An electric cracking furnace system and an operation method of the electric cracking furnace system

Abstract

The present invention provides an electric cracking furnace system and an operation method thereof. The electric cracking furnace system includes an electric cracking furnace, a displacement gas module, an energy storage module, and a flare module; the electric cracking furnace includes a displacement gas chamber and an electric heating cracking chamber disposed inside the displacement gas chamber; the displacement gas outlet of the displacement gas module is connected to the displacement gas inlet of the displacement gas chamber of the electric cracking furnace, and the displacement gas component detection inlet of the displacement gas module is connected to the displacement gas outlet of the displacement gas chamber of the electric cracking furnace; the feed inlet of the flare module is connected to the electric heating cracking chamber of the electric cracking furnace, and the flare module is used to receive the material in the electric heating cracking chamber when an abnormal condition occurs in the electric cracking furnace; the high-temperature medium outlet of the energy storage module is connected to the electric heating cracking chamber of the electric cracking furnace, and the energy storage module is used to provide a high-temperature medium to the electric heating cracking chamber when the flare module receives the material in the electric heating cracking chamber. The electric cracking furnace system ensures the long-term stable operation of the electric cracking furnace through the displacement gas module, the energy storage module, and the flare module.

Description

Technical Field

[0001] The present invention belongs to the technical field of steam cracking process, and relates to an electric cracking furnace system applicable to the steam cracking process and a method for operating the electric cracking furnace system. Background Art

[0002] The carbon emissions caused by steam cracking account for a large proportion of the carbon emissions in the chemical industry.

[0003] Traditional steam cracking furnaces generate high-temperature flue gas by mixing combustion gas with air, and the high-temperature flue gas is used to preheat raw materials, generate ultra-high-pressure steam, and supply heat for the cracking reaction. The structure of traditional steam cracking furnaces is as Figure 1As shown in the figure, it includes a radiant furnace A, a first-stage raw material preheater B, an economizer section C, a second-stage raw material preheater D, a first-stage raw material and dilution steam mixer E, a dilution steam preheater F, a first-stage high-pressure steam superheater G, a second-stage high-pressure steam superheater H, a second-stage raw material and dilution steam mixer I, a desuperheater J, a first quench cooler K, a second quench cooler L, a raw material / dilution steam mixer M, a steam drum N, and an air preheater R. During the steam cracking process using a traditional steam cracking furnace, the air stream 422 and the low-pressure steam or emergency process water stream 425 exchange heat in the air preheater R to obtain the preheated air stream 423 and the low-pressure steam or emergency process water stream 426 after hot air. The preheated air stream 423 and the fuel gas stream 424 enter the radiant furnace A for combustion to generate high-temperature flue gas. The high-temperature flue gas provides heat energy to the second-stage raw material and dilution steam mixer I, the second-stage high-pressure steam superheater H, the first-stage high-pressure steam superheater G, the dilution steam preheater F, the first-stage raw material and dilution steam mixer E, the second-stage raw material preheater D, the economizer section C, and the first-stage raw material preheater B in sequence; the raw material or decoking air and the dilution steam stream 41 enter the first-stage raw material preheater B for preheating to obtain the raw material stream 42 after the first-stage raw material preheater. The raw material stream 42 after the first-stage raw material preheater enters the second-stage raw material preheater D for preheating to obtain the raw material stream 43 after the second-stage raw material preheater. The total dilution steam stream 46 enters the dilution steam preheater F for preheating to obtain the superheated dilution steam stream 47. The raw material stream 43 after the second-stage raw material preheater and the superheated dilution steam stream 47 enter the raw material / dilution steam mixer M for mixing to obtain the raw material / dilution mixed stream 44. The raw material / dilution mixed stream 44 enters the first-stage raw material and dilution steam mixer E for mixing evenly to obtain the stream 45 after the first-stage raw material and dilution steam mixer. The stream 45 after the first-stage raw material and dilution steam mixer enters the second-stage raw material and dilution steam mixer I for mixing evenly to obtain the stream 48 after the second-stage raw material and dilution steam mixer. The stream 48 after the second-stage raw material and dilution steam mixer enters the radiant furnace A, and in the radiant furnace A, the stream 48 after the second-stage raw material and dilution steam mixer undergoes a cracking reaction using the heat energy provided by the high-temperature flue gas to obtain the cracked gas stream 49. The cracked gas stream 49 enters the first quench cooler K for cooling to obtain the cracked gas stream 410 after the first quench cooler. The cracked gas stream 10 after the first quench cooler enters the second quench cooler for cooling to obtain the cracked gas stream 411 after the second quench cooler; among them, the boiler feed water stream 413 enters the economizer section C and then obtains the preheated boiler feed water stream 414. The preheated boiler feed water stream 414 is sent to the second quench cooler L for further preheating to obtain the boiler feed water stream 415. The ultra-high pressure steam stream 416 generated by the steam drum N is sent to the first-stage high-pressure steam superheater G to obtain the ultra-high pressure steam stream 418. In the desuperheater J, the ultra-high pressure steam stream 418 is mixed with the boiler feed water stream 417 to obtain the ultra-high pressure steam stream 419. The ultra-high pressure steam stream 419 is sent to the second-stage high-pressure steam superheater H to obtain the ultra-high pressure steam stream 420 and sent out of the battery limit.Traditional cracking furnaces use fuel gas (methane hydrogen, liquefied gas, natural gas, etc.) mixed with air for combustion to generate high-temperature flue gas as the heat source for the cracking reaction, releasing a large amount of carbon dioxide, which goes against the current carbon reduction requirements.

[0004] In order to meet the carbon reduction requirements of the petrochemical industry, it is necessary to develop the core technology of electric cracking furnaces. Moreover, developing the core technology of electric cracking furnaces can effectively promote scientific and technological innovation and further open up and expand the refining and ethylene industrial chains. At present, technologies for electric cracking furnaces for steam cracking have been successively proposed. However, the electric cracking furnace systems currently emerging generally have poor long-term stable operation performance and cannot meet the requirements of industrial steam cracking.

[0005] In view of this, there is still a need to study an electric cracking furnace system suitable for the steam cracking process and an operation method for the electric cracking furnace system that can operate stably for a long period. Summary of the Invention

[0006] The purpose of the present invention is to provide an electric cracking furnace system suitable for the steam cracking process and an operation method for the electric cracking furnace system that can operate stably for a long period. To achieve the above purpose, the present invention provides the following two aspects of technical solutions.

[0007] In the first aspect, the present invention provides an electric cracking furnace system, which includes:

[0008] an electric cracking furnace, a purge gas module, an energy storage module, and a flare module;

[0009] The electric cracking furnace includes a purge gas chamber and an electrically heated cracking chamber, where the electrically heated cracking chamber is disposed inside the purge gas chamber (i.e., the purge gas chamber is sleeved outside the electrically heated cracking chamber);

[0010] The purge gas outlet of the purge gas module is connected to the purge gas inlet of the purge gas chamber of the electric cracking furnace, and the purge gas component detection inlet of the purge gas module is connected to the purge gas outlet of the purge gas chamber of the electric cracking furnace; the purge gas module is used to provide purge gas for the purge gas chamber of the electric cracking furnace and detect the components of the purge gas discharged from the purge gas chamber of the electric cracking furnace; 027 - 59183557 Zhu

[0011] The feed inlet of the flare module is connected to the electrically heated cracking chamber of the electric cracking furnace, and the flare module is used to receive the raw materials and product gas in the electrically heated cracking chamber when abnormal conditions occur in the electric cracking furnace (such as power failure of the electric cracking furnace, leakage of the electrically heated cracking chamber, etc.);

[0012] The high-temperature medium outlet of the energy storage module is connected to the electrically heated cracking chamber of the electric cracking furnace, and the energy storage module is used to provide high-temperature medium to the electrically heated cracking chamber when the flare module receives the raw materials and product gas in the electrically heated cracking chamber.

[0013] The electric cracking furnace system provided by the present invention uses a displacement gas module to detect the displacement gas discharged from the displacement gas chamber of the electric cracking furnace, so as to detect whether there is a leakage in the electric heating cracking chamber of the electric cracking furnace. If it is detected that the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace has changed, it is considered that there is a leakage in the electric heating cracking chamber of the electric cracking furnace. When an abnormal condition occurs in the electric cracking furnace (including leakage of the electric heating cracking chamber, etc.), the heating function of the electric heating cracking chamber of the electric cracking furnace is shut down, and the raw materials and product gases remaining in the electric heating cracking chamber of the electric cracking furnace are transported to the torch module, and at the same time, the high-temperature medium in the energy storage module is transported to the electric heating cracking chamber of the electric cracking furnace. When the electric cracking furnace is shut down normally, the raw material quantity gradually decreases, steam is kept flowing in, and finally it is switched to a hot standby state with only steam flowing in, and then the temperature is slowly decreased until it finally drops to a safe temperature and then the furnace is shut down, and the torch module and the energy storage module are not activated.

