Sulfur recovery system coupled with heat storage device

Abstract

The utility model provides a sulfur recovery system coupled with a heat storage device, which comprises a heat storage device, a reaction furnace, a sulfur recovery device and an incinerator, the sulfur recovery device comprises a reheater, a converter and a sulfur cooler, and the heat storage device comprises a high-temperature storage tank, a steam generator, a low-temperature storage tank and a heating device which are sequentially communicated end to end. A modified liquid sulfur material capable of being circularly conveyed is arranged in the heat storage device, the high-temperature storage tank is communicated with a reheater, the reheater is communicated with a steam generator and / or a low-temperature storage tank, the steam generator is connected with the low-temperature storage tank, the low-temperature storage tank is communicated with a sulfur cooler, the sulfur cooler is communicated with a waste heat boiler of a reaction furnace, and the waste heat boiler is connected with a heating device. The heating device is connected with the high-temperature storage tank; according to the device disclosed by the utility model, various different grades of energy in the sulfur recovery system can be gathered and complementarily coupled, process gas can be heated in the reheater, and medium-high pressure steam can be produced in a centralized manner.

Description

Technical Field

[0001] The utility model relates to the technical field of sulfur recovery, in particular to a sulfur recovery system coupled with a heat storage device. Background Art

[0002] The sulfur recovery system is the main system for treating H2S-containing acid gas produced by coal chemical, petrochemical and fine chemical plants, and can produce sulfur as a by-product. In the prior art, there are many sulfur recovery systems and processes, including two-stage Claus, three-stage Claus, improved three-stage Claus, two-stage Claus + selective hydrogenation + selective oxidation, two-stage Claus + conventional SCOT, two-stage Claus + LS SCOT, two-stage Claus + Super SCOT, etc. For example, Figure 1 Shown is a conventional two-stage Claus + selective oxidation process (or two-stage Claus + super Claus process).

[0003] In the existing sulfur recovery system, waste heat boilers, multi-stage sulfur coolers, multi-stage heaters, multi-stage converters, incinerators and other equipment are often installed. Among them, the sulfur cooler needs to release heat to the outside, and the heater needs to be heated by the outside. Therefore, in order to improve the efficiency of energy utilization, in the prior art, the heat generated by the combustion of acid gas usually produces high / medium pressure saturated steam (about 5.5MPa, 271℃) in the waste heat boiler, part of which is used as the heat source of the process gas heater, and the rest enters the steam pipeline network for other uses; the heat released by the process gas in the sulfur condensation cooler is usually used to generate low-pressure saturated steam (about 0.4MPa, 145℃).

[0004] However, for the entire sulfur recovery system (such as the attached Figure 1 As shown in the figure, steam with different calorific qualities is often generated during the operation of the entire system, and the distribution is relatively dispersed. Corresponding steam pipelines with different calorific qualities need to be built in the plant, resulting in a complex layout of steam pipelines in the system. At the same time, the generation of low calorific quality steam will increase the difficulty of heat reuse and may even be regarded as waste heat, which is not conducive to improving the energy efficiency of the entire system. Utility Model Content

[0005] In view of this, the utility model aims to propose a sulfur recovery system coupled with a heat storage device to solve the problem that the sulfur recovery system in the prior art will generate steam with different heat tastes, resulting in complex steam pipeline layout and low energy utilization efficiency of the entire system.

[0006] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0007] A sulfur recovery system coupled with a heat storage device comprises a heat storage device, a reaction furnace, a sulfur recovery device, and an incinerator, wherein the reaction furnace, the sulfur recovery device, and the incinerator are connected in sequence; the reaction furnace is provided with a waste heat boiler, the sulfur recovery device comprises at least two stages of sulfur recovery groups connected in sequence, any one of the sulfur recovery groups comprises a reheater, a converter, and a sulfur cooler connected in sequence; the heat storage device comprises a high-temperature storage tank, a steam generator, a low-temperature storage tank, and a heating device connected in sequence end to end, a modified liquid sulfur material that can be circulated and transported is arranged in the heat storage device, and the high The discharge port of the warm storage tank can be connected to the material inlet of each reheater, and the material outlet of each reheater can be connected to the feed port of the steam generator and / or the feed port of the low-temperature storage tank. The discharge port of the steam generator is connected to the feed port of the low-temperature storage tank, and the discharge port of the low-temperature storage tank can be connected to the material inlet of each sulfur cooler. The material outlet of each sulfur cooler can be connected to the material inlet of the waste heat boiler, the material outlet of the waste heat boiler is connected to the feed port of the heating device, and the discharge port of the heating device is connected to the feed port of the high-temperature storage tank.

[0008] Furthermore, the heat storage device includes a first main pipe, the feed port of the first main pipe is connected to the discharge port of the high-temperature storage tank, and the discharge port of the first main pipe is connected to the material inlet of each reheater.

[0009] Furthermore, the heat storage device includes a second main pipe, a feed port of the second main pipe is connected to a material outlet of each reheater, and a discharge port of the second main pipe is connected to a feed port of the steam generator and / or a feed port of the low-temperature storage tank.

[0010] Furthermore, the heat storage device includes a third main pipe and a fourth main pipe, the feed port of the third main pipe is connected to the discharge port of the low-temperature storage tank, the discharge port of the third main pipe is connected to the material inlet of each sulfur cooler, the feed port of the fourth main pipe is connected to the material outlet of each sulfur cooler, and the discharge port of the fourth main pipe is connected to the material inlet of the waste heat boiler.

[0011] Furthermore, the heat storage device includes a first tube, one end of which is connected to the third main tube, and the other end of which is connected to the fourth main tube.

[0012] Furthermore, the heat storage device includes a second tube and a third tube, one end of the second tube is connected to the third main tube, and the other end is connected to the material inlet of the incinerator, one end of the third tube is connected to the material outlet of the incinerator, and the other end is connected to the material outlet of the waste heat boiler.

[0013] Furthermore, a high-temperature pump is provided at the discharge port of the high-temperature storage tank, and a low-temperature pump is provided at the discharge port of the low-temperature storage tank.

