High-temperature flue gas heat recovery system of heat recovery coke oven

Abstract

The embodiment of the invention provides a high-temperature flue gas heat recovery system of a heat recovery coke oven. The high-temperature flue gas heat recovery system comprises a power generation system, a heat recovery coke oven system, a fuel combustion system and a high-temperature flue gas diffusion system, the heat recovery coke oven system comprises a heat recovery coke oven and a coke oven waste heat boiler; the fuel combustion system comprises a fuel combustion chamber and a fuel waste heat boiler, the fuel combustion chamber is provided with a fuel regulator, and the fuel combustion chamber is controlled by the fuel regulator and provides controllable heat for the fuel waste heat boiler, so that the fuel waste heat boiler generates controllable second steam to generate power for the generator set; under the condition that the first steam quantity generated by the coke oven waste heat boiler is unstable, the fuel combustion chamber can be controlled to provide controllable heat for the fuel waste heat boiler by adjusting a fuel adjuster of the fuel combustion chamber, and the controllable second steam quantity generated by the fuel waste heat boiler is complementary with the fluctuating first steam quantity; therefore, the generator set can output stable generating capacity, and impact on a power grid is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coking production and waste heat recovery, and in particular to a heat recovery system for high-temperature flue gas from a heat recovery coke oven. Background Art

[0002] Coking is the process of converting coking coal into coke and raw gas by high-temperature dry distillation (950-1050℃) in a coke oven isolated from air. Modern coking uses chamber coke oven technology, which is divided into chemical product recovery coking technology and heat recovery coking technology due to different ways of recovering raw gas.

[0003] The chemical product recovery coking technology uses a slightly positive pressure operation in the carbonization chamber, and draws the raw gas produced in the carbonization chamber from the riser to the gas collecting pipe. The benzene, ammonia, clean gas, tar, etc. in the raw gas are separated by cooling, gas-liquid separation, gas purification and other process measures. The clean gas is returned to the coke oven for heating, and other chemical products are further processed and utilized. In the process of coke oven production and chemical product recovery and processing, the "three wastes" and energy consumption are relatively high.

[0004] The heat recovery coking technology uses a slightly negative pressure operation in the carbonization chamber to directly introduce the raw gas produced in the carbonization chamber into the adjacent combustion chamber for combustion, providing the heat required for heating the coke oven. The remaining heat is carried out by the high-temperature flue gas and the waste heat boiler is used to recover the heat to generate water vapor, which is used for steam turbine power generation.

[0005] At present, the chemical product recovery coke oven technology is the mainstream, and the heat recovery coking technology, as an environmentally friendly coke oven technology, has begun to be favored by the industry.

[0006] As an important product of heat recovery coking technology besides coke, power generation has a huge impact on the technical and economic aspects of heat recovery coking technology. When heat recovery coking technology is used in steel joint ventures, power generation is incorporated into the internal power grid of the steel enterprise for consumption. Independent coking plants use heat recovery coking technology, and power generation is incorporated into the national power grid for consumption. In the process of power generation and grid connection, power generation by heat recovery coking technology needs to meet the basic requirements of power grid access, and must be input stably and continuously to avoid fluctuations and reduce the impact on the power grid. According to the rules of power trading, when the power generation side enterprise has a power deviation beyond a certain range due to shutdown, unplanned shutdown, etc., generally plus or minus 5%-10%, the power generation grid access enterprise shall be fined and assessed.

