Steam gradient utilization system of aromatic hydrocarbon combination device
By designing the steam gradient utilization system of the aromatic hydrocarbon joint device, the problem of mismatch between steam output and theoretical calculation in the device is solved, the stable and efficient operation of steam supply is achieved, and the operating elasticity and economic benefits of the device are improved.
Patent Information
- Application Number
- CN202421433836.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-21
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-06-21
AI Technical Summary
In the existing aromatic hydrocarbon combined device, the steam output does not match the theoretical calculation, resulting in the device being unable to operate stably, and the low-temperature heat utilization scheme fails to effectively utilize the self-produced low-temperature steam.
A steam gradient utilization system for aromatic hydrocarbon combined device is designed, including a steam pipe network arranged in parallel at least two stages, a steam water repellent device, a steam water dispensing tank, a pressure reducing device and a steam dehydration superheater are installed, so as to realize the gradient utilization of steam and the interconnection between the pipe network, and provide pressure replenishment and pressure relief measures.
The stable and efficient operation of steam supply in the aromatic hydrocarbon combined device is achieved, the operating elasticity of the device is improved, the waste of high and low steam compensation and emptied waste is avoided, the stable and efficient operation of the device is ensured, and economic benefits are increased.
Smart Images
Figure CN222559806U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of petrochemical industry, in particular to a steam gradient utilization system of an aromatics combined device. Background Art
[0002] The process medium at the top of the aromatics complex is generally cooled by an air cooler, which has a large cooling load and there are problems such as unreasonable steam grade utilization and low steam utilization rate, which leads to high steam consumption in the device. At the same time, the low-temperature heat utilization scheme in the existing aromatics complex only considers the matching of the amount used during normal and stable production. The low-temperature steam produced in the device is completely consumed in the device, which has certain technical defects. For example, the existing scheme design is too theoretical, and the design matches the production and consumption of steam without considering the deviation between actual operation and calculation; the internal steam pipeline network lacks pressure control means and has poor anti-interference ability; the start-up conditions are not considered, there is no steam at the start-up, and the heat users of the device cannot be heated synchronously; there are no pressure replenishment and relief measures under abnormal conditions, etc.
[0003] To this end, the utility model optimizes the steam gradient utilization system to solve the problem that the actual steam production does not match the theoretical calculation or the device cannot operate stably when the self-produced steam fluctuates, and can achieve the following functions:
[0004] 1) Consider using pipeline steam as a heat source for heating when self-produced steam is unqualified in the initial stage of start-up to shorten the start-up time.
[0005] 2) Avoid situations where the theoretical calculated steam volume does not match the actual steam production volume, resulting in obstruction of plant start-up or on-site venting losses.
[0006] 3) When steam fluctuates or the steam compressor fails, the network steam can be replenished in time to avoid large-scale shutdown of the device and increase the operating stability of the device.
[0007] 4) This process optimization improves the operational flexibility of the device and ensures a stable supply of reboiler heat source for the device. Utility Model Content
[0008] The purpose of the utility model is to overcome the problem in the prior art that the actual steam output does not match the theoretical calculation or the device cannot operate stably when the self-produced steam fluctuates, and to provide a steam gradient utilization system for an aromatics complex to achieve stable steam supply and efficient operation in the aromatics complex.
[0009] In order to achieve the above-mentioned purpose, the utility model provides a steam gradient utilization system for an aromatics complex, which contains at least two levels of steam pipelines arranged in parallel; the steam pipeline includes a first-level steam pipeline and a second-level steam pipeline, and the first-level steam pipeline and the second-level steam pipeline are respectively connected to a first unit; the first unit includes one or more of a disproportionation unit, an isomerization unit and a xylene fractionation unit in the aromatics complex.
[0010] The first-stage steam network and the second-stage steam network are provided with a steam trap, a steam water separation tank, a pressure reducing device and a steam dehydration superheater in sequence, so that steam from outside the aromatics complex can enter the steam network through the steam trap, and be led out of the steam network through the steam dehydration superheater to enter the first unit.