[0014] Furthermore, in the flow direction of the process gas, a primary sulfur cooler is arranged between the reactor and the sulfur recovery device, and the sulfur recovery device includes a primary reheater, a primary converter, a primary sulfur cooler, a secondary reheater, a secondary converter, a secondary sulfur cooler, a tertiary reheater, a tertiary converter, and a tertiary sulfur cooler which are connected in sequence, and the process gas outlet of the primary sulfur cooler is connected to the process gas inlet of the primary reheater, and the process gas outlet of the tertiary sulfur cooler is connected to the process gas inlet of the incinerator.

[0015] Furthermore, the heat storage device includes a first main pipe and a second main pipe, the feed port of the first main pipe is connected to the discharge port of the high-temperature storage tank, and the discharge port of the first main pipe is respectively connected to the material inlet of the first-stage reheater, the material inlet of the second-stage reheater, and the material inlet of the tertiary reheater; the feed port of the second main pipe is respectively connected to the material outlet of the first-stage reheater, the material outlet of the second-stage reheater, and the material outlet of the tertiary reheater, and the discharge port of the second main pipe is connected to the feed port of the steam generator.

[0016] Furthermore, the heat storage device includes a third main pipe and a fourth main pipe, the feed port of the third main pipe is connected to the discharge port of the low-temperature storage tank, the discharge port of the third main pipe is respectively connected to the material inlet of the primary sulfur cooler, the material inlet of the first sulfur cooler, the material inlet of the second sulfur cooler, and the material inlet of the tertiary sulfur cooler, the feed port of the fourth main pipe is respectively connected to the material outlet of the primary sulfur cooler, the material outlet of the first sulfur cooler, the material outlet of the second sulfur cooler, and the material outlet of the tertiary sulfur cooler, and the discharge port of the fourth main pipe is connected to the material inlet of the waste heat boiler.

[0017] Compared with the prior art, the sulfur recovery system coupled with a heat storage device described in the utility model has the following advantages:

[0018] The utility model discloses a sulfur recovery system coupled with a heat storage device. By coupling the heat storage device to the existing sulfur recovery system, the high-grade heat (about 1200°C) generated by the waste heat boiler and the low-grade heat (about 160°C) generated by the sulfur cooler can be stored and concentrated in the material, and the material can be supplemented with heat by a heating device (such as electric energy and chemical energy), thereby realizing the aggregation and complementary coupling of multiple different grades of energy in the sulfur recovery system. At the same time, the energy aggregated in the material can not only heat the process gas in the reheater, but also utilize the surplus energy of the entire sulfur recovery system, which is the only energy in the entire system. Medium and high pressure steam is centrally generated in the steam generator and can be uniformly sent to the external steam network for use. Compared with the existing sulfur recovery system, not only the overall thermal quality of the steam generated in the system is higher and the thermal quality type is more uniform, but also unnecessary low-calorie quality steam is not generated, which reduces the generation of waste heat and improves the energy utilization efficiency of the entire system. In addition, the steam generation location of the present application is more centralized, and the steam pipeline and the steam generator do not need to be arranged in the sulfur recovery device, which also avoids the situation in which the steam pipeline is too dispersed in the prior art, and can significantly reduce the complexity of the steam pipeline layout in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0020] Figure 1 It is a schematic diagram of a two-stage Claus + super Claus process in the prior art;

[0021] Figure 2 This is a first schematic diagram of a sulfur recovery system coupled with a heat storage device according to an embodiment of the utility model;

[0022] Figure 3 A second schematic diagram of a sulfur recovery system coupled with a heat storage device according to an embodiment of the utility model;

[0023] Figure 4 A third schematic diagram of a sulfur recovery system coupled with a heat storage device according to an embodiment of the utility model;

[0024] Figure 5 This is a fourth schematic diagram of a sulfur recovery system coupled with a heat storage device according to an embodiment of the utility model.

[0025] Description of reference numerals:

[0026] 1. High-temperature storage tank; 101. High-temperature pump; 2. Steam generator; 3. Low-temperature storage tank; 301. Low-temperature pump; 4. Electric heater; 5. Combustion heater; 6. First main pipe; 7. Second main pipe; 8. Third main pipe; 9. Fourth main pipe; 10. First pipe; 11. Second pipe; 12. Third pipe. DETAILED DESCRIPTION

[0027] The following will use the terms commonly used by those skilled in the art to convey the essence of their work to other technical personnel in the art to describe the utility model concepts of the present disclosure. However, these utility model concepts can be embodied in many different forms and should not be considered as limited to the embodiments described herein.

[0028] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present utility model can be combined with each other. Figure 2-5 ) and the two-stage Claus + super Claus process diagram in the prior art (attached Figure 1 ) in order to distinguish the pipelines related to the heat storage device improved in this application. This application distinguishes the attached Figure 2-5 The pipelines related to the heat storage device in the heat storage device are shown in red and blue. In the system of the present application, there are two groups of material flows. In the present application, the sulfur-containing process gas is referred to as "process gas" and the circulating modified liquid sulfur material is referred to as "material".

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

[0030] For the sulfur recovery system in the prior art, steam with different calorific qualities is often generated during the operation of the entire system, and the distribution is relatively dispersed. Corresponding steam pipelines with different calorific qualities need to be built in the plant area, resulting in a complex layout of the steam pipelines in the system. At the same time, the generation of low calorific quality steam will increase the difficulty of heat reuse, and may even be regarded as waste heat, which is not conducive to improving the energy utilization efficiency of the entire system.

[0031] In order to solve the problem that the sulfur recovery system in the prior art generates steam with different heat qualities, resulting in a complex steam pipeline layout and low energy utilization efficiency of the entire system, this embodiment proposes a sulfur recovery system coupled with a heat storage device, as shown in the attached Figure 2-5 As shown, the sulfur recovery system includes a heat storage device, a reaction furnace, a sulfur recovery device, an incinerator, and a chimney, and the reaction furnace, the sulfur recovery device, the incinerator, and the chimney are connected in sequence.