[0007] The heat recovery coke oven belongs to the internal heat coke oven. Part of the heat released by the combustion of raw gas is used for dry distillation, part is used for steam production and power generation, and the rest of the heat is lost with the flue gas and the system surface. In the high-temperature dry distillation process of the blended coal, the amount and composition changes of the raw gas are completely nonlinear, which is not only related to the quality of the blended coal, but also to factors such as the heating rate, the excess air coefficient, and the coking time. Among them, the temperature field, flow field, excess air coefficient, and composition changes are coupled with each other. At present, there is no mature mathematical model in the world to describe the occurrence law of raw gas. Therefore, the furnace design and process parameters of the heat recovery coke oven are based on the summary of production practice experience. The determination of process design parameters such as the exhaust gas temperature, flow rate, and coking time of the heat recovery coke oven is greatly deviated from the actual production. The waste heat power generation system matching it has the same problem, and the power generation system design will also deviate from the actual production situation. In addition, the heat recovery coke oven and power generation system, like other coke oven production and steam turbine power generation systems, also have production anomalies and accidents. When the heat recovery coke oven fails, the waste heat boiler fails, or the coke oven production plan is adjusted, the heat recovery coke oven high-temperature flue gas system also needs to be flexibly adjusted to maximize heat recovery and maintain stable and continuous power generation output. In order to solve the problems of heat recovery power generation from high-temperature flue gas of the heat recovery coke oven, we have proposed a new process to clear the obstacles for the large-scale promotion and application of heat recovery coking technology. Summary of the invention

[0008] The purpose of the embodiment of the present invention is to provide a heat recovery system for high-temperature flue gas from a heat recovery coke oven, so that the heat recovery system for high-temperature flue gas from a heat recovery coke oven can provide a stable power generation, reduce the impact on the power grid, and meet the needs of power generation and access to the grid. The specific technical solution is as follows:

[0009] In order to achieve the above-mentioned purpose, the present invention proposes a heat recovery system for high-temperature flue gas from a heat recovery coke oven, comprising:

[0010] Power generation systems, including generator sets;

[0011] A heat recovery coke oven system, comprising a heat recovery coke oven and a coke oven waste heat boiler, wherein the high temperature flue gas generated by the heat recovery coke oven is used to heat the coke oven waste heat boiler, so that the coke oven waste heat boiler generates first steam to generate electricity for the generator set;

[0012] A fuel combustion system, comprising a fuel combustion chamber and a fuel waste heat boiler, wherein the fuel combustion chamber has a fuel regulator, and the fuel combustion chamber is controlled by the fuel regulator to provide controllable heat to the fuel waste heat boiler, so that the fuel waste heat boiler generates controllable second steam to generate electricity for the generator set;

[0013] The high-temperature flue gas dissipation system is used to discharge the high-temperature flue gas for the heat recovery coke oven.

[0014] According to one embodiment of the present application, the heat recovery coke oven system further includes a first high-temperature flue gas dust collector, a first valve and a second valve;

[0015] The inlet of the first high-temperature flue gas precipitator is connected to the flue gas outlet of the heat recovery coke oven, and the outlet of the first high-temperature flue gas precipitator is respectively connected to the coke oven waste heat boiler and the first flue gas outlet of the fuel combustion chamber, so that the high-temperature flue gas generated by the heat recovery coke oven can provide heat to the coke oven waste heat boiler and the fuel combustion chamber respectively;

[0016] The first valve is disposed between the first high-temperature flue gas dust collector and the coke oven waste heat boiler, and is used to switch on and off the high-temperature flue gas generated by the heat recovery coke oven for supplying heat to the coke oven waste heat boiler;

[0017] The second valve is arranged between the first high-temperature flue gas dust collector and the first flue gas outlet of the fuel combustion chamber, and is used to turn on and off the high-temperature flue gas generated by the heat recovery coke oven to supply heat to the fuel combustion chamber.

[0018] According to one embodiment of the present application, the high-temperature smoke dissipation system includes: a third valve and a high-temperature chimney;

[0019] The high-temperature chimney is connected to the outlet of the first high-temperature flue gas dust collector, and the third valve is arranged between the high-temperature chimney and the outlet of the first high-temperature flue gas dust collector, and is used to discharge high-temperature flue gas for the heat recovery coke oven.

