Combustion type multi-target logistics heating furnace and process for petroleum processing

Abstract

The invention relates to a combustion type multi-target material flow heating furnace and process for petroleum processing, the heating furnace comprises a main heating furnace and an auxiliary heating furnace integrated with the main heating furnace, the main heating furnace is provided with a convection chamber and a radiation chamber which are arranged up and down, and a first material flow enters the radiation chamber to be heated to a first final temperature after being preheated by flue gas of the convection chamber; at least one second stream is heated in the radiation chamber and then enters at least one auxiliary heating furnace for heat compensation to a second final temperature, and flue gas of the auxiliary heating furnace is introduced into the convection chamber for waste heat recovery. The convection chamber is provided with a saturated steam heat exchange pipeline and an air preheating heat exchange chamber, and the upstream of the main heating furnace is integrated with a gas turbine or equipment meeting specific combustion conditions to achieve waste heat gradient utilization. Through integration of the main furnace and the auxiliary furnace and multi-target material flow graded heating, the heating efficiency is improved, the energy consumption is reduced, and the device is particularly suitable for synergistic heating of primary tower bottom oil and atmospheric tower bottom oil in crude oil distillation.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, specifically to a combustion-type multi-objective material heating furnace and process for petroleum processing. Background Technology

[0002] Process heaters are fundamental equipment in process industries, tasked with heating specific process materials to predetermined temperatures to accomplish specific process tasks such as reactions and separations. These heaters typically use fuel gas or fuel oil as fuel, and their energy consumption accounts for over 80% of the total energy consumption in process industries. For example, in crude oil distillation processes in petroleum processing, there are atmospheric furnaces and vacuum furnaces. The atmospheric furnace heats the crude oil bottoms from the crude oil heat exchange network from approximately 225°C to approximately 365°C (vaporization rate 30%–40%) before sending it to the atmospheric tower for distillation of naphtha, diesel oil, and light wax oil. The vacuum furnace heats the atmospheric tower bottoms from approximately 362°C to approximately 386°C–392°C (vaporization rate approximately 25%) before sending it to the vacuum tower for separation of wax oil and residue oil. The heat load of an atmospheric furnace is approximately 1.5–2 times that of a vacuum furnace, and their energy consumption accounts for about 85% of the total energy consumption of the unit. Because the final heating temperature of the target stream is controlled by fuel consumption, each furnace heats only one stream, resulting in a single process unit potentially having multiple process furnaces. For example, in a continuous reforming unit of an oil refinery, excluding the reforming reactor, there are 5 to 7 furnaces such as the stripper bottom reboiler, the depentanizer reboiler, and the thermal oil furnace. This process is complex, involves large investments, requires a large footprint, and generates significant heat. Furthermore, the relatively small heat load of each furnace complicates the integration of the process furnace with the gas turbine and CO2 enrichment. Therefore, developing a combustion-type multi-target stream heating furnace for petroleum processing is an urgent problem that needs to be solved. Summary of the Invention

[0003] To address the technical problems existing in the prior art, the first objective of this invention is to provide a combustion-type multi-target process material heating furnace for petroleum processing, so as to solve the problem that current process heating furnaces only heat one target process material per furnace, resulting in the operation of multiple furnaces. This invention uses a "multi-furnace integration" method to ensure that each process material is heated to the target temperature.

[0004] The second objective of this invention is to employ a combustion-type multi-target material heating furnace process, which concentrates multiple target materials requiring heating into a single main heating furnace, while auxiliary heating furnaces are used to achieve different target final temperatures. By replacing two or more independently operating heating furnaces with an integrated furnace, the process can be simplified, the footprint reduced, investment lowered, and system thermal efficiency improved. Furthermore, it makes the integration of the process furnace and gas turbine, as well as CO2 enrichment, possible, making it suitable for new process construction and the upgrading of existing processes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A combustion-type multi-objective material heating furnace for petroleum processing includes: a main furnace having a convection chamber and a radiation chamber arranged vertically; a first inlet for receiving a first material is formed on a first side of the convection chamber, and a first exhaust port for discharging flue gas is formed on its top; at least one second inlet for receiving a second material is formed on a first side of the radiation chamber, and at least one second outlet for discharging the first material and the second material is formed on its second side; a first air inlet for receiving fuel gas and a second air inlet for receiving combustion air are formed at the bottom of the radiation chamber; and the furnace is integrated with the main furnace. At least one auxiliary heating furnace is provided, wherein a third feed port for receiving the second material from the upstream radiation chamber is formed on a first side, a third discharge port for discharging the second material is formed on a second side, a third air inlet for receiving fuel gas and a fourth air inlet for receiving combustion air are formed at the bottom, and a second exhaust port for discharging flue gas and connecting to the second side of the convection chamber is formed at the top; wherein the first material exchanges heat with the flue gas in the convection chamber to preheat, and then enters the radiation chamber to be heated to a first final temperature, and the second material enters the auxiliary heating furnace for reheating to a second final temperature after being heated in the radiation chamber.

