A flue gas waste heat utilization system based on a slurry bed heating furnace

Abstract

This application relates to a flue gas waste heat utilization system based on a slurry bed heating furnace. Since the heat exchange device is installed at the smoke outlet of the fresh feed heating furnace; a water inlet pipe and a water outlet pipe are provided on the heat collection component in the heat exchange device, and a temperature sensor is provided in the water outlet pipe; the first heating plate is connected to the water inlet pipe and the water outlet pipe through a first pipeline loop; the first heating plate is sleeved outside the fresh feed buffer tank; the inner chamber of the second heating plate is connected to the water inlet pipe and the water outlet pipe through a second pipeline loop; the second heating plate is sleeved on the intake pipe of the fresh feed heating furnace; the control device controls the operation of the first pipeline loop and the second pipeline loop according to the detection value of the temperature sensor; through the above settings, the waste heat of the high-temperature flue gas can be recovered, thereby preheating the combustion air, improving the combustion efficiency, reducing fuel consumption, introducing heat into the fresh feed buffer tank, forming a double preheating mechanism, which not only increases the feed temperature but also reduces the load of the heating furnace.

Description

Technical Field

[0001] The present application relates to the technical field of petrochemical engineering, and particularly relates to a flue gas waste heat utilization system based on a slurry bed heating furnace. Background Art

[0002] The slurry bed residue hydrotreating unit uses vacuum residue from atmospheric and vacuum distillation as raw material, and undergoes hydrocracking reaction and hydrorefining reaction under the action of molybdenum-based catalyst. Due to thermal cracking, the carbon-carbon bonds are broken, and the catalyst promotes the hydrogenation of free radicals, reduces coking, promotes desulfurization, denitrification and deoxidation reactions, and can also remove halogens and metals, removing impurities such as sulfur, nitrogen and metals, and producing desulfurized fuel gas, liquefied gas, naphtha, diesel, wax oil and oil residue.

[0003] In the slurry bed reaction system, the fresh feed heating furnace is one of the crucial auxiliary equipment, used to preheat the fresh raw material entering the reactor to an appropriate temperature; this not only helps to improve the efficiency and selectivity of chemical reactions, but also optimizes the energy utilization of the entire production process.

[0004] The fresh feed heating furnace usually preheats the fresh raw material by direct heating. The flame generated by burning fuel (such as natural gas, light oil, etc.) directly heats the reactor wall, and then the heat is transferred to the internal reaction material. However, the high-temperature flue gas generated by its combustion is generally directly discharged. To realize the waste heat recovery and utilization, a flue gas waste heat utilization system based on a slurry bed heating furnace is proposed. Summary of the Invention

[0005] The embodiments of the present application provide a flue gas waste heat utilization system based on a slurry bed heating furnace to solve the problem that the high-temperature flue gas generated by the combustion of the fresh feed heating furnace in the related art is difficult to be effectively utilized.

[0006] In a first aspect, a flue gas waste heat utilization system based on a slurry bed heating furnace is provided, which includes:

[0007] A heat exchange device, which is installed at the smoke exhaust port of the fresh feed heating furnace of the process unit using the slurry bed hydrotreating technology to process ethylene tar; a channel for high-temperature flue gas to pass through is provided in the heat exchange device, and a heat collection component is provided in the channel; a water inlet pipe and a water outlet pipe communicating with the internal circulation medium flow channel of the heat collection component are provided on the heat collection component, and a temperature sensor is provided in the water outlet pipe;

[0008] A first heating plate, whose internal chamber is communicated with the water inlet pipe and the water outlet pipe through a first pipeline loop; the first heating plate is sleeved outside the fresh feed buffer tank of the process unit using the slurry bed hydrotreating technology to process ethylene tar;

[0009] A second heating plate, the internal chamber of which is communicated with the water inlet pipe and the water outlet pipe through a second pipeline loop; the second heating plate is sleeved on the air inlet pipeline of the fresh feed heating furnace;

[0010] A control device, which is connected to the first pipeline loop, the second pipeline loop and the temperature sensor, and is used to control the operation of the first pipeline loop and the second pipeline loop according to the detection value of the temperature sensor.

