Heating system utilizing device for preparing synthetic ammonia from coal

Abstract

The utility model relates to a heating system utilizing a device for preparing synthetic ammonia from coal. Comprising a heating outer net circulating water return pipeline and a heating outer net circulating water feeding pipeline, and the heating outer net circulating water return pipeline is connected with a circulating water heating unit coupled with a coal synthesis ammonia device through a heating heat net circulating pump; the circulating water heating unit is connected with a circulating water feeding pipeline of a heating outer net through a circulating water temperature adjusting unit coupled with the coal synthesis ammonia device; waste heat in the coal synthesis ammonia device is recycled on the basis of circulating return water in a heating system, so that the consumption of circulating water and noise pollution are reduced on the premise that the coal synthesis ammonia device operates normally.

Description

Technical Field

[0001] The utility model relates to the technical field of heat energy utilization in a coal-based synthetic ammonia device, in particular to a heating system utilizing the coal-based synthetic ammonia device. Background Art

[0002] The process route of the coal-to-ammonia synthesis unit is: the raw coal is crushed and sent to the gasifier for combustion to produce coal gas containing components such as H2 and CO. Then, various purification methods are used to remove dust, H2S, organic sulfides, CO, CO2 and other harmful impurities in the gas to obtain a clean 1:3 nitrogen-hydrogen mixed gas that meets the requirements of ammonia synthesis. Finally, the nitrogen-hydrogen mixed gas is compressed to above 13MPa and synthesized with the help of a catalyst. A large amount of waste heat resources will be generated in the above production process. The waste heat resources are directly discharged or cooled by a large amount of circulating water. Not only can the heat energy not be effectively utilized, but also a large amount of circulating water is consumed, resulting in resource waste and environmental pollution. For example, the condensate (temperature 100-120℃) in the condensate refining unit needs to be cooled to 25-30℃ by circulating water heat exchange when entering the condensate refining unit. Not only does it consume a large amount of circulating water, but the condensate heat energy is also wasted. The coal-to-ammonia system produces low-pressure flash steam from gasification, low-pressure flash steam from methanol washing, and low-pressure flash steam from urea. Venting during normal production not only wastes resources, but also has an impact on the environment (on-site venting not only generates noise but also requires safety alerts around the venting area). Utility Model Content

[0003] The utility model aims to provide a heating system utilizing a coal-based synthetic ammonia device to solve the problems raised in the above-mentioned background technology.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A heating system utilizing a coal-based synthetic ammonia device, the system comprising a heating external network circulating water return pipe and a heating external network circulating water supply pipe, the heating external network circulating water return pipe is connected to a circulating water heating unit coupled to the coal-based synthetic ammonia device via a heating network circulating pump; the circulating water heating unit is connected to the heating external network circulating water supply pipe via a circulating water temperature regulating unit coupled to the coal-based synthetic ammonia device; the circulating water heating unit at least comprises a heating circulating water main pipe, a process condenser, and a heating water heater arranged between the heating network circulating pump and the circulating water temperature regulating unit. The main heat exchanger comprises a shell, two baffles are arranged inside the shell, and the two baffles divide the inside of the shell into three independent channels, the third channel is arranged in the middle, and the first channel and the second channel are arranged on both sides of the third channel.

[0006] Preferably, the circulating water heating unit also includes a first tee and a second tee respectively arranged on both sides of the inlet and outlet of the main heat exchanger and a gasified black water low-pressure flash evaporation device, and the third end of the first tee and the third end of the second tee are connected through a refrigerant channel of the auxiliary heat exchanger; the gasified black water low-pressure flash evaporation device is connected to the gasified black water clarification tank through the heat medium channel of the auxiliary heat exchanger.

[0007] Preferably, the circulating water temperature control unit includes a heating circulating water main pipeline connected to the circulating water heating unit and the circulating water supply pipe of the heating external network, the heating circulating water main pipeline is provided with a third tee and a fourth tee, and a temperature compensation part is provided between the third end of the third tee and the third end of the fourth tee; a temperature sensor is provided on the heating circulating water main pipeline between the fourth tee and the circulating water supply pipe of the heating external network.