[0007] According to one example, the convection chamber is provided with a first heat exchange pipe that contains saturated steam, which exchanges heat with the flue gas inside the convection chamber.

[0008] As one example, the first discharge port is located above the second discharge port.

[0009] According to one example, the first stream is the bottom oil of the primary distillation column, and the second stream is the bottom oil of the atmospheric distillation column.

[0010] According to one example, the first final temperature is 355-365°C, preferably 355.8°C, and the second final temperature is 385-395°C, preferably 392.6°C.

[0011] According to one example, the top of the convection chamber also has a heat exchange chamber, through which a second heat exchange pipe for containing air is provided, so that the air and the flue gas can exchange heat. The output end of the second heat exchange pipe is divided into two streams, one of which is connected to the second air inlet and the other of which is connected to the fourth air inlet.

[0012] According to one example, when the number of main heating furnaces is one, the number of auxiliary heating furnaces is the total number of target materials minus one, and the auxiliary heating furnaces are used to heat the remaining materials that do not require direct temperature control by the main heating furnaces.

[0013] According to one example, a gas turbine integrated with the main heating furnace is also installed upstream of the main heating furnace. The gas turbine includes a compressor, a combustion chamber, and an expansion turbine connected in sequence. A first heat exchanger is installed on the first feed inlet pipe, and a second heat exchanger is installed on the second feed inlet pipe. The outlet pipe of the expansion turbine is divided into two branches: one branch connects to the second air inlet, and the other branch passes through the second heat exchanger and the first heat exchanger in sequence and connects to the second air inlet. In addition to the gas turbine, other equipment meeting specific combustion conditions can also be configured upstream of the main heating furnace. This equipment must be able to achieve complete combustion of excess air and fuel gas, ensuring that the oxygen content of the exhaust gas reaches more than 18%, thereby providing a stable heat source for the heating furnace and meeting the subsequent waste heat recovery requirements.

[0014] According to one example, a third heater is provided on the pipeline between the second discharge port and the third inlet port, the third heater being used to exchange heat between the second material stream and the outlet pipeline of the expansion turbine.

[0015] The process of the combustion-type multi-objective material heating furnace for petroleum processing described above includes the following steps: The first material is introduced into the convection chamber through a first feed inlet, allowing heat exchange between the first material and the flue gas in the convection chamber to preheat the first material; the flue gas is discharged from the top of the convection chamber through a first exhaust port; the preheated first material is introduced into the radiation chamber, and fuel gas and combustion air are supplied to the burner in the radiation chamber through the first and second air inlets for combustion, heating the first material to a first final temperature before discharge from the first outlet; the second material is introduced into the radiation chamber through a second feed inlet, and heated synchronously with the first material; the heated second material is discharged from the second outlet of the radiation chamber and introduced into the auxiliary heating furnace through a third feed inlet; fuel gas and combustion air are supplied to the burner in the auxiliary heating furnace through the third and fourth air inlets for combustion, reheating the second material to a second final temperature before discharge from the third outlet; the flue gas generated by the auxiliary heating furnace is introduced into the second side of the radiation chamber through the second exhaust port.

[0016] This invention improves the traditional single-furnace structure into an integrated furnace with auxiliary heating furnaces, achieving precise heating of multiple target logistics through the coordinated operation of the main and auxiliary furnaces. When there is one main heating furnace, the number of auxiliary heating furnaces is configured by subtracting one from the total number of target logistics, and their function is to specifically heat the remaining logistics that do not require direct temperature control by the main heating furnace.

[0017] The first logistics stream consists of one strand, and the second logistics stream consists of one or more strands. The number of the first feed inlet, the second feed inlet, the first discharge outlet, and the second discharge outlet is configured according to the number of target logistics streams, thereby achieving efficient and coordinated heating of multiple target logistics streams in petroleum processing.

[0018] The main heating furnace includes a radiant chamber, a convection chamber, and a heat exchange chamber, as well as a supporting blower and induced draft system and a chimney; the auxiliary heating furnace only has a radiant chamber, and its exhaust gas can flow by gravity into the convection chamber of the main heating furnace. Therefore, it does not need to be separately configured with a convection chamber, heat exchange chamber, induced draft system, and chimney, and can share the blower system with the main heating furnace.