[0011] Preferably, the steam gradient utilization system comprises a third-stage steam network arranged in parallel, and the third-stage steam network is connected to the second unit; the second unit comprises one or more of an aromatic extraction unit, a disproportionation unit, an isomerization unit and a xylene fractionation unit;
[0012] The third-level steam network is provided with a steam trap, a pressure reducing device and a steam dehydration superheater in sequence, so that steam from outside the aromatics complex can enter the third-level steam network through the steam trap, and be led out of the third-level steam network through the steam dehydration superheater and enter the second unit.
[0013] Preferably, the system is further provided with a number of steam pressure control devices adapted to the steam pipe network; the steam pressure control device is arranged between the steam drain device and the pressure reducing device.
[0014] Preferably, the steam pressure control device comprises a steam control valve and a pressure indicator.
[0015] According to a preferred embodiment, the first-level steam network is also provided with a steam transmission channel, so that a part of the steam downstream of the steam water separation tank in the first-level steam network can flow through the pressure reducing device and the steam dehydration superheater in sequence and then enter the first unit, and the other part of the steam enters the third steam network through the steam transmission channel.
[0016] Preferably, a pressure reducing device is provided on the steam transmission channel, so that the downstream steam from the steam water separation tank enters the steam transmission channel through the pressure reducing device, and is led out of the steam transmission channel by the steam dehydration superheater and enters the third steam pipeline network.
[0017] According to another preferred embodiment, the third steam network is also provided with a steam return network, so that a part of the steam downstream of the steam dehydration superheater in the third steam network can enter the first unit, and the other part can enter the second steam network through the steam return network.
[0018] Preferably, a pressure reducing device and a reflux steam dehydration superheater are sequentially arranged in the steam reflux pipe network, so that the steam downstream of the steam dehydration superheater in the third steam pipe network can enter the steam reflux pipe network through the pressure reducing device, and can be led out of the steam reflux pipe network through the reflux steam dehydration superheater and enter the second steam pipe network.
[0019] Preferably, the system further comprises a deoxygenated water network whose number matches that of the steam network; the deoxygenated water network is connected with steam networks at various levels so that the deoxygenated water can enter the steam networks at various levels.
[0020] Preferably, the deoxygenated water network includes a number of deoxygenated water pressure reducing devices adapted to the steam network, so that deoxygenated water can be led out of the deoxygenated water network by the deoxygenated water pressure reducing devices and enter each stage of steam dehydration superheater.
[0021] Through the above technical solution, the existing steam of similar grade is introduced to supplement the pressure of the internal pipe network, providing a backup means, which can eliminate the problem that the pressure level of the internal steam pipe network does not match the existing steam pipe network. At the same time, pressure supplement and pressure relief measures are set up in each internal steam pipe network, and interconnected with the nearby pipe network, which can avoid the waste of high steam supplement and low steam, and avoid the waste of steam venting, and realize efficient cascade interconnection of steam.
[0022] In addition, by interconnecting the pipelines at all levels, the device can be started up efficiently, and large-scale shutdowns caused by fluctuations in the steam pipeline network can be avoided, thereby solving the problems of no steam at start-up and difficult emergency response. On this basis, the stable and efficient operation of the aromatics complex can be ensured. In addition, the technical solution of the utility model can avoid the steam venting phenomenon caused by design and actual deviations, greatly increasing economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 Schematic diagram of a steam gradient utilization system for an aromatics complex in a specific embodiment.
[0024] Description of Reference Numerals
[0025] 1. First-level steam network; 2. Second-level steam network; 3. Third-level steam network; 4. First unit; 5. Second unit; 6. Steam return network; 7. Steam transmission channel; 8. Steam drain device; 9. Steam water distribution tank; 10. Pressure reducing device; 12. Reflux steam dehydration superheater; 13. Deoxygenated water network; 14. Deoxygenated water pressure reducing device; 15. Steam pressure control device. DETAILED DESCRIPTION
[0026] The specific implementation of the embodiment of the utility model is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the utility model, and is not used to limit the embodiment of the utility model.
[0027] In the present utility model, unless otherwise stated, directional words contained in terms such as "up, down, left, right, front, back, inside, outside" merely represent the orientation of the terms in normal usage, or are common names understood by those skilled in the art, and should not be regarded as limitations on the terms.