[0011] Through the above settings, the waste heat of the high-temperature flue gas can be recovered, thereby preheating the combustion air, improving the combustion efficiency, reducing the fuel consumption, introducing the heat into the fresh feed buffer tank, forming a double preheating mechanism, which not only increases the feed temperature but also reduces the load of the heating furnace; that is, the control device is used to close the first pipeline loop and open the second pipeline loop when the detection value is less than the first threshold, and to open the first pipeline loop and open the second pipeline loop when the detection value is greater than the first threshold; at the above first threshold, the heat recovered from the high-temperature flue gas can only heat the combustion air, and when it is greater than the first threshold, the recovered heat can simultaneously meet the heating requirements of the fresh feed buffer tank and the combustion air; through the control device, corresponding control of different scenarios can be achieved.

[0012] In some embodiments, the first pipeline loop includes a first pipeline, a second pipeline, a first solenoid valve, and a first circulation pump;

[0013] One end of the first pipeline is connected to the water outlet pipe, and the other end is connected to the inlet of the first heating plate; the first solenoid valve is arranged on the first pipeline;

[0014] One end of the second pipeline is connected to the outlet of the first heating plate, and the other end is connected to the water inlet pipe; the first circulation pump is arranged on the second pipeline.

[0015] In some embodiments, the second pipeline loop includes a third pipeline, a fourth pipeline, a second solenoid valve, and a second circulation pump;

[0016] One end of the third pipeline is connected to the water outlet pipe, and the other end is connected to the inlet of the second heating plate; the second solenoid valve is arranged on the third pipeline;

[0017] One end of the fourth pipeline is connected to the outlet of the second heating plate, and the other end is connected to the water inlet pipe; the second circulation pump is arranged on the fourth pipeline.

[0018] In some embodiments, the heat exchange device further includes a cylinder, and the heat collection assembly is installed in the cylinder;

[0019] The heat collection component includes a first ring and a second ring which are arranged at intervals up and down. The first ring and the second ring are connected by a plurality of inclined rods; the internal cavities of the first ring, the second ring, and the inclined rods are all interconnected; the outer diameter of the first ring is smaller than the outer diameter of the second ring;

[0020] The water inlet pipe is connected to the second ring, and the water outlet pipe is connected to the first ring.

[0021] Based on the principle of thermal expansion and contraction of the circulating medium above, when the cold circulating medium enters the second ring from the water inlet pipe, it is heated to generate high pressure and moves upward into the first ring, and then is discharged from the water outlet pipe. This can reduce the load on the first circulation pump and the second circulation pump; in addition, for the above structure, the high-temperature flue gas passes through a plurality of inclined rods, and it is also convenient to carry out subsequent cleaning after being attached with soot for a long time.

[0022] In some embodiments, the number of the cylinders is multiple and they are arranged in series; each cylinder is provided with one of the heat collection components.

[0023] In some embodiments, in the length direction of the inclined rod, the cross-sectional area of the internal cavity of the inclined rod gradually decreases from bottom to top.

[0024] In some embodiments, the first ring, the second ring, and the inclined rods are all made of copper material;

[0025] The outer sides of the first ring, the second ring, and the inclined rods are all coated with a corrosion-resistant coating.

[0026] In some embodiments, a plurality of the inclined rods are distributed in a circular array centered on the center of the second ring;

[0027] A metal partition net is provided between two adjacent inclined rods.

[0028] In some embodiments, the first heating plate is cylindrical, and its inner wall fits with the outer side of the fresh feed buffer tank, and its outer wall is provided with a heat-insulating layer;

[0029] The second heating plate is cylindrical, and its inner wall fits with the outer side of the intake pipe of the fresh feed heating furnace, and its outer wall is provided with a heat-insulating layer.

[0030] In some embodiments, the control device is used to close the first pipeline loop when the detected value is less than the first threshold, open the second pipeline loop, and is used to open the first pipeline loop and open the second pipeline loop when the detected value is greater than the first threshold.