[0014] The steam cracking reaction is a strongly endothermic reaction, and the fluid temperature can reach above 800 °C during the cracking reaction process. In a traditional steam cracking furnace, a large amount of high-temperature flue gas is generated by burning fuel gas to provide the required heat for the cracking chamber in the radiant furnace chamber. Subsequently, the flue gas enters the convection section and finally is discharged into the atmosphere through the chimney. The cracking reaction process can monitor the entire radiant furnace chamber through the sight hole. Due to the special heating method of the electric cracking furnace, it is impossible to directly monitor the working state of the electric heating cracking chamber. Once the electric heating cracking chamber leaks, the electric cracking furnace is prone to accidents such as combustion and explosion. In order to ensure the long-term stable operation of the electric cracking furnace, a displacement gas module is added to play a role in protecting and monitoring the electric heating cracking chamber.

[0015] The torch module receives the raw materials and product gases in the electric heating cracking chamber under abnormal conditions such as power failure or leakage of the electric heating cracking chamber in the electric cracking furnace, plays a protective role in the electric cracking furnace system, and ensures the long-term stable operation of the electric cracking furnace.

[0016] When the raw materials and product gases in the electric heating cracking chamber of the electric cracking furnace are discharged into the torch module, the temperature of the electric heating cracking chamber will drop rapidly. Too fast a temperature drop will cause the electric heating cracking chamber to deform or even break. The energy storage module provides a high-temperature medium to the electric heating cracking chamber to control the cooling rate of the electric heating cracking chamber and protect the electric heating cracking chamber under abnormal conditions.

[0017] According to the preferred embodiment provided in the first aspect, the electric cracking furnace system further includes a cooling module. The electric cracking furnace is further provided with an electric heating element cooling pipe. The cooling medium outlet of the cooling module is connected to the cooling medium inlet of the electric heating element cooling pipe of the electric cracking furnace;

[0018] Furthermore, the cooling medium recovery port of the cooling module is connected to the cooling medium outlet of the electric heating element cooling pipe of the electric cracking furnace;

[0019] Further, the cooling medium includes one of air, water, alcohol, Freon, ammonia, carbon dioxide, liquid metal, liquid helium, and liquid nitrogen;

[0020] In a traditional steam cracking furnace, after the high-temperature flue gas generated by the combustion of fuel gas provides heat for the cracking reaction, the flue gas enters the convection section for heat exchange and temperature reduction to preheat the raw material or utility engineering logistics, and finally is discharged into the atmosphere, and the waste heat is effectively removed; in an electric cracking furnace, while the electric heating element heats the electric heating cracking chamber, it will generate waste heat by itself, and the accumulation of waste heat will cause the temperature of the electric heating element to rise, deviating from the original working temperature. The cooling module removes the waste heat generated by the electric heating element through the cooling medium to ensure the stable operation of the electric heating element.

[0021] According to the preferred embodiment provided in the first aspect, the electric cracking furnace system further includes a preheater, a mixer, a superheater, a quenching module, and a steam module;

[0022] The feed inlet of the preheater is used for feeding the cracking raw material, the discharge outlet of the preheater is connected to the feed inlet of the mixer, the steam outlet of the steam module is connected to the feed inlet of the mixer, the discharge outlet of the mixer is connected to the feed inlet of the superheater, the discharge outlet of the superheater is connected to the feed inlet of the electric heating cracking chamber of the electric cracking furnace, and the feed inlet of the quenching module is connected to the discharge outlet of the electric heating cracking chamber of the electric cracking furnace;

[0023] The preheater is used to preheat the cracking raw material; the mixer is used to mix the cracking raw material and steam; the superheater is used to heat the mixture of the cracking raw material and steam; the quenching module is used to quickly reduce the temperature of the cracked gas, maximize the ethylene yield in the cracked gas, and recover the waste heat in the cracked gas;

[0024] Further, the electric cracking furnace system further includes a decoking air module and a blowdown module; the discharge outlet of the decoking air module is connected to the feed inlet of the preheater, the steam outlet of the steam module is connected to the connecting pipeline between the discharge outlet of the decoking air module and the feed inlet of the preheater, and the blowdown module is connected to the blowdown port of the electric heating cracking chamber of the electric cracking furnace;

[0025] Further, the steam module includes a dilution steam sub-module and a medium-pressure steam sub-module;

[0026] The dilution steam sub-module is used to provide steam at 120 - 300 °C and 0.5 - 2 MPa. The steam provided by the dilution steam sub-module can be used to dilute the cracking raw material (thereby reducing the hydrocarbon partial pressure to increase the yield and reducing coking in the electric cracking furnace), purge the electric cracking furnace system, and cooperate with the decoking air to carry out decoking of the electric cracking furnace system;

[0027] The medium-pressure steam submodule is used to provide steam at 300-450℃ and 1.0-5.0MPa. The steam provided by the medium-pressure steam submodule can be used to purge the electric cracking furnace system and to clean the electric cracking furnace system in conjunction with the decoking air.

[0028] Furthermore, the quenching module can reduce the cracking gas temperature to 150-550℃ according to the needs and the type of cracking gas;

[0029] Furthermore, the steam outlet of the steam module is connected to the cooling medium inlet of the quench module, thereby utilizing the steam of the steam module to cool the cracked gas in the quench module;

[0030] Furthermore, the cooling medium inlet of the quenching module is connected to the water outlet of the process water system, so that the process water of the process water system is used to cool the cracked gas in the quenching module;

[0031] Furthermore, the electric cracking furnace system also includes a waste boiler module, and the cooling medium inlet and cooling medium outlet of the quenching module are both connected to the boiler feed water pipeline of the waste boiler module, so that the boiler feed water and the cracked gas are heat exchanged in the quenching module, the boiler feed water is used to cool the cracked gas, and the cracked gas is used to heat the boiler feed water; further, the waste boiler module can generate steam at 350-450°C; further, the electric cracking furnace system also includes a steam gradient utilization module, the steam inlet of the steam gradient utilization module is connected to the steam outlet of the waste boiler module, and the steam outlet of the steam gradient utilization module is connected to the steam supply inlet of the steam module and / or the steam inlet of the steam heating pipeline of the energy storage module; in a specific embodiment, the steam outlet of the steam gradient utilization module is respectively connected to the steam supply inlet of the dilution steam submodule of the steam module, the steam supply inlet of the medium-pressure steam submodule of the steam module, and the steam inlet of the steam heating pipeline of the energy storage module;

[0032] In the above preferred embodiment, the waste boiler module is provided to utilize the heat of the cracked gas in the quenching module to generate steam, thereby improving energy utilization and reducing the energy consumption of the electric cracking furnace system; the steam cascade utilization module is provided to utilize the steam generated by the waste boiler module to generate steam required by the steam module (e.g., dilution steam, medium-pressure steam) and to deliver it to the steam module and / or to generate steam required by the energy storage module to heat the cooling medium and to deliver it to the energy storage module, thereby achieving internal circulation of the entire steam and reducing the increase in energy consumption caused by external steam introduction;

[0033] Furthermore, the preheater is an electric preheater; furthermore, the heating range of the electric preheater is 25-300°C;

[0034] Furthermore, the superheater is an electric superheater; furthermore, the heating range of the electric superheater is 150-650°C;

[0035] Compared with traditional steam cracking furnaces, the electric cracking furnace lacks high-temperature flue gas. The waste heat of the high-temperature flue gas in traditional steam cracking furnaces is an important heat source for preheating raw materials. The electric cracking furnace system lacking high-temperature flue gas can heat the raw materials by adding preheaters and superheaters with heating functions. Electric heating preheaters and superheaters can be selected to heat the raw materials to ensure more uniform heat distribution and higher thermal stability, improve thermal efficiency, and reduce energy consumption;

[0036] Further, the mixing form adopted by the mixer can be but is not limited to Venturi type, nozzle type, vortex type, special-shaped pipeline, etc.;

[0037] Further, the electric cracking furnace system further includes a raw material distribution module. The discharge port of the raw material distribution module is connected to the feed port of the preheater. The raw material distribution module is used to provide cracking raw materials to the preheater according to requirements; Further, the cracking raw materials provided by the raw material distribution module include but are not limited to at least one of crude oil, heavy oil, diesel, liquefied gas, butane, and propane;

[0038] Further, the electric cracking furnace system further includes a post-separation module. The feed port of the post-separation module is connected to the discharge port of the quenching module; The post-separation module is used to separate and purify the cracked gas.

[0039] According to the preferred implementation provided in the first aspect, the heating method of the electric heating cracking chamber of the electric cracking furnace includes but is not limited to at least one of electromagnetic heating, resistance heating, plasma heating, and kinetic energy conversion heating, etc.

[0040] According to the preferred implementation provided in the first aspect, the replacement gas provided by the replacement gas module for the replacement gas chamber of the electric cracking furnace includes but is not limited to at least one of nitrogen, argon, and helium.

[0041] According to the preferred implementation provided in the first aspect, the high-temperature medium provided by the energy storage module includes but is not limited to at least one of steam, nitrogen, and helium.