[0008] Preferably, the temperature compensation part includes a compensating heat exchanger, which has the same structure as the main heat exchanger; the first channel inlet of the compensating heat exchanger is connected to the low-pressure flash steam pipeline network, and the first channel outlet of the compensating heat exchanger is connected to the water-coal slurry preparation part; the second channel inlet of the compensating heat exchanger is connected to the low-pressure steam pipeline network, and the second channel outlet of the compensating heat exchanger is connected to the steam condensate recovery device; the inlet end of the second channel of the compensating heat exchanger is connected to the third end of the third tee, and the outlet end of the second channel of the compensating heat exchanger is connected to the third end of the fourth tee.

[0009] Preferably, the water-coal slurry preparation part includes a gas-liquid separation device connected to the first channel outlet of the compensating heat exchanger, the gas phase outlet at the top of the gas-liquid separation device is connected to the flare pipe network, and the liquid phase outlet of the gas-liquid separation device is connected to the water-coal slurry preparation system through a condensate delivery pump; a liquid level sensor is provided on the gas-liquid separation device, and a seventeenth valve is provided between the liquid phase outlet of the gas-liquid separation device and the condensate delivery pump.

[0010] Preferably, a first valve and a fifth tee are provided on the heating circulating water main pipeline at the outlet of the heating external network circulating water return pipeline; the third end of the fifth tee is connected to the process desalted water pipeline through the second valve.

[0011] Preferably, a third valve is provided between the first tee and the inlet of the main heat exchanger, a fourth valve is provided between the third end of the first tee and the inlet of the auxiliary heat exchanger, a fifth valve is provided between the auxiliary heat exchanger and the third end of the second tee, and a sixth valve is provided between the gasified black water low-pressure flash evaporation device and the auxiliary heat exchanger.

[0012] Preferably, a seventh valve is provided between the process condensate network and the first channel of the main heat exchanger, an eighth valve is provided between the first channel of the main heat exchanger and the condensate refining device, a ninth valve is provided between the urea high-pressure water network and the second channel of the main heat exchanger, and a tenth valve is provided between the second channel of the main heat exchanger and the urea high-pressure water network.

[0013] Preferably, an eleventh valve is provided between the third end of the third tee and the compensating heat exchanger; a twelfth valve is provided between the compensating heat exchanger and the third end of the fourth tee; a thirteenth valve is provided between the low-pressure flash steam pipeline and the first channel inlet of the compensating heat exchanger, and a fourteenth valve is provided between the first channel outlet of the compensating heat exchanger and the water-coal slurry preparation part; a fifteenth valve is provided between the low-pressure steam pipeline and the second channel inlet of the compensating heat exchanger, and a sixteenth valve is provided between the second channel inlet of the compensating heat exchanger and the steam condensate recovery device.

[0014] Preferably, the inner walls of the three independent channels are coated with a graphene composite coating.

[0015] A heating system utilizing a coal-to-ammonia synthesis device manufactured according to the above scheme, by arranging a circulating water heating unit coupled to the coal-to-ammonia synthesis device and a circulating water temperature control unit coupled to the coal-to-ammonia synthesis device, so as to realize effective recovery of the heat energy generated in the coal-to-ammonia synthesis device, and using the above heat energy in the heating system, not only reduces the use of circulating water in the coal-to-ammonia synthesis device, but also avoids defects such as noise pollution; further, the utility model heats the circulating water for heating by the circulating water heating unit coupled to the coal-to-ammonia synthesis device, and performs temperature treatment on the circulating water for heating by the circulating water temperature control unit coupled to the coal-to-ammonia synthesis device, thereby achieving the characteristic of meeting the heating needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 It is a structural schematic diagram of the main heat exchanger of the utility model.

