Water-steam loop system of gasification furnace
By integrating the burner cooling water system into the gasifier water-steam circuit system and sharing the cooling water cycle, the problems of high system costs and complex processes in the existing technology are solved, and the effects of cost reduction, process simplification and thermal efficiency improvement are achieved.
Patent Information
- Application Number
- CN202422110307.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-08-29
AI Technical Summary
In the existing pulverized coal gasification process, the gasifier water-steam circuit system and the burner cooling water system are independent of the system, resulting in high system cost and complex process flow.
The burner cooling water system is integrated into the gasifier water-steam circuit system, and the cooling water circulation is shared through components such as steam drums and circulation pumps to achieve unified cooling of the gasifier wall and burner.
It reduces the initial investment cost and subsequent operation cost of the project, simplifies the process flow, improves thermal efficiency, and reduces energy consumption.
Smart Images
Figure CN223002894U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a water-steam circuit system of a gasifier, in which a burner cooling water system is integrated. Background Art
[0002] As the basis and core of clean coal technology, coal gasification technology has a history of more than 200 years. The development of modern coal gasification technology benefits from the oil crisis. The first worldwide oil crisis in the 1970s made people clearly realize that oil and natural gas are not infinite resources compared with coal. Due to the prediction of the supply prospects of oil and natural gas by developed countries, they have put the development of coal gasification as an alternative energy source back on the agenda and accelerated the development and industrialization of new coal gasification processes.
[0003] Coal gasification technology is a technology that converts solid coal into gaseous hydrocarbons, CO, H2 and other gases, aiming to obtain clean energy and chemical raw materials. Its principle is to make coal, coal coke or petroleum coke react with gasifying agents (air, oxygen, steam, hydrogen, etc.) at a certain temperature and pressure, and convert the organic matter in coal, coal coke or petroleum coke into coal gas. The entrained flow coal gasification process can be further divided into water coal slurry gasification and pulverized coal gasification. Compared with water coal slurry gasification, pulverized coal gasification has the characteristics of high gasification efficiency, good performance indicators and wide application coal types, and has high technical, economic and environmental protection advantages.
[0004] During normal operation, due to the high temperature inside the gasifier, it is necessary to cool the wall and burner of the gasifier to extend its service life. In the current pulverized coal gasification process, the water-steam circuit system of the gasifier is used to cool the wall of the gasifier. The water-steam circuit system of the gasifier is a closed system composed of a steam drum, a circulating pump, and the corresponding water-cooled wall heating surface of the gasifier. Boiler feed water enters the steam drum, and the boiler water (saturated water) in the steam drum enters the circulating pump through the bottom pipeline of the steam drum. It is pressurized by the circulating pump and distributed to the corresponding heating surface of the gasifier to cool and protect the gasifier. The water-steam mixture after absorbing heat returns to the steam drum through the pipeline and undergoes gas-liquid separation inside the steam drum. The steam is sent into the pipe network through the pipeline at the top of the steam drum. The boiler feed water pipeline at the bottom sends boiler feed water into the steam drum from outside the battery limit to supplement the circulating water volume and ensure the stability of the steam drum liquid level. However, the burner adopts an independent closed-loop cooling water system, which includes: a cooling water buffer tank (the buffer tank also has the functions of independent nitrogen charging and nitrogen sealing), one open and one standby cooling water pumps, a heat exchanger, a filter, and the corresponding control system, etc. This results in a high cost of the gasifier system and a complex process flow.
[0005] The utility model provides a water-steam circuit system of a gasifier, in which a burner cooling water system is integrated, so as to reduce the initial investment cost and subsequent operation cost of the project, simplify the process flow, improve the thermal efficiency, and reduce the energy consumption. Summary of the Utility Model
[0006] Aspects and advantages of the present utility model will be set forth in part in the following description, or may be obvious from the description, or may be learned by practice of the present utility model.