[0042] According to the preferred implementation provided in the first aspect, the temperature of the high-temperature medium provided by the energy storage module is 300-900°C.

[0043] According to the preferred implementation provided in the first aspect, the energy storage module can heat the high-temperature medium by at least one of electricity, fuel gas, and high-temperature steam.

[0044] In the second aspect, the present invention provides a method for operating an electric cracking furnace system, which is carried out using the electric cracking furnace system provided in the first aspect of the present invention. The method includes:

[0045] During the steam cracking process using an electric cracking furnace system, a displacement gas module is used to continuously supply displacement gas to the displacement gas chamber of the electric cracking furnace and to continuously monitor the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace; if it is monitored that the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace is the same as the composition of the displacement gas supplied to the displacement gas chamber of the electric cracking furnace, then there is no leakage in the electric heating cracking chamber of the electric cracking furnace; if it is monitored that the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace is different from the composition of the displacement gas supplied to the displacement gas chamber of the electric cracking furnace, then there is a leakage in the electric heating cracking chamber of the electric cracking furnace, and the electric cracking furnace system is in an abnormal operating condition;

[0046] During the steam cracking process using an electric cracking furnace system, when the electric cracking furnace system is in an abnormal operating condition, the supply of materials to the electric cracking furnace is stopped, and the heating function of the electric heating cracking chamber of the electric cracking furnace is stopped. The materials in the electric heating cracking chamber of the electric cracking furnace are discharged into a flare module, and at the same time, an energy storage module is used to inject a high-temperature medium into the electric heating cracking chamber of the electric cracking furnace; wherein, the temperature of the high-temperature medium is 300 - 900 °C.

[0047] According to the preferred embodiment provided in the second aspect, wherein the high-temperature medium includes, but is not limited to, at least one of steam, nitrogen, and helium.

[0048] According to the preferred embodiment provided in the second aspect, wherein the displacement gas includes, but is not limited to, at least one of nitrogen, argon, and helium.

[0049] According to the preferred embodiment provided in the second aspect, wherein the operating method of the electric cracking furnace system further includes:

[0050] During the steam cracking process using an electric cracking furnace system, the cracked raw material logistics is preheated and heated up using a preheater to obtain preheated cracked raw material logistics. The preheated cracked raw material logistics and the first steam logistics provided by a steam module are mixed using a mixer to obtain a cracked raw material and steam mixed logistics. The cracked raw material and steam mixed logistics is preheated and heated up using a superheater to obtain a to-be-cracked logistics. The to-be-cracked logistics enters the electric heating cracking gas chamber of the electric cracking furnace to undergo a steam cracking reaction to obtain a cracked gas logistics. The cracked gas logistics is quenched and cooled down using a quench module to obtain a cooled cracked gas logistics;

[0051] Furthermore, the operating method of the electric cracking furnace system further includes: during the steam cracking process using an electric cracking furnace system, the cooled cracked gas logistics is separated and purified using a post-separation module.

[0052] Further, during the steam cracking process using the electro-cracking furnace system, the first steam stream includes steam at 120 - 300°C and 0.5 - 2 MPa provided by the dilution steam sub-module in the steam module and / or steam at 200 - 450°C and 1.0 - 5.0 MPa provided by the medium-pressure steam sub-module in the steam module;

[0053] Further, the operation method of the electro-cracking furnace system further includes coking removal treatment for the electro-cracking furnace system: the coking removal air stream is mixed with the second steam stream provided by the steam module, and then sequentially preheated and heated up by a preheater, mixed by a mixer, and reheated and heated up again by a superheater to obtain a coking removal stream. The coking removal stream enters the electro-heated cracking gas chamber of the electro-cracking furnace for coking combustion reaction, and the products after the coking combustion reaction are discharged into the sewage discharge module; Further, during the coking removal treatment of the electro-cracking furnace system, the second steam stream includes steam at 120 - 300°C and 0.5 - 2 MPa provided by the dilution steam sub-module in the steam module and / or steam at 200 - 450°C and 1.0 - 5.0 MPa provided by the medium-pressure steam sub-module in the steam module;

[0054] Further, the operation method of the electro-cracking furnace system further includes purging treatment for the electro-cracking furnace system: the third steam stream provided by the steam module purges the preheater, mixer, superheater, and the electro-heated cracking gas chamber of the electro-cracking furnace in sequence, and the purged stream is discharged into the sewage discharge module;

[0055] Further, the operation method of the electro-cracking furnace system further includes using the cooling module to cool down the heating elements in the electro-heated cracking chamber of the electro-cracking furnace through a cooling medium; Further, the cooling medium includes but is not limited to one of air, water, alcohol, freon, ammonia, carbon dioxide, liquid metal, liquid helium, and liquid nitrogen;

[0056] Further, the operation method of the electro-cracking furnace system further includes: during the steam cracking process using the electro-cracking furnace system, using the fourth steam stream provided by the steam module as the cooling medium of the quench module to rapidly cool down the cracked gas stream entering the quench module; Further, the fourth steam stream includes steam at 120 - 300°C and 0.5 - 2 MPa provided by the dilution steam sub-module in the steam module and / or steam at 200 - 450°C and 1.0 - 5.0 MPa provided by the medium-pressure steam sub-module in the steam module;

[0057] Further, the operation method of the electro-cracking furnace system further includes: during the steam cracking process using the electro-cracking furnace system, using the process water provided by the process water system as the cooling medium of the quench module to rapidly cool down the cracked gas stream entering the quench module;

[0058] Further, the operation method of the electric cracking furnace system further includes: during the steam cracking process using the electric cracking furnace system, using the boiler feed water of the waste heat boiler module as the cooling medium of the quench module to rapidly cool the cracked gas stream entering the quench module, and re-transporting the boiler feed water after completing the rapid cooling of the cracked gas stream back to the waste heat boiler module; furthermore, the operation method of the electric cracking furnace system further includes: during the steam cracking process using the electric cracking furnace system, transporting the steam generated by the waste heat boiler module to the steam cascade utilization module, using the steam cascade utilization module to prepare the steam required by the steam generation module to supply the steam generation module or using the steam cascade utilization module to prepare the steam for heating the high-temperature medium of the energy storage module and entering the energy storage module for heating the high-temperature medium; in a specific embodiment, the operation method of the electric cracking furnace system further includes: during the steam cracking process using the electric cracking furnace system, transporting the steam generated by the waste heat boiler module to the steam cascade utilization module, using the steam cascade utilization module to prepare the steam required by the dilution steam sub-module to supply the dilution steam sub-module, using the steam cascade utilization module to prepare the steam required by the medium-pressure steam sub-module to supply the medium-pressure steam sub-module, using the steam cascade utilization module to prepare the steam for heating the high-temperature medium of the energy storage module and entering the energy storage module for heating the high-temperature medium;

[0059] Further, the heating temperature of the preheater is 25 - 300 °C;

[0060] Further, the heating temperature of the superheater is 150 - 650 °C;

[0061] Further, the quench module reduces the cracked gas to 150 - 550 °C;

[0062] Further, the cracking raw materials include but are not limited to at least one of crude oil, heavy oil, diesel, liquefied gas, butane and propane.

[0063] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0064] (1) The technical solution provided by the present invention uses the displacement gas module, the energy storage module and the flare module to ensure the long-term stable operation of the electric cracking furnace.

[0065] (2) The technical solution provided by the present invention uses an electric cracking furnace for steam cracking, and uses an electric heating type to provide the heat required for the cracking reaction, achieving near-zero carbon emissions.

[0066] (3) The technical solution provided by the present invention has a simple process and is easy to implement.

[0067] (4) The preferred solution of the technical solution provided by the present invention uses the waste heat boiler module and the steam cascade utilization module to cool the cracked gas, recover the heat of the cracked gas, and provide steam supply for the steam generation module, reducing the energy consumption of the electric cracking furnace system. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic structural diagram of a traditional steam cracking furnace.

[0069] Figure 2 It is a schematic structural diagram of the electric cracking furnace system provided in Embodiment 1 of the present invention.

[0070] Figure 3 It is a schematic structural diagram of the electric cracking furnace system provided in Embodiment 2 of the present invention.

[0071] Figure 4 It is a schematic structural diagram of the electric cracking furnace system provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0072] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0073] Embodiment 1

[0074] This embodiment provides an electric cracking furnace system, as Figure 2 shown. The system includes a raw material distribution module 1, a steam module 2, a coke cleaning air module 3, a preheater 4, a mixer 5, a superheater 6, an electric cracking furnace 7, a purge gas module 8, an energy storage module 9, a flare module 10, a cooling module 11, a blowdown module 12, a quench module 13, and a post-separation module 14.

[0075] The electric cracking furnace 7 includes a purge gas chamber and an electrically heated cracking chamber. The electrically heated cracking chamber is disposed inside the purge gas chamber (i.e., the purge gas chamber is sleeved outside the electrically heated cracking chamber). The electric cracking furnace 7 is provided with an electric heating element cooling pipe. The steam module 2 includes a dilution steam sub-module 15 and a medium-pressure steam sub-module 16. The steam outlet of the dilution steam sub-module 15 is connected to the steam outlet of the medium-pressure steam sub-module 16 and then serves as the steam outlet of the steam module 2.

