Gasification black water heat recovery system

Abstract

The utility model belongs to a kind of gasification black water heat recovery system;Including gasification black water evaporation hot water tower, gasification black water evaporation hot water tower is connected with the import of clarification tank by vacuum flash tank, desalted water pipeline is connected with the first passage import of heat exchange unit by desalted water pump and transformation desalted water preheater, and the import of thermal deaerator is connected with the first passage export of heat exchange unit;Black water evaporation hot water tower is connected with the import of vacuum flash tank by the second passage of heat exchange unit;With process design reasonable, realize the deep coupling of gasification black water system and boiler desalted water supply system, not only can energy saving and consumption reduction, reduce the use amount of circulating water, but also can by-product steam, and using by-product steam to carry out thermal deaeration to desalted water, to reach the advantage of reducing the use amount of purchased steam.

Description

Technical Field

[0001] This utility model belongs to the field of energy recovery technology for gasified black water, specifically a heat recovery system for gasified black water. Background Technology

[0002] After the raw coal is gasified, it is cooled through a quenching process. The gasifier discharges high-temperature, high-pressure gasified black water, which is generally treated by high-pressure flash evaporation, low-pressure flash evaporation, and vacuum flash evaporation. The above-mentioned flash evaporation process is a concentration and cooling process. Since the flash steam contains impurities such as dust and acidic gases, it is difficult to utilize. It is generally cooled by circulating water. The black water in the flash evaporation system is heated by heat exchange equipment. Due to the low quality of the heat source, it is generally used for heating, ORC power generation, bromine refrigeration, etc., and has different problems such as short utilization time, low utilization rate, and difficulty in subsequent resource utilization. Utility Model Content

[0003] To overcome the above deficiencies, this utility model provides a gasification black water heat recovery system to solve the technical problems existing in the prior art.

[0004] The technical solution adopted by this utility model to solve its technical problem is:

[0005] A heat recovery system for gasified black water includes a gasified black water evaporation hot water tower, which is connected to the inlet of a clarification tank via a vacuum flash tank. A demineralized water pipeline is connected to the inlet of the first channel of a heat exchange unit via a demineralized water pump and a demineralized water preheater. The outlet of the first channel of the heat exchange unit is connected to the inlet of a thermal deaerator. The black water evaporation hot water tower is connected to the inlet of the vacuum flash tank via the second channel of the heat exchange unit.

[0006] The beneficial effects of this utility model are as follows: This utility model abandons the technical solution of purchasing new equipment for heat exchange in the traditional technology, and instead uses the heat of gasified black water to exchange heat with demineralized water to achieve heating of demineralized water, thereby reducing the consumption of thermal deoxygenation steam in the thermal deaerator.

[0007] Preferably, a low-temperature deaerator is provided between the demineralized water pump and the demineralized water preheater; a first tee is provided at the outlet of the first channel of the heat exchange unit, the third end of the first tee is connected to the hot water flash tank, and the gas phase outlet at the top of the hot water flash tank is connected to the steam pressurization section.

[0008] Preferably, the liquid phase outlet at the bottom of the hot water flash tank is connected to the third end of the second tee located at the inlet of the first channel of the heat exchange unit via a hot water pump.

[0009] Preferably, the steam pressurization section includes a steam ejector, the first inlet of which is connected to a 2.5MPa steam pipeline, the second inlet of which is connected to the gas phase outlet at the top of the hot water flash tank, the outlet of which is connected to the steam inlet of the thermal deaerator via a buffer tank, and the demineralized water outlet of the thermal deaerator is connected to the boiler feedwater pump.

[0010] Preferably, a third tee and a fourth tee are provided between the gasification black water evaporation hot water tower and the vacuum flash tank. A first valve is provided between the second end of the third tee and the inlet of the second channel of the heat exchange unit. A second valve is provided between the fourth tee and the outlet of the second channel of the heat exchange unit. A shortcut pipe with a third valve is provided between the third end of the third tee and the third end of the fourth tee. A fourth valve is provided between the inlet of the vacuum flash tank and the clarification tank.