[0031] The beneficial effects brought by the technical solution provided by this application include:

[0032] An embodiment of the present application provides a flue gas waste heat utilization system based on a slurry bed heating furnace. Since the heat exchange device is installed at the flue gas outlet of the fresh feed heating furnace; a water inlet pipe and a water outlet pipe are provided on the heat collection component in the heat exchange device, and a temperature sensor is provided in the water outlet pipe; the first heating plate is communicated with the water inlet pipe and the water outlet pipe through a first pipeline loop; the first heating plate is sleeved outside the fresh feed buffer tank; the inner cavity of the second heating plate is communicated with the water inlet pipe and the water outlet pipe through a second pipeline loop; the second heating plate is sleeved on the air inlet pipeline of the fresh feed heating furnace; the control device controls the operation of the first pipeline loop and the second pipeline loop according to the detection value of the temperature sensor; through the above settings, the waste heat of the high-temperature flue gas can be recovered, thereby preheating the combustion air, improving the combustion efficiency, reducing the fuel consumption, introducing the heat into the fresh feed buffer tank, forming a double preheating mechanism, which not only improves the feed temperature but also reduces the load of the heating furnace. Description of the Drawings

[0033] Figure 1 It is a connection schematic diagram of the flue gas waste heat utilization system based on the slurry bed heating furnace provided by the embodiment of the present application and the process device using the slurry bed hydrogenation technology to process ethylene tar;

[0034] Figure 2 It is a structural schematic diagram of the heat exchange device provided by the embodiment of the present application;

[0035] Figure 3 It is a connection schematic diagram of the heat collection component and the cylinder provided by the embodiment of the present application;

[0036] Figure 4 It is a structural schematic diagram of the heat collection component provided by the embodiment of the present application;

[0037] Figure 5 It is a structural schematic diagram of the heat collection component with a metal mesh provided by the embodiment of the present application.

[0038] In the figure: 1, fresh feed heating furnace; 2, heat collection component; 200, first ring; 201, second ring; 202, inclined rod; 3, water inlet pipe; 4, water outlet pipe; 5, first heating plate; 6, fresh feed buffer tank; 7, second heating plate; 8, first pipeline; 9, second pipeline; 10, first solenoid valve; 11, first circulation pump; 12, third pipeline; 13, fourth pipeline; 14, second solenoid valve; 15, second circulation pump; 16, cylinder. Detailed Embodiments

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0040] The process unit for processing ethylene tar by using the slurry bed hydrogenation technology described later can refer to the relevant descriptions in Chinese Patent CN221319891U. The process flow is as follows: The vacuum residue from the atmospheric and vacuum distillation unit, the vacuum residue from the tank farm, and the catalytic slurry oil from the tank farm are mixed and then enter the fresh feed buffer tank of the unit. The feedstock oil is pumped out by the fresh feed pump, preheated successively through E-1001, E-1002, and E-1003, and then heated to 342 °C by the fresh feed heating furnace and enters the mixed feed buffer tank, where it is mixed with the fresh catalyst precursor and the vacuum tower bottom recycle oil. The mixed raw materials in the mixed feed buffer tank are sent to the reactor after being boosted by the reaction feed pump.

[0041] Among them, E-1001, E-1002, and E-1003 are series-connected multi-stage heat exchangers, which use the gas phase at the top of the preflash column, the HVGO reflux, and the middle section reflux of the preflash column as heat sources respectively to perform gradient preheating on the feedstock oil.

[0042] The embodiment of the present application provides a flue gas waste heat utilization system based on a slurry bed heating furnace to solve the problem that the high-temperature flue gas generated by the combustion of the fresh feed heating furnace in the related technology is difficult to be effectively utilized.

[0043] Please refer to Figure 1 , a flue gas waste heat utilization system based on a slurry bed heating furnace, which includes:

[0044] A heat exchange device, which is installed at the smoke exhaust port of the fresh feed heating furnace 1 of the process unit for processing ethylene tar by using the slurry bed hydrogenation technology; a channel for the high-temperature flue gas to pass through is provided inside the heat exchange device, and a heat collection component 2 is provided in the channel; a water inlet pipe 3 and a water outlet pipe 4 communicating with the internal circulating medium flow channel of the heat collection component 2 are provided on the heat collection component 2, and a temperature sensor is provided in the water outlet pipe 4.

