Coke oven raw gas waste heat gradient utilization system

Abstract

The utility model relates to the technical field of raw coke oven gas coke oven systems, and mainly discloses a coke oven raw coke oven gas waste heat gradient utilization system, which comprises a coke oven, an ascending pipe, a bridge pipe, a gas collecting pipe, a gas-liquid separator, a transverse pipe primary cooler, an ascending pipe waste heat utilization system, a circulating ammonia water waste heat utilization system and a primary cooler waste heat utilization system, according to the raw gas waste heat gradient utilization system, gradient utilization is achieved, all waste heat is used for production and living, the ascending pipe waste heat utilization system utilizes high-temperature raw gas to generate a high-grade steam heat source, and the circulating ammonia water waste heat utilization system and the primary cooler waste heat utilization system utilize a low-grade heat source to be used for refrigeration or heating. Crude gas waste heat gradient utilization is adopted, the low-temperature water consumption requirement of a gas purification system low-temperature water user is completely met, a steam or electric drive refrigerator does not need to be additionally arranged, and energy is saved; the heating requirement of a production area can be met in the heating season, and residual heat can be externally supplied.

Description

Technical Field

[0001] The utility model relates to the technical field of raw coke oven gas systems, in particular to a system for cascaded utilization of waste heat from raw coke oven gas in coke ovens. Background Art

[0002] Coal coking, also known as high-temperature carbonization of coal, is a process in which coal is used as raw material, heated to about 1000 °C under the condition of isolating air in a coke oven, and coke, raw coke oven gas and coking chemical products are produced through high-temperature carbonization. In the production process, various media need to be heated and cooled frequently, steam and gas are required as heat sources, medium-temperature water and chilled water are required as heat exchange media, and a large amount of energy is consumed in the whole process. For example, steam is consumed in the deaerated water production process of dry quenching of coke or waste heat utilization of flue gas, and gas or steam is consumed by refrigerators. On the one hand, a large amount of waste heat from raw coke oven gas is not effectively utilized, resulting in a large amount of energy waste. On the other hand, a large amount of energy media need to be consumed, which does not conform to the development direction of energy conservation, emission reduction, low-carbon and environmental protection in the coking industry.

[0003] In the coke oven system, the temperature of raw coke oven gas is generally 650 - 850 °C. In recent years, most of the newly built large coke ovens are equipped with waste heat utilization devices for riser pipes. At this time, the raw coke oven gas is cooled to about 500 °C after passing through the waste heat utilization device for riser pipes and enters the bridge pipe and the collecting pipe. In the bridge pipe and the collecting pipe, it is cooled to about 80 °C by spraying circulating ammonia water and then enters the horizontal primary cooler, where it is cooled to about 22 °C and enters the subsequent process. The horizontal primary cooler operates in two or three sections. The waste heat of the circulating ammonia water entering and the waste heat of the high-temperature section of the horizontal primary cooler can be used for heating in winter and for refrigeration in other seasons.

[0004] The existing technology has the following problems: the waste heat of the riser pipe, the waste heat of the circulating ammonia water and the waste heat of the high-temperature section of the horizontal primary cooler are not utilized simultaneously, and only one or at most two of these waste heat utilization methods are selected, resulting in heat waste. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a system for cascaded utilization of waste heat from raw coke oven gas in coke ovens, which solves the above technical problems, can generate high-grade steam heat sources, can also be used for heating in winter and refrigeration in summer and other seasons, realizes the cascaded utilization of waste heat from raw coke oven gas, and all the waste heat from raw coke oven gas is utilized.