[0076] The discharge port of the raw material distribution module 1 is connected to the feed port of the preheater 4, the discharge port of the preheater 4 is connected to the feed port of the mixer 5, the steam outlet of the steam module 2 is connected to the feed port of the mixer 5, the discharge port of the mixer 5 is connected to the feed port of the superheater 6, the discharge port of the superheater 6 is connected to the feed port of the electric heating cracking chamber of the electric cracking furnace 7, the feed port of the quench module 13 is connected to the discharge port of the electric heating cracking chamber of the electric cracking furnace 7, the purge gas outlet of the purge gas module 8 is connected to the purge gas inlet of the purge gas chamber of the electric cracking furnace 7, the purge gas composition detection inlet of the purge gas module 8 is connected to the purge gas outlet of the purge gas chamber of the electric cracking furnace 7, the feed port of the flare module 10 is connected to the electric heating cracking chamber of the electric cracking furnace 7, the high-temperature medium outlet of the energy storage module 9 is connected to the electric heating cracking chamber of the electric cracking furnace 7, the cooling medium outlet of the cooling module 11 is connected to the cooling medium inlet of the cooling pipe of the electric heating element of the electric cracking furnace 7, the discharge port of the decoking air module 3 is connected to the feed port of the preheater 4, the steam outlet of the steam module 2 is connected to the connecting pipeline between the discharge port of the decoking air module 3 and the feed port of the preheater 4, the blowdown module 12 is connected to the blowdown port of the electric heating cracking chamber of the electric cracking furnace 7, the steam outlet of the steam module 2 is connected to the cooling medium inlet of the quench module 13 to realize cooling the cracked gas in the quench module 13 with the steam of the steam module 2, the cooling medium inlet of the quench module 13 is connected to the water outlet of the process water system 17 to realize cooling the cracked gas in the quench module 13 with the process water of the process water system 17, and the feed port of the post-separation module 14 is connected to the discharge port of the quench module 13.

[0077] The raw material distribution module 1 is used to supply cracking raw materials to the preheater according to requirements; the preheater 4 is used to preheat the cracking raw materials; the mixer 5 is used to mix the cracking raw materials and steam; the superheater 6 is used to heat the mixture of the cracking raw materials and steam; the quench module 13 is used to rapidly reduce the temperature of the cracked gas, maximize the ethylene yield in the cracked gas and recover the waste heat in the cracked gas; the purge gas module 8 is used to provide purge gas for the purge gas chamber of the electric cracking furnace 7 and detect the composition of the purge gas discharged from the purge gas chamber of the electric cracking furnace 7; the flare module 10 is used to receive the raw materials and product gas in the electric heating cracking chamber when abnormal conditions occur in the electric cracking furnace 7 (such as power failure, leakage of the electric heating cracking chamber, etc. in the electric cracking furnace 7); the energy storage module 9 is used to provide high-temperature medium for the electric heating cracking chamber when the flare module 10 receives the raw materials and product gas in the electric heating cracking chamber; the post-separation module 14 is used to separate and purify the cracked gas.

[0078] The dilution steam sub-module 15 is used to provide steam at 120 - 300 °C and 0.5 - 2 MPa. The steam provided by the dilution steam sub-module 15 can be used to dilute the cracking raw materials, purge the electric cracking furnace system, and cooperate with the decoking air for decoking the electric cracking furnace system.

[0079] The medium-pressure steam sub-module 16 is used to provide steam at 300 - 450 °C and 1.0 - 5.0 MPa. The steam provided by the medium-pressure steam sub-module can be used for purging the electric cracking furnace system and for coke removal in the electric cracking furnace system in cooperation with the coke removal air.

[0080] The quench module 13 can reduce the cracking gas to 150 - 550 °C according to requirements and the type of cracking gas.

[0081] The preheater 4 is an electric preheater, and the heating range of the electric preheater is 25 - 300 °C.

[0082] The superheater 6 is an electric superheater, and the heating range of the electric superheater is 150 - 650 °C.

[0083] The temperature of the high-temperature medium provided by the energy storage module 9 is 300 - 900 °C.

[0084] The mixer 5 adopts a Venturi mixing form.

[0085] The cracking raw materials provided by the raw material distribution module 1 include but are not limited to crude oil, heavy oil, diesel, liquefied gas, butane, and propane.

[0086] The heating method of the electric heating cracking chamber of the electric cracking furnace 7 is electromagnetic heating.

[0087] The cooling medium of the cooling module 11 includes but is not limited to one of air, water, alcohol, Freon, ammonia, carbon dioxide, liquid metal, liquid helium, and liquid nitrogen.

[0088] The purge gas provided by the purge gas module 8 for the purge gas chamber of the electric cracking furnace includes but is not limited to at least one of nitrogen, argon, and helium.

[0089] The high-temperature medium provided by the energy storage module 9 includes but is not limited to at least one of steam, nitrogen, and helium.

[0090] The energy storage module 9 heats the high-temperature medium by resistance heating and heat recovery methods.

[0091] This embodiment also provides an operation method of the electric cracking furnace system, which is carried out using the electric cracking furnace system provided in this embodiment. The method includes:

[0092] Purging the electric cracking furnace system: Using the third steam stream provided by the steam module 2 to purge the preheater 4, mixer 5, superheater 6, and the electric heating cracking gas chamber of the electric cracking furnace 7 in sequence, and the purged stream is discharged into the sewage discharge module 12; wherein, the third steam stream is obtained by mixing the steam provided by the dilution steam sub-module 15 at 800 - 2000 kg / h, 185 °C, and 1.5 MPa and the steam provided by the medium-pressure steam sub-module at 400 - 1500 kg / h, 300 °C, and 1.35 MPa.

[0093] Steam cracking using an electric cracking furnace system: The feed distribution module 1 provides a cracking feed stream of 4000 kg / h, and the cracking feed selected is naphtha. The cracking feed stream is preheated to 210 °C using the preheater 4 to obtain a preheated cracking feed stream. The dilution steam sub-module 15 provides a first steam stream of 2000 kg / h, 185 °C, and 1.5 MPa. The preheated cracking feed stream and the first steam stream are mixed using the mixer 5 to obtain a cracking feed and steam mixed stream. The cracking feed and steam mixed stream is preheated to 540 °C using the superheater 6 to obtain a cracking-ready stream. The cracking-ready stream enters the electric heating cracking gas chamber of the electric cracking furnace 7 and undergoes a steam cracking reaction at 850 °C to obtain a cracked gas stream. The cracked gas stream is quenched to 350 °C using the quench module 13 to obtain a cooled cracked gas stream. Among them, the fourth steam stream provided by the steam module 2 and the process water provided by the process water system are respectively used as the cooling media of the quench module 13 to quench and cool the cracked gas stream entering the quench module 13. The fourth steam stream is a steam of 4800 kg / h, 180 °C, and 0.8 MPa provided by the dilution steam sub-module 15. The cooled cracked gas stream is separated and purified using the post-separation module 14.

[0094] Decoking treatment of the electric cracking furnace system: The decoking air stream of 800 kg / h provided by the decoking air module 3 and the second steam stream provided by the steam module 2 are mixed and then preheated to 300 °C using the preheater 4 in sequence, mixed evenly using the mixer 5, and preheated to 550 °C using the superheater 6 to obtain a decoking-ready stream. Among them, the second steam stream is a steam of 2700 kg / h, 180 °C, and 0.8 MPa provided by the dilution steam sub-module 15. The decoking-ready stream enters the electric heating cracking gas chamber of the electric cracking furnace 7 to undergo a burning reaction, and the products after the burning reaction are discharged into the blowdown module 12.

[0095] During the process of steam cracking using the electric cracking furnace system and decoking treatment of the electric cracking furnace system, the cooling module 11 is used to cool the heating elements of the electric heating cracking chamber of the electric cracking furnace 7 through a cooling medium. Among them, the cooling medium selected is process water.

[0096] ​During the steam cracking process using an electric cracking furnace system, the displacement gas module 8 is used to continuously supply displacement gas to the displacement gas chamber of the electric cracking furnace 7 and continuously monitor the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace 7. If it is monitored that the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace 7 is the same as the composition of the displacement gas supplied to the displacement gas chamber of the electric cracking furnace 7, then there is no leakage in the electric heating cracking chamber of the electric cracking furnace 7. If it is monitored that the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace 7 is different from the composition of the displacement gas supplied to the displacement gas chamber of the electric cracking furnace 7, then there is a leakage in the electric heating cracking chamber of the electric cracking furnace 7, and the electric cracking furnace system is in an abnormal operating condition. Among them, nitrogen is selected as the displacement gas.