[0018] In the figure: 1. Return water pipeline of external heating network; 2. Process desalted water pipeline; 3. Low-pressure flash evaporation device of gasified black water; 4. Auxiliary heat exchanger; 5. Gasified black water clarification tank; 6. Urea high-pressure water pipe network; 7. Process condensate pipe network; 8. Heating network circulating pump; 9. Main heat exchanger; 10. Condensate refining device; 11. Urea high-pressure water pipe network; 12. Low-pressure flash steam pipe network; 13. Low-pressure steam pipe network; 14. Compensating heat exchanger; 15. Steam condensate recovery device; 16. Temperature sensor; 17. Water supply pipeline of external heating network circulating water; 18. Gas-liquid separation device; 19. Flare pipe network; 20. Liquid level sensor; 21. Condensate delivery pump; 22. Coal-water slurry preparation system; 23. First valve; 24. Second valve; 25. Third valve; 26. Fourth valve; 27. Fifth valve; 28. Sixth valve; 29. ​​Seventh valve; 30. Eighth valve; 31. Ninth valve; 32. Tenth valve; 33. Eleventh valve; 34. Twelfth valve; 35. Thirteenth valve; 36. Fourteenth valve; 37. Fifteenth valve; 38. Sixteenth valve; 39. Seventeenth valve; 40. First three-way valve; 41. Second three-way valve; 42. Third three-way valve; 43. Fourth three-way valve; 44. Fifth three-way valve; 45. Shell; 46. Baffle; 47. Graphene composite coating. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0020] Reference Figure 1 , 2As shown, the utility model is a heating system using a coal-based synthetic ammonia device, the system includes a heating external network circulating water return pipe 1 and a heating external network circulating water supply pipe 17, the heating external network circulating water return pipe 1 is connected to a circulating water heating unit coupled to the coal-based synthetic ammonia device through a heating network circulating pump 8; the circulating water heating unit is connected to the heating external network circulating water supply pipe 17 through a circulating water temperature regulating unit coupled to the coal-based synthetic ammonia device; the circulating water heating unit at least includes a heating circulating water main pipe, a process condensate pipe network, and a heating water supply pipe 17 arranged between the heating network circulating pump 8 and the circulating water temperature regulating unit. 7 and urea high-pressure water pipe network 6, a main heat exchanger 9 is arranged on the heating circulating water main pipeline, the process condensate pipe network 7 is connected to the condensate refining device 10 through the first channel of the main heat exchanger 9, the urea high-pressure water pipe network 6 is connected to the urea high-pressure water pipe network 11 through the second channel of the main heat exchanger 9, and the heating circulating water main pipeline is connected to the circulating water temperature control unit through the third channel of the main heat exchanger 9; the main heat exchanger 9 includes a shell 45, and two baffles 46 are arranged inside the shell 45. The two baffles 46 divide the inside of the shell 45 into three independent channels, the third channel is arranged in the middle, and the first channel and the second channel are arranged on both sides of the third channel. The utility model recycles the waste heat in the coal-to-synthetic ammonia device based on the circulating return water in the heating system to ensure that the coal-to-synthetic ammonia device reduces the amount of circulating water and noise pollution under the premise of normal operation; the above method can realize the effective utilization of the internal heat energy of the coal-to-synthetic ammonia device. Furthermore, the main heat exchanger 9 of the utility model adopts the form of three independent channels, so that the refrigerant channel is between two heat medium channels, thereby achieving the characteristics of improving heat exchange efficiency and realizing further utilization of thermal energy; the circulating water heating unit coupled with the coal-to-synthetic ammonia device described in the utility model at least includes a process condensate pipe network 7 and a urea high-pressure water pipe network 6, wherein the condensate (temperature 100-120°C) in the process condensate pipe network 7 needs to be cooled to 25-30°C by circulating water heat exchange before entering the condensate refining device 10, which not only requires an increase in the amount of circulating water, but also causes an increase in energy consumption and waste of thermal energy; the utility model The above-mentioned arrangement can realize effective recovery of heat energy on the basis of reducing the amount of circulating water used in normal production; in the normal production process of urea high-pressure water, high-pressure water is pressurized by the high-pressure water pump and sent to the high-pressure water cooler for heat exchange with circulating water to cool down to 110°C, and then sent to the shell side and tube side of the high-pressure washer for heat exchange at 175°C. The return water temperature reaches 130-145°C and returns to the inlet of the high-pressure water pump, which is a closed-loop self-circulating process; through the arrangement of the utility model, urea high-pressure water is sent to the second channel of the main heat exchanger 9 for heat exchange with circulating heating water, which not only reduces the amount of circulating water, but also fully recycles heat energy. The condensate refining device 10 described in the utility model includes: a condensate heat exchanger, a condensate water tank, a process front cation bed, a high-speed mixed bed, etc., which can be directly purchased on the market, so its structure is not repeated.