[0019] Both the main heating furnace and auxiliary heating furnaces are equipped with control systems, employing either furnace outlet temperature-fuel valve opening control or furnace outlet temperature-furnace temperature-fuel valve opening control. The fuel valve opening of both furnaces is adjusted based on the final temperature of the target stream. Customized control schemes can also be adopted according to the process characteristics of the integrated furnace. The convection chamber of the main heating furnace uses a single or double furnace tube arrangement to heat the first and second streams. The furnace tube design comprehensively considers parameters such as the initial temperature, final temperature, flow rate, heat load, and medium characteristics of both streams. The radiation chamber uses a double furnace tube design to ensure that the first stream is heated to the target final temperature T1. The first stream is the temperature-controlled stream of the main heating furnace. When the main furnace convection chamber uses a single furnace tube design, the first stream enters the convection chamber of the main heating furnace, while other target streams enter the radiation chamber. When the main heating furnace convection chamber uses a multi-furnace tube design, some or all of the target streams enter through the convection chamber, and the remainder enters the radiation chamber. The number of furnace tubes is the same as the number of target streams, used to heat all target streams. Streams not controlled by the main heating furnace exit the main heating furnace and enter their corresponding auxiliary heating furnaces, where the fuel gas flow rate is controlled by their respective target final temperatures.

[0020] After being heated by the main furnace, the second stream, with a temperature below the target value T2, flows by gravity into an auxiliary furnace adjacent to or attached to the main furnace to reduce heat loss. The auxiliary furnace, by controlling fuel consumption, reheats the second stream to its final temperature T2. The resulting flue gas flows by gravity into the bottom of the convection chamber of the main furnace, at the junction of the convection and radiation chambers. The bottom of the main furnace's convection chamber has a high temperature and low density, creating a negative pressure that allows the auxiliary furnace's flue gas to flow in by gravity. Combustion air is supplied by the heat exchange chamber of the main furnace. The main furnace retains its original blower, induced draft fan, and flue gas monitoring system. This multi-furnace design achieves centralized regional combustion and, by optimizing fuel consumption and heat load distribution in the main furnace, enables regional thermal integration and carbon emission reduction.

[0021] The present invention has the following advantages:

[0022] This invention achieves efficient and coordinated heating of multiple target streams in petroleum processing through an integrated architecture of a main heating furnace and an auxiliary heating furnace. It also enables precise temperature control of multiple target streams in stages. The main heating furnace heats the first stream to a first final temperature through stepwise processing of preheating in the convection chamber and heating in the radiation chamber. The second stream is first heated synchronously in the radiation chamber and then enters the auxiliary heating furnace for supplemental heating to the required final temperature, thus meeting the differentiated temperature requirements of different streams. It is especially suitable for the heating process of bottom oil from the primary distillation column and bottom oil from the atmospheric distillation column.

[0023] The flue gas generated by the auxiliary heater is introduced into the convection chamber through the second exhaust port, where it participates in heat exchange with the flue gas from the main heater, reducing waste heat. The saturated steam heat exchange pipeline in the convection chamber and the air preheating system in the top heat exchange chamber further recover heat from the flue gas, achieving cascaded energy utilization. At the same time, the integration of the gas turbine with the main heater and the addition of a third heater allow for full utilization of the exhaust heat from the expansion turbine, reducing the system's dependence on fuel gas.

[0024] The auxiliary heating furnace does not require a separate convection chamber, heat exchange chamber, and chimney system. It can share the blower equipment with the main heating furnace, reducing the space occupied and cost of the equipment. When there is one main heating furnace, the number of auxiliary heating furnaces is configured by subtracting one from the total number of target materials. This can flexibly adapt to the heating needs of multiple materials and improve the equipment's compatibility with different process scenarios. Attached Figure Description

[0025] Figure 1 This is a flow diagram of a comparative example 1 of an existing crude oil distillation unit using an atmospheric furnace and a vacuum furnace. In this diagram, 1 is the atmospheric furnace radiant chamber, 2 is the atmospheric furnace convection chamber, 3 is the heat exchange chamber, 4 is the vacuum furnace radiant chamber, and 5 is the vacuum furnace convection chamber.

[0026] Figure 2 This is a schematic flow diagram of Embodiment 1 of the combustion-type multi-objective material heating furnace for petroleum processing according to the present invention. Wherein, 1 is the main heating furnace, 101 is the radiation chamber, 101a is the second feed inlet, 101b is the first discharge outlet, 101c is the second discharge outlet, 101d is the first air inlet, 101e is the second air inlet, 102 is the convection chamber, 102a is the first feed inlet, 102b is the first exhaust outlet, 3 is the heat exchange chamber, 4 is the auxiliary heating furnace, 401 is the third feed inlet, 402 is the third discharge outlet, 403 is the third air inlet, 404 is the second exhaust outlet, and 405 is the fourth air inlet.