[0028] As attached Figure 1 The steam gradient utilization system of the aromatics complex shown in the figure contains at least two levels of steam pipelines arranged in parallel; the steam pipelines include a first-level steam pipeline 1 and a second-level steam pipeline 2, and the first-level steam pipeline 1 and the second-level steam pipeline 2 are respectively connected to a first unit 4; the first unit 4 includes one or more of the disproportionation unit, isomerization unit and xylene fractionation unit in the aromatics complex.
[0029] The first-stage steam network 1 and the second-stage steam network 2 are provided with a steam trap 8, a steam water separation tank 9, a pressure reducing device 10 and a steam dehydration superheater 11 in sequence, so that steam from outside the aromatics complex can enter the steam network through the steam trap 8, and be led out of the steam network through the steam dehydration superheater 11 and enter the first unit 4.
[0030] The traditional aromatics complex consists of multiple parts, including a pre-hydrogenation reforming unit, a xylene fractionation unit, an aromatics extraction unit, a disproportionation and alkyl transfer unit, and a xylene adsorption separation and isomerization unit.
[0031] In the utility model, the first-stage steam network 1 and the second-stage steam network 2 produce corresponding steam by adopting high-throughput heat exchangers, which are suitable for the disproportionation and alkyl transfer units, isomerization units and xylene fractionation units in the aromatics complex, as a heat source for the steam heater in the aromatics complex or for heating the heat exchanger required for low temperature.
[0032] Preferably, the steam gradient utilization system contains a third-stage steam network 3 arranged in parallel, and the third-stage steam network 3 is connected to the second unit 5; the second unit 5 includes one or more of an aromatic extraction unit, a disproportionation unit, an isomerization unit and a xylene fractionation unit.
[0033] The third-stage steam network 3 is provided with a steam trap 8, a pressure reducing device 10 and a steam dehydration superheater 11 in sequence, so that steam from outside the aromatics complex can enter the third-stage steam network 3 through the steam trap 8, and be led out of the third-stage steam network through the steam dehydration superheater 11 and enter the second unit 5.
[0034] In the utility model, the steam produced by the third-stage steam network 3 has a wider application range, including aromatic extraction units, disproportionation units, isomerization units and xylene fractionation units, which is related to the higher grade of steam produced by the third-stage steam network 3.
[0035] There is no limitation to the aforementioned steam from outside the aromatics complex, which may be steam produced by any device in the plant, for example, it may be corresponding steam from a power station, a catalytic device and a plant pipeline network.
[0036] Preferably, the system is further provided with a steam pressure control device having a number adapted to the steam pipe network; the steam pressure control device is arranged between the steam trap device 8 and the pressure reducing device 10. The steam pressure control device (15) includes a steam control valve and a pressure indicator.
[0037] For the first-stage steam pipe network 1 and the second-stage steam pipe network 2, the steam pressure control device is arranged between the steam trap 8 and the steam water separation tank 9. The aforementioned steam control valve and pressure indicator are both common equipment in this field.
[0038] According to a preferred embodiment, the first-level steam network 1 is further provided with a steam transmission channel 7, so that a part of the steam downstream of the steam water separation tank 9 in the first-level steam network 1 can flow through the pressure reducing device 10 and the steam dehydration superheater 11 in sequence and then enter the first unit 4, and the other part of the steam enters the third-level steam network 3 through the steam transmission channel 7.
[0039] Preferably, a pressure reducing device 10 is provided on the steam transmission channel 7, so that the downstream steam from the steam water separation tank 9 enters the steam transmission channel 7 through the pressure reducing device 10, and is led out of the steam transmission channel 7 by the steam dehydration superheater 11 and enters the third-level steam pipeline network 3.
[0040] The utility model connects the first-level steam network 1 and the third-level steam network 3 by setting a steam transmission channel 7. According to the steam demand of the subsequent device, the steam volume between the first-level steam network 1 and the third-level steam network 3 can be adjusted in time, thereby ensuring that the steam is discharged and wasted and improving the utilization rate of the steam.
[0041] According to another preferred embodiment, the third-level steam network 3 is also provided with a steam return network 6, so that a part of the steam downstream of the steam dehydration superheater 11 in the third-level steam network 3 can enter the first unit 4, and the other part can enter the second-level steam network 2 through the steam return network 6.