[0097] During the steam cracking process using an electric cracking furnace system, when the electric cracking furnace system is in an abnormal operating condition, stop supplying materials to the electric cracking furnace 7 and stop the heating function of the electric heating cracking chamber of the electric cracking furnace 7. Discharge the materials in the electric heating cracking chamber of the electric cracking furnace 7 into the flare module 10, and at the same time use the energy storage module 9 to inject a high-temperature medium into the electric heating cracking chamber of the electric cracking furnace 7. Among them, the high-temperature medium is medium-pressure steam with a temperature of 300°C.

[0098] In this embodiment, during the operation of the electric cracking furnace system, after the electric cracking furnace 7 reaches the end-of-operation conditions (the furnace tube wall temperature of the electric cracking furnace 7 is within 1100 - 1115°C, and the absolute pressure ratio of the Venturi tube is 0.9), the electric cracking furnace system performs coking removal treatment to remove the coke layer inside the furnace tubes of the electric cracking furnace 7. After coking removal, the operation cycle is 60 - 80 days. By switching between the normal operation and coking removal operation modes, the long-term operation of the electric cracking furnace system is ensured.

[0099] For an electrolysis furnace system lacking the displacement gas module 8 and the energy storage module 9, when encountering an abnormal operating condition, after the heating function of the electric heating cracking chamber of the electric cracking furnace 7 is urgently shut down, the furnace tubes of the electric cracking furnace 7 will break and need to be replaced. However, for the electric cracking furnace system in this embodiment, when encountering an abnormal operating condition and the heating function of the electric heating cracking chamber of the electric cracking furnace 7 is urgently shut down, the furnace tubes of the electric cracking furnace 7 will not be damaged and can still be used. The electric cracking furnace system in this embodiment can effectively ensure that the furnace tubes of the electric cracking furnace 7 are not damaged after the heating function is urgently shut down when encountering an abnormal operating condition, thereby increasing the service life of the furnace tubes of the electric cracking furnace 7 and further improving the long-term stable operation performance of the electric cracking furnace system.

[0100] Embodiment 2

[0101] This embodiment provides an electric cracking furnace system, as Figure 3As shown in the figure, the system includes a raw material distribution module 21, a steam module 22, a decoking air module 23, a preheater 24, a mixer 25, a superheater 26, an electric cracking furnace 27, a displacement gas module 28, an energy storage module 29, a flare module 210, a cooling module 211, a blowdown module 212, a quench module 213, a post-separation module 214, and a waste heat boiler module 217.

[0102] The electric cracking furnace 27 includes a displacement gas chamber and an electrically heated cracking chamber. The electrically heated cracking chamber is disposed inside the displacement gas chamber (i.e., the displacement gas chamber is sleeved outside the electrically heated cracking chamber). The electric cracking furnace 27 is provided with an electric heating element cooling pipe. The steam module 22 includes a dilution steam sub-module 215 and a medium-pressure steam sub-module 216. The steam outlet of the dilution steam sub-module 215 is connected to the steam outlet of the medium-pressure steam sub-module 216 and then serves as the steam outlet of the steam module 22.

[0103] The discharge port of the raw material distribution module 21 is connected to the feed port of the preheater 24. The discharge port of the preheater 24 is connected to the feed port of the mixer 25. The steam outlet of the steam module 22 is connected to the feed port of the mixer 25. The discharge port of the mixer 25 is connected to the feed port of the superheater 26. The discharge port of the superheater 26 is connected to the feed port of the electrically heated cracking chamber of the electric cracking furnace 27. The feed port of the quench module 213 is connected to the discharge port of the electrically heated cracking chamber of the electric cracking furnace 27. The displacement gas outlet of the displacement gas module 28 is connected to the displacement gas inlet of the displacement gas chamber of the electric cracking furnace 27. The displacement gas component detection inlet of the displacement gas module 28 is connected to the displacement gas outlet of the displacement gas chamber of the electric cracking furnace 27. The feed port of the flare module 210 is connected to the electrically heated cracking chamber of the electric cracking furnace 27. The high-temperature medium outlet of the energy storage module 29 is connected to the electrically heated cracking chamber of the electric cracking furnace 27. The cooling medium outlet of the cooling module 211 is connected to the cooling medium inlet of the electric heating element cooling pipe of the electric cracking furnace 27. The discharge port of the decoking air module 23 is connected to the feed port of the preheater 24. The steam outlet of the steam module 22 is connected to the connecting pipeline between the discharge port of the decoking air module 23 and the feed port of the preheater 24. The blowdown module 212 is connected to the blowdown port of the electrically heated cracking chamber of the electric cracking furnace 27. The feed port of the post-separation module 214 is connected to the discharge port of the quench module 213. The cooling medium inlet and the cooling medium outlet of the quench module 213 are both connected to the boiler feed water pipeline of the waste heat boiler module 217, thereby realizing the heat exchange between the boiler feed water and the cracked gas in the quench module 213, using the boiler feed water to cool the cracked gas, and using the cracked gas to heat the boiler feed water.

[0104] The raw material distribution module 21 is used to supply pyrolysis raw materials to the preheater according to requirements; the preheater 24 is used to preheat the pyrolysis raw materials; the mixer 25 is used to mix the pyrolysis raw materials and steam; the superheater 26 is used to heat the mixture of pyrolysis raw materials and steam; the quench module 213 is used to rapidly reduce the temperature of the pyrolysis gas, maximize the ethylene yield in the pyrolysis gas and recover the waste heat in the pyrolysis gas; the purge gas module 28 is used to supply purge gas to the purge gas chamber of the electric pyrolysis furnace 27 and detect the composition of the purge gas discharged from the purge gas chamber of the electric pyrolysis furnace 27; the flare module 210 is used to receive the raw materials and product gas in the electric heating pyrolysis chamber when abnormal conditions occur in the electric pyrolysis furnace 27 (such as power failure of the electric pyrolysis furnace 27, leakage of the electric heating pyrolysis chamber, etc.); the energy storage module 29 is used to supply high-temperature medium to the electric heating pyrolysis chamber when the flare module 210 receives the raw materials and product gas in the electric heating pyrolysis chamber; the post-separation module 214 is used to separate and purify the pyrolysis gas.

[0105] The dilution steam sub-module 215 is used to supply steam at 120 - 300°C and 0.5 - 2 MPa. The steam supplied by the dilution steam sub-module 215 can be used to dilute the pyrolysis raw materials, purge the electric pyrolysis furnace system, and cooperate with the coke removal air for coke removal of the electric pyrolysis furnace system.

[0106] The medium-pressure steam sub-module 216 is used to supply steam at 200 - 450°C and 1.0 - 5.0 MPa. The steam supplied by the medium-pressure steam sub-module can be used to purge the electric pyrolysis furnace system and cooperate with the coke removal air for coke removal of the electric pyrolysis furnace system.

[0107] The quench module 213 can reduce the pyrolysis gas to 150 - 550°C according to requirements and the type of pyrolysis gas.

[0108] The preheater 24 selects an electric preheater, and the heating range of the electric preheater is 25 - 300°C.

[0109] The superheater 26 selects an electric superheater, and the heating range of the electric superheater is 150 - 650°C.

[0110] The temperature of the high-temperature medium supplied by the energy storage module 29 is 300 - 900°C.

[0111] The mixer 25 adopts a Venturi mixing form.

[0112] The pyrolysis raw materials provided by the raw material distribution module 21 include but are not limited to crude oil, heavy oil, diesel, liquefied gas, butane and propane.

[0113] The heating method of the electric heating pyrolysis chamber of the electric pyrolysis furnace 27 is resistance heating.

[0114] The cooling medium of the cooling module 211 includes but is not limited to one of air, water, alcohol, freon, ammonia, carbon dioxide, liquid metal, liquid helium and liquid nitrogen.

[0115] The replacement gas provided by the replacement gas module 28 for the replacement gas chamber of the electric cracking furnace includes at least one of, but is not limited to, nitrogen, argon, and helium.

[0116] The high-temperature medium provided by the energy storage module 29 includes at least one of, but is not limited to, steam, nitrogen, and helium.

[0117] The energy storage module 29 heats the high-temperature medium by means of resistance heating and heat recovery.

[0118] The waste heat boiler module 217 can generate steam at 350 - 450 °C.