[0027] Figure 3 This is a schematic flow diagram of Embodiment 2 of the combustion-type multi-objective material heating furnace for petroleum processing of the present invention, wherein, Figure 3 The mark and Figure 2The same applies, with the following new markings: 5 for gas turbine, 501 for compressor, 502 for combustion chamber, 503 for expansion turbine, 6 for first heat exchanger, 7 for second heat exchanger, and 8 for waste heat boiler.

[0028] Figure 4 This is a schematic flow diagram of Embodiment 3 of the combustion-type multi-objective material heating furnace for petroleum processing of the present invention, wherein, Figure 4 The mark and Figure 3 Same as above, the new label is: 9 for the third heat exchanger. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] Unless otherwise specified, the connection methods of the equipment, devices, or systems in the following embodiments and comparative examples are all pipeline connections, which are conventional techniques in the art. The placement of metering and control components such as valves, flow meters, thermometers, and pressure gauges on pipelines is also conventional in the art.

[0031] Taking a crude oil distillation unit with a capacity of 3.5 million tons / year in a refinery as an example, the main operating conditions of Comparative Example 1, Example 1, Example 2 and Example 3 are explained.

[0032] Comparative Example 1

[0033] Reference Figure 1 The diagram illustrates the arrangement and operation of the atmospheric and vacuum furnaces in a crude oil distillation unit. The atmospheric and vacuum furnaces are arranged side-by-side, each containing vertically arranged convection and radiation chambers, and sharing a common heat exchange chamber 3 at the top. The specific heating process is as follows:

[0034] The bottom oil of the primary distillation column is pumped and heated to 314.3℃ at a flow rate of 333.7t / h, and then sent to the convection chamber 2 of the atmospheric furnace. After being preheated in the convection chamber 2, it enters the radiation chamber 1 of the atmospheric furnace and is heated to 355.8℃ with a vaporization rate of 30.5%, and then enters the atmospheric tower.

[0035] The bottom oil of the atmospheric pressure tower is pumped to 347.2℃ at a flow rate of 251.2t / h and then sent to the convection chamber 5 of the vacuum furnace. After being preheated in the convection chamber 5, it enters the radiation chamber 4 of the vacuum furnace and is heated to 392.6℃ with a vaporization rate of 49.6%. Then it enters the vacuum tower through the oil transfer line.

[0036] The combined fuel gas consumption of the atmospheric and vacuum furnaces was 4235.6 Nm³. 3 The target stream temperature is regulated by a closed-loop control method based on the outlet temperature and the opening of the fuel gas valve. In addition, two streams of 1.0 MPa saturated steam (totaling 10 t / h) are introduced into the atmospheric pressure furnace convection chamber 2 and the vacuum furnace convection chamber 5, respectively, and after being heated to 420℃ by the flue gas, they are delivered to various steam consumption points; 42000 Nm3 The ambient temperature air is preheated to 255°C by the flue gas and enters the furnace from the bottom of the atmospheric pressure furnace radiation chamber 1 and the bottom of the vacuum furnace radiation chamber 4 to participate in combustion. Finally, the flue gas is cooled to 110°C and then discharged.

[0037] Table 1 shows the composition of the fuel gas.

[0038] Table 1

[0039] No. Components unit numerical values No. Components unit numerical values 1 hydrogen ％v 41.5 9 Butene ％v 0.1 2 methane ％v 40.6 10 Isobutylene ％v 0.1 3 Ethane ％v 13.1 11 transbutene ％v 0.1 4 ethylene ％v 0.0 12 maleic butene ％v 0.0 5 propane ％v 1.3 13 isopentane ％v 0.3 6 propylene ％v 0.9 14 n-Pentane ％v 0.2 7 Isobutane ％v 0.9 total 100.0 8 n-Butane ％v 0.9

[0040] Calculations show that the lower calorific value of this fuel gas is 8183.5 kcal / Nm³. 3 .

[0041] Table 2 shows the heat distribution of the atmospheric furnace and vacuum furnace in Comparative Example 1.

[0042] Table 2

[0043] No. unit heated logistics Initial temperature / ℃ Final temperature / ℃ <![CDATA[Heat load / 10 4 kcal / h]]> 1 Heat exchange chamber 3 room temperature air 25.0 255.0 303.4 2 Atmospheric pressure furnace convection chamber 2 Saturated steam 1 184.1 420.0 62.7 3 Pressure reducing furnace convection chamber 5 Saturated steam 2 184.1 420.0 62.7 4 Atmospheric pressure furnace convection chamber 2 / radiation chamber 1 Target Logistics 1 314.3 355.8 1363.2 5 Pressure reducing furnace convection chamber 5 / radiation chamber 4 Target Logistics 2 347.2 392.6 1349.2 6 total 3141.2

[0044] The calculated oxygen content in the flue gas is 2.92% v, and the total heat supply from the fuel gas is 3473.0 × 10⁻⁶. 4 kcal / h, the effective heat load of the two furnaces is 3141.2×10 4 kcal / h, heating furnace efficiency 90.4%.

