Heat exchange system of cracking gas condenser
By introducing a steam condensate flash tank and a control valve group into the cracking gas condenser heat exchange system, the water strike problem caused by the mixing of two phases is solved, the stable operation of the system and the efficient utilization of energy are achieved, and the risk of equipment damage is reduced.
Patent Information
- Application Number
- CN202422365496.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-09-27
AI Technical Summary
During the heat exchange process of the cracking gas condenser, the mixing of two phases causes frequent water strikes, resulting in frequent vibration of pipelines and equipment, affecting service life and production efficiency.
A cracking gas condenser heat exchange system is designed. By introducing a steam condenser flash tank and a regulating valve group, water vapor and condensate are separated, steam is used reasonably, two-phase flow mixing is reduced, pipeline pressure is stabilized, and water strike frequency is reduced.
It effectively avoids water hit phenomenon, stabilizes pipeline pressure changes, reduces the risk of equipment vibration and damage, and improves the stability and energy utilization of process operation.
Smart Images
Figure CN223165960U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of pyrolysis gas separation, in particular to a heat exchange system for a pyrolysis gas condenser. Background Art
[0002] Pyrolysis gas is a multi-component mixed gas generated in the process of high-temperature pyrolysis of petroleum hydrocarbons to produce lower olefins. The pyrolysis gas generated by the depolymerization reactor needs to be further processed in the subsequent process. Among them, hot water is used for cooling in the tube layer during the operation of the pyrolysis gas condenser. This process reduces the temperature of the gas phase of the depolymerization reactor to about 200°C. The hot water after heat exchange enters the hot water pipe network and mixes with the return water for heat tracing. Since the two-phase flow is generated after the hot water exchanges heat and mixes in the pressure pipeline, water hammer phenomenon is likely to occur in the pressure pipeline.
[0003] However, in the process of chemical production, water hammer phenomenon frequently occurs in the pressure pipeline. The pipeline and the equipment connected thereto will also vibrate unnecessarily due to frequent water hammer, which is likely to further cause damage to the pipeline and equipment, reduce the service life, and thus affect the production efficiency. Therefore, in the pyrolysis gas heat exchange process, it is very important to effectively reduce the water hammer phenomenon in the pressure pipeline. Summary of the Utility Model
[0004] In view of the defects of the prior art, the utility model provides a heat exchange system for a pyrolysis gas condenser, which avoids the water hammer phenomenon caused by the mixing of two-phase flow and improves the operation stability of the process.
[0005] In order to achieve the above purpose, the technical solution provided by the utility model is a heat exchange system for a pyrolysis gas condenser, which includes a pyrolysis gas condenser, a pyrolysis reactor, a reaction liquid intermediate tank, a component separation tower, a hot water pipe network, a steam pipeline, a steam condensate flash tank, a steam pipe network and a steam condensate external delivery pipeline; the pyrolysis reactor is connected to the pyrolysis gas condenser; the reaction liquid intermediate tank is connected to the pyrolysis gas condenser; the component separation tower is connected to the reaction liquid intermediate tank; the hot water pipe network is connected to the pyrolysis gas condenser; the steam pipeline is connected to the pyrolysis gas condenser, the steam pipeline is connected to the hot water pipe network, and a regulating valve group is arranged on the steam pipeline; the steam condensate flash tank is connected to the steam pipeline through a steam inlet pipeline, and a first valve is arranged on the steam inlet pipeline; the steam pipe network is connected to the steam condensate flash tank; the steam condensate external delivery pipeline is connected to the steam condensate flash tank.
[0006] Further, a hot water pump and a first flow regulating valve are arranged on the steam condensate external delivery pipeline.
[0007] Further, the hot water pipe network is connected to the pyrolysis gas condenser through a circulating hot water pipeline, and a hot water circulating pump is arranged on the circulating hot water pipeline.
[0008] Further, a second valve, a check valve and a third valve are sequentially arranged on the circulating hot water pipeline downstream of the hot water circulation pump.
[0009] Further, the steam pipe network is a 0.45 MPa steam pipe network.
[0010] Further, the regulating valve group includes a fourth valve, a second flow regulating valve and a fifth valve arranged sequentially along the material flow direction. A crossover line is arranged between the upstream of the fourth valve and the downstream of the fifth valve, and a bypass valve is arranged on the crossover line.
[0011] Further, the meeting point of the steam inlet pipeline and the steam pipeline is located between the second flow regulating valve and the fifth valve.
[0012] Further, a tee joint is arranged between the second flow regulating valve and the fifth valve, and one end of the steam inlet pipeline is connected to the tee joint.
[0013] Further, a feed pump is arranged on the pipeline between the reaction liquid intermediate tank and the component separation tower.