[0006] To achieve the above object, the technical solution of the present utility model is a coke oven raw gas waste heat cascade utilization system, which includes a coke oven, a riser pipe, a bridge pipe, a collecting pipe, a gas-liquid separator and a horizontal tube primary cooler. A riser pipe waste heat utilization system, a circulating ammonia water waste heat utilization system and a primary cooler waste heat utilization system are also provided. The coke oven is connected with a riser pipe, the riser pipe is connected with the bridge pipe, the bridge pipe is connected with the collecting pipe through a raw gas first pipeline, the collecting pipe is connected with the gas-liquid separator through a raw gas second pipeline, the gas-liquid separator is connected with the inlet end of the horizontal tube primary cooler through a raw gas third pipeline, the outlet end of the horizontal tube primary cooler is connected with a raw gas fourth pipeline, and the raw gas fourth pipeline is connected with a chemical product recovery pipeline. The riser pipe waste heat utilization system includes a steam drum, a forced circulation pump, a feed water system and an external supply steam pipeline. The feed water system is connected with the steam drum to provide deaerated water for the steam drum. The steam drum is connected with the inlet end of the coil of the riser pipe through the forced circulation pump. The outlet end of the coil of the riser pipe is connected with the steam drum. The steam drum is also connected with the external supply steam pipeline. The circulating ammonia water waste heat utilization system includes a circulating ammonia water waste heat refrigeration unit, a circulating ammonia water inlet pipeline, a circulating ammonia water return pipeline and a circulating ammonia water treatment system. The gas-liquid separator is connected with the circulating ammonia water treatment system. The circulating ammonia water treatment system is connected with the circulating ammonia water waste heat refrigeration unit through the circulating ammonia water return pipeline. The circulating ammonia water waste heat refrigeration unit is connected with the coke oven through the circulating ammonia water inlet pipeline. The primary cooler waste heat utilization system includes a low-temperature hot water circulation pump, a heating user pipeline, a low-temperature hot water inlet pipeline and a low-temperature hot water return pipeline. The heating hot water user pipeline is connected with the low-temperature hot water circulation pump. The low-temperature hot water circulation pump is connected with the inlet end of the coil of the horizontal tube primary cooler through the low-temperature hot water inlet pipeline. The outlet end of the coil of the horizontal tube primary cooler is connected with the heating user pipeline through the low-temperature hot water return pipeline.

[0007] Through the above technical solution, the raw gas at 650-850°C generated by the coke oven enters the riser through a pipeline. The deaerated water provided by the water supply system is sent into the steam drum by a pump. From the steam drum, it is sent into the inlet end of the heat exchange coil in the riser through a forced circulation pump. The deaerated water in the coil absorbs heat from the riser during the upward flow process and becomes a steam-water mixture. The steam-water mixture enters the steam drum, where steam-liquid separation occurs. The saturated steam enters the external supply steam pipeline to provide a high-quality steam heat source, and the separated water continues to enter the riser for heat exchange, repeating this cycle. At this time, the temperature of the raw gas drops to about 500°C after passing through the riser, enters the bridge pipe, and then enters the collecting pipe through the bridge pipe. The circulating ammonia water waste heat system sprays circulating ammonia water into the coke oven. The low-temperature ammonia water at about 65°C enters the bridge pipe and the collecting pipe for heat exchange. The high-temperature ammonia water and the raw gas mixture at about 80°C coming out of the collecting pipe enter the gas-liquid separator. The gas-liquid separator separates the raw gas at about 80°C and sends it into the horizontal tube primary cooler. The circulating ammonia water at about 74°C separated by the gas-liquid separator is treated by the circulating ammonia water treatment system and then recycled. The circulating ammonia water at about 74°C is used for waste heat utilization through the circulating ammonia water waste heat refrigeration unit. After waste heat utilization, the circulating ammonia water becomes circulating ammonia water at about 65°C and re-enters the bridge pipe and the collecting pipe of the coke oven for use, repeating this cycle. At this time, the temperature of the raw gas drops to about 80°C and enters the horizontal tube primary cooler through the third raw gas pipeline. The low-temperature hot water circulating pump sends the low-temperature hot water at about 60°C into the horizontal tube primary cooler through the low-temperature hot water inlet pipeline to cool the high-temperature section of the horizontal tube primary cooler. The low-temperature hot water at about 70°C in the high-temperature section of the horizontal tube primary cooler is sent into the heating user pipeline through the low-temperature hot water return pipeline for waste heat utilization. The return water of the heating user pipeline is sent back into the horizontal tube primary cooler by the low-temperature hot water circulating pump again. Finally, the temperature of the raw gas drops to about 22°C after passing through the horizontal tube primary cooler and enters the subsequent chemical product recovery pipeline process through the fourth raw gas pipeline.

