CN-122010142-A - Double-tower dynamic series-parallel flexible ammonia synthesis system and control method

CN122010142ACN 122010142 ACN122010142 ACN 122010142ACN-122010142-A

Abstract

The invention discloses a double-tower dynamic serial-parallel flexible ammonia synthesis system and a control method, and relates to the technical field of ammonia synthesis preparation. The number of the synthesis towers for synthesizing ammonia is increased to two, the load minimum value of the synthesis ammonia system can be further reduced, and the load maximum value of the synthesis ammonia system is increased, so that the load range of the whole system is widened, the load range of the whole system can be matched with the output fluctuation characteristic of renewable energy sources, and the high-temperature synthesis gas in the first synthesis tower can be directly connected into the second synthesis tower under extremely low load, so that the temperature of the catalyst in the second synthesis tower is maintained as much as possible.

Inventors

XIANG YAOHUA
LI ZHENGZI
JIANG MING
ZHANG WENYANG

Assignees

安徽中科禾成绿色能源有限公司

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (10)

1. The double-tower dynamic serial-parallel flexible ammonia synthesis system is characterized by comprising a first synthesis tower (1), a second synthesis tower (2) and a raw material supply source (3); the first synthesis tower (1) and the second synthesis tower (2) are respectively provided with an input system and an output system; The pipeline system (4) comprises a first pipeline group arranged between the raw material supply source (3) and an input system on the first synthesis tower (1), a second pipeline group arranged between the raw material supply source (3) and an input system on the second synthesis tower (2), a third pipeline group arranged between the input system of the first synthesis tower (1) and an output system of the second synthesis tower (2), and a fourth pipeline group arranged between the output system of the first synthesis tower (1) and the input system of the second synthesis tower (2), wherein the fourth pipeline group is not communicated with the third pipeline group in the second synthesis tower (2); the valve system (5) is used for controlling the on-off of corresponding pipelines in the pipeline system (4), and the valve system (5) at least has a first working condition and a second working condition; Under the first working condition, the first pipeline group is communicated, the second pipeline group is communicated, the third pipeline group is disconnected, and the fourth pipeline group is disconnected; under the second working condition, the second pipeline group is communicated, the third pipeline group is communicated, the fourth pipeline group is communicated, and the first pipeline group is disconnected.
2. A dual column dynamic series-parallel flexible ammonia synthesis system according to claim 1, wherein the maximum load of the first synthesis column (1) is lower than the maximum load of the second synthesis column (2).
3. The double-tower dynamic series-parallel flexible ammonia synthesis system and the control method according to claim 2, wherein the ratio of the maximum load of the first synthesis tower (1) to the maximum load of the second synthesis tower (2) is between 0.25 and 0.5.
4. The dual-column dynamic series-parallel flexible ammonia synthesis system according to claim 2, wherein the input system of the second synthesis column (2) comprises a column wall gas input end (63), the output system of the second synthesis column (2) comprises a column wall gas output end (71), the column wall gas input end (63) is communicated with the column wall gas output end (71) in the second synthesis column (2), the input system of the second synthesis column (2) further comprises a supplementary input end (64), a supplementary pipeline (41) is arranged between the column wall gas output end (71) and the corresponding supplementary input end (64), a supplementary valve (51) is arranged in the supplementary pipeline (41), the valve system (5) is opened under a first working condition, the supplementary valve (51) is communicated, the supplementary pipeline (41) is disconnected by the valve system (5) under a second working condition, the input system further comprises a heating gas input end (61) and a branch gas input end (62), the heating gas input end (61) is connected with the reaction gas output end (72) in the second synthesis column (2) through a pipeline (8), the heating gas input (61), the make-up input (64) and the shunt gas input (62) are in communication with a corresponding reactant gas output (72).