[0045] Example 1

[0046] This embodiment takes heating two streams as an example. The material and energy balance parameters are the same as those in Comparative Example 1. The first final temperature of the first stream is T1, and the second final temperature of the second stream is T2. A conventional cylindrical furnace is selected. The first stream is the bottom oil of the primary distillation column, and the second stream is the bottom oil of the atmospheric distillation column.

[0047] The combustion-type multi-objective logistics heating furnace in this embodiment adopts an integrated system of main heating furnace 1 + auxiliary heating furnace 4. It achieves precise temperature control of the two logistics streams through staged heating, and at the same time, it utilizes waste heat recovery from flue gas to improve system energy efficiency.

[0048] Reference Figure 2The main heating furnace 1 has a convection chamber 102 and a radiation chamber 101 arranged vertically, which are interconnected to form a continuous heat exchange space. The first side of the convection chamber 102 has a first feed inlet 102a for receiving a first stream of material, and its top has a first exhaust port 102b for discharging flue gas. A first heat exchange pipe for containing saturated steam is installed inside the convection chamber 102 for heat exchange between the saturated steam and the flue gas. The first side of the radiation chamber 101 has a second feed inlet 101a for receiving a second stream of material, and its second side has a first discharge port 101b and a second discharge port 101c for discharging the first and second streams of material, respectively. The first discharge port 101b is located above the second discharge port 101c to prevent mixing and interference when the two streams are discharged. The bottom of the radiation chamber 101 has a first air inlet 101d for receiving fuel gas and a second air inlet 101e for receiving combustion air. A burner is installed at the bottom for mixing the fuel gas and preheated air for combustion. The main heating furnace 1 is also equipped with a first furnace tube and a second furnace tube. The first furnace tube connects the first feed port 102a and the first discharge port 101b, and the second furnace tube connects the second feed port 101a and the second discharge port 101c. The furnace tube can adopt a disc-shaped or zigzag structure to extend the residence time of the material in the furnace and improve the heat exchange efficiency.

[0049] The auxiliary heater 4 is arranged adjacent to the second side of the main heater 1 and is integrated with the main heater 1. The first side of the auxiliary heater 4 has a third inlet 401 for receiving the second material from the second outlet 101c of the radiation chamber 101, and the second side has a third outlet 402 for discharging the second material. The bottom has a third air inlet 403 for receiving fuel gas and a fourth air inlet 405 for receiving combustion air. A burner is installed at the bottom for mixing the fuel gas with preheated air and then burning it. The top of the auxiliary heater 4 has a second exhaust port 404 for discharging flue gas. This exhaust port is connected to the second side of the convection chamber 102 via a pipeline, allowing the flue gas generated by the auxiliary heater 4 to enter the convection chamber 102, mix with the flue gas, and then be discharged.

[0050] The top of the convection chamber 102 also has a heat exchange chamber 3, through which a second heat exchange pipe for containing air is installed, so that the air and the flue gas can exchange heat. The output end of the second heat exchange pipe is divided into two streams, one of which is connected to the second air inlet 101e and the other of which is connected to the fourth air inlet 405, to provide preheated air for fuel combustion.

[0051] The specific process is as follows:

[0052] The bottom oil of the primary distillation column is pressurized and heated to 314.3°C by a pump at a flow rate of 333.7 t / h. It is then introduced into the convection chamber 102 through the first feed port 102a to exchange heat with the flue gas in the convection chamber 102, thus completing the preheating process. The preheated bottom oil of the primary distillation column enters the radiation chamber 101, where fuel gas is supplied through the first air inlet 101d. The fuel gas is heated to 355.8°C by the burner, with a gasification rate of 30.5%, and finally discharged from the first outlet port 101b and enters the atmospheric distillation column. The flue gas at the top of the convection chamber 102 is discharged through the first exhaust port 102b.

[0053] The bottom oil from the atmospheric distillation column is pressurized and heated to 347.2°C at a flow rate of 251.2 t / h by a pump. It is then introduced into the radiation chamber 101 through the second feed port 101a, where it is heated to 370°C simultaneously with the bottom oil from the primary distillation column, achieving a vaporization rate of 11.5%. Subsequently, it is discharged from the second outlet port 101c of the radiation chamber 101 and introduced into the auxiliary heater 4 through the third feed port 401. Fuel gas and combustion air are supplied to the burner of the auxiliary heater 4 through the third air inlet 403 and the fourth air inlet 405. After combustion and reheating in the burner, the temperature is increased to 392.6°C. Finally, it passes through the oil transfer line with a vaporization rate of 49.6% and is discharged from the third outlet port 402 into the vacuum distillation column.

