30 through the main feedwater pipeline 80 for heating, and then is sent to the steam drum 32 of the dry quenching boiler 30.

[0047] In this embodiment of the solution, due to the addition of a deaerator feedwater recirculation pipeline 70, during the operation of the deaerator feedwater system of the coke quenching boiler, the deaerator feedwater recirculation pipeline 70 transports a portion of the 104°C deaerator water (boiler feedwater treated by deaerator 20) to the deaerator feedwater supply pipeline 15, and from there to the heat pipe heat exchanger 13. This increases the inlet water temperature of the heat pipe heat exchanger 13 and raises the low-temperature makeup water preheating temperature of the heat pipe heat exchanger 13 to above 60°C. Therefore, it reduces the heat obtained by the deaerator 20 from the steam, significantly reducing the steam consumption of the deaerator 20.

[0048] The embodiments of this solution have at least the following advantages:

[0049] 1. Improved operational reliability: The boiler feedwater pump 40 is less prone to cavitation, which significantly improves the stability of the deaeration water supply system of the dry quenching coke boiler 30. In some cases, it can reduce cavitation-related maintenance costs by more than 90%.

[0050] 2. Significant economic benefits: On the one hand, there is no need to construct a separate deaeration water supply pumping station, saving the cost of such a station. On the other hand, since the dry quenching boiler 30 and the deaerator 20 are both located on the same frame 50, the distance between the pipelines of the dry quenching boiler 30 and the deaerator 20 is shortened, thereby reducing pipeline pressure loss. In some cases, this can reduce pipeline pressure by 15-20%, resulting in an overall energy efficiency improvement of 8-12% for the deaeration water supply system of the dry quenching boiler 30.

[0051] 3. Space optimization: By making full use of the frame 50, the dry quenching boiler 30 and the deaerator 20 are arranged in a compact and reasonable manner, which can save 30-40% of the floor space.

[0052] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

Claims

1. A deoxidized water supply system for a dry quenching boiler, characterized by, include: Desalination water supply device (10); A deaerator (20) is connected to the desalination water supply device (10) and is used to deoxygenate the water supply from the desalination water supply device (10); Dry quenching coke boiler (30); A boiler feedwater pump (40) is connected to the deaerator (20) and the dry quenching boiler (30) respectively, and is used to transport the feedwater after deoxygenation by the deaerator (20) to the dry quenching boiler (30). Frame (50); among which, The dry quenching boiler (30) and the deaerator (20) are both installed on the frame (50), and the deaerator (20) is installed above the ground at a height of h1. The boiler feed water pump (40) is installed at a height of h2. The height difference H between the deaerator (20) and the boiler feed water pump (40) is h1-h2, and H≥8m.

2. The deaerator water supply system for a dry quenching coke boiler according to claim 1, characterized in that, H≤12m; The inlet static head of the boiler feed pump (40) is P, where P ≥ 0.1 MPa.

3. The deaeration water supply system for a dry quenching coke boiler according to claim 1, characterized in that, The desalination water supply device (10) includes: a desalination water tank (11), a deoxygenated water supply pump (12), a heat pipe heat exchanger (13), a desalination water tank outlet pipe (14), a deoxygenated water supply pipe (15), and a deoxygenated water return pipe (16); wherein, The demineralized water tank outlet pipe (14) is connected to the demineralized water tank (11) and the deoxygenated water supply pump (12) respectively. The deoxygenated water supply pipe (15) is connected to the deoxygenated water supply pump (12) and the heat pipe heat exchanger (13) respectively. The deoxygenated water supply return pipe (16) is connected to the heat pipe heat exchanger (13) and the deaerator (20) respectively. A deoxygenated water pipeline (60) is provided, through which the deaerator (20) and the boiler feed water pump (40) are connected; The deoxygenated water recirculation pipeline (70) is connected to the deoxygenated water pipeline (60) and the deoxygenated water supply pipeline (15), respectively.

4. The deaeration water supply system for a dry quenching coke boiler according to claim 1, characterized in that, The boiler feedwater pump (40) is located at the bottom of the dry quenching boiler (30).

5. The deaerator water supply system for a dry quenching coke boiler according to claim 4, characterized in that, h2 = 0m.

6. The deaerator water supply system for a dry quenching coke boiler according to claim 4, characterized in that, The bottom of the dry quenching coke boiler (30) is provided with a tight-fitting enclosed structure, and the boiler feed water pump (40) is located inside the tight-fitting enclosed structure.

7. The deaerator water supply system for a dry quenching coke boiler according to claim 6, characterized in that, The outer wall of the tight-fitting enclosed structure includes a double-layer insulated steel plate and rock wool disposed between the double-layer insulated steel plates, wherein the thickness of the rock wool is d, and d≥50mm.

8. The deaerator water supply system for a dry quenching coke boiler according to claim 1, characterized in that, The frame (50) is an integral steel structure frame.

9. The deaerator water supply system for a dry quenching coke boiler according to claim 8, characterized in that, The steel structure frame is provided with a support platform (51) higher than the ground, and the deaerator (20) is provided on the support platform (51).

10. The deaerator water supply system for a dry quenching coke boiler according to claim 8, characterized in that, The deaerator (20) is located on one side of the dry quenching boiler (30).

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