[0007] The present utility model relates to a water-steam circuit system for a gasifier, comprising:
[0008] At least one water-cooled wall of the gasifier;
[0009] A steam drum, which includes a first steam drum inlet, a second steam drum inlet and a first steam drum outlet. The first steam drum outlet is connected to the inlet of at least one water-cooled wall of the gasifier to supply cooling water to the inlet of at least one water-cooled wall of the gasifier. Under normal operating conditions, the cooling water is heated into a water-steam mixture by at least one water-cooled wall of the gasifier, and the first steam drum inlet is connected to the outlet of at least one water-cooled wall of the gasifier to receive the water-steam mixture from the outlet of at least one water-cooled wall of the gasifier;
[0010] A circulation pump, which is arranged between the first steam drum outlet and the inlet of at least one water-cooled wall of the gasifier; and
[0011] A water jacket for the coal burner of the gasifier, which is used to cool the coal burner of the gasifier;
[0012] It is characterized in that the second steam drum inlet is connected to the outlet of the water jacket for the coal burner. Description of the Drawings
[0013] In the description with reference to the accompanying drawings, a complete and enabling disclosure of the present utility model for those of ordinary skill in the art is set forth, including its best mode, in the drawings:
[0014] Figure 1 A schematic diagram of a water-steam circuit system for a gasifier according to an embodiment of the present utility model is shown; and
[0015] Figure 2 A schematic diagram of a water-steam circuit system for a gasifier according to another embodiment of the present utility model is shown. Detailed Description of the Embodiments
[0016] Reference will now be made in detail to embodiments of the present utility model, one or more examples of which are shown in the drawings. Each example is provided by way of explanation of the present utility model and not limitation thereof. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the present utility model without departing from the scope thereof. For example, features shown or described as part of one embodiment can be used with another embodiment to yield yet another embodiment. Accordingly, the present utility model is intended to cover such modifications and variations as fall within the scope of the appended claims and their equivalents.
[0017] The gasifier is a system containing a water-cooled wall heating surface of cooling water. Through the start-up burner, the gasifier can be heated from the cold state to the hot start-up state, and then through the coal burner, the gasification materials can be fed into the gasifier for gasification reaction. The heat generated during the gasification reaction is carried out of the gasifier in the form of a water-steam mixture by the cooling water wall of the gasifier, and enters the steam drum. During operation, due to the high temperature inside the gasifier, it is necessary to cool the wall and burners of the gasifier.
[0018] Figure 1 Shown is a gasifier water-steam circuit system 10 according to an embodiment of the present invention, for cooling the wall, coal burner and start-up burner of the gasifier.
[0019] The gasifier water-steam circuit system 10 may include at least one gasifier water-cooled wall 15. The gasifier water-steam circuit system 10 may further include a steam drum 20, which may include a first steam drum inlet 21, a second steam drum inlet 22 and a first steam drum outlet 23. The first steam drum outlet 23 may be connected to the inlet of at least one gasifier water-cooled wall 15 to supply cooling water to the inlet of at least one gasifier water-cooled wall 15. Under normal operating conditions of the gasifier, the cooling water may be heated into a water-steam mixture by at least one gasifier water-cooled wall 15, and the first steam drum inlet 21 may be connected to the outlet of at least one gasifier water-cooled wall 15 to receive the water-steam mixture from the outlet of at least one gasifier water-cooled wall 15.
[0020] The gasifier water-steam circuit system 10 may further include a circulation pump 30, which may be arranged between the first steam drum outlet 23 and the inlet of at least one gasifier water-cooled wall 15. The circulation pump (or called the circulating water pump) 30 may take water from the first steam drum outlet 23 at the bottom of the steam drum, and then distribute the circulating water to the heating surface of the gasifier cooling water through the circulation pump to provide cooling protection for the gasifier equipment (such as the wall).
[0021] The steam drum 20 may further include a second steam drum outlet 24 and a third steam drum inlet 25. The second steam drum outlet 24 is used to discharge steam, and the third steam drum inlet 25 may be connected to a boiler feed water source (not labeled) via a boiler feed water pump 60 to receive boiler feed water from the boiler feed water source.