[0032] The sulfur recovery device may be any sulfur recovery system in the prior art, such as two-stage Claus, three-stage Claus, improved three-stage Claus, two-stage Claus + selective hydrogenation + selective oxidation, two-stage Claus + conventional SCOT, two-stage Claus + LS SCOT, two-stage Claus + Super SCOT, etc. In order to facilitate the introduction of related equipment below, the present application briefly introduces the sulfur recovery device, which includes at least two sulfur recovery groups connected in sequence, any one of which includes a reheater, a converter, and a sulfur cooler connected in sequence, and a sulfur sealing tank is provided at the sulfur outlet of any one of the sulfur coolers to collect and recover sulfur. For two adjacent sulfur recovery groups upstream and downstream, the process gas outlet of the sulfur cooler of the upstream sulfur recovery group is connected to the process gas inlet of the reheater of the downstream sulfur recovery group; the process gas outlet of the last sulfur cooler is connected to the process gas inlet of the incinerator.

[0033] For existing sulfur recovery technologies, an additional sulfur cooler and a corresponding sulfur sealing tank are often set between the reactor and the sulfur recovery device, such as the primary sulfur cooler and the corresponding sulfur sealing tank shown in the drawings of this application. Of course, in some existing sulfur recovery technologies, there are also solutions without additionally setting a primary sulfur cooler, that is, the reactor is directly connected to the reheater of the first-stage sulfur recovery device, which will not be elaborated in this application.

[0034] In the existing sulfur recovery system, low-pressure steam is often generated by heat exchange between high-temperature process gas and water in each stage of sulfur cooler. In addition, the existing reaction furnace includes a waste heat boiler, in which high-temperature process gas and water are exchanged for heat, and water is often heated by high-temperature process gas to generate medium- and high-pressure steam. Therefore, during operation, the sulfur recovery system in the prior art will generate steam of different heat qualities at multiple steam generation locations, and the distribution is relatively dispersed.

[0035] On this basis, the main technical improvement of this application is to set up a heat storage device in the sulfur recovery system to heat or cool some equipment in the sulfur recovery system, and use the heat storage device to centrally generate steam, so that there is only one steam generating location in the entire sulfur recovery system, and correspondingly generates steam of the same type of thermal quality.

[0036] Specifically: the heat storage device comprises a high-temperature storage tank 1, a steam generator 2, a low-temperature storage tank 3, and a heating device which are connected end to end in sequence. The heat storage device is provided with a modified liquid sulfur material which can be circulated and transported. The discharge port of the high-temperature storage tank 1 can be connected to the material inlet of each reheater, and the material outlet of each reheater can be connected to the feed port of the steam generator 2 and / or the feed port of the low-temperature storage tank 3. The discharge port of the steam generator 2 is connected to the feed port of the low-temperature storage tank 3, and the discharge port of the low-temperature storage tank 3 can be connected to the material inlet of each sulfur cooler. The material outlet of each sulfur cooler can be connected to the material inlet of the waste heat boiler, the material outlet of the waste heat boiler is connected to the feed port of the heating device, and the discharge port of the heating device is connected to the feed port of the high-temperature storage tank 1.

[0037] The present application sets a heat storage device in the sulfur recovery system. Through the circulation of materials, between the high-temperature storage tank 1 and the low-temperature storage tank 3, the high-temperature material (about 430°C) in the high-temperature storage tank 1 is sent to the reheater to heat the process gas. The medium and high temperature materials after heat exchange enter the only steam generator 2 in the entire system to centrally generate medium and high pressure steam. Then, the low-temperature material (about 120°C) flows out of the steam generator 2 and flows into the low-temperature storage tank 3; of course, in some cases, the material after heat exchange in the reheater can be cooled to about 120°C-150°C and can be directly transported to the low-temperature storage tank 3.

[0038] Between the low-temperature storage tank 3 and the high-temperature storage tank 1, the low-temperature material (about 120°C) in the low-temperature storage tank 3 is sent to the sulfur cooler to cool the process gas, and the medium- and low-temperature materials (about 160°C) after heat exchange are sent from the sulfur cooler to the waste heat boiler to exchange heat with the high-temperature process gas generated by the reactor to form medium- and high-temperature materials (above 300°C). The medium- and high-temperature materials flowing out of the waste heat boiler enter the heating device for heat supplement to form high-temperature materials (about 430°C), and are sent to the high-temperature storage tank 1.

[0039] Therefore, by coupling a heat storage device to the existing sulfur recovery system, the present application can store and concentrate the high-grade heat (about 1200°C) generated by the waste heat boiler and the low-grade heat (about 160°C) generated by the sulfur cooler in the material, and can supplement the heat of the material through a heating device (such as electrical energy, chemical energy), thereby realizing the aggregation and complementary coupling of multiple different grades of energy in the sulfur recovery system; at the same time, the energy aggregated in the material can not only heat the process gas in the reheater, but also utilize the surplus energy of the entire sulfur recovery system to be concentrated in the only steam generator 2 in the entire system. The method generates medium and high pressure steam and can be uniformly sent to the external steam network for use. Compared with the existing sulfur recovery system, not only the overall thermal quality of the steam generated in the system is higher and the thermal quality type is more uniform, but also unnecessary low-calorie quality steam is not generated, which reduces the generation of waste heat and improves the energy utilization efficiency of the entire system. In addition, the steam generation location of the present application is more concentrated, and the steam pipeline and the steam generator 2 do not need to be arranged in the sulfur recovery device, which also avoids the situation in which the steam pipeline is too dispersed in the prior art, and can significantly reduce the complexity of the steam pipeline layout in the prior art.

[0040] The heating device may be an electric heater 4 and / or a combustion heater 5. In actual implementation, since the heat storage device can couple and concentrate the heat of the waste heat boiler and the sulfur cooler, if the heat generated by the sulfur recovery system itself can reach a dynamic balance or be slightly surplus, the heating device may not be provided in the present application, or only one of the electric heater 4 and the combustion heater 5 may be provided.

[0041] Preferably, the present application sets an electric heater 4 and a combustion heater 5 between the material outlet of the waste heat boiler and the feed port of the high-temperature storage tank 1, and can use electric heating to supplement the heat of the material, or can use chemical heat such as gas combustion to supplement the heat of the material. Compared with the traditional electric heating method of the reheater in the prior art (directly electrically heating the process gas), the present application can turn on the electric heater 4 only during the off-peak period, and use the high-temperature storage tank 1 for energy storage, thereby realizing "peak shaving and valley filling" of electricity resources and effectively reducing operating costs.