[0054] The flue gas generated by the auxiliary heating furnace 4 is introduced into the top of the second side of the radiation chamber 101 through the second exhaust port 404 under pressure. After mixing with the flue gas of the main heating furnace 1, it is cooled to 110°C and then discharged. Room temperature air enters the heat exchange chamber 3 and is preheated to 255°C. It is then introduced into the burners of the main heating furnace 1 and the auxiliary heating furnace 4 as combustion air.

[0055] Table 3 shows the heat distribution of the combustion-type multi-objective logistics heating furnace in Example 1.

[0056] Table 3

[0057]

[0058]

[0059] The effective heat load in this embodiment is 3141.2 × 10⁻⁶. 4 The heat output is the same as in Comparative Example 1, with 82.4% of the heat supplied by the main heating furnace 1, while the auxiliary heating furnace 4 only handles the remaining low load. Due to the low load share of the auxiliary heating furnace 4, its floor space and equipment investment are significantly reduced compared to the traditional solution.

[0060] Example 2

[0061] This embodiment, based on Embodiment 1, further integrates with a gas turbine 5 and a waste heat boiler 8. The gas turbine 5 is located upstream of the main heating furnace 1. A first heat exchanger 6 is added to the first feed inlet 102a pipeline, and a second heat exchanger 7 is added to the second feed inlet 101a pipeline, forming a cascade energy utilization system. All other processes not described herein are the same as in Embodiment 1.

[0062] Reference Figure 3 The gas turbine 5 includes a compressor 501, a combustion chamber 502, and an expansion turbine 503 connected in sequence. Its operating process is as follows: 2000 t / h of ambient temperature and pressure air enters the compressor 501, is boosted to 1.20 MPa and 237.3°C through two stages, and then enters the combustion chamber 502; the combustion chamber 502 consumes 35 t / h of fuel gas and produces flue gas at 994.6°C and 1.15 MPa, which enters the expansion turbine 503 and is expanded to 0.10 MPa and 579.7°C through back pressure; part of the turbine power generation is used to drive the compressor 501, and the other part is transported outward.

[0063] The outlet pipeline of the expansion turbine 503 is divided into two streams: one stream is directly connected to the second inlet 101e, and the other stream passes through the second heat exchanger 7 and the first heat exchanger 6 in sequence before connecting to the second inlet 101e. The specific heat exchange process is as follows: the exhaust gas after expansion is divided into two streams. One stream, with a flow rate of 300 t / h, enters the second heat exchanger 7, where it exchanges heat with the bottom oil of the atmospheric distillation column and is cooled to 517.4°C. This preheats the bottom oil of the atmospheric distillation column from 347.2°C to 360.0°C, with a vaporization rate of 3.5%, before entering the radiation chamber 101. The exhaust gas is then cooled to 448.7°C by the first heat exchanger 6 and mixed with the other tail gas stream. At the same time, it preheats the bottom oil of the primary distillation column from 314.3°C to 335.0°C, with a vaporization rate of 6.6%, before being sent to the convection chamber 102.

[0064] Finally, of the high-temperature mixed tail gas with an oxygen content of 14.0% and a temperature of 560.7℃, 24.2t / h is used to supplement the main heating furnace 1 for combustion, and the remaining 2016.9t / h enters the waste heat boiler 8 to produce steam.

[0065] Table 4 shows the heat distribution of the combustion-type multi-objective logistics heating furnace in Example 2.

[0066] Table 4

[0067]

[0068]

[0069] The preheating load before the target material enters the furnace is 1074.3 × 10⁻⁶. 4 kcal / h, the reduction in air preheating due to supplemental combustion is 231.2 × 10 kcal / h. 4kcal / h, the effective heat load of the integrated heating furnace is reduced by 1305.5×10 4 kcal / h. Meanwhile, the heat brought in by the high-temperature exhaust gas maintained a stable oxygen content of 2.92% in the flue gas, reducing fuel gas consumption by 2044.3 Nm³. 3 / h; the steam generation heat load of waste heat boiler 8 is reduced by 1300.0×10 4 kcal / h corresponds to a 19.3t / h reduction in steam production at 3.5MPa.

[0070] Based on the overall heat transfer coefficient of 120 kcal / (h·m 2 Based on calculations (°C), the parameters of the two additional heat exchangers in Example 2 are as follows: the average heat transfer temperature difference of the second heat exchanger 7 is 193.2°C, and the heat transfer area is 222.2 m². 2 The first heat exchanger 6 has an average heat transfer temperature difference of 155.7℃ and a heat transfer area of ​​299.2m². 2 .