[0022] The steam drum 20 is a tank with internal components and is an important part of the gasifier cooling water system. It is the tank where the boiler feed water outside the battery limit and the water-steam mixture generated during the cooling of the gasifier return. The water-steam mixture generated by cooling the gasifier is separated in the steam drum, and the steam leaves from the second steam drum outlet 24 at the top of the steam drum and is incorporated into the steam pipe network outside the battery limit through the pipeline. After the boiler feed water and the separated saturated water are mixed in the steam drum, they enter the circulation pump 30 through the first steam drum outlet 23 at the bottom of the steam drum.
[0023] The gasifier water-steam circuit system 10 may further include a coal burner water jacket 40 for cooling the coal burner of the gasifier. The coal burner water jacket 40 may be an integral part of the coal burner. The second steam drum inlet 22 may be connected to the outlet of the coal burner water jacket 40. The gasification coal burner is a key equipment for gasification. During the gasification process, pulverized coal and the oxidant (oxygen or oxygen / steam mixture) for gasification can be fed into the gasifier through the coal burner, so that the gasification medium can complete the gasification reaction well in the gasifier.
[0024] The gasifier water-steam circuit system 10 may further include a mixer 50. The first mixer inlet of the mixer 50 may be connected downstream of the circulation pump 30 to receive cooling water from the circulation pump 30. The second mixer inlet of the mixer 50 may be connected downstream of the boiler feed water pump 60 to receive boiler feed water from the boiler feed water pump 60, thereby forming a cooling water-boiler feed water mixture. The mixer outlet of the mixer 50 may be connected to the inlet of the coal burner water jacket 40 to supply the cooling water-boiler feed water mixture to the inlet of the coal burner water jacket 40. The second steam drum inlet 22 may receive the cooling water-boiler feed water mixture heated by the coal burner water jacket 40 from the outlet of the coal burner water jacket 40. The mixer 50 may include a mixing tee or a static mixer.
[0025] The gasifier water-steam circuit system 10 may further include a first start-up burner water jacket 70 for cooling the first start-up burner of the gasifier. The inlet of the first start-up burner water jacket 70 may be connected in parallel with the inlet of the coal burner water jacket 40 to the mixer outlet of the mixer 50 to receive the cooling water-boiler feed water mixture. The start-up burner is an auxiliary burner that provides heat for the gasifier before the gasifier starts up, raises the gasifier from the cold state to the hot state, and meets the start-up feeding conditions. The first start-up burner water jacket 70 may be an integral part of the first start-up burner. The start-up burner is only used during the start-up stage of the gasifier.
[0026] The gasifier water-steam circuit system 10 may further include a first pressure reducing orifice plate 80. The inlet of the first pressure reducing orifice plate 80 is connected to the outlets of the coal burner water jacket 40 and the first start-up burner water jacket 70. The first pressure reducing orifice plate 80 is configured to reduce the pressure of the heated cooling water-boiler feed water mixture from the outlets of the coal burner water jacket 40 and the first start-up burner water jacket 70 and cause it to flash during the start-up and shutdown conditions of the gasifier, thereby generating a water-steam mixture.
[0027] The gasifier water-steam circuit system 10 may further include a first steam and water separation tank 90. The first steam and water separation tank 90 is connected to the outlet of the first pressure reducing orifice plate 80 to separate the water-steam mixture from the outlet of the first pressure reducing orifice plate 80 into saturated water and low-pressure steam.
[0028] The saturated water from the first steam and water separation tank 90 can be supplied to the boiler feed pump or an external low-pressure boiler feed water user. The low-pressure steam from the first steam and water separation tank 90 can be supplied to the low-pressure steam pipe network.
[0029] In this embodiment, the boiler feed water entering the steam drum 20 is divided into two parts. One part of the boiler feed water is sent to the burners (including coal burners and start-up burners) as burner cooling water, and the remaining boiler feed water is sent to the steam drum from the third steam drum inlet 25 at the bottom of the steam drum. In order to maintain the temperature of the burner cooling water (about 210 degrees), downstream of the circulation pump, a part of the circulating water is taken and mixed with the boiler feed water going to the burners through a mixer 50. The mixed cooling water enters the burners for cooling and finally returns to the steam drum 20 to maintain the steam drum liquid level. Under normal operating conditions, the heat absorbed by the coal burner cooling water will also be recovered into the steam drum 20, increasing the steam output of the steam drum.