[0042] At the same time, when there is surplus "gas" or other heat sources in the plant area that are temporarily inconvenient to store, this part of the surplus energy can be stored in the material of the heat storage device through the heating device. When there is an external heat demand, this part of the surplus energy can be converted into abundant medium and high pressure steam for transportation and use, or supplied to the reheater. It is equivalent to the heat storage device equipping the sulfur recovery system and the entire plant with a heat "heat charging treasure", which can take on the peak load and buffering effect of the energy of the entire plant. Correspondingly, the discharge port of the high-temperature storage tank 1 can also be connected to the feed port of the steam generator 2, so that when there is surplus energy stored in the system, the high-temperature storage tank 1 can directly transport high-temperature materials to the steam generator 2, which can not only output the surplus energy in the system to the outside world, but also help to ensure the demand for steam or heating from the outside world.

[0043] As for the piping arrangement of the heat storage device (the red line and the blue line in the drawings of the present application), specifically:

[0044] The heat storage device includes a first main pipe 6, the feed port of the first main pipe 6 is connected to the discharge port of the high-temperature storage tank 1, and the discharge port of the first main pipe 6 is connected to the material inlet of each reheater, or the discharge port of the first main pipe 6 is respectively connected to the feed port of the steam generator 2 and the material inlet of each reheater. In which, with reference to the flow of materials, each reheater in the present application is preferably arranged in parallel. Of course, each reheater can also be arranged in series, that is, the material flows through each reheater in sequence.

[0045] The heat storage device includes a second main pipe 7, a feed port of the second main pipe 7 is connected to the material outlet of each reheater, and a discharge port of the second main pipe 7 is connected to the feed port of the steam generator 2 and / or the feed port of the low-temperature storage tank 3, so that the material after heat exchange in the reheater can be sent to the steam generator 2 or the low-temperature storage tank 3.

[0046] For different pipeline design layouts related to the first main pipe 6 and the second main pipe 7:

[0047] As attached Figure 2 As shown, when the first main pipe 6 is connected only to the material inlet of each reheater, the outlet of the second main pipe 7 is connected to the feed inlet of the steam generator 2, or the outlet of the second main pipe 7 is connected to the feed inlet of the steam generator 2 and the feed inlet of the low-temperature storage tank 3 at the same time, so that the flow direction of the material can be adjusted according to the actual situation after the temperature of the material after heat exchange in the reheater fluctuates. At this time, the reheater and the steam generator 2 can be regarded as a series relationship.

[0048] As attached Figure 3As shown, when the discharge port of the first main pipe 6 is respectively connected to the feed port of the steam generator 2 and the material inlet of each reheater, preferably, the discharge port of the second main pipe 7 is connected to the feed port of the low-temperature storage tank 3, so that a parallel relationship is formed between the first main pipe 6 and the second main pipe 7, the steam generator 2 and each reheater, so that the amount of material flowing to each reheater and the steam generator 2 can be more accurately controlled, and it is also beneficial for the high-temperature material in the high-temperature storage tank 1 to carry surplus energy to participate in steam generation, thereby ensuring the quality of steam generated by the steam generator 2, so that the overall heat quality of the steam generated by the system is higher and the heat quality type is more uniform.

[0049] The heat storage device includes a third main pipe 8 and a fourth main pipe 9, wherein the feed port of the third main pipe 8 is connected to the discharge port of the low-temperature storage tank 3, the discharge port of the third main pipe 8 is connected to the material inlet of each sulfur cooler, the feed port of the fourth main pipe 9 is connected to the material outlet of each sulfur cooler, and the discharge port of the fourth main pipe 9 is connected to the material inlet of the waste heat boiler. Preferably, between the third main pipe 8 and the fourth main pipe 9, each sulfur cooler is connected in parallel, so that the material flow to each sulfur cooler can be more accurately controlled. Of course, each sulfur cooler can also be arranged in series, that is, the material flows through each sulfur cooler in turn.

[0050] The heat storage device includes a first pipe 10, one end of which is connected to the third main pipe 8, and the other end is connected to the fourth main pipe 9, so that the low-temperature material in the low-temperature storage tank 3 can be directly transported to the waste heat boiler for heat exchange with the process gas. In particular, when part of the material is used for steam generation, the low-temperature material accumulated in the low-temperature storage tank 3 can be directly sent to the waste heat boiler and the heating device, and circulated back to the high-temperature storage tank 1. Even after the reactor, sulfur recovery device, incinerator and other equipment are stopped, the material in the heat storage device can still be circulated through the first pipe 10 to maintain the normal steam output of the steam generator 2.

[0051] The heat storage device includes a second pipe 11 and a third pipe 12. One end of the second pipe 11 is connected to the third main pipe 8, and the other end is connected to the material inlet of the incinerator. One end of the third pipe 12 is connected to the material outlet of the incinerator, and the other end is connected to the material outlet of the waste heat boiler. After a certain amount of low-temperature materials are gathered in the low-temperature storage tank 3, in order to ensure the heat balance in the sulfur recovery system and avoid excessive low-temperature materials from causing low-temperature impact on the process gas in the sulfur cooler and the waste heat boiler, affecting the balance of the upstream and downstream sulfur recovery process reactions, part of the low-temperature materials in the low-temperature storage tank 3 can be directly guided to the second pipe 11, first through the incinerator and the high-temperature tail gas heat exchange, and then through the third pipe 12 to the heating device, and after heating, flow into the high-temperature storage tank 1 for storage. Even after the reactor, sulfur recovery device, incinerator and other equipment are stopped, the material circulation in the heat storage device can still be carried out through the second pipe 11 and the third pipe 12 to maintain the normal steam output of the steam generator 2. At the same time, the second tube 11 and the third tube 12 allow the low-temperature material to exchange heat with the high-temperature exhaust gas of the incinerator, which is beneficial to recover part of the heat carried in the exhaust gas and couple it to the heat storage device, which is beneficial to improve energy utilization efficiency and avoid heat waste.