[0008] A further solution of the present invention lies in that the water supply system includes a demineralized water tank, a demineralized water feed pump, a deaerator tank, and a boiler feed pump. The demineralized water tank, the demineralized water feed pump, the deaerator tank, and the boiler feed pump are sequentially connected through pipelines. The boiler feed pump is connected to the steam drum. Through the above technical solution, the demineralized water in the demineralized water tank enters the deaerator tank through the demineralized water feed pump, and then undergoes thermal deaeration through the deaerator in the deaerated water. The deaerated water after deaeration is sent into the steam drum through the boiler feed pump and flows out from the steam drum downcomer and is sent into the coil of the riser through a forced circulation pump.

[0009] A further solution of the present utility model is that the circulating ammonia water treatment system includes a tar residue pre-separator, a tar-ammonia water separation tank and a circulating ammonia water pump. The tar residue pre-separator is connected to a gas-liquid separator. The tar residue pre-separator, the tar-ammonia water separation tank and the circulating ammonia water pump are connected in sequence. The circulating ammonia water pump is connected to a circulating ammonia water waste heat refrigeration unit through a circulating ammonia water return pipeline. Through the above technical solution, the liquid phase separated by the gas-liquid separator first enters the tar residue pre-separator to preliminarily separate large-particle tar residues. The tar-ammonia water mixture then enters the tar-ammonia water separation tank. After static precipitation separation, the circulating ammonia water at about 74 °C is pressurized by the circulating ammonia water pump and sent to the circulating ammonia water waste heat refrigeration unit.

[0010] A further solution of the present utility model is that the low-temperature hot water return pipeline is also connected to a low-temperature hot water type refrigerating machine. The low-temperature hot water type refrigerating machine is connected to a low-temperature hot water circulating pump. The low-temperature hot water type refrigerating machine is also connected to a low-temperature water user pipeline. The low-temperature water user pipeline is connected to the low-temperature hot water type refrigerating machine through a chilled water circulating pump. Through the above technical solution, in summer, the low-temperature hot water at about 70 °C in the low-temperature hot water return pipeline enters the low-temperature hot water type refrigerating machine. The low-temperature hot water at about 60 °C from the low-temperature hot water type refrigerating machine enters the horizontal tube primary cooler through the low-temperature hot water circulating pump for recycling. The low-temperature hot water type refrigerating machine can produce chilled water at about 16 °C and enters the low-temperature water user pipeline for use by the net low-temperature water users. After being used by the net low-temperature water users, the chilled water at about 23 °C enters the low-temperature hot water type refrigerating machine again through the chilled water circulating pump for re-refrigeration.

[0011] A further solution of the present utility model is that the circulating ammonia water waste heat refrigeration unit is also connected to the low-temperature water user pipeline. The chilled water produced by the circulating ammonia water waste heat refrigeration unit can also be used by the low-temperature water users.

[0012] A further solution of the present utility model is that the circulating ammonia water waste heat refrigeration unit is a lithium bromide absorption refrigerating machine.

[0013] A further solution of the present utility model is that the low-temperature hot water type refrigerating machine is a lithium bromide absorption refrigerating machine.

[0014] A further solution of the present utility model is that a valve is provided between the low-temperature hot water return pipeline and the heating user pipeline, and a valve is provided between the heating user pipeline and the low-temperature hot water circulating pump.

[0015] A further solution of the present utility model is that a valve is provided between the low-temperature hot water return pipeline and the low-temperature hot water type refrigerating machine, and a valve is provided between the low-temperature hot water type refrigerating machine and the low-temperature hot water circulating pump. Through the above technical solution, the valve can be better used for switching between heating and refrigeration.

[0016] Compared with the prior art, the beneficial effects of the present utility model are:

[0017] The waste gas heat cascade utilization system of the present utility model realizes cascade utilization, and all the waste heat is used for production and living needs. The high-temperature waste gas generates high-grade steam heat sources, and the low-grade heat sources are used for refrigeration or heating. By adopting the waste gas heat cascade utilization, the demand for low-temperature water of the low-temperature water users in the gas purification system is fully met, and there is no need to separately set up steam or electric-driven refrigerators, saving energy; by the waste gas heat cascade utilization, the heating demand of the production area can be met during the heating season, and the surplus heat can be supplied externally. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic structural diagram of the waste gas heat cascade utilization system of the present utility model.