[0045] A first heating plate 5, whose internal chamber is communicated with the water inlet pipe 3 and the water outlet pipe 4 through a first pipeline loop; the first heating plate 5 is sleeved outside the fresh feed buffer tank 6 of the process unit for processing ethylene tar by using the slurry bed hydrogenation technology.

[0046] A second heating plate 7, whose internal chamber is communicated with the water inlet pipe 3 and the water outlet pipe 4 through a second pipeline loop; the second heating plate 7 is sleeved on the intake pipe of the fresh feed heating furnace 1.

[0047] A control device, which is connected to the first pipeline loop, the second pipeline loop, and the temperature sensor, and is used to control the operation of the first pipeline loop and the second pipeline loop according to the detection value of the temperature sensor.

[0048] Through the above settings, the waste heat of the high-temperature flue gas can be recovered, thereby preheating the combustion air, improving the combustion efficiency, reducing fuel consumption, introducing heat into the fresh feed buffer tank 6, forming a double preheating mechanism, which not only increases the feed temperature but also reduces the load of the heating furnace.

[0049] That is, the control device is used to close the first pipeline loop and open the second pipeline loop when the detected value is less than the first threshold, and to open the first pipeline loop and open the second pipeline loop when the detected value is greater than the first threshold.

[0050] When the detected value is less than the first threshold, the heat of the waste heat recovered from the high-temperature flue gas can only heat the combustion air. When it is greater than the first threshold, the recovered heat can simultaneously meet the heating requirements of the fresh feed buffer tank 6 and the heating requirements of the combustion air; through the control device, corresponding control of different scenarios can be achieved.

[0051] In some preferred embodiments, to further illustrate the relationship between the control device and the first pipeline loop and the second pipeline loop, the following description is provided:

[0052] The first pipeline loop includes a first pipeline 8, a second pipeline 9, a first solenoid valve 10, and a first circulation pump 11;

[0053] One end of the first pipeline 8 is connected to the water outlet pipe 4, and the other end is connected to the inlet of the first heating plate 5; a first solenoid valve 10 is provided on the first pipeline 8;

[0054] One end of the second pipeline 9 is connected to the outlet of the first heating plate 5, and the other end is connected to the water inlet pipe 3; a first circulation pump 11 is provided on the second pipeline 9.

[0055] The second pipeline loop includes a third pipeline 12, a fourth pipeline 13, a second solenoid valve 14, and a second circulation pump 15;

[0056] One end of the third pipeline 12 is connected to the water outlet pipe 4, and the other end is connected to the inlet of the second heating plate 7; a second solenoid valve 14 is provided on the third pipeline 12;

[0057] One end of the fourth pipeline 13 is connected to the outlet of the second heating plate 7, and the other end is connected to the water inlet pipe 3; a second circulation pump 15 is provided on the fourth pipeline 13.

[0058] The control device is connected to the first solenoid valve 10, the first circulation pump 11, the second solenoid valve 14, and the second circulation pump 15 through power lines and control lines. The above-mentioned first solenoid valve 10 controls the opening and closing of the first pipeline loop; the second solenoid valve 14 controls the opening and closing of the second pipeline loop; the first circulation pump 11 and the second circulation pump 15 accelerate heat exchange.

[0059] ReferenceFigures 2 - 5 , in some preferred embodiments, the structure of the heat collection assembly 2 is described in detail:

[0060] The heat exchange device further includes a cylinder 16, and the heat collection assembly 2 is installed inside the cylinder 16;

[0061] The heat collection assembly 2 includes a first ring 200 and a second ring 201 which are arranged at intervals up and down. The first ring 200 and the second ring 201 are connected by a plurality of inclined rods 202; the inner cavities of the first ring 200, the second ring 201, and the inclined rods 202 are all interconnected; the outer diameter of the first ring 200 is smaller than the outer diameter of the second ring 201;

[0062] The water inlet pipe 3 is connected to the second ring 201, and the water outlet pipe 4 is connected to the first ring 200.