[0021] Furthermore, the circulating water heating unit also includes a first tee 40 and a second tee 41 respectively arranged on both sides of the inlet and outlet of the main heat exchanger 9 and a gasification black water low-pressure flash evaporation device 3, the third end of the first tee 40 and the third end of the second tee 41 are connected through the refrigerant channel of the auxiliary heat exchanger 4; the gasification black water low-pressure flash evaporation device 3 is connected to the gasification black water clarification tank 5 through the heat medium channel of the auxiliary heat exchanger 4. Since the flow rate of heating circulating water is large during the heating season, in order to achieve effective recovery of heat energy and ensure the temperature of heating circulating water, the utility model is specially provided with an auxiliary heat exchanger 4, and the purpose of increasing the temperature of heating circulating water is achieved by diverting and exchanging heat for heating circulating water. During normal production, the gasification low-pressure flash black water needs to enter the vacuum flash evaporation to reduce the temperature of the low-pressure flash black water to 60-70°C, and then be sent to the gasification clarification tank for flocculation and sedimentation. The utility model can not only reduce the load of the gasification vacuum flash evaporation system and reduce energy consumption by utilizing the waste heat of gasification low-pressure flash evaporation black water, but also effectively recover heat energy for heating.

[0022] Furthermore, the circulating water temperature regulating unit includes a heating circulating water main pipe connected to the circulating water heating unit and the heating external network circulating water supply pipe 17, the heating circulating water main pipe is provided with a third tee 42 and a fourth tee 43, a temperature compensation part is provided between the third end of the third tee 42 and the third end of the fourth tee 43; a temperature sensor 16 is provided on the heating circulating water main pipe between the fourth tee 43 and the heating external network circulating water supply pipe 17. In the utility model, a part of the heating circulating water enters the heating external network circulating water supply pipe 17 through the heating circulating water main pipe for heating, and the other part enters the temperature compensation part for heat exchange based on the heating circulating water temperature detected by the temperature sensor 16, thereby adjusting the heating circulating water temperature in the heating circulating water main pipe to meet the heating needs.

[0023] Furthermore, the temperature compensation part includes a compensating heat exchanger 14, which has the same structure as the main heat exchanger 9; the first channel inlet of the compensating heat exchanger 14 is connected to the low-pressure flash steam pipeline 12, and the first channel outlet of the compensating heat exchanger 14 is connected to the water-coal slurry preparation part; the second channel inlet of the compensating heat exchanger 14 is connected to the low-pressure steam pipeline 13, and the second channel outlet of the compensating heat exchanger 14 is connected to the steam condensate recovery device 15; the inlet end of the second channel of the compensating heat exchanger 14 is connected to the third end of the third tee 42, and the outlet end of the second channel of the compensating heat exchanger 14 is connected to the third end of the fourth tee 43. The heat source used for heat exchange of heating circulating water in the utility model mainly comes from the low-pressure flash steam network 12 and the low-pressure steam network 13, wherein the low-pressure flash steam is the gasification low-pressure flash steam, methanol washing low-pressure flash steam and urea low-pressure flash steam produced in coal-to-synthetic ammonia; during normal production, since the by-product low-pressure flash steam has no users, it needs to be vented, which not only wastes resources but also affects the environment; the utility model can not only realize the waste heat recovery and reuse through the above-mentioned setting, but also improve the on-site environment (the on-site venting not only generates noise but also requires safety alerts around the venting area). The steam condensate recovery device 15 described in the utility model includes a condensate tank, a condensate pump, etc., which can be directly purchased on the market, so its structure is not repeated.