[0011] Preferably, the fifth and sixth valves are provided between the demineralized water pump and the shift demineralized water preheater. The sixth valve has a fifth tee and a sixth tee at its two ends, respectively. The third end of the fifth tee is connected to the inlet of the low-temperature deaerator through the seventh valve, and the third end of the sixth tee is connected to the outlet of the low-temperature deaerator through the eighth valve. The shift demineralized water preheater and the thermal deaerator have a seventh tee and an eighth tee. The seventh tee is connected to the second tee through the ninth valve, and the eighth tee is connected to the first tee through the tenth valve. A shortcut pipe with an eleventh valve is provided between the seventh tee and the eighth tee.

[0012] Preferably, a twelfth valve is provided between the third end of the first three-way valve and the hot water flash tank, and a thirteenth valve is provided between the second inlet of the steam ejector and the gas phase outlet at the top of the hot water flash tank.

[0013] Preferably, the 2.5MPa steam pipeline is equipped with a fourteenth valve, and a fifteenth valve is provided between the buffer tank and the steam inlet of the thermal deaerator.

[0014] A heat recovery system for gasified black water, manufactured according to the above scheme, employs deep coupling between gasified black water and demineralized water sent to the boiler. This achieves the goal of utilizing the heat from the gasified black water while simultaneously reducing steam consumption during thermal deoxygenation. Specifically: First, the system preheats the demineralized water with the gasified black water to reduce the consumption of circulating water in the gasified black water system, while also preheating the demineralized water to achieve energy saving and consumption reduction. Second, the system utilizes a low-temperature deaerator and a hot water flash tank to produce low-pressure steam. This low-pressure steam can be pressurized by a steam booster and then fed into the steam pipeline network. Features: Secondly, by setting up a hot water flash tank, the higher-temperature demineralized water can be directly mixed and heated with the lower-temperature demineralized water while producing low-pressure steam, achieving energy saving and consumption reduction. Finally, by setting up a steam ejector, the low-pressure steam can be pressurized to 0.5MPa, and this 0.5MPa steam can be used as the gas source for thermal deoxygenation in the thermal deaerator, thus meeting the requirements for thermal deoxygenation of demineralized water. It features a reasonable process design, achieving deep coupling between the gasification black water system and the boiler demineralized water supply system. This not only saves energy and reduces consumption, lowering the amount of circulating water used, but also produces by-product steam, which is then used for thermal deoxygenation of the demineralized water, further reducing steam consumption. Attached Figure Description

[0015] 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 without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] In the diagram: 1. Gasification black water evaporation hot water tower; 2. Demineralized water pipeline; 3. Vacuum flash tank; 4. Heat exchanger unit; 5. Clarifying tank; 6. Demineralized water pump; 7. Hot water flash tank; 8. Hot water pump; 9. Shift-change demineralized water preheater; 10. Low-temperature deaerator; 11. Thermal deaerator; 12. Steam ejector; 13. 2.5MPa steam pipeline; 14. Buffer tank; 15. Boiler feed water pump; 16. First tee; 17. Second tee; 18. Third tee; 19. 20. Third valve; 21. Fourth valve; 22. Fifth valve; 23. Sixth valve; 24. Seventh valve; 25. Eighth valve; 26. First valve; 27. Second valve; 28. Third valve; 29. ​​Fourth valve; 20. Fifth valve; 20. Sixth valve; 31. Seventh valve; 32. Eighth valve; 33. Ninth valve; 34. Tenth valve; 35. Eleventh valve; 36. Twelfth valve; 37. Thirteenth valve; 38. Fourteenth valve; 39. Fifteenth valve. Detailed Implementation

[0018] 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 without creative effort are within the scope of protection of the present utility model.