[0052] The modified liquid sulfur material includes elemental sulfur and depolymer, the mass proportion of elemental sulfur is 90%-95%, and the mass proportion of depolymer is 5%-10%; the depolymer is a substance that can enhance the depolymerization of sulfur long-chain molecules to reduce the viscosity of liquid sulfur, so that the modified liquid sulfur material has good fluidity in the temperature range of 120-440°C, and the viscosity is always maintained below 0.05Pa·s. Specifically, the depolymer is H2S or a halogen molecule. In the heat storage device of the present application, the modified liquid sulfur material mainly bears the heat carrier and flows and exchanges heat between the corresponding equipment.

[0053] A high-temperature pump 101 is provided at the discharge port of the high-temperature storage tank 1, and a low-temperature pump 301 is provided at the discharge port of the low-temperature storage tank 3 to ensure the flow of the modified liquid sulfur material in the heat storage device. For the high-temperature storage tank 1 and the low-temperature storage tank 3 provided in this application, the material and the energy carried by the material can be stored, which can buffer the fluctuations in the operation of the system related to process gas, material, energy, etc., and help maintain a stable temperature environment in the sulfur recovery system to ensure the balance of related reactions. When the entire system is running stably, the material temperature in the low-temperature liquid sulfur tank 3 is maintained at about 130°C, and the material temperature in the high-temperature liquid sulfur tank 1 is maintained at about 430°C.

[0054] If it is under relatively ideal conditions, or the influence of material fluctuations and energy fluctuations is not considered, the high-temperature storage tank 1 and the low-temperature storage tank 3 may not be provided in the heat storage device, and only a material pump may be provided in the heat storage device to meet the flow circulation of the material. At this time, the heat storage device does not need to store heat, and the material only serves as a heat transfer medium to transfer and transport heat.

[0055] For the steam generator 2, it includes a preheater, an evaporator, and a superheater connected in sequence. The material flows through the material flow channel of the preheater, the material flow channel of the evaporator, and the material flow channel of the preheater in sequence. The water component flows through the water component flow channel of the preheater, the water component flow channel of the evaporator, and the water component flow channel of the superheater in sequence, so that the water and the material are fully exchanged to form medium and high pressure steam, which can be transported to the steam network outside the system. Among them, the water component can be regarded as water and / or steam, which needs to be determined according to the actual working conditions of the material. In view of the principle that water is heated to form steam, the relevant literature can be consulted, and this application will not elaborate on it.

[0056] This application takes the "two-stage Claus + selective oxidation process" as an example to further introduce the relevant technical improvements in this application.

[0057] Example 1

[0058] As attached Figure 2 As shown, for the "two-stage Claus + selective oxidation process", the sulfur recovery device can be regarded as including three-stage sulfur recovery groups connected in sequence, the acid gas and a part of the air are sent to the reactor, and the other part of the air is sent to the converter of the third-stage sulfur recovery group, so that the first two-stage sulfur recovery groups form a two-stage Claus system, and the third-stage sulfur recovery group forms a selective oxidation system (or super Claus system).

[0059] Specifically, in the flow direction of the process gas, a primary sulfur cooler is arranged between the reactor and the sulfur recovery device, and the sulfur recovery device includes a primary reheater, a primary converter, a primary sulfur cooler, a secondary reheater, a secondary converter, a secondary sulfur cooler, a tertiary reheater, a tertiary converter, and a tertiary sulfur cooler which are connected in sequence. The process gas outlet of the primary sulfur cooler is connected to the process gas inlet of the primary reheater, and the process gas outlet of the tertiary sulfur cooler is connected to the process gas inlet of the incinerator.

[0060] The heat storage device includes a high-temperature storage tank 1, a steam generator 2, a low-temperature storage tank 3, and a heating device which are connected end to end in sequence. As they have been introduced above, they will not be described in detail.

[0061] For the main pipeline arrangement of the heat storage device in this embodiment (see the attached Figure 2The feed port of the first main pipe 6 is connected to the discharge port of the high-temperature storage tank 1, and the discharge port of the first main pipe 6 is respectively connected to the material inlet of the first reheater, the material inlet of the second reheater, and the material inlet of the third reheater;

[0062] The feed inlet of the second main pipe 7 is connected to the material outlet of the first-stage reheater, the material outlet of the second-stage reheater, and the material outlet of the tertiary reheater respectively, and the discharge port of the second main pipe 7 is connected to the feed inlet of the steam generator 2 .

[0063] The feed port of the third main pipe 8 is connected to the discharge port of the low-temperature storage tank 3, and the discharge port of the third main pipe 8 is respectively connected to the material inlet of the primary sulfur cooler, the material inlet of the first sulfur cooler, the material inlet of the second sulfur cooler, and the material inlet of the tertiary sulfur cooler. The feed port of the fourth main pipe 9 is respectively connected to the material outlet of the primary sulfur cooler, the material outlet of the first sulfur cooler, the material outlet of the second sulfur cooler, and the material outlet of the tertiary sulfur cooler, and the discharge port of the fourth main pipe 9 is connected to the material inlet of the waste heat boiler.

[0064] Example 2

[0065] As attached Figure 3 As shown, most of the technical contents in this embodiment are exactly the same as those in Embodiment 1, except that the connection conditions of the first main pipe 6 and the second main pipe 7 in this embodiment are different from those in Embodiment 1.

[0066] Specifically, the discharge port of the first main pipe 6 is respectively connected to the feed port of the steam generator 2, the material inlet of the first reheater, the material inlet of the second reheater, and the material inlet of the third reheater. The discharge port of the second main pipe 7 is connected to the feed port of the low-temperature storage tank 3. Accordingly, a parallel relationship is formed between the first main pipe 6 and the second main pipe 7, and between the steam generator 2, the first reheater, the second reheater, and the third reheater.

[0067] Example 3

[0068] As attached Figure 4 As shown, most of the technical contents of this embodiment are exactly the same as those of embodiment 2, except that two additional auxiliary pipelines are provided in this embodiment (in the attached Figure 4 Indicated by blue lines in the figure), they are respectively recorded as form one and form two; the heat storage device can be set in form one or form two, or can be set in form one and form two at the same time. Specifically:

[0069] Form 1: The heat storage device includes a first tube 10 , one end of which is connected to the third main tube 8 , and the other end of which is connected to the fourth main tube 9 .