[0014] Beneficial effects of the present utility model: The phenomenon of water hammer generated by the mixing of two-phase flows is avoided, the pipeline pressure change is stable, the pressure fluctuation of the pipeline network outside the battery limit is stabilized accordingly, the water hammer frequency is greatly reduced, the water hammer sound and vibration are weakened, the risk of pipeline damage due to vibration is effectively reduced, and the stability of the process operation is improved. Description of the Drawings
[0015] Figure 1 is a process flow diagram of a cracking gas condenser heat exchange system in an embodiment of the present utility model;
[0016] Figure 2 is a graph of the outlet pressure trend of the hot water pump in a cracking gas condenser heat exchange system in an embodiment of the present utility model;
[0017] Figure 3 is a graph of the changing trend of the hot water temperature downstream of the cracking gas condenser in the prior art;
[0018] In the figure:
[0019] 100, cracking gas condenser,
[0020] 200, cracking reactor,
[0021] 300, reaction liquid intermediate tank, 310, feed pump,
[0022] 400, component separation tower,
[0023] 500, Hot water pipe network, 510, Circulating hot water pipeline, 511, Hot water circulation pump, 512, Second valve, 513, Check valve, 514, Third valve,
[0024] 600, Steam pipeline, 610, Control valve group, 611, Fourth valve, 612, Second flow control valve, 613, Fifth valve, 614, Tee, 620, Steam inlet pipeline, 621, First valve, 630, Cross line, 631, Bypass valve,
[0025] 700, Steam condensate flash tank,
[0026] 800, Steam pipe network,
[0027] 900, Steam condensate external delivery pipeline, 910, Hot water pump, 920, First flow control valve. Detailed implementation manners
[0028] To make the above objects, features and advantages of the present utility model more obvious and understandable, the following detailed description of the specific implementation manners of the present utility model will be given with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.
[0029] Refer to Figure 3 , in the prior art, the hot water after heat exchange in the cracking reactor enters the hot water pipe network and mixes with the heat tracing return water. It can be seen from the figure that the temperature fluctuates between 77°C and 114°C. The main reason is that the presence of steam in the water causes large temperature and pressure fluctuations. Since the hot water after heat exchange generates a two-phase flow and mixes in the pressure pipeline, water hammer phenomena are likely to occur in the pressure pipeline.
[0030] Refer to Figure 1, showing a pyrolysis gas condenser heat exchange system in an embodiment of the present utility model, which includes a pyrolysis gas condenser 100, a pyrolysis reactor 200, a reaction liquid intermediate tank 300, a component separation tower 400, a hot water pipe network 500, a steam pipeline 600, a steam condensate flash tank 700, a steam pipe network 800, and a steam condensate external delivery pipeline 900. The pyrolysis reactor 200 is connected to the pyrolysis gas condenser 100; the reaction liquid intermediate tank 300 is connected to the pyrolysis gas condenser 100; the component separation tower 400 is connected to the reaction liquid intermediate tank 300; the hot water pipe network 500 is connected to the pyrolysis gas condenser 100; the steam pipeline 600 is connected to the pyrolysis gas condenser 100, the steam pipeline 600 is connected to the hot water pipe network 500, and a regulating valve group 610 is arranged on the steam pipeline 600; the steam condensate flash tank 700 is connected to the steam pipeline 600 through a steam inlet pipeline 620, and a first valve 621 is arranged on the steam inlet pipeline 620; the steam pipe network 800 is connected to the steam condensate flash tank 700; the steam condensate external delivery pipeline 900 is connected to the steam condensate flash tank 700.
[0031] In one embodiment, a hot water pump 910 and a first flow regulating valve 920 are arranged on the steam condensate external delivery pipeline 900. Arranging the first flow regulating valve 920 can control the flow rate in the steam condensate external delivery pipeline 900 and improve the stability of the system operation.
[0032] In one embodiment, the hot water pipe network 500 is connected to the pyrolysis gas condenser 100 through a circulating hot water pipeline 510, and a hot water circulation pump 511 is arranged on the circulating hot water pipeline 510.
[0033] In one embodiment, a second valve 512, a check valve 513, and a third valve 514 are sequentially arranged on the circulating hot water pipeline 510 downstream of the hot water circulation pump 511. Arranging the check valve 513 can effectively control the fluid flow direction inside the circulating hot water pipeline 510, avoid material backflow, and thus improve the stability of the system operation.
[0034] In one embodiment, the steam pipe network 800 is a 0.45 MPa steam pipe network. In this way, steam is effectively recovered and the energy utilization rate is improved.
[0035] In one embodiment, the regulating valve group 610 includes a fourth valve 611, a second flow regulating valve 612, and a fifth valve 613 arranged in sequence along the material flow direction. A cross line 630 is arranged between the upstream of the fourth valve 611 and the downstream of the fifth valve 613, and a bypass valve 631 is arranged on the cross line 630. Arranging the cross line 630 and the bypass valve 631 facilitates isolating the regulating valve group 610 between the cross line 630, and thus facilitates transformation and connection tests.
[0036] In one embodiment, the connection point of the steam inlet pipeline 620 to the steam pipeline 600 is located between the second flow regulating valve 612 and the fifth valve 613.
[0037] In one embodiment, a tee 614 is provided between the second flow regulating valve 612 and the fifth valve 613, and one end of the tee 614 is connected to the steam inlet pipeline 620.