[0042] Preferably, a pressure reducing device 10 and a reflux steam dehydration superheater 12 are sequentially arranged in the steam return pipe network 6, so that the steam downstream of the steam dehydration superheater 11 in the third-stage steam pipe network 3 can enter the steam return pipe network 6 through the pressure reducing device 10, and can be led out of the steam return pipe network 6 through the reflux steam dehydration superheater 12 and enter the second-stage steam pipe network 2.
[0043] The utility model connects the second-stage steam network 2 and the third-stage steam network 3 by providing a steam return network 6. When there is no large steam demand in the subsequent units of the third-stage steam network 3, the generated steam is returned to the second-stage steam network 2 through the steam return network 6, which not only avoids the waste of steam discharge, but also ensures the stable operation of the aromatics combined device.
[0044] In addition, the steam generated by the second-stage steam network 2 can be compressed to a corresponding pressure by a compressor and then transported to the third-stage steam network 3 as supplementary steam for the third-stage steam network. When steam production is reduced, it will not cause large-scale shutdown of the device.
[0045] Preferably, the system further comprises a deoxygenated water network 13 having a number matching that of the steam network; the deoxygenated water network is connected to the steam networks at various levels so that the deoxygenated water can enter the steam networks at various levels.
[0046] Preferably, the deoxygenated water network 13 includes a number of deoxygenated water pressure reducing devices 14 adapted to the steam network, so that deoxygenated water can be led out of the deoxygenated water network 13 by the deoxygenated water pressure reducing devices 14 and enter each stage of steam dehydration superheater.
[0047] The adoption of the above technical solution can not only eliminate the problem of mismatch between the pressure level of the internal steam network and the existing steam network, but also avoid waste caused by steam venting, realize efficient cascade interconnection of steam, and ensure the stable and efficient operation of the aromatics complex, thereby increasing economic benefits.
[0048] The present invention will be described in detail below through embodiments, but the protection scope of the present invention is not limited thereto.
[0049] Example 1
[0050] Take Figure 1 The steam gradient utilization system of the aromatics complex is shown, wherein the first-stage steam network 1, the second-stage steam network 2 and the third-stage steam network 3 respectively use 3.5Mpa(g), 1.1Mpa(g) and 2.5Mpa(g) steam outside the aromatics complex.
[0051] Among them, 3.5Mpa(g) comes from the company's system pipeline network; 1.1Mpa(g) comes from the company's system pipeline network; 2.5Mpa(g) comes from the heating company.
[0052] After separation through the steam water separation tank 9 of the first-level steam network 1, a part of the 3.5Mpa(g) steam reaches the first unit 4 (specifically, the xylene fractionation / isomerization unit), and the other part of the steam enters the third-level steam network 3 through the steam transmission channel 7; after transmission through the second-level steam network 2, the 1.1Mpa(g) steam reaches the first unit 4 (specifically, the xylene fractionation / disproportionation / isomerization / adsorption separation / extraction unit); after transmission through the third-level steam network 3, a part of the 2.5Mpa(g) steam reaches the second unit 5 (specifically, the extraction / xylene fractionation / disproportionation / isomerization unit), and the other part flows back to the second-level steam network 2 through the steam reflux network 6.
[0053] The steam gradient utilization system of Example 1 has the following advantages:
[0054] 1. The start-up progress was greatly improved: In the early stage of the start-up and heating, a large amount of 3.5MPa steam and 2.5MPa steam were introduced, which greatly improved the progress of the device's heating and hot oil transportation, avoiding the dilemma of no steam available during the start-up process.
[0055] 2. The device's ability to resist fluctuations has been greatly improved: With the backup means of pipeline steam, the shutdown of a single steam compressor and the reduction of 1.8Mpa steam production will not cause a large-scale shutdown of the device.
[0056] 3. The operational flexibility of the device has been greatly improved: the excess or decrease in steam production at all levels can be balanced through the pipeline network, which completely solves the problem of the overly rigid design of the steam pipeline network.
[0057] 4. Increase economic benefits: In Example 1, the steam venting volume of the aromatics complex without the steam gradient utilization system is reduced by 8 t / h, and the annual efficiency increase can reach more than 10 million.
[0058] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.