[0119] This embodiment also provides an operation mode of the electric cracking furnace system, which is carried out using the electric cracking furnace system provided in this embodiment. The method includes:

[0120] Performing a purging process on the electric cracking furnace system: Using the third steam stream provided by the steam module 22 to purge the preheater 24, mixer 25, superheater 26, and the electric heating cracking gas chamber of the electric cracking furnace 27 in sequence, and discharging the purged stream into the blowdown module 12; wherein, the third steam stream is obtained by mixing the steam provided by the dilution steam sub-module 215 at 1000 kg / h, 185 °C, 1.0 MPa and the steam provided by the medium-pressure steam sub-module at 1000 kg / h, 350 °C, 1.35 MPa;

[0121] Performing steam cracking using the electric cracking furnace system: Supplying a cracking raw material stream of 4000 kg / h through the raw material distribution module 21, and the cracking raw material is selected as naphtha; heating and raising the temperature of the cracking raw material stream to 210 °C using the preheater 24 to obtain a preheated cracking raw material stream; mixing the steam provided by the dilution steam sub-module 215 at 1000 kg / h, 185 °C, 1.5 MPa and the steam provided by the medium-pressure steam sub-module at 1000 kg / h, 350 °C, 1.35 MPa to obtain a first steam stream; mixing the preheated cracking raw material stream and the first steam stream using the mixer 25 to obtain a cracking raw material and steam mixed stream; heating and raising the temperature of the cracking raw material and steam mixed stream to 540 °C using the superheater 26 to obtain a to-be-cracked stream; feeding the to-be-cracked stream into the electric heating cracking gas chamber of the electric cracking furnace 27 to perform a steam cracking reaction at 850 °C to obtain a cracked gas stream; rapidly cooling the cracked gas stream to 250 °C using the quench module 213 to obtain a cooled cracked gas stream, wherein, using the boiler feed water of the waste heat boiler module 217 as the cooling medium of the quench module 213 to rapidly cool the cracked gas stream entering the quench module 213, and re-transporting the boiler feed water after completing the rapid cooling process of the cracked gas stream back to the waste heat boiler module 217; separating and purifying the cooled cracked gas stream using the post-separation module 214;

[0122] Decoking treatment is carried out on the electric cracking furnace system: The decoking air logistics of 800 kg / h provided by the decoking air module 23 is mixed with the second steam logistics provided by the steam module 22, and then preheated and heated up to 300 °C by the preheater 24 in sequence, mixed by the mixer 25, and preheated and heated up to 550 °C by the superheater 26 to obtain the logistics for decoking. Among them, the second steam logistics is obtained by mixing the steam of 2000 kg / h, 180 °C, 1.0 MPa provided by the dilution steam sub-module 215 and the steam of 800 kg / h, 350 °C, 1.35 MPa provided by the medium-pressure steam sub-module; The logistics for decoking enters the electric heating cracking gas chamber of the electric cracking furnace 27 for coking reaction, and the products after the coking reaction are discharged into the sewage discharge module 12;

[0123] During the steam cracking process using the electric cracking furnace system and the decoking treatment of the electric cracking furnace system, the cooling module 211 is used to cool down the heating elements of the electric heating cracking chamber of the electric cracking furnace 27 through the cooling medium; Among them, the cooling medium is selected as boiler feed water;

[0124] During the steam cracking process using the electric cracking furnace system, the displacement gas module 28 is used to provide displacement gas to the displacement gas chamber of the electric cracking furnace 27 in real time and monitor the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace 27; If it is monitored that the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace 27 is the same as the composition of the displacement gas provided to the displacement gas chamber of the electric cracking furnace 27, it means that there is no leakage in the electric heating cracking chamber of the electric cracking furnace 27; If it is monitored that the composition of the displacement gas discharged from the displacement gas chamber of the electric cracking furnace 27 is different from the composition of the displacement gas provided to the displacement gas chamber of the electric cracking furnace 27, it means that there is a leakage in the electric heating cracking chamber of the electric cracking furnace 27, and the electric cracking furnace system is in an abnormal working condition; Among them, the displacement gas is selected as nitrogen;

[0125] During the steam cracking process using the electric cracking furnace system, when the electric cracking furnace system is in an abnormal working condition, stop feeding materials to the electric cracking furnace 27 and stop the heating function of the electric heating cracking chamber of the electric cracking furnace 27, discharge the materials in the electric heating cracking chamber of the electric cracking furnace 27 into the flare module 210, and at the same time use the energy storage module 29 to inject high-temperature medium into the electric heating cracking chamber of the electric cracking furnace 27; Among them, the high-temperature medium is medium-pressure steam at a temperature of 420 °C.

[0126] In this embodiment, during the operation of the electric cracking furnace system, after the electric cracking furnace 7 reaches the end-of-operation conditions (the furnace tube wall temperature of the electric cracking furnace 7 is within 1100 - 1115 °C, and the absolute pressure ratio of the Venturi tube is 0.9), the electric cracking furnace system performs decoking treatment to remove the coke layer in the furnace tubes of the electric cracking furnace 7. After decoking, the operation cycle is 60 - 80 days. By switching between the normal operation and decoking working conditions, the long-term operation of the electric cracking furnace system is ensured.

[0127] The electrolyzer system lacking the purge gas module 28 and the energy storage module 29 encounters an abnormal operating condition. After the heating function of the electric heating cracking chamber of the electric cracking furnace 27 is urgently shut down, the furnace tubes of the electric cracking furnace 27 will break and need to be replaced. However, in the electrolyzer system of this embodiment, when the electrolyzer system encounters an abnormal operating condition and the heating function of the electric heating cracking chamber of the electric cracking furnace 27 is urgently shut down, the furnace tubes of the electric cracking furnace 27 will not be damaged and can still be used continuously. The electrolyzer system in this embodiment can effectively ensure that the furnace tubes of the electric cracking furnace 27 are not damaged after the heating function is urgently shut down under abnormal operating conditions, thereby increasing the service life of the furnace tubes of the electric cracking furnace 27 and further improving the long-term stable operation performance of the electrolyzer system.

[0128] Embodiment 3

[0129] This embodiment provides an electrolyzer system, as Figure 4 shown. The system includes a raw material distribution module 31, a steam module 32, a coke removal air module 33, a preheater 34, a mixer 35, a superheater 36, an electric cracking furnace 37, a purge gas module 38, an energy storage module 39, a flare module 310, a cooling module 311, a blowdown module 312, a quench module 313, a post-separation module 314, a waste heat boiler module 317, and a steam cascade utilization module 318.

[0130] The electric cracking furnace 37 includes a purge gas chamber and an electric heating cracking chamber. The electric heating cracking chamber is arranged inside the purge gas chamber (i.e., the purge gas chamber is sleeved outside the electric heating cracking chamber). The electric cracking furnace 37 is provided with an electric heating element cooling pipe; the steam module 32 includes a diluted steam sub-module 315 and a medium-pressure steam sub-module 316. The steam outlet of the diluted steam sub-module 315 is connected to the steam outlet of the medium-pressure steam sub-module 316 and then serves as the steam outlet of the steam module 32.

[0131] The discharge port of the raw material distribution module 31 is connected to the feed port of the preheater 34. The discharge port of the preheater 34 is connected to the feed port of the mixer 35. The steam outlet of the steam module 32 is connected to the feed port of the mixer 35. The discharge port of the mixer 35 is connected to the feed port of the superheater 36. The discharge port of the superheater 36 is connected to the feed port of the electric heating cracking chamber of the electric cracking furnace 37. The feed port of the quench module 313 is connected to the discharge port of the electric heating cracking chamber of the electric cracking furnace 37. The purge gas outlet of the purge gas module 38 is connected to the purge gas inlet of the purge gas chamber of the electric cracking furnace 37. The purge gas composition detection inlet of the purge gas module 38 is connected to the purge gas outlet of the purge gas chamber of the electric cracking furnace 37. The feed port of the flare module 310 is connected to the electric heating cracking chamber of the electric cracking furnace 37. The high-temperature medium outlet of the energy storage module 39 is connected to the electric heating cracking chamber of the electric cracking furnace 37. The cooling medium outlet of the cooling module 311 is connected to the cooling medium inlet of the cooling pipe of the electric heating element of the electric cracking furnace 37. The discharge port of the coke removal air module 33 is connected to the feed port of the preheater 34. The steam outlet of the steam module 32 is connected to the connecting pipeline between the discharge port of the coke removal air module 33 and the feed port of the preheater 34. The blowdown module 312 is connected to the blowdown port of the electric heating cracking chamber of the electric cracking furnace 37. The feed port of the post-separation module 314 is connected to the discharge port of the quench module 313. The cooling medium inlet and the cooling medium outlet of the quench module 313 are both connected to the boiler feed water pipeline of the waste heat boiler module 317, so as to realize the heat exchange between the boiler feed water and the cracked gas in the quench module 313, use the boiler feed water to cool the cracked gas, use the cracked gas to heat the boiler feed water, and the steam outlets of the steam gradient utilization module 318 are respectively connected to the steam supply inlet of the dilution steam sub-module 315 of the steam module 32, the steam supply inlet of the medium-pressure steam sub-module 316 of the steam module 32, and the steam inlet of the steam heating pipeline of the energy storage module 39.

[0132] The raw material distribution module 31 is used to supply cracking raw materials to the preheater according to requirements; the preheater 34 is used to preheat the cracking raw materials; the mixer 35 is used to mix the cracking raw materials and steam; the superheater 36 is used to heat the mixture of the cracking raw materials and steam; the quench module 313 is used to rapidly reduce the temperature of the cracked gas, maximize the ethylene yield in the cracked gas and recover the waste heat in the cracked gas; the purge gas module 38 is used to supply purge gas to the purge gas chamber of the electric cracking furnace 37 and detect the composition of the purge gas discharged from the purge gas chamber of the electric cracking furnace 37; the flare module 310 is used to receive the raw materials and product gas in the electric heating cracking chamber when abnormal conditions occur in the electric cracking furnace 37 (such as power failure of the electric cracking furnace 37, leakage of the electric heating cracking chamber, etc.); the energy storage module 39 is used to supply high-temperature medium to the electric heating cracking chamber when the flare module 310 receives the raw materials and product gas in the electric heating cracking chamber; the post-separation module 314 is used to separate and purify the cracked gas.