[0070] Form 2: The heat storage device includes a second tube 11 and a third tube 12. One end of the second tube 11 is connected to the third main tube 8, and the other end is connected to the material inlet of the incinerator. One end of the third tube 12 is connected to the material outlet of the incinerator, and the other end is connected to the material outlet of the waste heat boiler.

[0071] On the basis of Example 3, for the sulfur recovery system, especially the sulfur recovery process combined with the heat storage device, in order to improve the stability of the operation of the entire system and its intelligence, as shown in the attached Figure 5 As shown, a temperature detector A is provided at the process gas outlet of the waste heat boiler, a regulating valve B is provided in the first pipe 10, a temperature detector C is provided at the process gas outlet of the primary sulfur cooler, a regulating valve D is provided at the material inlet of the primary sulfur cooler, a temperature detector E is provided at the process gas outlet of the first reheater, a regulating valve F is provided at the material inlet of the first reheater, a temperature detector G is provided at the process gas outlet of the first sulfur cooler, a regulating valve H is provided at the material inlet of the first sulfur cooler, a temperature detector I is provided at the process gas outlet of the second reheater, a regulating valve J is provided at the material inlet of the second reheater, and a temperature detector G is provided at the process gas outlet of the first sulfur cooler. A temperature detector K is set at the process gas outlet of the device, a regulating valve L is set at the material inlet of the secondary sulfur cooler, a temperature detector M is set at the process gas outlet of the tertiary reheater, a regulating valve N is set at the material inlet of the tertiary reheater, a temperature detector O is set at the process gas outlet of the tertiary sulfur cooler, a regulating valve P is set at the material inlet of the tertiary sulfur cooler, a temperature detector Q is set at the tail gas outlet of the incinerator, a regulating valve R is set in the second pipe 11, a temperature detector S is set at the feed inlet of the high-temperature storage tank 1, a temperature detector T is set at the feed inlet of the low-temperature storage tank 3, and a regulating valve U is set at the water inlet of the steam generator 2.

[0072] On this basis, the present application proposes a control method for a sulfur recovery system coupled with a heat storage device, comprising:

[0073] S1. Real-time acquisition of the process gas outlet temperature Ta of the waste heat boiler;

[0074] S2. If Ta>260°C, increase the output flow of the cryopump 301 (i.e., increase the discharge flow of the cryogenic storage tank 3 discharge port), and increase the opening of the regulating valve B in the first pipe 10; if Ta<230°C, reduce the output flow of the cryogenic pump 301 (i.e., reduce the discharge flow of the cryogenic storage tank 3 discharge port), and reduce the opening of the regulating valve B in the first pipe 10;

[0075] S3, obtaining the process gas outlet temperature Tbi of each sulfur cooler and the process gas outlet temperature Tci of each reheater in real time;

[0076] Since at least two reheaters and at least two sulfur coolers are set in the present application, in order to facilitate the distinction in the following text and maintain the naming consistency, the natural number i is used as a reference and is consistent with the reheaters and sulfur coolers at each level. For example: the process gas outlet temperature of the first-stage sulfur cooler is recorded as Tb1, the process gas outlet temperature of the second-stage reheater is recorded as Tc2, and correspondingly, the process gas outlet temperature of the primary sulfur cooler is recorded as Tb0.

[0077] S4. If Tbi>160℃, adjust the regulating valve of the corresponding sulfur cooler material inlet to a larger value; if Tbi<150℃, adjust the regulating valve of the corresponding sulfur cooler material inlet to a smaller value; if Tci<240℃, adjust the regulating valve of the corresponding reheater material inlet to a larger value; if Tci>260℃, adjust the regulating valve of the corresponding reheater material inlet to a smaller value;

[0078] S5. Real-time acquisition of the exhaust gas outlet temperature Td of the incinerator;

[0079] S6. If Td>160°C, increase the opening of the regulating valve R in the second pipe 11; if Td<150°C, decrease the opening of the regulating valve R in the second pipe 11.

[0080] Therefore, the present application detects, analyzes and regulates each equipment node (such as waste heat boilers, each reheater, each sulfur cooler, incinerator, etc.) for heat exchange between materials and process gases, and adjusts the material flow of the corresponding equipment node. It can timely and accurately regulate the process gas temperature in each equipment node, so that the process gas in the sulfur recovery system can always be maintained within the temperature range required for the reaction, so as to ensure the normal and stable continuation of the sulfur recovery process.

[0081] Although the above control method can intelligently and accurately regulate the working conditions of each equipment node, since there is an upstream and downstream (series) relationship between the various equipment nodes in the process gas flow upward, and there is a parallel or series relationship in the material flow direction, the regulation of the material flow in a certain equipment node may affect the working conditions in other equipment nodes, resulting in a "domino effect". As a result, the entire sulfur recovery system may produce continuous operating condition fluctuations due to individual regulation operations, which is not conducive to the continuous and stable operation of the entire system; if the system is in the start-up stage that requires frequent adjustments, the process from startup to stable operation of the system will require a relatively long regulation period, which is undoubtedly not conducive to shortening the system start-up time and affecting the actual production efficiency.

[0082] Therefore, in order to improve the stability of the entire control process and minimize the overall impact of a single control, the present application optimizes and improves the control method, specifically:

[0083] The control method (if the method is executed during the system startup phase, it can also be referred to as a startup method for a sulfur recovery system coupled with a heat storage device) includes:

[0084] A1. Obtain the process gas outlet temperature Ta of the waste heat boiler in real time;

[0085] A2. If Ta>260℃, increase the output flow of the cryopump 301, increase the opening of the regulating valve B in the first tube 10, and return to step A1; if Ta<230℃, reduce the output flow of the cryopump 301, reduce the opening of the regulating valve B in the first tube 10, and return to step A1; if 230℃≤Ta≤260℃, proceed to step A3;

[0086] A3. Real-time acquisition of the process gas outlet temperature Tb0 of the primary sulfur cooler;