[0020] Reference Numerals: 1, coke oven; 2, riser pipe; 3, bridge pipe; 4, collecting pipe; 5, gas-liquid separator; 6, horizontal tube primary cooler; 7, first waste gas pipeline; 8, second waste gas pipeline; 9, third waste gas pipeline; 10, fourth waste gas pipeline; 11, chemical product recovery pipeline; 100, riser pipe waste heat utilization system; 200, circulating ammonia water waste heat utilization system; 300, primary cooler waste heat utilization system; 12, demineralized water tank; 13, demineralized water feed pump; 14, deaerator tank; 15, boiler feed pump; 16, steam drum; 17, forced circulation pump; 18, external supply steam pipeline; 19, tar slag pre-separator; 20, tar-ammonia separation tank; 21, circulating ammonia water pump; 22, circulating ammonia water waste heat refrigeration unit; 23, circulating ammonia water return pipeline; 24, circulating ammonia water inlet pipeline; 25, low-temperature hot water circulation pump; 26, low-temperature hot water inlet pipeline; 27, low-temperature hot water return pipeline; 28, heating hot user pipeline; 29, low-temperature hot water type refrigerator; 30, low-temperature water user pipeline; 31, chilled water circulation pump. Detailed Embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than 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 efforts belong to the scope of protection of the present utility model.

[0022] Embodiment 1

[0023] As shown Figure 1 in the figure, a coke oven raw gas waste heat cascade utilization system includes a coke oven 1, a riser pipe 2, a bridge pipe 3, a collecting pipe 4, a gas-liquid separator 5, and a horizontal tube primary cooler 6. A riser pipe waste heat utilization system 100, a circulating ammonia water waste heat utilization system 200, and a primary cooler waste heat utilization system 300 are also provided.

[0024] The riser pipe 2 is connected to the coke oven 1, the riser pipe 2 is connected to the bridge pipe 3, the bridge pipe 3 is connected to the collecting pipe 4 through a raw gas first pipe 7, the collecting pipe 4 is connected to the gas-liquid separator 5 through a raw gas second pipe 8, the gas-liquid separator 5 is connected to the inlet end of the horizontal tube primary cooler 6 through a raw gas third pipe 9, the outlet end of the horizontal tube primary cooler 6 is connected to a raw gas fourth pipe 10, and the raw gas fourth pipe 10 is connected to a chemical product recovery pipe 11.

[0025] The riser pipe waste heat utilization system 100 includes a steam drum 16, a forced circulation pump 17, a feed water system, and an external supply steam pipe 18. The feed water system is connected to the steam drum 16 to provide deaerated water for the steam drum 16. The steam drum 16 is connected to the inlet end of the coil of the riser pipe 2 through the forced circulation pump 17. The outlet end of the coil of the riser pipe 2 is connected to the steam drum 16, and the steam drum 16 is also connected to the external supply steam pipe 18.

[0026] Through the riser pipe waste heat utilization system 100, the raw gas at 650 - 850 °C generated by the coke oven 1 enters the riser pipe 2 through a pipe. The deaerated water provided by the feed water system is sent into the steam drum 16 by a pump, and then sent from the steam drum 16 into the inlet end of the heat exchange coil of the riser pipe 2 through the forced circulation pump 17. The deaerated water in the coil absorbs heat from the riser pipe 2 and becomes a steam-water mixture during the upward flow from bottom to top. The steam-water mixture enters the steam drum 16, where steam-liquid separation is carried out. The saturated steam enters the external supply steam pipe 18 to provide a high-quality steam heat source, and the separated water continues to enter the riser pipe 2 for heat exchange, and so on in a cycle.

[0027] The circulating ammonia water waste heat utilization system 200 includes a circulating ammonia water waste heat refrigeration unit 22, a circulating ammonia water inlet pipe 24, a circulating ammonia water return pipe 23, and a circulating ammonia water treatment system. The gas-liquid separator 5 is connected to the circulating ammonia water treatment system, the circulating ammonia water treatment system is connected to the circulating ammonia water waste heat refrigeration unit 22 through the circulating ammonia water return pipe 23, and the circulating ammonia water waste heat refrigeration unit 22 is connected to the coke oven 1 through the circulating ammonia water inlet pipe 24.