[0019] The following is in conjunction with the appendix Figure 1 This application provides a further detailed description of a gasification black water heat recovery system, comprising a gasification black water evaporation hot water tower 1. The gasification black water evaporation hot water tower 1 is connected to the inlet of a clarification tank 5 via a vacuum flash tank 3. A demineralized water pipeline 2 is connected to the inlet of the first channel of a heat exchanger unit 4 via a demineralized water pump 6 and a shift demineralized water preheater 9. The outlet of the first channel of the heat exchanger unit 4 is connected to the inlet of a thermal deaerator 11. The black water evaporation hot water tower 1 is connected to the inlet of the vacuum flash tank 3 via the second channel of the heat exchanger unit 4. The essence of this invention is to couple the gasification black water system with the boiler demineralized water supply system, utilizing the demineralized water and gasification black water for heat exchange. This not only reduces the consumption of demineralized water in the gasification black water system but also preheats the demineralized water, thereby achieving energy saving and consumption reduction.

[0020] Furthermore, a low-temperature deaerator 10 is provided between the demineralized water pump 6 and the demineralized water preheater 9; a first tee 16 is provided at the first channel outlet of the heat exchange unit 4, the third end of the first tee 16 is connected to the hot water flash tank 7, and the gas phase outlet at the top of the hot water flash tank 7 is connected to the steam pressurization section. This invention achieves low-temperature deoxygenation of the demineralized water by setting the low-temperature deaerator 10, creating conditions for subsequent passage through the heat exchange unit 4 and the production of low-pressure steam. The hot water flash tank 7 is used to generate low-pressure steam (the pressure of the low-pressure steam is 0.05 MPaG), and the steam pressurization section can pressurize the low-pressure steam, which can then be sent to the steam usage device or steam pipeline network. It should be noted that the steam pressurization section in this invention can increase the pressure of the low-pressure steam to 0.5 MPa, 1 MPa, or 1.5 MPa, etc., depending on the actual situation.

[0021] Furthermore, the liquid phase outlet at the bottom of the hot water flash tank 7 is connected to the third end of the second three-way valve 17 located at the inlet of the first channel of the heat exchanger unit 4 via a hot water pump 8. In this invention, the demineralized water in the hot water flash tank 7 can be pumped into the inlet of the first channel of the heat exchanger unit 4 via the hot water pump 8, so that it can be mixed and heated with the low-temperature demineralized water (the low-temperature demineralized water refers to the demineralized water after passing through the demineralized water preheater 9); the heated demineralized water then enters the first channel of the heat exchanger unit 4 for heat exchange, thereby achieving full utilization of the demineralized water and heat, and realizing energy saving and consumption reduction.

[0022] Furthermore, the steam pressurization section includes a steam ejector 12. The first inlet of the steam ejector 12 is connected to a 2.5MPa steam pipe 13, and the second inlet of the steam ejector 12 is connected to the vapor phase outlet at the top of the hot water flash tank 7. The outlet of the steam ejector 12 is connected to the steam inlet of the thermal deaerator 11 via a buffer tank 14, and the demineralized water outlet of the thermal deaerator 11 is connected to the boiler feedwater pump 15. This invention selects 2.5MPa steam to enter the steam ejector 12 and mix with the aforementioned low-pressure steam to increase the low-pressure steam pressure. This feature allows the low-pressure steam pressure to be increased to 0.5MPa. After buffering in the buffer tank 14, the steam is sent to the thermal deaerator 11 for deoxygenation of the demineralized water before being fed into the subsequent boiler. This method reduces the purchase of 0.5MPa steam, achieving energy saving, consumption reduction, and lower production costs for enterprises.

[0023] Furthermore, a third tee 18 and a fourth tee 19 are provided between the gasification black water evaporation hot water tower 1 and the vacuum flash tank 3. A first valve 24 is provided between the second end of the third tee 18 and the second channel inlet of the heat exchange unit 4. A second valve 25 is provided between the fourth tee 19 and the second channel outlet of the heat exchange unit 4. A shortcut pipe with a third valve 26 is provided between the third end of the third tee 18 and the third end of the fourth tee 19. A fourth valve 27 is provided between the inlet of the vacuum flash tank 3 and the clarification tank 5.