[0030] When in the start-up and shutdown conditions, since the gasification reaction does not occur in the gasifier or the heat load of the gasifier is not sufficient to generate steam, at this time, in order to prevent the steam drum liquid level from being too high due to the supplementary boiler feed water, resulting in the boiler water entering the steam pipe network, in this condition, the cooling water after the burner cooling is depressurized through a pressure-reducing orifice plate. The flashed water and steam enter the steam and water separation tank. The steam is sent to the low-pressure steam pipe network, and the saturated water can be sent to the external low-pressure boiler feed water user outside the battery limit or returned to the inlet of the boiler feed pump for recycling according to customer requirements (not shown in Figure 1 but shown in Figure 2 ).
[0031] According to the process requirements, corresponding valves and pressure gauges can be included in each pipeline, which are not described in detail herein.
[0032] Figure 2 Fig. shows a gasifier water-steam circuit system 100 according to another embodiment of the present invention, for cooling the wall of the gasifier, coal burners and start-up burners. Similar to the gasifier water-steam circuit system 10, the gasifier water-steam circuit system 100 may include at least one gasifier water-cooled wall, a circulation pump and related pipelines. For the sake of brevity, Figure 2 only the differences from Figure 1 are shown herein.
[0033] The gasifier water-steam circuit system 100 may further include a heat exchanger 110 and a filter 120 upstream of the heat exchanger 110. The inlet of the coal burner water jacket 40 is connected to the downstream of the boiler feed pump 60 via the heat exchanger 110 and the filter 120 to receive boiler feed water from the boiler feed pump 60.
[0034] The low-temperature medium inlet of the heat exchanger 110 can be connected to the filter 120, and the low-temperature medium outlet of the heat exchanger 110 is connected to the inlet of the coal burner water jacket 40. The high-temperature medium inlet of the heat exchanger 110 can be connected downstream of the circulation pump 30, and the high-temperature medium outlet of the heat exchanger 110 can be connected to the fourth steam drum inlet of the steam drum 20. The heat exchanger 110 can be configured to heat the boiler feed water from the boiler feed pump 60 using the cooling water from the circulation pump 30.
[0035] The gasifier water-steam circuit system 100 may further include a second start-up burner water jacket 130 for cooling the second start-up burner of the gasifier. The second start-up burner water jacket 130 may be an integral part of the second start-up burner. The inlet of the second start-up burner water jacket 130 can be connected in parallel with the coal burner water jacket 40, the heat exchanger 110, and the filter 120 downstream of the boiler feed pump 60 to receive the boiler feed water from the boiler feed pump 60.
[0036] The gasifier water-steam circuit system 100 further includes a second pressure-reducing orifice plate 180. The inlet of the second pressure-reducing orifice plate 180 is connected to the outlet of the coal burner water jacket 40 and the outlet of the second start-up burner water jacket 130. The second pressure-reducing orifice plate 180 is configured to reduce the pressure and cause flashing of the heated boiler feed water from the outlet of the coal burner water jacket 40 and the outlet of the second start-up burner water jacket 130 under the start-up and shutdown conditions of the gasifier, thereby generating a water-steam mixture.
[0037] The gasifier water-steam circuit system 100 further includes a second steam and water separation tank 190. The second steam and water separation tank 190 is connected to the outlet of the second pressure-reducing orifice plate 180 to separate the water-steam mixture from the outlet of the second pressure-reducing orifice plate 180 into saturated water and low-pressure steam.
[0038] The saturated water from the second steam and water separation tank 190 can be supplied to the boiler feed pump or an external low-pressure boiler feed water user. The low-pressure steam from the second steam and water separation tank 190 can be supplied to the low-pressure steam network.