5. The dual-tower dynamic serial-parallel flexible ammonia synthesis system according to claim 4, wherein the first pipeline group comprises a first main pipeline (43) and a first secondary pipeline (431) which are communicated with a raw material supply source (3), one end of the first main pipeline (43) is communicated with one end of all the first secondary pipelines (431), a heating device (8) and a branching gas input end (62) on the first synthesis tower (1) are communicated with one of the first secondary pipelines (431), and the valve system (5) comprises a first main valve (52) arranged on the first main pipeline (43), a first secondary valve (53) arranged on the first secondary pipeline (431) communicated with the heating device (8) and a second secondary valve (54) arranged on the other first secondary pipelines (431); The second pipeline group comprises a second main pipeline (44) and second secondary pipelines (441) which are communicated with the raw material supply source (3), one end of the second main pipeline (44) is communicated with one end of all the second secondary pipelines (441), a heating device (8), a branching gas input end (62) and a tower wall gas input end (63) on the second synthesis tower (2) are communicated with one of the second secondary pipelines (441), and the valve system (5) comprises a third valve (55) arranged on each second secondary pipeline (441); The third pipeline group comprises a third main pipeline (45), one end of the third main pipeline (45) is communicated with a tower wall gas output end (71) of the second synthesis tower (2), the other end of the third main pipeline (45) is communicated with the first main pipeline (43), a communication point is positioned between the first main valve (52) and the first secondary pipeline (431), and the valve system (5) comprises a second main valve (56) arranged on the third main pipeline (45); the fourth pipeline group comprises a fourth main pipeline (46), one end of the fourth main pipeline (46) is communicated with a reaction gas output end (72) of the first synthesis tower (1), the other end of the fourth main pipeline (46) is communicated with a heating device (8) on the second synthesis tower (2), the communication point is positioned on a pipeline between the input end of the heating device (8) and a corresponding third valve (55), and the valve system (5) comprises a third main valve (57) arranged on the fourth main pipeline (46).
6. The double-tower dynamic series-parallel flexible ammonia synthesis system according to claim 4, wherein the number of the branched gas input ends (62) on the first synthesis tower (1) is n, the number of the branched gas input ends (62) on the second synthesis tower (2) is m, n is an integer not less than 1, and m is an integer not less than 0.
7. The dual-column dynamic series-parallel flexible ammonia synthesis system according to claim 5, wherein the pipeline system (4) comprises a discharge pipeline (42), the discharge pipeline (42) on the second synthesis column (2) is communicated with a corresponding reaction gas output end (72), the discharge pipeline (42) on the first synthesis column (1) is communicated with the corresponding reaction gas output end (72) or is communicated with a fourth main pipeline (46), the communication point is positioned on the pipeline of the third main valve (57) and the corresponding reaction gas output end (72), the valve system (5) comprises a discharge valve (58) arranged in the discharge pipeline (42) on the first synthesis column (1), the raw material supply source (3) comprises a heat exchanger (31) and a main input line (32), the pipeline system (4) comprises a main output line (33), a first channel and a second channel are arranged in the heat exchanger (31), one end of the first channel is communicated with the main input line (32), the other end of the first channel is communicated with the first main pipeline (43) and the other end of the second main pipeline (44), and the other end of the second channel is communicated with the main output line (42).
8. A control method based on the double-tower dynamic serial-parallel flexible ammonia synthesis system as claimed in any one of claims 1-7, comprising the following steps of S10a, controlling a valve system (5), enabling a second pipeline group to be communicated, a third pipeline group to be communicated, a fourth pipeline group to be communicated, and enabling the first pipeline group to be disconnected.
9. A control method based on a double-tower dynamic series-parallel flexible ammonia synthesis system according to any one of claims 1-7, comprising the steps of S10b, controlling the valve system (5) such that the first pipeline group is connected, the second pipeline group is connected, the third pipeline group is disconnected, and the fourth pipeline group is disconnected.
10. A control method according to claim 8, characterized in that step S10a comprises controlling the closing of a first main valve (52) in the valve system (5), controlling the opening of a third valve (55) on a second sub-line (441) communicating with the tower wall gas input (63), controlling the closing of the remaining third valves (55), controlling the closing of a supplementary valve (51), controlling the opening of a second main valve (56), controlling the closing of a first sub-valve (53), controlling the opening of a second sub-valve (54), controlling the closing of a discharge valve (58), and controlling the opening of a third main valve (57).