[0063] Based on the principle of the thermal expansion and contraction of the circulating medium above, when the cold circulating medium enters the second ring 201 from the water inlet pipe 3, it is heated to generate high pressure and moves upward into the first ring 200, and then is discharged from the water outlet pipe 4. This can reduce the load on the first circulation pump 11 and the second circulation pump 15; in addition, for the above structure, the high-temperature flue gas passes through a plurality of inclined rods 202, and it is also convenient for subsequent cleaning after being attached with soot for a long time.

[0064] Furthermore, to fully recover the waste heat of the high-temperature flue gas, the number of cylinders 16 is multiple and they are arranged in series; each cylinder 16 is provided with a heat collection assembly 2, which can extend the contact time between the high-temperature flue gas and the heat exchange device and increase the heat exchange time.

[0065] Furthermore, in the length direction of the inclined rod 202, the cross-sectional area of the inner cavity of the inclined rod 202 gradually decreases from bottom to top. The above further strengthens the principle of thermal expansion and contraction. The narrower the channel is upwards, the more pressure will be increased, which is convenient for the heated medium to spray out from the top.

[0066] The first ring 200, the second ring 201, and the inclined rods 202 are all made of copper material; the outer sides of the first ring 200, the second ring 201, and the inclined rods 202 are all coated with a corrosion-resistant coating, which can increase the service life.

[0067] A plurality of inclined rods 202 are distributed in a circular ring array centered on the center of the second ring 201; a metal partition net is provided between adjacent two inclined rods 202; such a structure can increase the contact area with the high-temperature flue gas and improve the heat exchange efficiency. The metal partition net is Figure 5 the mark a in

[0068] In some preferred embodiments, the first heating plate 5 is cylindrical, and its inner wall fits against the outer side of the fresh feed buffer tank 6, and its outer wall is provided with a heat insulation layer;

[0069] The second heating plate 7 is cylindrical, and its inner wall fits against the outer side of the air inlet pipe of the fresh feed heating furnace 1, and its outer wall is provided with a heat insulation layer. The above structure facilitates heat exchange.

[0070] Advantages of this application:

[0071] First, through the above settings, the waste heat of the high-temperature flue gas can be recovered, thereby preheating the combustion air, improving the combustion efficiency, reducing fuel consumption, introducing heat into the fresh feed buffer tank 6, forming a double preheating mechanism, which not only increases the feed temperature but also reduces the load of the heating furnace.

[0072] That is, the control device is used to close the first pipeline loop and open the second pipeline loop when the detected value is less than the first threshold, and to open the first pipeline loop and open the second pipeline loop when the detected value is greater than the first threshold.

[0073] At the above first threshold, the heat of the waste heat recovered by the high-temperature flue gas can only heat the combustion air. When it is greater than the first threshold, the recovered heat can simultaneously meet the heating requirements of the fresh feed buffer tank 6 and the combustion air; through the control device, corresponding control for different scenarios can be achieved.

[0074] Second, the heat exchange device further includes a cylinder 16, and the heat collection assembly 2 is installed inside the cylinder 16;

[0075] The heat collection assembly 2 includes a first ring 200 and a second ring 201 arranged at intervals up and down. The first ring 200 and the second ring 201 are connected by a plurality of inclined rods 202; the internal cavities of the first ring 200, the second ring 201, and the inclined rods 202 are all interconnected; the outer diameter of the first ring 200 is smaller than the outer diameter of the second ring 201;

[0076] The water inlet pipe 3 is connected to the second ring 201, and the water outlet pipe 4 is connected to the first ring 200.

[0077] Based on the principle of thermal expansion and contraction of the circulating medium, when the cold circulating medium enters the second ring 201 from the water inlet pipe 3, it is heated to generate high pressure and moves upward into the first ring 200, and then is discharged from the water outlet pipe 4. This can reduce the load on the first circulation pump 11 and the second circulation pump 15; in addition, in the above structure, the high-temperature flue gas passes through a plurality of inclined rods 202, and it is also convenient to clean the subsequent soot after a long time of soot attachment.