[0071] Based on a fuel gas unit price of 4.36 yuan / Nm 3 With a unit price of 300 yuan / t for 3.5MPa steam, and considering the 10-year investment depreciation of the new heat exchanger and 8,000 hours of operation per year, Example 2 increases efficiency by 26.002 million yuan per year compared to Comparative Example 1. At the same time, due to the reduction in fuel consumption of the process heating furnace, CO2 emissions can be reduced by 27,136 tons per year.

[0072] Example 3

[0073] Based on Example 2, this embodiment has a third heater installed on the pipeline between the second discharge port 101c and the third inlet port 401. The third heater is used to exchange heat between the second material after the radiation chamber 101 is heated and the outlet pipeline of the expansion turbine 503. The rest of the process is the same as in Example 2.

[0074] Reference Figure 4 The second stream is heated to 380.0°C in the radiation chamber 101, with a gasification rate of 14.2%, and then discharged from the second outlet 101c and enters the third heat exchanger 9, where it exchanges heat with the exhaust gas after work to 385.0°C, with a gasification rate of 19.9%. Subsequently, it is introduced into the auxiliary combustion chamber 502 through the third inlet 401, where it is further heated to 392.6°C, and finally enters the pressure reducing tower through the oil transfer line with a gasification rate of 49.6%.

[0075] The heat exchange path for the exhaust gas is as follows: it is first cooled to 560.7℃, then sequentially exchanged heat with the second and first streams before entering the furnace, and cooled to 429.1℃. Afterward, it is mixed with another exhaust gas stream to form a high-temperature mixed exhaust gas at 557.9℃. Of this mixed exhaust gas, 20.7 t / h is used to supplement the combustion of the main heating furnace 1, and the remaining 2014.3 t / h enters the waste heat boiler 8 to produce steam.

[0076] Table 5 shows the heat distribution of the combustion-type multi-objective logistics heating furnace in Example 3.

[0077] Table 5

[0078] No. heat exchange equipment heated logistics Initial temperature / ℃ Final temperature / ℃ <![CDATA[Heat load / 10 4 kcal / h]]> 1 Heat exchange chamber 3 room temperature air 25.0 255.0 72.2 2 Convection chamber 102 saturated steam 184.1 420.0 125.4 3 First heat exchanger 6 First Logistics 314.3 335.0 559.0 4 Second heat exchanger 7 Second Logistics 346.6 360.0 515.3 5 Convection chamber 102, radiation chamber 101 First Logistics 335.0 355.8 804.2 6 Radiation Room 101 Second Logistics 360.0 380.0 498.7 7 Third heat exchanger 9 Second Logistics 380.0 385.0 158.0 8 Auxiliary heating furnace 4 Second Logistics 380.0 392.6 177.2 total 2910.0

[0079] Example 3 reduces the effective heat load of the integrated heating furnace by 1463.5 × 10⁻⁶ by further utilizing the waste gas heat. 4 kcal / h, fuel gas consumption reduced by 2214.5 Nm 3 / h; simultaneously, the steam generation heat load of waste heat boiler 8 decreased by 1430.0×10 4 kcal / h corresponds to a 21.1 t / h reduction in steam production at 3.5 MPa.

[0080] Based on the overall heat transfer coefficient of 120 kcal / (h·m 2 Based on calculations (·℃), the average heat transfer temperature difference of the second heat exchanger 7 in Example 3 is 173.9℃, and the heat transfer area is 247.0m². 2 The average heat transfer temperature difference of the first heat exchanger 6 is 135.8℃, and the heat transfer area is 343.0 m². 2 .

[0081] Based on a fuel gas unit price of 4.36 yuan / Nm 3 With a steam unit price of 300 yuan / t at 3.5MPa, combined with the 10-year investment depreciation of the newly added third heat exchanger 9 and 8000 hours of annual operation, Example 3 increases efficiency by 27.659 million yuan per year compared to Comparative Example 1, and reduces CO2 emissions by 26,828 tons per year due to reduced fuel gas consumption.

[0082] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. The embodiments described in this disclosure are intended as non-limiting examples, and other embodiments may take various and alternative forms. Furthermore, the drawings are not necessarily to scale and may present simplified expressions of various features of the present disclosure, including, for example, specific dimensions, orientations, positions, and shapes. Details associated with such features will be determined in part by the intended application and usage environment of the described embodiments.