[0039] In this embodiment, when the outlet pressure of the circulation pump 30 is insufficient to overcome the pressure drop of the coal burner cooling water passage, all boiler feed water can be used as the coal burner cooling water, and then the temperature of the boiler feed water entering the coal burner can be raised to the required 210 degrees in the form of the heat exchanger 110. The heat source of the heat exchanger can be the circulating water of the gasifier or other heat sources in the chemical plant (medium-pressure steam or waste heat, etc.). If it is circulating water, after heat exchange, the circulating water returns to the steam drum 20; if it is other heat sources, it is sent out of the battery limit to the designated position of the customer after heat exchange. During normal operation, the boiler feed water heated to 210 degrees enters the coal burner to cool the coal burner, and then enters the steam drum 20 to supplement the steam drum liquid level. During this process, the heat absorbed by the boiler feed water (including the heat absorbed in the heat exchanger and in the coal burner) enters the steam drum, increasing the steam output of the steam drum.
[0040] The start-up burner is only used in the start-up stage of the gasifier, and boiler feed water can be directly used to cool the start-up burner. Since the start-up burner is used in the start-up stage of the gasifier, and there is no steam generated in the steam drum at this time, the cooling water of the start-up burner is merged with the cooling water of the coal burner and sent out of the battery limit through the orifice plate.
[0041] This written description uses examples to disclose the present invention including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system and performing any incorporated method. The patentable scope of the present invention is defined by the claims, and may include other examples that occur to those skilled in the art. If these other examples include structural elements that are identical to the literal language of the claims, or if they include equivalent structural elements that have insubstantial differences from the literal language of the claims, then these other examples are intended to be within the scope of the claims.
Claims
1. A gasifier water-steam loop system, comprising: at least one gasifier water-cooled wall (15); A steam drum (20), comprising a first steam drum inlet (21), a second steam drum inlet (22) and a first steam drum outlet (23), wherein the first steam drum outlet (23) is connected to the inlet of the at least one gasifier water-cooled wall (15) to supply cooling water to the inlet of the at least one gasifier water-cooled wall (15), and under normal operating conditions of the gasifier, the cooling water is heated by the at least one gasifier water-cooled wall (15) to form a water-steam mixture, and the first steam drum inlet (21) is connected to the outlet of the at least one gasifier water-cooled wall (15) to receive the water-steam mixture from the outlet of the at least one gasifier water-cooled wall (15); a circulating pump (30) disposed between the first steam drum outlet (23) and the inlet of the at least one gasifier water-cooled wall (15); as well as A coal burner water jacket (40) for cooling the coal burner of the gasifier; It is characterized in that the second steam drum inlet (22) is connected to the outlet of the coal burner water jacket (40).
2. The gasifier water-steam loop system according to claim 1, characterized in that: The drum (20) further comprises a second drum outlet (24) and a third drum inlet (25), and the third drum inlet (25) is connected to a boiler feed water source via a boiler feed water pump (60) to receive boiler feed water from the boiler feed water source. The drum (20) is configured to separate the water-steam mixture into saturated water and steam, the separated steam is discharged from the second drum outlet (24) and merged into the steam network outside the limit area through a pipeline, and the separated saturated water is mixed with the boiler feed water in the drum (20) and then discharged from the first drum outlet (23) as cooling water.
3. The gasifier water-steam loop system according to claim 2, characterized in that: The invention also includes a mixer (50), wherein a first mixer inlet of the mixer (50) is connected to the downstream of the circulation pump (30) to receive cooling water from the circulation pump (30), a second mixer inlet of the mixer (50) is connected to the downstream of the boiler feed water pump (60) to receive boiler feed water from the boiler feed water pump (60), thereby forming a cooling water-boiler feed water mixture, a mixer outlet of the mixer (50) is connected to the inlet of the coal burner water jacket (40) to supply the cooling water-boiler feed water mixture to the inlet of the coal burner water jacket (40), and the second drum inlet (22) receives the cooling water-boiler feed water mixture heated by the coal burner water jacket (40) from the outlet of the coal burner water jacket (40).