Description

Double-tower dynamic series-parallel flexible ammonia synthesis system and control method Technical Field The invention relates to the technical field of synthetic ammonia preparation, in particular to a double-tower dynamic serial-parallel flexible synthetic ammonia system and a control method. Background Under the global 'double carbon' goal, the green ammonia is taken as zero carbon fuel and the core value of green chemical raw materials is highlighted, the green ammonia is electrolyzed by renewable energy sources to prepare green hydrogen and then is synthesized with nitrogen to realize near zero emission in the whole life cycle, wind and light energy can be further assisted to be consumed and stored, but the intermittent nature of wind and light power generation leads to rapid load fluctuation of a front-end hydrogen production section, contradicts with the stable operation mode of the traditional synthetic ammonia section, and restricts the industrialized propulsion of the green ammonia. The traditional single-tower ammonia synthesis device is limited by the catalyst activity window, the bed heat balance regulation and control capability and the reaction dynamics characteristic, has a narrow load regulation range and slow response, and can generally only operate efficiently in a narrow steady-state interval. In order to match the fluctuation of wind, light and electricity resources, the load of the synthesizing tower needs to be adjusted in a wide range. There is a general need in the industry for green ammonia synthesis plants having wide load operating capacities of 30% -110% or more to match the output fluctuation characteristics of renewable energy sources. Disclosure of Invention The invention aims to solve the problem of narrower load of the existing single-tower ammonia synthesis device. In order to solve the problems, in a first aspect, the invention provides a double-tower dynamic serial-parallel flexible ammonia synthesis system, which comprises a first synthesis tower, a second synthesis tower and a raw material supply source; The first synthesis tower and the second synthesis tower are respectively provided with an input system and an output system; The pipeline system comprises a first pipeline group arranged between the raw material supply source and the input system on the first synthesis tower, a second pipeline group arranged between the raw material supply source and the input system on the second synthesis tower, a third pipeline group arranged between the input system of the first synthesis tower and the output system of the second synthesis tower, and a fourth pipeline group arranged between the output system of the first synthesis tower and the input system of the second synthesis tower, wherein the fourth pipeline group is not communicated with the third pipeline group in the second synthesis tower; The valve system is used for controlling the on-off of corresponding pipelines in the pipeline system and at least has a first working condition and a second working condition; Under the first working condition, the first pipeline group is communicated, the second pipeline group is communicated, the third pipeline group is disconnected, and the fourth pipeline group is disconnected; under the second working condition, the second pipeline group is communicated, the third pipeline group is communicated, the fourth pipeline group is communicated, and the first pipeline group is disconnected. Compared with the prior art, the double-tower dynamic serial-parallel flexible ammonia synthesis system and the control method provided by the invention have the following beneficial effects: Because the lowest load of one synthesis tower meeting the self-heating balance is still higher, the number of the synthesis towers for synthesizing ammonia is increased to two, the load minimum value of the synthesis ammonia system can be further reduced when the synthesis towers are connected in series, and the load maximum value of the synthesis ammonia system is increased when the synthesis towers are connected in parallel, so that the load range of the whole system is widened, the load range of the whole system can be matched with the output fluctuation characteristic of renewable energy sources, in the system, the system has two working conditions by controlling the on-off of corresponding pipelines in a pipeline system through a valve system, the first pipeline group and the second pipeline group are in a communicated state in the first working condition, the corresponding first synthesis tower and the second synthesis tower can independently work, the system is operated under high load or meets the operating conditions of the system on the first synthesis tower and the second synthesis tower, so that the loads of the system are independently and steadily increased, and in the second operating condition, the second pipeline group, the third pipeline group and the fourth pipeline group are in a communicat