[0024] Furthermore, the water-coal slurry preparation unit includes a gas-liquid separation device 18 connected to the first channel outlet of the compensating heat exchanger 14, the gas phase outlet at the top of the gas-liquid separation device 18 is connected to the flare pipe network 19, and the liquid phase outlet of the gas-liquid separation device 18 is connected to the water-coal slurry preparation system 22 through the condensate delivery pump 21; a liquid level sensor 20 is provided on the gas-liquid separation device 18, and a seventeenth valve 39 is provided between the liquid phase outlet of the gas-liquid separation device 18 and the condensate delivery pump 21. A first valve 23 and a fifth tee 44 are provided on the heating circulating water main pipeline at the outlet of the heating external network circulating water return pipeline 1; the third end of the fifth tee 44 is connected to the process desalted water pipeline 2 through the second valve 24. A third valve 25 is provided between the first three-way valve 40 and the inlet of the main heat exchanger 9, a fourth valve 26 is provided between the third end of the first three-way valve 40 and the inlet of the auxiliary heat exchanger 4, a fifth valve 27 is provided between the auxiliary heat exchanger 4 and the third end of the second three-way valve 41, and a sixth valve 28 is provided between the gasified black water low-pressure flash evaporation device 3 and the auxiliary heat exchanger 4. A seventh valve 29 is provided between the process condensate pipe network 7 and the first channel of the main heat exchanger 9, an eighth valve 30 is provided between the first channel of the main heat exchanger 9 and the condensate refining device 10, a ninth valve 31 is provided between the urea high-pressure water pipe network 6 and the second channel of the main heat exchanger 9, and a tenth valve 32 is provided between the second channel of the main heat exchanger 9 and the urea high-pressure water pipe network 11. An eleventh valve 33 is provided between the third end of the third three-way 42 and the compensating heat exchanger 14; a twelfth valve 34 is provided between the compensating heat exchanger 14 and the third end of the fourth three-way 43; a thirteenth valve 35 is provided between the low-pressure flash steam pipe network 12 and the first channel inlet of the compensating heat exchanger 14, and a fourteenth valve 36 is provided between the first channel outlet of the compensating heat exchanger 14 and the water-coal slurry preparation part; a fifteenth valve 37 is provided between the low-pressure steam pipe network 13 and the second channel inlet of the compensating heat exchanger 14, and a sixteenth valve 38 is provided between the second channel outlet of the compensating heat exchanger 14 and the steam condensate recovery device 15. The utility model can realize the characteristics of conveniently controlling the temperature of the heating circulation water and flexibly adjusting the relevant process routes according to the operation conditions of the coal-to-synthetic ammonia device through the above-mentioned settings.

[0025] Furthermore, the inner walls of the three independent channels are coated with a graphene composite coating 47. The graphene composite coating described in the utility model can be directly purchased on the market. Preferably, the graphene composite coating is prepared from graphene, graphite powder, epoxy resin, etc. as raw materials, wherein the mass fraction of graphene is 5-15%; it has the characteristics of high heat exchange efficiency and corrosion resistance.