[0028] Through the circulating ammonia water waste heat utilization system 200, the temperature of the raw coke oven gas drops to ~500°C after passing through the riser pipe 2 and enters the bridge pipe 3, and then enters the collecting pipe 4 through the bridge pipe 3. The circulating ammonia water waste heat system sprays circulating ammonia water into the coke oven 1. The low-temperature ammonia water at ~65°C enters the bridge pipe 3 and the collecting pipe 4 for heat exchange. The high-temperature ammonia water and the ~80°C raw coke oven gas mixture coming out of the collecting pipe 4 enter the gas-liquid separator 5. The gas-liquid separator 5 separates the ~80°C raw coke oven gas and enters the horizontal tube primary cooler 6. The ~74°C circulating ammonia water separated by the gas-liquid separator 5 is treated by the circulating ammonia water treatment system and then recycled. The ~74°C circulating ammonia water is used for waste heat utilization through the circulating ammonia water waste heat refrigeration unit 22. After the waste heat utilization, the circulating ammonia water becomes ~65°C circulating ammonia water and then re-enters the bridge pipe 3 and the collecting pipe 4 of the coke oven 1 for use, and so on in a cycle.

[0029] The primary cooler waste heat utilization system 300 described above includes a low-temperature hot water circulation pump 25, a heating hot user pipeline 28, a low-temperature hot water inlet pipeline 26, and a low-temperature hot water return pipeline 27. The heating hot water user pipeline is connected to the low-temperature hot water circulation pump 25. The low-temperature hot water circulation pump 25 is connected to the water inlet end of the coil of the horizontal tube primary cooler 6 through the low-temperature hot water inlet pipeline 26. The water outlet end of the coil of the horizontal tube primary cooler 6 is connected to the heating hot user pipeline 28 through the low-temperature hot water return pipeline 27.

[0030] Through the primary cooler waste heat utilization system 300, the temperature of the raw coke oven gas drops to ~80°C and enters the horizontal tube primary cooler 6 through the third raw coke oven gas pipeline 9. The low-temperature hot water circulation pump 25 sends the ~60°C low-temperature hot water into the horizontal tube primary cooler 6 through the low-temperature hot water inlet pipeline 26 to cool the high-temperature section of the horizontal tube primary cooler 6. The ~70°C low-temperature hot water in the high-temperature section of the horizontal tube primary cooler 6 is sent to the heating hot user pipeline 28 through the low-temperature hot water return pipeline 27 for waste heat utilization. The return water of the heating hot user pipeline 28 is sent back into the horizontal tube primary cooler 6 through the low-temperature hot water circulation pump 25 again. Finally, after passing through the horizontal tube primary cooler 6, the temperature of the raw coke oven gas drops to ~22°C and enters the subsequent chemical product recovery pipeline 11 process through the fourth raw coke oven gas pipeline 10.

[0031] Example 2

[0032] This example is based on Example 1, and its further solution lies in:

[0033] The water supply system described above includes a demineralized water tank 12, a demineralized water feed pump 13, a deaerator tank 14, and a boiler feed pump 15. The demineralized water tank 12, the demineralized water feed pump 13, the deaerator tank 14, and the boiler feed pump 15 are connected in sequence through pipelines. The boiler feed pump 15 is connected to the steam drum 16.

[0034] Through the above technical solution, the demineralized water in the demineralized water tank 12 enters the deaerator tank 14 through the demineralized water feed pump 13, and then undergoes thermal deaeration through the deaerator in the deaerated water. The deaerated water after deaeration is sent into the steam drum 16 through the boiler feed pump 15, and flows out from the downcomer of the steam drum 16 and is sent into the coil of the riser 2 by the forced circulation pump 17.

[0035] The described circulating ammonia water treatment system includes a tar residue pre-separator 19, a tar-ammonia water separation tank 20 and a circulating ammonia water pump 21. The tar residue pre-separator 19 is connected to the gas-liquid separator 5. The tar residue pre-separator 19, the tar-ammonia water separation tank 20 and the circulating ammonia water pump 21 are connected in sequence. The circulating ammonia water pump 21 is connected to the circulating ammonia water waste heat refrigeration unit 22 through the circulating ammonia water return pipe 23.

[0036] Through the above technical solution, the liquid phase separated by the gas-liquid separator 5 first enters the tar residue pre-separator 19 to preliminarily separate large-particle tar residues. The tar-ammonia water mixture then enters the tar-ammonia water separation tank 20. After static precipitation separation, the circulating ammonia water at about 74 °C is pressurized by the circulating ammonia water pump 21 and sent to the circulating ammonia water waste heat refrigeration unit 22.