Claims
1. A steam gradient utilization system for an aromatics complex, characterized in that: The steam gradient utilization system comprises at least two stages of steam pipe networks arranged in parallel; the steam pipe network comprises a first stage steam pipe network (1) and a second stage steam pipe network (2), and the first stage steam pipe network (1) and the second stage steam pipe network (2) are respectively connected to a first unit (4); the first unit (4) comprises one or more of a disproportionation unit, an isomerization unit and a xylene fractionation unit in an aromatics complex; The first-stage steam pipe network (1) and the second-stage steam pipe network (2) are provided with a steam trap (8), a steam water separation tank (9), a pressure reducing device (10) and a steam dehydration superheater (11) in sequence, so that steam from outside the aromatics complex can enter the steam pipe network through the steam trap (8), and be led out of the steam pipe network through the steam dehydration superheater (11) and enter the first unit (4).
2. The steam gradient utilization system of the aromatics complex according to claim 1, characterized in that: The steam gradient utilization system comprises a third-stage steam pipe network (3) arranged in parallel, and the third-stage steam pipe network (3) is connected to a second unit (5); the second unit (5) comprises one or more of an aromatic extraction unit, a disproportionation unit, an isomerization unit and a xylene fractionation unit; The third-level steam pipe network (3) is provided with a steam drain device (8), a pressure reducing device (10) and a steam dehydration superheater (11) in sequence, so that steam from outside the aromatics complex can enter the third-level steam pipe network (3) through the steam drain device (8), and be led out of the third-level steam pipe network through the steam dehydration superheater (11) and enter the second unit (5).
3. The steam gradient utilization system of the aromatics complex according to claim 2, characterized in that: The system is also provided with a number of steam pressure control devices (15) adapted to the steam pipe network; the steam pressure control device (15) is arranged between the steam drain device (8) and the pressure reducing device (10).
4. The steam gradient utilization system of the aromatics complex according to claim 3, characterized in that: The steam pressure control device (15) comprises a steam control valve and a pressure indicator.
5. The steam gradient utilization system of the aromatics complex according to claim 2, characterized in that: The first-stage steam network (1) is also provided with a steam transmission channel (7), so that a portion of the steam downstream of the steam water separation tank (9) in the first-stage steam network (1) can flow through the pressure reducing device (10) and the steam dehydration superheater (11) in sequence and then enter the first unit (4), and another portion of the steam can enter the third-stage steam network (3) through the steam transmission channel (7).
6. The steam gradient utilization system of the aromatics complex according to claim 5, characterized in that: The steam transmission channel (7) is provided with a pressure reducing device (10), so that at least part of the downstream steam from the steam water separation tank (9) enters the steam transmission channel (7) through the pressure reducing device (10), and is led out of the steam transmission channel (7) by the steam dehydration superheater (11) and enters the third-level steam pipe network (3).
7. The steam gradient utilization system of the aromatics complex according to claim 6, characterized in that: The third-level steam network (3) is also provided with a steam return network (6), so that a portion of the steam downstream of the steam dehydration superheater (11) in the third-level steam network (3) can enter the first unit (4), while another portion can enter the second-level steam network (2) through the steam return network (6).
8. The steam gradient utilization system of the aromatics complex according to claim 7, characterized in that: The steam return pipe network (6) is provided with a pressure reducing device (10) and a return steam dehydration superheater (12) in sequence, so that the steam downstream of the steam dehydration superheater (11) in the third-level steam pipe network (3) can enter the steam return pipe network (6) through the pressure reducing device (10), and can be led out of the steam return pipe network (6) through the return steam dehydration superheater (12) and enter the second-level steam pipe network (2).
9. The steam gradient utilization system of an aromatics complex according to any one of claims 1 to 8, characterized in that: The system also includes a deoxygenated water pipe network (13) whose number matches that of the steam pipe network; the deoxygenated water pipe network is connected to the steam pipe networks at various levels so that the deoxygenated water can enter the steam pipe networks at various levels.
10. The steam gradient utilization system of the aromatics complex according to claim 9, characterized in that: The deoxygenated water pipe network (13) comprises a number of deoxygenated water pressure reducing devices (14) adapted to the steam pipe network, so that the deoxygenated water can be led out of the deoxygenated water pipe network (13) through the deoxygenated water pressure reducing devices (14) and enter the steam dehydration superheaters at various levels.