[0026] The working principle of the utility model is as follows: the temperature of the circulating heating water in the circulating water return pipe 1 of the heating external network is 40-55°C. When the circulating heating water needs to be supplemented, the second valve 24 can be opened to allow the desalted water in the process desalted water pipe 2 to enter the heating circulating water main pipe; the circulating heating water enters the main heat exchanger 9 and the auxiliary heat exchanger 4 respectively through the heating network circulating pump 8 for heat exchange and temperature increase. The circulating heating water after temperature increase is 60-70°C. A part of the circulating heating water after heat exchange moves to the fourth tee 43 through the heating circulating water main pipe, and the other part moves to the fourth tee 43 after heat exchange through the compensating heat exchanger 14; the above two parts of the heating circulating water are combined at the fourth tee 43 and then pass through the heating external network circulating water supply pipe 1 7 to provide heating to the park or the city; the temperature of the heating circulating water after the fourth three-way 43 is combined is preferably 70-98°C, and the temperature adjustment is controlled by the opening of the eleventh valve 33; the circulating heating water in the main heat exchanger 9 described in the utility model is mainly heat exchanged by the condensate in the waste heat process condensate network 7 (the condensate temperature is 100-120°C) and the high-adjustment water in the urea system high-adjustment water network 6 (the high-adjustment water temperature is 130-145°C), and the condensate enters the condensate refining device 10 after heat exchange through the main heat exchanger 9, and the high-adjustment water enters the urea high-adjustment water network 11 after heat exchange through the main heat exchanger 9; the circulating heating water in the auxiliary heat exchanger 4 is mainly heat exchanged by the gasification low pressure flash evaporation device 3 of the gasification black water The low-pressure black water (gasified low-pressure black water temperature is 130-150°C) is heat exchanged, and the gasified low-pressure black water enters the gasified black water clarification tank 5 after heat exchange through the auxiliary heat exchanger 4; the compensating heat exchanger 14 for the circulating heating water mainly includes the low-pressure flash steam in the low-pressure flash steam pipe network 12 and the low-pressure steam in the low-pressure steam pipe network 13, and the temperature of the low-pressure steam is 160-200°C. After heat exchange through the compensating heat exchanger 14, it enters the steam condensate recovery device 15; the temperature of the low-pressure flash steam in the low-pressure flash steam pipe network 12 is 150-200°C; after heat exchange through the compensating heat exchanger 14, it enters the gas-liquid separator device 18 for gas-liquid separation, and the gas phase after gas-liquid separation is sent to the flare pipe network 19 The liquid phase after gas-liquid separation remains in the gas-liquid separation device 18, and the liquid level in the gas-liquid separation device 18 is detected by the liquid level sensor 20. When the liquid level meets the predetermined threshold value (for example, the liquid level may be at 70% of the height of the gas-liquid separation device 18), the seventeenth valve 39 is opened, and the condensate is transported to the water-coal slurry preparation system 22 through the condensate delivery pump 21; when the liquid level is lower than the predetermined threshold value (for example, the liquid level may be at 30% of the height of the gas-liquid separation device 18), the seventeenth valve 39 is closed; the above process can realize the stable operation of the coal-to-synthetic ammonia device, and on this basis can realize the reduction of the use of circulating water in the coal-to-synthetic ammonia device, and transfer heat energy to the heating system to reduce the fuel loss in the heating system.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heating system using a coal-based synthetic ammonia device, the system comprising a heating external network circulating water return pipe (1) and a heating external network circulating water supply pipe (17), characterized in that: The heating external network circulating water return pipe (1) is connected to a circulating water heating unit coupled to a coal-to-ammonia synthesis device via a heating network circulating pump (8); the circulating water heating unit is connected to a heating external network circulating water supply pipe (17) via a circulating water temperature regulating unit coupled to the coal-to-ammonia synthesis device; The circulating water heating unit at least comprises a heating circulating water main pipeline, a process condensate pipeline network (7) and a urea high-pressure water pipeline network outlet pipeline (6) arranged between a heating network circulating pump (8) and a circulating water temperature regulating unit, a main heat exchanger (9) is arranged on the heating circulating water main pipeline, the process condensate pipeline network (7) is connected to a condensate refining device (10) via a first channel of the main heat exchanger (9), the urea high-pressure water pipeline network outlet pipeline (6) is connected to a urea high-pressure water pipeline network inlet pipeline (11) via a second channel of the main heat exchanger (9), and the heating circulating water main pipeline is connected to the circulating water temperature regulating unit via a third channel of the main heat exchanger (9); The main heat exchanger (9) comprises a shell (45), two baffles (46) are arranged inside the shell (45), and the two baffles (46) divide the inside of the shell (45) into three independent channels, the third channel is arranged in the middle, and the first channel and the second channel are arranged on both sides of the third channel.

2. A heating system using a coal-to-synthetic ammonia device according to claim 1, characterized in that: The circulating water heating unit further comprises a first tee (40) and a second tee (41) respectively arranged on both sides of the inlet and outlet of the main heat exchanger (9) and a gasified black water low-pressure flash evaporation device (3); the third end of the first tee (40) and the third end of the second tee (41) are connected via a refrigerant channel of the auxiliary heat exchanger (4); and the gasified black water low-pressure flash evaporation device (3) is connected to the gasified black water clarification tank (5) via a heat medium channel of the auxiliary heat exchanger (4).