4. The gasifier water-steam loop system according to claim 3, characterized in that: It also includes a first start-up burner water jacket (70) for cooling the first start-up burner of the gasifier, and the inlet of the first start-up burner water jacket (70) is connected in parallel with the inlet of the coal burner water jacket (40) to the mixer outlet of the mixer (50) to receive the cooling water-boiler feed water mixture.
5. The gasifier water-steam loop system according to claim 4, characterized in that: It also includes a first pressure reducing orifice plate (80), the inlet of which is connected to the outlet of the coal burner water jacket (40) and the outlet of the first start-up burner water jacket (70), and the first pressure reducing orifice plate (80) is configured to reduce the pressure of the heated cooling water-boiler feed water mixture from the outlet of the coal burner water jacket (40) and the outlet of the first start-up burner water jacket (70) and flash evaporate the mixture under the start-up and shutdown conditions of the gasifier, thereby generating a water-steam mixture.
6. The gasifier water-steam loop system according to claim 5, characterized in that: It also includes a first steam and water separation tank (90), which is connected to the outlet of the first pressure reducing orifice (80) to separate the water-steam mixture from the outlet of the first pressure reducing orifice (80) into saturated water and low-pressure steam.
7. The gasifier water-steam loop system according to claim 6, characterized in that: The saturated water from the first steam and water separation drum (90) is supplied to the boiler feed water pump or an external low pressure boiler feed water user.
8. The gasifier water-steam loop system according to claim 6, characterized in that: The low-pressure steam from the first steam and water separation tank (90) is supplied to the low-pressure steam network.
9. The gasifier water-steam loop system according to claim 2, characterized in that: It also includes a heat exchanger (110) and a filter (120) upstream of the heat exchanger (110), wherein the inlet of the coal burner water jacket (40) is connected to the downstream of the boiler feed water pump (60) via the heat exchanger (110) and the filter (120) to receive boiler feed water from the boiler feed water pump (60), wherein the low-temperature medium inlet of the heat exchanger (110) is connected to the filter (120), and the low-temperature medium outlet of the heat exchanger (110) is connected to the inlet of the coal burner water jacket (40).
10. The gasifier water-steam loop system according to claim 9, characterized in that: The high temperature medium inlet of the heat exchanger (110) is connected to the downstream of the circulation pump (30), and the high temperature medium outlet of the heat exchanger (110) is connected to the fourth drum inlet of the drum (20), and the heat exchanger (110) is configured to heat the boiler feed water from the boiler feed water pump (60) using the cooling water from the circulation pump (30).
11. The gasifier water-steam loop system according to claim 10, characterized in that: It also includes a second start-up burner water jacket (130) for cooling the second start-up burner of the gasifier, and the inlet of the second start-up burner water jacket (130) is connected in parallel with the coal burner water jacket (40), the heat exchanger (110) and the filter (120) to the downstream of the boiler feed water pump (60) to receive boiler feed water from the boiler feed water pump (60).
12. The gasifier water-steam loop system according to claim 11, characterized in that: It also includes a second pressure reducing orifice plate (180), the inlet of which is connected to the outlet of the coal burner water jacket (40) and the outlet of the second start-up burner water jacket (130), and the second pressure reducing orifice plate (180) is configured to reduce the pressure of the heated boiler feed water from the outlet of the coal burner water jacket (40) and the outlet of the second start-up burner water jacket (130) and flash evaporate the heated boiler feed water under the start-up and shutdown conditions of the gasifier, thereby generating a water-steam mixture.
13. The gasifier water-steam loop system according to claim 12, characterized in that: Also included is a second steam and water separation tank (190), which is connected to the outlet of the second pressure reducing orifice plate (180) to separate the water-steam mixture from the outlet of the second pressure reducing orifice plate (180) into saturated water and low-pressure steam.
14. The gasifier water-steam loop system according to claim 13, characterized in that: The saturated water from the second steam and water separation drum (190) is supplied to the boiler feed water pump or an external low pressure boiler feed water user.
15. The gasifier water-steam loop system according to claim 13, characterized in that: The low-pressure steam from the second steam and water separation tank (190) is supplied to the low-pressure steam network.