[0087] A4. If Tb0>160°C, adjust the regulating valve D at the material inlet of the primary sulfur cooler, and return to step A1; if Tb0<150°C, adjust the regulating valve D at the material inlet of the primary sulfur cooler, and return to step A1; if 150°C≤Tb0≤160°C, proceed to step A5;

[0088] A5. Obtain the process gas outlet temperature Tc1 of the first-stage reheater in real time;

[0089] A6. If Tc1 is less than 240°C, increase the output flow of the high temperature pump 101 (i.e., increase the discharge flow of the high temperature storage tank 1 discharge port), adjust the regulating valve F at the material inlet of the first reheater, and return to step A5; if Tc1 is greater than 260°C, reduce the output flow of the high temperature pump 101 (i.e., reduce the discharge flow of the high temperature storage tank 1 discharge port), adjust the regulating valve F at the material inlet of the first reheater, and return to step A5; if 240°C≤Tc1≤260°C, proceed to step A7;

[0090] A7. Obtain the process gas outlet temperature Tb1 of the first-stage sulfur cooler in real time;

[0091] A8. If Tb1>160°C, adjust the regulating valve H at the material inlet of the first-stage sulfur cooler, and return to step A3; if Tb1<150°C, adjust the regulating valve H at the material inlet of the first-stage sulfur cooler, and return to step A3; if 150°C≤Tb1≤160°C, proceed to step A9;

[0092] A9. Obtain the process gas outlet temperature Tc2 of the secondary reheater in real time;

[0093] A10, if Tc2<240℃, adjust the regulating valve J at the secondary reheater material inlet, and return to step A5; if Tc2>260℃, adjust the regulating valve J at the secondary reheater material inlet, and return to step A5; if 240℃≤Tc2≤260℃, proceed to step A11;

[0094] A11, real-time acquisition of the process gas outlet temperature Tb2 of the secondary sulfur cooler;

[0095] A12, if Tb2>160°C, adjust the regulating valve L at the material inlet of the secondary sulfur cooler, and return to step A7; if Tb2<150°C, adjust the regulating valve L at the material inlet of the secondary sulfur cooler, and return to step A7; if 150°C≤Tb2≤160°C, proceed to step A13;

[0096] A13, real-time acquisition of the process gas outlet temperature Tc3 of the third-stage reheater;

[0097] A14, if Tc3<240℃, adjust the regulating valve N at the material inlet of the tertiary reheater, and return to step A9; if Tc3>260℃, adjust the regulating valve N at the material inlet of the tertiary reheater, and return to step A9; if 240℃≤Tc3≤260℃, proceed to step A15;

[0098] A15. Real-time acquisition of the process gas outlet temperature Tb3 of the third-stage sulfur cooler;

[0099] A16. If Tb3>160°C, adjust the regulating valve P at the material inlet of the tertiary sulfur cooler, and return to step A11; if Tb3<150°C, adjust the regulating valve P at the material inlet of the tertiary sulfur cooler, and return to step A11; if 150°C≤Tb3≤160°C, proceed to step A17;

[0100] A17. Obtain the exhaust gas outlet temperature Td of the incinerator in real time;

[0101] A18. If Td>160℃, increase the opening of the regulating valve R in the second tube 11 and return to step A15; if Td<150℃, decrease the opening of the regulating valve R in the second tube 11 and return to step A15; if 150℃≤Td≤160℃, then end, or return to step S1 (forming a logical closed loop).

[0102] Thus, for each device node related to the heat exchange between materials and process gas, the present application uses the control method to more accurately control the process gas temperature and material flow of each related device; especially in the analysis and control process of steps A4, A8, A10, A12, A14, and A16, based on the upstream and downstream relationship of each device node in the process gas flow direction, when the relevant process gas temperature does not meet the preset temperature, on the one hand, the corresponding material valve is adjusted in time, and on the other hand, after adjusting a single device node, it can be fed back to the upstream device of the device node in time, and the upstream device node is adjusted again. The nodes are regulated in sequence, forming an "upward iteration" within a certain regulation range. In the face of the unavoidable situation that "the regulation of downstream device nodes induces fluctuations in upstream operating conditions", the upstream device nodes can be regulated in an "upward iteration" manner in a timely and effective manner. On the one hand, the fluctuations in the operating conditions of other devices induced by the regulation of a single device can be eliminated in a timely and effective manner, which is beneficial to reducing the impact of related fluctuations on each device node and can effectively improve the accuracy of the regulation of each device node. On the other hand, it also prevents the accumulation of fluctuations induced by the regulation of each device node in the system, which is beneficial to the continuous and stable operation of the entire system.

[0103] In addition, this control method can also be used in the start-up phase of the entire sulfur recovery system. With the "upward iteration" after each regulation, it can quickly and effectively eliminate the fluctuations induced by the relevant regulation, effectively shorten the time from system startup to stable operation, improve the system's start-up efficiency, and enable the system to enter a normal and continuously stable operating state more quickly, which is conducive to improving production efficiency.

[0104] In addition to the control contents related to each equipment node related to the heat exchange between the material and the process gas, the control method of the present application also includes: a material temperature control method of the high temperature storage tank 1 and a material temperature control method of the low temperature storage tank 3, so as to ensure that the material conditions in the high temperature storage tank 1 and the low temperature storage tank 3 can meet the use requirements of the relevant downstream equipment nodes as much as possible. Specifically:

[0105] The material temperature control method of the high temperature storage tank 1 includes:

[0106] B1. Real-time acquisition of the feed inlet temperature Te of the high-temperature storage tank 1;

[0107] B2. Determine whether Te is less than 430°C; if so, start the heating device to heat the material to be introduced into the high-temperature storage tank 1; if not, maintain the current operating state.

[0108] Among them, the material entering the high-temperature storage tank 1 is the material flowing out after heat exchange in the waste heat boiler, and the process gas temperature entering the waste heat boiler is about 600-700°C, and the flue gas temperature generated by the incinerator is about 1200-1300°C. In terms of the structure and performance of the waste heat boiler currently used by the applicant, if the temperature of the material entering the waste heat boiler is around 130°C, the temperature of the material flowing out of the waste heat boiler will often not be greater than 430°C, and it is necessary to regulate the material temperature of the high-temperature storage tank 1, and supplement the heat to the material through the electric heater 4 and / or the combustion heater 5.