[0037] The described low-temperature hot water return pipe 27 is also connected to a low-temperature hot water chiller 29. The low-temperature hot water chiller 29 is connected to a low-temperature hot water circulation pump 25. The low-temperature hot water chiller 29 is also connected to a low-temperature water user pipe 30. The low-temperature water user pipe 30 is connected to the low-temperature hot water chiller 29 through a chilled water circulation pump 31. The circulating ammonia water waste heat refrigeration unit 22 is also connected to the low-temperature water user pipe 30. The chilled water produced by the circulating ammonia water waste heat refrigeration unit 22 can also be used by low-temperature water users.

[0038] Through the above technical solution, in summer, the low-temperature hot water at ~70 °C in the low-temperature hot water return pipe 27 enters the low-temperature hot water chiller 29. The low-temperature hot water at ~60 °C from the low-temperature hot water chiller 29 enters the horizontal tube primary cooler 6 through the low-temperature hot water circulation pump 25 for recycling. The ~16 °C chilled water produced by the low-temperature hot water chiller 29 enters the low-temperature water user pipe 30 for use by pure low-temperature water users. After being used by pure low-temperature water users, the ~23 °C chilled water enters the low-temperature hot water chiller 29 again through the chilled water circulation pump 31 for re-refrigeration.

[0039] The described circulating ammonia water waste heat refrigeration unit 22 is a lithium bromide absorption refrigerating machine. The described low-temperature hot water refrigerating machine 29 is a lithium bromide absorption refrigerating machine. Among them, the lithium bromide absorption refrigerating machine is a prior art, using an aqueous solution of lithium bromide as the working medium, where water is the refrigerant and lithium bromide is the absorbent. Lithium bromide belongs to salts, is a white crystal, is easily soluble in water and alcohol, is non-toxic, has stable chemical properties and will not deteriorate. When there is air in the aqueous solution of lithium bromide, it has strong corrosiveness to steel. Since the lithium bromide absorption refrigerating machine uses water as the refrigerant and the evaporation temperature is above 0°C, it can only be used for air conditioning equipment and preparing cold water for the production process. This refrigerating machine can use low-pressure steam or hot water at about 70°C as the heat source, so it plays an important role in the utilization of waste gas, waste heat, solar energy and low-grade heat energy. A valve is provided between the described low-temperature hot water return pipe 27 and the heating user pipe 28, and a valve is provided between the described heating user pipe 28 and the low-temperature hot water circulation pump 25. A valve is provided between the described low-temperature hot water return pipe 27 and the low-temperature hot water refrigerating machine 29, and a valve is provided between the low-temperature hot water refrigerating machine 29 and the low-temperature hot water circulation pump 25. Through the above technical solution, the valve can be better used for switching between heating and refrigeration.

[0040] The waste gas heat cascade utilization system of the present utility model realizes cascade utilization, and all the waste heat is used for production and living needs. The high-temperature waste gas generates a high-grade steam heat source, and the low-grade heat source is used for refrigeration or heating. By adopting the waste gas heat cascade utilization, the demand for low-temperature water of the low-temperature water users in the gas purification system can be completely met, and there is no need to additionally set up a steam or electric-driven refrigerating machine, saving energy; by the waste gas heat cascade utilization, the heating demand in the production area can be met during the heating season, and the remaining heat can be supplied externally.