[0083] The detailed description and accompanying drawings are supporting and descriptive of this teaching, but the scope of this teaching is defined only by the claims. While the best mode and some other embodiments for carrying out this teaching have been described in detail, various alternative designs and embodiments exist for practicing the teaching as defined in the appended claims. Furthermore, this disclosure expressly includes combinations and sub-combinations of the elements and features set forth above and below.

Claims

1. A combustion-type multi-objective material heating furnace for petroleum processing, characterized in that, include: The main heating furnace has a convection chamber and a radiation chamber arranged vertically. The first side of the convection chamber has a first feed inlet for receiving the first material, and the top of the chamber has a first exhaust outlet for discharging flue gas. The first side of the radiation chamber has at least one second inlet for receiving the second material, and the second side has a first outlet for discharging the first material and at least one second outlet for discharging the second material. The bottom of the radiation chamber has a first air inlet for receiving fuel gas and a second air inlet for receiving combustion air. At least one auxiliary heating furnace is integrated with the main heating furnace. The auxiliary heating furnace has a third feed port on its first side for receiving the second material from the upstream radiation chamber, a third discharge port on its second side for discharging the second material, a third air inlet for receiving fuel gas and a fourth air inlet for receiving combustion air at its bottom, and a second exhaust port for discharging flue gas and communicating with the second side of the convection chamber at its top. The first material is preheated by exchanging heat with the flue gas in the convection chamber, and then enters the radiation chamber to be heated to a first final temperature. The second material is heated in the radiation chamber and then enters the auxiliary heating furnace to be reheated to a second final temperature.

2. The combustion-type multi-objective logistics heating furnace according to claim 1, characterized in that, The convection chamber is provided with a first heat exchange pipe that contains saturated steam, and the saturated steam exchanges heat with the flue gas inside the convection chamber.

3. The combustion-type multi-objective logistics heating furnace according to claim 1, characterized in that, The first discharge port is located above the second discharge port.

4. The combustion-type multi-objective logistics heating furnace according to claim 1, characterized in that, The first stream is the bottom oil of the primary distillation column, and the second stream is the bottom oil of the atmospheric distillation column.

5. The combustion-type multi-objective logistics heating furnace according to claim 1, characterized in that, The first final temperature is 355-365℃, and the second final temperature is 385-395℃.

6. The combustion-type multi-objective logistics heating furnace according to claim 1, characterized in that, The top of the convection chamber also has a heat exchange chamber, through which a second heat exchange pipe for containing air is installed, allowing the air to exchange heat with the flue gas. The output end of the second heat exchange pipe is divided into two streams, one connected to the second air inlet and the other connected to the fourth air inlet.

7. The combustion-type multi-objective logistics heating furnace according to claim 1, characterized in that, When there is one main heating furnace, the number of auxiliary heating furnaces is one less than the total number of target materials. The auxiliary heating furnaces are used to heat the remaining materials that do not require direct temperature control by the main heating furnace.

8. The combustion-type multi-objective logistics heating furnace according to claim 1, characterized in that, An integrated gas turbine is also installed upstream of the main heating furnace. The gas turbine includes a compressor, a combustion chamber, and an expansion turbine connected in sequence. A first heat exchanger is installed on the first feed inlet pipe, and a second heat exchanger is installed on the second feed inlet pipe. The outlet pipe of the expansion turbine is divided into two branches, one of which is connected to the second air inlet, and the other branch passes through the second heat exchanger and the first heat exchanger in sequence and is connected to the second air inlet.

9. The combustion-type multi-objective logistics heating furnace according to claim 8, characterized in that, A third heater is installed on the pipeline between the second discharge port and the third inlet port. The third heater is used to exchange heat between the second material and the outlet pipeline of the expansion turbine.

10. The process for a combustion-type multi-objective material heating furnace for petroleum processing according to any one of claims 1-9, characterized in that, Includes the following steps: The first material is introduced into the convection chamber through the first feed port of the convection chamber, so that the first material exchanges heat with the flue gas in the convection chamber to preheat the first material, and the flue gas is discharged from the top of the convection chamber through the first exhaust port. The preheated first material is introduced into the radiant chamber, and fuel gas and combustion air are supplied to the burner of the radiant chamber through the first air inlet and the second air inlet for combustion. The first material is heated to the first final temperature and then discharged from the first outlet. The second material is introduced into the radiation chamber through the second inlet of the radiation chamber and heated synchronously with the first material; The heated second material is discharged from the second outlet of the radiation chamber and introduced into the auxiliary heating furnace through the third inlet; Fuel gas and combustion air are supplied to the burner of the auxiliary heating furnace through the third and fourth air inlets and burned to reheat the second material to the second final temperature before being discharged from the third outlet. The flue gas generated by the auxiliary heating furnace is introduced into the second side of the radiation chamber through the second exhaust port.

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