Claims

1. A flue gas waste heat utilization system based on a slurry bed heating furnace, characterized in that, It includes: A heat exchange device, which is installed at the smoke outlet of the fresh feed heating furnace (1) of the process device that processes ethylene tar by using the slurry bed hydrogenation technology; a channel for high-temperature flue gas to pass through is provided in the heat exchange device, and a heat collection component (2) is provided in the channel; a water inlet pipe (3) and a water outlet pipe (4) that are communicated with the internal circulation medium flow channel of the heat collection component (2) are provided on the heat collection component (2), and a temperature sensor is provided in the water outlet pipe (4). A first heating plate (5), the internal chamber of which is communicated with the water inlet pipe (3) and the water outlet pipe (4) through a first pipeline loop; the first heating plate (5) is sleeved outside the fresh feed buffer tank (6) of the process device that processes ethylene tar by using the slurry bed hydrogenation technology. A second heating plate (7), the internal chamber of which is communicated with the water inlet pipe (3) and the water outlet pipe (4) through a second pipeline loop; the second heating plate (7) is sleeved on the intake pipe of the fresh feed heating furnace (1). A control device, which is connected to the first pipeline loop, the second pipeline loop and the temperature sensor, and is used to control the operation of the first pipeline loop and the second pipeline loop according to the detection value of the temperature sensor.

2. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 1, wherein: The first pipeline loop includes a first pipeline (8), a second pipeline (9), a first solenoid valve (10), and a first circulation pump (11). One end of the first pipeline (8) is connected to the water outlet pipe (4), and the other end is connected to the inlet of the first heating plate (5); the first solenoid valve (10) is arranged on the first pipeline (8). One end of the second pipeline (9) is connected to the outlet of the first heating plate (5), and the other end is connected to the water inlet pipe (3); the first circulation pump (11) is arranged on the second pipeline (9).

3. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 1, wherein: The second pipeline loop includes a third pipeline (12), a fourth pipeline (13), a second solenoid valve (14), and a second circulation pump (15). One end of the third pipeline (12) is connected to the water outlet pipe (4), and the other end is connected to the inlet of the second heating plate (7); the second solenoid valve (14) is arranged on the third pipeline (12). One end of the fourth pipeline (13) is connected to the outlet of the second heating plate (7), and the other end is connected to the water inlet pipe (3); the second circulation pump (15) is arranged on the fourth pipeline (13).

4. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 1, wherein: The heat exchange device further includes a cylinder (16), and the heat collection component (2) is installed in the cylinder (16). The heat collection assembly (2) includes a first ring (200) and a second ring (201) which are arranged at intervals up and down. The first ring (200) and the second ring (201) are connected by a plurality of inclined rods (202). The internal cavities of the first ring (200), the second ring (201), and the inclined rods (202) are all interconnected. The outer diameter of the first ring (200) is smaller than the outer diameter of the second ring (201). The water inlet pipe (3) is connected to the second ring (201), and the water outlet pipe (4) is connected to the first ring (200).

5. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 4, wherein: The number of the cylinders (16) is multiple, and they are arranged in series. Each cylinder (16) is provided with a heat collection assembly (2).

6. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 4, wherein: In the length direction of the inclined rod (202), the cross-sectional area of the internal cavity of the inclined rod (202) gradually decreases from bottom to top.

7. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 4, wherein: The first ring (200), the second ring (201), and the inclined rods (202) are all made of copper material; The outer sides of the first ring (200), the second ring (201), and the inclined rods (202) are all coated with a corrosion-resistant coating.

8. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 4, wherein: The plurality of inclined rods (202) are distributed in a circular ring array centered on the center of the second ring (201); A metal partition net is provided between two adjacent inclined rods (202).

9. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 1, wherein: The first heating plate (5) is cylindrical, and its inner wall is attached to the outer side of the fresh feed buffer tank (6), and its outer wall is provided with a heat insulation layer; The second heating plate (7) is cylindrical, and its inner wall is attached to the outer side of the intake pipe of the fresh feed heating furnace (1), and its outer wall is provided with a heat insulation layer.

10. The flue gas waste heat utilization system based on a slurry bed heating furnace according to claim 1, wherein: The control device is used to close the first pipeline loop when the detected value is less than the first threshold, open the second pipeline loop, and is used to open the first pipeline loop and open the second pipeline loop when the detected value is greater than the first threshold.

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