[0038] In one embodiment, a feed pump 310 is provided on the pipeline between the reaction liquid intermediate tank 300 and the component separation tower 400.
[0039] During the transformation, the bypass valve 631 at the tube side outlet of the cracked gas condenser 100 is opened, the section between the second flow regulating valve 612 and the fifth valve 613 is changed to a tee 614, and a rubber hose is connected to introduce steam into the steam condensate flash tank 700. After the test, the water hammer frequency is greatly reduced, and the vibration of the water hammer sound is weakened. During the experiment, due to the connection test with a rubber hose, the gas displacement is insufficient, and the bypass valve 631 on the cross line 630 still needs to have a certain opening. During the construction transformation, a DN80 carbon steel pipeline is used for connection.
[0040] The above-mentioned cracked gas condenser heat exchange system introduces the heat-exchanged water vapor into the steam condensate flash tank 700, separates the water vapor and the steam condensate in the steam condensate flash tank 700, reasonably utilizes and recovers the flashed steam, improves the energy utilization rate, saves energy, the temperature change after heat exchange is stable, and the operation stability rate is improved to ensure the safe and stable operation of production.
[0041] During production operation, the second flow regulating valve 612, the fifth valve 613 and the bypass valve 631 are closed to cut off the channel for steam to enter the hot water pipe network 500, and the steam is introduced into the downstream steam condensate flash tank 700. When a failure occurs in the pipeline and device downstream of the steam condensate flash tank 700, the fifth valve 613 can be opened, the second flow regulating valve 612 can be gradually opened, the first flow regulating valve 920 can be gradually closed, and the first valve 621 can be closed to switch back to the process before the transformation to repair the downstream equipment and pipeline. Although water hammer phenomenon will still occur, it is not necessary to completely stop production. After the repair is completed, it can be restored to the process of the steam condensate flash tank 700, which improves the flexibility of the entire heat exchange system.
[0042] See Figure 2 , which shows the hot water pump outlet pressure trend chart of a cracked gas condenser heat exchange system in an embodiment of the present invention; the curve change of the cracked gas after heat exchange is more stable. It can be seen from the hot water pump 910 outlet pressure trend chart that the pressure change is stable, and the pressure fluctuation of the off-site pipe network also stabilizes. After applying the heat exchange system of this embodiment, the outlet water temperature is stably controlled at 83±1°C, the water hammer frequency is greatly reduced, the water hammer sound and vibration are weakened, and the risk of pipeline damage due to vibration is effectively reduced.
[0043] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.
[0044] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.
[0045] In the present utility model, unless otherwise clearly specified and defined, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0046] In the present utility model, unless otherwise clearly stipulated and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature. It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.
Claims
1. A cracked gas condenser heat exchange system, characterized in that: including pyrolysis gas condenser; pyrolysis reactor, connected to the pyrolysis gas condenser; reaction liquid intermediate tank, connected to the pyrolysis gas condenser; component separation column, connected to the reaction liquid intermediate tank; hot water pipe network, connected to the pyrolysis gas condenser; steam pipeline, connected to the pyrolysis gas condenser, the steam pipeline is connected to the hot water pipe network, and a regulating valve group is arranged on the steam pipeline; steam condensate flash tank, connected to the steam pipeline through a steam inlet pipeline, and a first valve is arranged on the steam inlet pipeline; steam pipe network, connected to the steam condensate flash tank; steam condensate external delivery pipeline, connected to the steam condensate flash tank.
2. The heat exchange system of a cracking gas condenser according to claim 1, wherein: A hot water pump and a first flow regulating valve are arranged on the steam condensate external delivery pipeline.
3. The heat exchange system of a cracked gas condenser according to claim 1, wherein: The hot water pipe network is connected to the pyrolysis gas condenser through a circulating hot water pipeline, and a hot water circulation pump is arranged on the circulating hot water pipeline.
4. The heat exchange system of a cracked gas condenser according to claim 3, characterized in that: A second valve, a check valve and a third valve are sequentially arranged on the circulating hot water pipeline downstream of the hot water circulation pump.
5. The heat exchange system of a cracking gas condenser according to claim 1, wherein: The steam pipe network is a 0.45 MPa steam pipe network.
6. A cracking gas condenser heat exchange system according to any one of claims 1-5, characterized in that: The regulating valve group includes a fourth valve, a second flow regulating valve and a fifth valve arranged in sequence along the material flow direction. A cross line is arranged between the upstream of the fourth valve and the downstream of the fifth valve, and a bypass valve is arranged on the cross line.
7. The heat exchange system of a pyrolysis gas condenser according to claim 6, wherein: The connection point of the steam inlet pipeline on the steam pipeline is located between the second flow regulating valve and the fifth valve.
8. A cracking gas condenser heat exchange system according to claim 6, characterized in that: A tee is arranged between the second flow regulating valve and the fifth valve, and one end of the steam inlet pipeline is connected to the tee.
9. A cracking gas condenser heat exchange system according to any one of claims 1-5, characterized in that: A feed pump is arranged on the pipeline between the reaction liquid intermediate tank and the component separation column.