[0041] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present utility model. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A coke oven raw gas waste heat cascade utilization system, characterized in that: It includes a coke oven (1), a riser pipe (2), a bridge pipe (3), a collecting pipe (4), a gas-liquid separator (5) and a horizontal tube primary cooler (6). There is also provided a riser pipe waste heat utilization system (100), a circulating ammonia water waste heat utilization system (200) and a primary cooler waste heat utilization system (300). The coke oven (1) is connected to the riser pipe (2). The riser pipe (2) is connected to the bridge pipe (3). The bridge pipe (3) is connected to the collecting pipe (4) through a raw gas first pipe (7). The collecting pipe (4) is connected to the gas-liquid separator (5) through a raw gas second pipe (8). The gas-liquid separator (5) is connected to the inlet end of the horizontal tube primary cooler (6) through a raw gas third pipe (9). The outlet end of the horizontal tube primary cooler (6) is connected to a raw gas fourth pipe (10). The raw gas fourth pipe (10) is connected to a chemical product recovery pipe (11). The riser pipe waste heat utilization system (100) includes a steam drum (16), a forced circulation pump (17), a feed water system and an external supply steam pipe (18). The feed water system is connected to the steam drum (16) to provide deaerated water for the steam drum (16). The steam drum (16) is connected to the inlet end of the coil of the riser pipe (2) through the forced circulation pump (17). The outlet end of the coil of the riser pipe (2) is connected to the steam drum (16). The steam drum (16) is also connected to the external supply steam pipe (18). The circulating ammonia water waste heat utilization system (200) includes a circulating ammonia water waste heat refrigeration unit (22), a circulating ammonia water inlet pipe (24), a circulating ammonia water return pipe (23) and a circulating ammonia water treatment system. The gas-liquid separator (5) is connected to the circulating ammonia water treatment system. The circulating ammonia water treatment system is connected to the circulating ammonia water waste heat refrigeration unit (22) through the circulating ammonia water return pipe (23). The circulating ammonia water waste heat refrigeration unit (22) is connected to the coke oven (1) through the circulating ammonia water inlet pipe (24). The primary cooler waste heat utilization system (300) includes a low-temperature hot water circulation pump (25), a heating heat user pipe (28), a low-temperature hot water inlet pipe (26) and a low-temperature hot water return pipe (27). The heating heat user pipe (28) is connected to the low-temperature hot water circulation pump (25). The low-temperature hot water circulation pump (25) is connected to the inlet end of the coil of the horizontal tube primary cooler (6) through the low-temperature hot water inlet pipe (26). The outlet end of the coil of the horizontal tube primary cooler (6) is connected to the heating heat user pipe (28) through the low-temperature hot water return pipe (27).

2. The coke oven raw gas waste heat cascade utilization system according to claim 1, characterized in that: The feed water system includes a demineralized water tank (12), a demineralized water feed pump (13), a deaerator tank (14) and a boiler feed pump (15). The demineralized water tank (12), the demineralized water feed pump (13), the deaerator tank (14) and the boiler feed pump (15) are connected in sequence through pipes. The boiler feed pump (15) is connected to the steam drum (16).

3. The coking furnace raw gas waste heat cascade utilization system according to claim 2, wherein: The described circulating ammonia water treatment system includes a tar residue pre-separator (19), a tar-ammonia water separation tank (20), and a circulating ammonia water pump (21). The tar residue pre-separator (19) is connected to the gas-liquid separator (5). The tar residue pre-separator (19), the tar-ammonia water separation tank (20), and the circulating ammonia water pump (21) are connected in sequence. The circulating ammonia water pump (21) is connected to a circulating ammonia water waste heat refrigeration unit (22) through a circulating ammonia water return pipe (23).

4. A coke oven raw gas waste heat cascade utilization system according to claim 3, characterized in that: The described low-temperature hot water return pipe (27) is also connected to a low-temperature hot water chiller (29). The low-temperature hot water chiller (29) is connected to a low-temperature hot water circulation pump (25). The low-temperature hot water chiller (29) is also connected to a low-temperature water user pipe (30). The low-temperature water user pipe (30) is connected to the low-temperature hot water chiller (29) through a chilled water circulation pump (31).

5. The coke oven raw gas waste heat cascade utilization system according to any one of claims 1-4, characterized in that: The circulating ammonia water waste heat refrigeration unit (22) is also connected to the low-temperature water user pipe (30).

6. The coke oven raw gas waste heat cascade utilization system according to claim 4, characterized in that: The circulating ammonia water waste heat refrigeration unit (22) is a lithium bromide absorption chiller, and the low-temperature hot water chiller (29) is a lithium bromide absorption chiller.

7. A coke oven raw gas waste heat cascade utilization system according to claim 6, characterized in that: A valve is provided between the low-temperature hot water return pipe (27) and the heating hot user pipe (28), and a valve is provided between the heating hot user pipe (28) and the low-temperature hot water circulation pump (25).

8. A coke oven raw gas waste heat cascade utilization system according to claim 7, characterized in that: A valve is provided between the low-temperature hot water return pipe (27) and the low-temperature hot water chiller (29), and a valve is provided between the low-temperature hot water chiller (29) and the low-temperature hot water circulation pump (25).

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