3. A heating system using a coal-to-synthetic ammonia device according to claim 2, characterized in that: The circulating water temperature control unit comprises a heating circulating water main pipeline connected to a circulating water heating unit and a circulating water supply pipe (17) of a heating external network; a third tee (42) and a fourth tee (43) are provided on the heating circulating water main pipeline; a temperature compensation portion is provided between the third end of the third tee (42) and the third end of the fourth tee (43); and a temperature sensor (16) is provided on the heating circulating water main pipeline between the fourth tee (43) and the circulating water supply pipe (17) of the heating external network.

4. A heating system using a coal-to-synthetic ammonia device according to claim 3, characterized in that: The temperature compensation unit comprises a compensation heat exchanger (14), and the compensation heat exchanger (14) has the same structure as the main heat exchanger (9); The first channel inlet of the compensating heat exchanger (14) is connected to the low-pressure flash steam pipe network (12), and the first channel outlet of the compensating heat exchanger (14) is connected to the water-coal slurry preparation section; The inlet of the second channel of the compensating heat exchanger (14) is connected to the low-pressure steam pipe network (13), and the outlet of the second channel of the compensating heat exchanger (14) is connected to the steam condensate recovery device (15); The inlet end of the second channel of the compensating heat exchanger (14) is connected to the third end of the third tee (42), and the outlet end of the second channel of the compensating heat exchanger (14) is connected to the third end of the fourth tee (43).

5. A heating system using a coal-to-synthetic ammonia device according to claim 4, characterized in that: The water-coal slurry preparation section comprises a gas-liquid separation device (18) connected to the first channel outlet of the compensating heat exchanger (14); the gas phase outlet at the top of the gas-liquid separation device (18) is connected to the flare pipe network (19); the liquid phase outlet of the gas-liquid separation device (18) is connected to the water-coal slurry preparation system (22) via a condensate delivery pump (21); a liquid level sensor (20) is provided on the gas-liquid separation device (18); and a seventeenth valve (39) is provided between the liquid phase outlet of the gas-liquid separation device (18) and the condensate delivery pump (21).

6. A heating system using a coal-to-synthetic ammonia device according to claim 1, characterized in that: A first valve (23) and a fifth tee (44) are provided on the heating circulating water main pipeline at the outlet of the heating external network circulating water return pipeline (1); the third end of the fifth tee (44) is connected to the process desalted water pipeline (2) via the second valve (24).

7. A heating system using a coal-to-synthetic ammonia device according to claim 2, characterized in that: A third valve (25) is provided between the first tee (40) and the inlet of the main heat exchanger (9), a fourth valve (26) is provided between the third end of the first tee (40) and the inlet of the auxiliary heat exchanger (4), a fifth valve (27) is provided between the auxiliary heat exchanger (4) and the third end of the second tee (41), and a sixth valve (28) is provided between the gasified black water low-pressure flash evaporation device (3) and the auxiliary heat exchanger (4).

8. A heating system using a coal-to-synthetic ammonia device according to claim 1, characterized in that: A seventh valve (29) is provided between the process condensate network (7) and the first channel of the main heat exchanger (9), an eighth valve (30) is provided between the first channel of the main heat exchanger (9) and the condensate refining device (10), a ninth valve (31) is provided between the urea high-pressure water network outlet pipe (6) and the second channel of the main heat exchanger (9), and a tenth valve (32) is provided between the second channel of the main heat exchanger (9) and the urea high-pressure water network inlet pipe (11).

9. A heating system using a coal-to-synthetic ammonia device according to claim 4, characterized in that: An eleventh valve (33) is provided between the third end of the third three-way connection (42) and the compensating heat exchanger (14); a twelfth valve (34) is provided between the compensating heat exchanger (14) and the third end of the fourth three-way connection (43); A thirteenth valve (35) is provided between the low-pressure flash steam pipe network (12) and the first channel inlet of the compensating heat exchanger (14), and a fourteenth valve (36) is provided between the first channel outlet of the compensating heat exchanger (14) and the water-coal slurry preparation section; A fifteenth valve (37) is provided between the low-pressure steam pipe network (13) and the second channel inlet of the compensating heat exchanger (14), and a sixteenth valve (38) is provided between the second channel inlet of the compensating heat exchanger (14) and the steam condensate recovery device (15).

10. A heating system using a coal-to-synthetic ammonia device according to claim 1, characterized in that: The inner walls of the three independent channels are coated with a graphene composite coating (47).

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