[0133] The dilution steam sub-module 315 is used to provide steam at 150 - 350 °C and 0.5 - 2 MPa. The steam provided by the dilution steam sub-module 315 can be used to dilute the cracking feedstock, purge the electric cracking furnace system, and cooperate with the decoking air to decoke the electric cracking furnace system.

[0134] The medium-pressure steam sub-module 316 is used to provide steam at 200 - 450 °C and 1.0 - 5.0 MPa. The steam provided by the medium-pressure steam sub-module can be used to purge the electric cracking furnace system and cooperate with the decoking air to decoke the electric cracking furnace system.

[0135] The quench module 313 can reduce the cracking gas to 150 - 550 °C according to the needs and the type of cracking gas.

[0136] The preheater 34 is selected as an electric preheater, and the heating range of the electric preheater is 35 - 300 °C.

[0137] The superheater 36 is selected as an electric superheater, and the heating range of the electric superheater is 150 - 650 °C.

[0138] The temperature of the high-temperature medium provided by the energy storage module 39 is 300 - 900 °C.

[0139] The mixer 35 adopts a Venturi mixing form.

[0140] The cracking feedstock provided by the feedstock distribution module 31 includes but is not limited to crude oil, heavy oil, diesel, liquefied gas, butane, and propane.

[0141] The heating method of the electric heating cracking chamber of the electric cracking furnace 37 is electromagnetic heating.

[0142] The cooling medium of the cooling module 311 includes but is not limited to one of air, water, alcohol, Freon, ammonia, carbon dioxide, liquid metal, liquid helium, and liquid nitrogen.

[0143] The displacement gas provided by the displacement gas module 38 for the displacement gas chamber of the electric cracking furnace includes but is not limited to at least one of nitrogen, argon, and helium.

[0144] The high-temperature medium provided by the energy storage module 39 includes but is not limited to at least one of steam, nitrogen, and helium.

[0145] The energy storage module 39 heats the high-temperature medium by means of resistance heating.

[0146] The waste heat boiler module 317 can generate steam at 350 - 450 °C.

[0147] This embodiment also provides an operation method of the electric cracking furnace system, which is carried out using the electric cracking furnace system provided in this embodiment. The method includes:

[0148] Purge the electric cracking furnace system: Use the third steam stream provided by the steam module 32 to purge the preheater 34, mixer 35, superheater 36, and the electric heating cracking gas chamber of the electric cracking furnace 37 in sequence. The purged stream is discharged into the blowdown module 12. Among them, the third steam stream is obtained by mixing the steam provided by the dilution steam sub-module 315 at 1000 kg / h, 185 °C, 1.0 MPa and the steam provided by the medium-pressure steam sub-module at 1000 kg / h, 350 °C, 1.35 MPa.

[0149] Perform steam cracking using the electric cracking furnace system: Provide a cracking raw material stream of 4000 kg / h through the raw material distribution module 31, and the cracking raw material is selected as naphtha. The cracking raw material stream is preheated to 210 °C using the preheater 34 to obtain a preheated cracking raw material stream. The first steam stream is obtained by mixing the steam provided by the dilution steam sub-module 315 at 1000 kg / h, 185 °C, 1.5 MPa and the steam provided by the medium-pressure steam sub-module at 1000 kg / h, 350 °C, 1.35 MPa. The preheated cracking raw material stream and the first steam stream are mixed using the mixer 35 to obtain a mixed stream of cracking raw material and steam. The mixed stream of cracking raw material and steam is preheated to 540 °C using the superheater 36 to obtain a stream to be cracked. The stream to be cracked enters the electric heating cracking gas chamber of the electric cracking furnace 37 and undergoes a steam cracking reaction at 850 °C to obtain a cracking gas stream. The cracking gas stream is rapidly cooled to 250 °C using the quench module 313 to obtain a cooled cracking gas stream. Among them, the boiler feed water of the waste heat boiler module 317 is used as the cooling medium of the quench module 313 to rapidly cool the cracking gas stream entering the quench module 313, and the boiler feed water after completing the rapid cooling of the cracking gas stream is re-transported back to the waste heat boiler module 317. The cooled cracking gas stream is separated and purified using the post-separation module 314. Among them, the 400 °C steam generated by the waste heat boiler module 317 is transported to the steam cascade utilization module 318, and the steam required by the dilution steam sub-module 315 is prepared using the steam cascade utilization module 318 to supply the dilution steam sub-module 315, the steam required by the medium-pressure steam sub-module 316 is prepared using the steam cascade utilization module 318 to supply the medium-pressure steam sub-module 316, and the steam for heating the high-temperature medium of the energy storage module 39 is prepared using the steam cascade utilization module 318 and enters the energy storage module 39 for heating the high-temperature medium.

[0150] Decoking treatment is carried out on the electric cracking furnace system: The decoking air logistics of 800 kg / h provided by the decoking air module 33 is mixed with the second steam logistics provided by the steam module 32, and then preheated and heated to 300 °C by the preheater 34 in sequence, mixed by the mixer 35, and preheated and heated to 550 °C by the superheater 36 to obtain the decoking used logistics. Among them, the second steam logistics is obtained by mixing the steam of 2000 kg / h, 180 °C, 1.0 MPa provided by the dilution steam sub-module 315 and the steam of 800 kg / h, 350 °C, 1.35 MPa provided by the medium-pressure steam sub-module; The decoking used logistics enters the electric heating cracking gas cavity of the electric cracking furnace 37 for coking reaction, and the products after the coking reaction are discharged into the sewage discharge module 12;

[0151] During the steam cracking process using the electric cracking furnace system and the decoking treatment of the electric cracking furnace system, the cooling module 311 is used to cool down the heating elements of the electric heating cracking cavity of the electric cracking furnace 37 through the cooling medium; Among them, the cooling medium is selected as boiler feed water;

[0152] During the steam cracking process using the electric cracking furnace system, the displacement gas module 38 is used to provide displacement gas to the displacement gas cavity of the electric cracking furnace 37 in real time and monitor the composition of the displacement gas discharged from the displacement gas cavity of the electric cracking furnace 37; If it is monitored that the composition of the displacement gas discharged from the displacement gas cavity of the electric cracking furnace 37 is the same as the composition of the displacement gas provided to the displacement gas cavity of the electric cracking furnace 37, then there is no leakage in the electric heating cracking cavity of the electric cracking furnace 37; If it is monitored that the composition of the displacement gas discharged from the displacement gas cavity of the electric cracking furnace 37 is different from the composition of the displacement gas provided to the displacement gas cavity of the electric cracking furnace 37, then there is a leakage in the electric heating cracking cavity of the electric cracking furnace 37, and the electric cracking furnace system is in an abnormal working condition; Among them, the displacement gas is selected as nitrogen;

[0153] During the steam cracking process using the electric cracking furnace system, when the electric cracking furnace system is in an abnormal working condition, stop feeding materials to the electric cracking furnace 37 and stop the heating function of the electric heating cracking cavity of the electric cracking furnace 37, discharge the materials in the electric heating cracking cavity of the electric cracking furnace 37 into the flare module 310, and at the same time use the energy storage module 39 to inject high-temperature medium into the electric heating cracking cavity of the electric cracking furnace 37; Among them, the high-temperature medium is medium-pressure steam at a temperature of 420 °C.

[0154] The electrolysis furnace system lacking the replacement gas module 38 and the energy storage module 39 encounters an abnormal operating condition. After the heating function of the electric heating cracking chamber of the electric cracking furnace 37 is urgently shut down, the furnace tubes of the electric cracking furnace 37 will break and need to be replaced. However, in the electrolysis furnace system of this embodiment, when encountering an abnormal operating condition and the heating function of the electric heating cracking chamber of the electric cracking furnace 37 is urgently shut down, the furnace tubes of the electric cracking furnace 37 will not be damaged and can still be used continuously. The electrolysis furnace system in this embodiment can effectively ensure that the furnace tubes of the electric cracking furnace 37 are not damaged after the heating function is urgently shut down under abnormal operating conditions, thereby increasing the service life of the furnace tubes of the electric cracking furnace 37 and further improving the long-term stable operation performance of the electrolysis furnace system.