[0109] The material temperature control method of the low temperature storage tank 3 includes:

[0110] C1. Real-time acquisition of the feed inlet temperature Tf of the low-temperature storage tank 3;

[0111] C2. Determine whether Tf>140°C; if so, increase the opening of the regulating valve U at the water inlet of the steam generator 2; if not, maintain the current operating state.

[0112] Therefore, when the temperature of the material to be introduced into the low-temperature storage tank 3 is greater than 140° C., the water intake into the steam generator 2 can be increased so that the surplus heat carried by the material can be used to produce more medium-pressure steam.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sulfur recovery system coupled with a heat storage device, characterized in that: The sulfur recovery system comprises a heat storage device, a reactor, a sulfur recovery device, and an incinerator, wherein the reactor, the sulfur recovery device, and the incinerator are connected in sequence; the reactor is provided with a waste heat boiler, and the sulfur recovery device comprises at least two stages of sulfur recovery groups connected in sequence, and any one of the sulfur recovery groups comprises a reheater, a converter, and a sulfur cooler connected in sequence; The heat storage device comprises a high-temperature storage tank (1), a steam generator (2), a low-temperature storage tank (3), and a heating device, which are connected end to end in sequence. The heat storage device is provided with a modified liquid sulfur material that can be circulated and transported. The discharge port of the high-temperature storage tank (1) can be connected to the material inlet of each reheater, and the material outlet of each reheater can be connected to the feed port of the steam generator (2) and / or the feed port of the low-temperature storage tank (3). The discharge port of the steam generator (2) is connected to the feed port of the low-temperature storage tank (3), and the discharge port of the low-temperature storage tank (3) can be connected to the material inlet of each sulfur cooler. The material outlet of each sulfur cooler can be connected to the material inlet of the waste heat boiler. The material outlet of the waste heat boiler is connected to the feed port of the heating device, and the discharge port of the heating device is connected to the feed port of the high-temperature storage tank (1).

2. A sulfur recovery system coupled with a heat storage device according to claim 1, characterized in that: The heat storage device comprises a first main pipe (6), the feed port of the first main pipe (6) is connected to the discharge port of the high-temperature storage tank (1), and the discharge port of the first main pipe (6) is connected to the material inlet of each reheater.

3. A sulfur recovery system coupled with a heat storage device according to claim 1, characterized in that: The heat storage device comprises a second main pipe (7), the feed port of the second main pipe (7) is connected to the material outlet of each reheater, and the discharge port of the second main pipe (7) is connected to the feed port of the steam generator (2) and / or the feed port of the low-temperature storage tank (3).

4. The sulfur recovery system coupled with a heat storage device according to claim 1, characterized in that: The heat storage device comprises a third main pipe (8) and a fourth main pipe (9), the feed port of the third main pipe (8) is connected to the discharge port of the low-temperature storage tank (3), the discharge port of the third main pipe (8) is connected to the material inlet of each sulfur cooler, the feed port of the fourth main pipe (9) is connected to the material outlet of each sulfur cooler, and the discharge port of the fourth main pipe (9) is connected to the material inlet of the waste heat boiler.

5. A sulfur recovery system coupled with a heat storage device according to claim 4, characterized in that: The heat storage device comprises a first tube (10), one end of the first tube (10) is connected to the third main tube (8), and the other end of the first tube (10) is connected to the fourth main tube (9).

6. A sulfur recovery system coupled with a heat storage device according to claim 4, characterized in that: The heat storage device comprises a second tube (11) and a third tube (12); one end of the second tube (11) is connected to the third main tube (8), and the other end is connected to the material inlet of the incinerator; one end of the third tube (12) is connected to the material outlet of the incinerator, and the other end is connected to the material outlet of the waste heat boiler.

7. The sulfur recovery system coupled with a heat storage device according to claim 1, characterized in that: A high-temperature pump (101) is provided at the discharge port of the high-temperature storage tank (1), and a low-temperature pump (301) is provided at the discharge port of the low-temperature storage tank (3).

8. The sulfur recovery system coupled with a heat storage device according to claim 1, characterized in that: In the flow direction of the process gas, a primary sulfur cooler is arranged between the reaction furnace and the sulfur recovery device. The sulfur recovery device includes a primary reheater, a primary converter, a primary sulfur cooler, a secondary reheater, a secondary converter, a secondary sulfur cooler, a tertiary reheater, a tertiary converter, and a tertiary sulfur cooler which are connected in sequence. The process gas outlet of the primary sulfur cooler is connected to the process gas inlet of the primary reheater, and the process gas outlet of the tertiary sulfur cooler is connected to the process gas inlet of the incinerator.

9. A sulfur recovery system coupled with a heat storage device according to claim 8, characterized in that: The heat storage device comprises a first main pipe (6) and a second main pipe (7); the feed port of the first main pipe (6) is connected to the discharge port of the high-temperature storage tank (1); the discharge port of the first main pipe (6) is respectively connected to the material inlet of the first-stage reheater, the material inlet of the second-stage reheater, and the material inlet of the tertiary reheater; the feed port of the second main pipe (7) is respectively connected to the material outlet of the first-stage reheater, the material outlet of the second-stage reheater, and the material outlet of the tertiary reheater; the discharge port of the second main pipe (7) is connected to the feed port of the steam generator (2).

10. The sulfur recovery system coupled with a heat storage device according to claim 8, characterized in that: The heat storage device comprises a third main pipe (8) and a fourth main pipe (9), the feed port of the third main pipe (8) is connected to the discharge port of the low-temperature storage tank (3), the discharge port of the third main pipe (8) is respectively connected to the material inlet of the primary sulfur cooler, the material inlet of the first sulfur cooler, the material inlet of the second sulfur cooler, and the material inlet of the tertiary sulfur cooler, the feed port of the fourth main pipe (9) is respectively connected to the material outlet of the primary sulfur cooler, the material outlet of the first sulfur cooler, the material outlet of the second sulfur cooler, and the material outlet of the tertiary sulfur cooler, and the discharge port of the fourth main pipe (9) is connected to the material inlet of the waste heat boiler.

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