[0024] Furthermore, a fifth valve 28 and a sixth valve 29 are provided between the demineralized water pump 6 and the shift demineralized water preheater 9. The sixth valve 29 has a fifth three-way valve 20 and a sixth three-way valve 21 at its two ends. The third end of the fifth three-way valve 20 is connected to the inlet of the low-temperature deaerator 10 through a seventh valve 30, and the third end of the sixth three-way valve 21 is connected to the outlet of the low-temperature deaerator 10 through an eighth valve 31. A seventh three-way valve 22 and an eighth three-way valve 23 are provided between the shift demineralized water preheater 9 and the thermal deaerator 11. The seventh three-way valve 22 is connected to the second three-way valve 17 through a ninth valve 32, and the eighth three-way valve 23 is connected to the first three-way valve 16 through a tenth valve 33. A shortcut pipe with an eleventh valve 34 is provided between the seventh three-way valve 22 and the eighth three-way valve 23.

[0025] Furthermore, a twelfth valve 35 is provided between the third end of the first three-way valve 16 and the hot water flash tank 7, and a thirteenth valve 36 is provided between the second inlet of the steam ejector 12 and the gas phase outlet at the top of the hot water flash tank 7.

[0026] Furthermore, the 2.5MPa steam pipeline 13 is equipped with a fourteenth valve 37, and a fifteenth valve 38 is provided between the buffer tank 14 and the steam inlet of the thermal deaerator 11.

[0027] The specific working process of this utility model is as follows: Black water from the gasification black water flash evaporation system enters the gasification black water evaporation hot water tower 1. The black water in the gasification black water evaporation hot water tower 1 enters the vacuum flash tank 3 through the second channel of the heat exchange unit 4. The black water in the vacuum flash tank 3 enters the subsequent process through the clarification tank 5. The demineralized water in the demineralized water pipeline 2 enters the low-temperature deaerator 10 through the demineralized water pump 6. At low temperature, the dissolved oxygen in the water is ≤7μg / l, which can ensure that the hot water flash tank 7 flashes out qualified low-pressure steam and avoids contamination of subsequent equipment. The demineralized water after low-temperature deaeration is preheated by the demineralized water preheater 9 and then enters the first channel of the heat exchange unit 4. The demineralized water in the first channel of the heat exchange unit 4 exchanges heat with the black water in the second channel of the heat exchange unit 4. Most of the demineralized water after heat exchange is then purified. A portion of the demineralized water enters the thermal deaerator 11 for deoxygenation, while a smaller portion enters the hot water flash tank 7 to flash out low-pressure steam. This low-pressure steam enters the steam ejector 12 through the second inlet, while steam from the 2.5MPa steam pipe 13 enters the steam ejector 12 through the first inlet. The steam pressure after mixing rises to 0.5MPa. This 0.5MPa steam enters the thermal deaerator 11 through the buffer tank 14 and the steam inlet, deoxygenating the demineralized water that has undergone black water heat exchange. The deoxygenated demineralized water is then pumped into the subsequent boiler via the boiler feed pump 15. The liquid phase in the hot water flash tank 7 can enter the demineralized water at the front of the first channel of the heat exchanger unit 4 to achieve the reuse of the demineralized water and heat. This invention, by setting up a bypass pipe with a third valve 26, a bypass pipe with an eleventh valve 34, and a sixth valve 29, enables the smooth disconnection of the gasification black water flash evaporation system and / or the demineralized water supply system in the event of system fluctuations or malfunctions, preventing mutual interference between the two systems and achieving long-term stable operation of the system. This invention also features convenient control through the appropriate valves; furthermore, the 0.5MPa steam described in this invention can be connected to a 0.5MPa steam pipeline network, which is simultaneously connected to the steam inlet of the thermal deaerator 11, thus ensuring stable system operation.