[0155] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electric cracking furnace system, wherein: The system includes: Electric cracking furnace, replacement gas module, energy storage module, flare module, preheater, mixer, superheater, quenching module and steam module; The electric cracking furnace comprises a displacement gas chamber and an electric heating cracking chamber, wherein the electric heating cracking chamber is arranged inside the displacement gas chamber; The replacement gas outlet of the replacement gas module is connected to the replacement gas inlet of the replacement gas cavity of the electric cracking furnace, and the replacement gas component detection inlet of the replacement gas module is connected to the replacement gas outlet of the replacement gas cavity of the electric cracking furnace; the replacement gas module is used to provide replacement gas to the replacement gas cavity of the electric cracking furnace and detect the composition of the replacement gas discharged from the replacement gas cavity of the electric cracking furnace; The feed port of the flare module is connected to the electrically heated cracking chamber of the electric cracking furnace. The flare module is used to receive the raw materials and product gases in the electrically heated cracking chamber when the electric cracking furnace has an abnormal operating condition. The high-temperature medium outlet of the energy storage module is connected to the electric heating cracking chamber of the electric cracking furnace. The energy storage module is used to provide high-temperature medium to the electric heating cracking chamber when the flare module receives the raw materials and product gases in the electric heating cracking chamber; The feed port of the preheater is used to feed cracking raw materials, the discharge port of the preheater is connected to the feed port of the mixer, the steam outlet of the steam module is connected to the feed port of the mixer, the discharge port of the mixer is connected to the feed port of the superheater, the discharge port of the superheater is connected to the feed port of the electrically heated cracking chamber of the electric cracking furnace, and the feed port of the quenching module is connected to the discharge port of the electrically heated cracking chamber of the electric cracking furnace; The steam module includes a dilution steam submodule and a medium-pressure steam submodule; the dilution steam submodule is used to provide steam at 120-300°C and 0.5-2MPa; the medium-pressure steam submodule is used to provide steam at 200-450°C and 1.0-5.0MPa.

2. The system according to claim 1, wherein: The electric cracking furnace system also includes a cooling module, and the electric cracking furnace is also provided with an electric heating element cooling pipe. The cooling medium outlet of the cooling module is connected to the cooling medium inlet of the electric heating element cooling pipe of the electric cracking furnace, and the cooling medium recovery port of the cooling module is connected to the cooling medium outlet of the electric heating element cooling pipe of the electric cracking furnace.

3. The system according to claim 1, wherein: The electric cracking furnace system also includes a decoking air module and a sewage discharge module; the discharge port of the decoking air module is connected to the feed port of the preheater, the steam outlet of the steam module is connected to the connecting pipeline between the discharge port of the decoking air module and the feed port of the preheater, and the sewage discharge module is connected to the sewage discharge port of the electrically heated cracking chamber of the electric cracking furnace.

4. The system according to claim 3, wherein: The steam outlet of the steam module is connected to the cooling medium inlet of the quench module, so that the steam of the steam module is used to cool the cracked gas in the quench module.

5. The system according to claim 1 or 4, wherein: The cooling medium inlet of the quenching module is connected to the water outlet of the process water system, so that the process water of the process water system is used to cool the cracked gas in the quenching module.

6. The system according to claim 1, wherein: The electric cracking furnace system also includes a waste boiler module. The cooling medium inlet and cooling medium outlet of the quenching module are connected to the boiler feed water pipeline of the waste boiler module, so that the boiler feed water and the cracking gas can be heat exchanged in the quenching module, and the boiler feed water is used to cool the cracking gas, and the cracking gas is used to heat the boiler feed water.

7. The system according to claim 6, wherein: The electric cracking furnace system also includes a steam gradient utilization module, the steam inlet of the steam gradient utilization module is connected to the steam outlet of the waste boiler module, the steam outlet of the steam gradient utilization module is connected to the steam supply inlet of the steam module and / or is connected to the steam inlet of the steam heating pipeline of the energy storage module.

8. A method for operating an electric cracking furnace system, using the electric cracking furnace system according to any one of claims 1 to 7, the method comprising: During steam cracking using an electric cracking furnace system, a replacement gas module is used to provide replacement gas to a replacement gas chamber of the electric cracking furnace in real time and to monitor the composition of the replacement gas discharged from the replacement gas chamber of the electric cracking furnace in real time; if it is monitored that the composition of the replacement gas discharged from the replacement gas chamber of the electric cracking furnace is the same as the composition of the replacement gas provided to the replacement gas chamber of the electric cracking furnace, then the electrically heated cracking chamber of the electric cracking furnace has not leaked; if it is monitored that the composition of the replacement gas discharged from the replacement gas chamber of the electric cracking furnace is different from the composition of the replacement gas provided to the replacement gas chamber of the electric cracking furnace, then the electrically heated cracking chamber of the electric cracking furnace has leaked and the electric cracking furnace system is in an abnormal operating condition; During steam cracking using an electric cracking furnace system, when the electric cracking furnace system is in an abnormal operating condition, the material supply to the electric cracking furnace is stopped, and the heating function of the electric heating cracking chamber of the electric cracking furnace is stopped. The material in the electric heating cracking chamber of the electric cracking furnace is discharged into the flare module, and at the same time, a high-temperature medium is injected into the electric heating cracking chamber of the electric cracking furnace using the energy storage module; wherein the temperature of the high-temperature medium is 300-900°C.

9. The method according to claim 8, wherein The high temperature medium includes at least one of steam, nitrogen and helium; The replacement gas includes at least one of nitrogen, argon, and helium.

10. The method according to claim 8, wherein The electric cracking furnace system operation method further includes: During steam cracking using an electric cracking furnace system, the cracking feedstock flow is preheated and heated using a preheater to obtain a preheated cracking feedstock flow, the preheated cracking feedstock flow and the first steam flow provided by the steam module are mixed using a mixer to obtain a cracking feedstock and steam mixed flow, the cracking feedstock and steam mixed flow are preheated and heated using a superheater to obtain a flow to be cracked, the flow to be cracked enters the electrically heated cracking gas chamber of the electric cracking furnace to undergo a steam cracking reaction to obtain a cracking gas flow, and the cracking gas flow is rapidly cooled using a quenching module to obtain a cooled cracking gas flow.

11. The method according to claim 10, wherein: During steam cracking using an electric cracking furnace system, the first steam flow includes steam at 120-300°C and 0.5-2 MPa provided by a dilution steam submodule in the steam module and / or steam at 200-450°C and 1.0-5.0 MPa provided by a medium-pressure steam submodule in the steam module.

12. The method according to claim 10, wherein: The operation method of the electric cracking furnace system also includes performing a decoking treatment on the electric cracking furnace system: the decoking air flow is mixed with the second steam flow provided by the steam module, and then preheated and heated in sequence by a preheater, mixed by a mixer, and preheated and heated again by a superheater to obtain a decoking flow, and the decoking flow enters the electrically heated cracking gas chamber of the electric cracking furnace to undergo a coking reaction, and the product after the coking reaction is discharged into the sewage discharge module.

13. The method according to claim 12, wherein: During the decoking process of the electric cracking furnace system, the second steam flow includes 120-300°C, 0.5-2MPa steam provided by the dilution steam submodule in the steam module and / or 200-450°C, 1.0-5.0MPa steam provided by the medium pressure steam submodule in the steam module.

14. The method according to claim 10, wherein: The operation method of the electric cracking furnace system also includes purging the electric cracking furnace system: the third steam flow provided by the steam module sequentially purges the preheater, mixer, superheater, and electrically heated cracking gas chamber of the electric cracking furnace, and the purged flow is discharged into the sewage discharge module.

15. The method according to claim 10, wherein The electric cracking furnace system operation method further includes utilizing a cooling module to cool down a heating element of an electrically heated cracking chamber of the electric cracking furnace through a cooling medium.

16. The method according to claim 10, wherein The electric cracking furnace system operation method also includes: during the steam cracking process using the electric cracking furnace system, using the steam module to provide a fourth steam flow as a cooling medium for the quenching module to quench the cracked gas flow entering the quenching module.

17. The method according to claim 16, wherein: The fourth steam stream includes steam at 120-300° C. and 0.5-2 MPa provided by the dilution steam submodule in the steam module and / or steam at 200-450° C. and 1.0-5.0 MPa provided by the medium pressure steam submodule in the steam module.

18. The method according to claim 10 or 16, wherein The electric cracking furnace system operation method further includes: during steam cracking using the electric cracking furnace system, using process water provided by the process water system as a cooling medium of the quenching module to quench the cracked gas flow entering the quenching module.

19. The method according to claim 10, wherein The method for operating the electric cracking furnace system also includes: during steam cracking using the electric cracking furnace system, using the boiler feed water of the waste boiler module as the cooling medium of the quenching module to quench the cracked gas flow entering the quenching module, and re-transporting the boiler feed water after the quenching treatment of the cracked gas flow back to the waste boiler module.

20. The method according to claim 10, wherein The operation method of the electric cracking furnace system also includes: during the steam cracking process using the electric cracking furnace system, the steam generated by the waste boiler module is transported to the steam cascade utilization module, and the steam required by the steam module is prepared by the steam cascade utilization module to supply the steam module, or the steam cascade utilization module is used to prepare the steam for heating the high-temperature medium of the energy storage module, and the steam enters the energy storage module to heat the high-temperature medium.

21. The method according to claim 10, wherein The heating temperature of the preheater is 25-300℃; The heating temperature of the superheater is 150-650℃; The quenching module reduces the cracking gas temperature to 150-550℃; The cracking feedstock includes at least one of crude oil, heavy oil, diesel, liquefied gas, butane and propane.

Images