[0028] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A heat recovery system for gasified black water, comprising a gasified black water evaporation hot water tower (1), wherein the gasified black water evaporation hot water tower (1) is connected to the inlet of a clarification tank (5) via a vacuum flash tank (3), characterized in that: The demineralized water pipeline (2) is connected to the first channel inlet of the heat exchange unit (4) via the demineralized water pump (6) and the demineralized water preheater (9), and the first channel outlet of the heat exchange unit (4) is connected to the inlet of the thermal deaerator (11). The black water evaporation hot water tower (1) is connected to the inlet of the vacuum flash tank (3) through the second channel of the heat exchange unit (4).

2. The gasification black water heat recovery system according to claim 1, characterized in that: A low-temperature deaerator (10) is provided between the demineralized water pump (6) and the demineralized water preheater (9); a first tee (16) is provided at the first channel outlet of the heat exchange unit (4), the third end of the first tee (16) is connected to the hot water flash tank (7), and the gas phase outlet at the top of the hot water flash tank (7) is connected to the steam pressure boosting section.

3. The gasification black water heat recovery system according to claim 2, characterized in that: The liquid phase outlet at the bottom of the hot water flash tank (7) is connected to the third end of the second tee (17) located at the inlet of the first channel of the heat exchange unit (4) via a hot water pump (8).

4. A gasification black water heat recovery system according to claim 2 or 3, characterized in that: The steam booster section includes a steam ejector (12). The first inlet of the steam ejector (12) is connected to a 2.5MPa steam pipe (13). The second inlet of the steam ejector (12) is connected to the gas phase outlet at the top of the hot water flash tank (7). The outlet of the steam ejector (12) is connected to the steam inlet of the thermal deaerator (11) through a buffer tank (14). The demineralized water outlet of the thermal deaerator (11) is connected to the boiler feedwater pump (15).

5. The gasification black water heat recovery system according to claim 2, characterized in that: A third tee (18) and a fourth tee (19) are provided between the gasification black water evaporation hot water tower (1) and the vacuum flash tank (3). A first valve (24) is provided between the second end of the third tee (18) and the second channel inlet of the heat exchange unit (4). A second valve (25) is provided between the fourth tee (19) and the second channel outlet of the heat exchange unit (4). A shortcut pipe with a third valve (26) is provided between the third end of the third tee (18) and the third end of the fourth tee (19). A fourth valve (27) is provided between the inlet of the vacuum flash tank (3) and the clarification tank (5).

6. The gasification black water heat recovery system according to claim 3, characterized in that: The fifth valve (28) and the sixth valve (29) are connected between the demineralized water pump (6) and the demineralized water preheater (9). The sixth valve (29) has a fifth three-way valve (20) and a sixth three-way valve (21) at both ends. The third end of the fifth three-way valve (20) is connected to the inlet of the low-temperature deaerator (10) through the seventh valve (30), and the third end of the sixth three-way valve (21) is connected to the outlet of the low-temperature deaerator (10) through the eighth valve (31). A seventh three-way valve (22) and an eighth three-way valve (23) are provided between the demineralized water preheater (9) and the thermal deaerator (11). The seventh three-way valve (22) is connected to the second three-way valve (17) through the ninth valve (32), and the eighth three-way valve (23) is connected to the first three-way valve (16) through the tenth valve (33). A shortcut pipe with an eleventh valve (34) is provided between the seventh three-way valve (22) and the eighth three-way valve (23).

7. The gasification black water heat recovery system according to claim 4, characterized in that: A twelfth valve (35) is provided between the third end of the first three-way valve (16) and the hot water flash tank (7). A thirteenth valve (36) is provided between the second inlet of the steam ejector (12) and the gas phase outlet at the top of the hot water flash tank (7).

8. The gasification black water heat recovery system according to claim 4, characterized in that: The 2.5MPa steam pipeline (13) is equipped with a fourteenth valve (37), and a fifteenth valve (38) is provided between the buffer tank (14) and the steam inlet of the thermal deaerator (11).

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