[0020] According to one embodiment of the present application, the fuel combustion system further comprises: a second high-temperature flue gas dust collector and a fourth valve;

[0021] The inlet of the second high-temperature flue gas dust collector is connected to the second flue gas outlet of the fuel combustion chamber and the fuel waste heat boiler, so that the high-temperature flue gas generated by the fuel combustion chamber can provide heat for the fuel waste heat boiler;

[0022] The fourth valve is arranged between the inlet of the second high-temperature flue gas dust collector and the second flue gas outlet of the fuel combustion chamber, and is used to switch on and off the high-temperature flue gas generated by the fuel combustion chamber to supply the fuel waste heat boiler.

[0023] According to an embodiment of the present invention, the invention further includes:

[0024] The combustion-supporting gas supply system provides combustion-supporting gas to the heat recovery coke oven and the fuel combustion chamber.

[0025] According to one embodiment of the present application, the heat recovery coke oven system also includes: a secondary combustion chamber, which is arranged between the high-temperature flue gas outlet of the heat recovery coke oven and the inlet of the first high-temperature flue gas dust collector, and is used for secondary combustion of the high-temperature flue gas generated by the heat recovery coke oven.

[0026] According to one embodiment of the present invention, the combustion-supporting gas supply system also provides combustion-supporting gas to the secondary combustion chamber.

[0027] According to one embodiment of the present application, the heat recovery coke oven system further comprises: a first flue gas desulfurization and denitrification device, a first induced draft fan and a chimney;

[0028] The first flue gas desulfurization and denitrification device is connected to the exhaust port of the coke oven waste heat boiler and the chimney respectively, and the first induced draft fan is arranged between the exhaust port of the first flue gas desulfurization and denitrification device and the chimney.

[0029] According to one embodiment of the present application, the fuel combustion system further comprises: a second flue gas desulfurization and denitrification device and a second induced draft fan;

[0030] The second flue gas desulfurization and denitrification device is connected to the exhaust port of the fuel waste heat boiler and the chimney respectively, and the second induced draft fan is arranged between the exhaust port of the second flue gas desulfurization and denitrification device and the chimney.

[0031] According to an embodiment of the present invention, the invention further includes:

[0032] The desalted water supply system provides desalted water to the coke oven waste heat boiler and the fuel waste heat boiler.

[0033] Beneficial effects of the embodiments of the present invention:

[0034] The heat recovery system for high-temperature flue gas from a heat recovery coke oven provided in an embodiment of the present invention comprises a power generation system, a heat recovery coke oven system, a fuel combustion system and a high-temperature flue gas dissipation system. The heat recovery coke oven system includes a heat recovery coke oven and a coke oven waste heat boiler, the high-temperature flue gas generated by the heat recovery coke oven provides heat for the coke oven waste heat boiler, so that the coke oven waste heat boiler generates a first steam to generate electricity for the generator set; the fuel combustion system includes a fuel combustion chamber and a fuel waste heat boiler, the fuel combustion chamber has a fuel regulator, the fuel combustion chamber is controlled by the fuel regulator, and provides controllable heat for the fuel waste heat boiler, so that the fuel waste heat boiler generates a controllable second steam to generate electricity for the generator set; in an embodiment of the present application, when the high-temperature flue gas generated by the heat recovery coke oven is unstable and the amount of first steam generated by the coke oven waste heat boiler is unstable, the fuel regulator of the fuel combustion chamber can be adjusted to control the fuel combustion chamber to provide controllable heat for the fuel waste heat boiler, and the controllable second steam amount generated by the fuel waste heat boiler complements the fluctuating first steam amount, thereby providing a relatively stable total steam amount for the generator set, so that the generator set can output a relatively stable power generation and reduce the impact on the power grid.

[0035] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0037] Figure 1 This is a schematic structural diagram of a heat recovery system for high-temperature flue gas from a heat recovery coke oven according to an embodiment of the present application.

[0038] The reference numerals are as follows:

[0039] Generator set 11, heat recovery coke oven 21, coke oven waste heat boiler 22, first high-temperature flue gas dust collector 23, first valve 24, second valve 25, secondary combustion chamber 26, first flue gas desulfurization and denitrification device 27, first induced draft fan 28, chimney 29, fuel combustion chamber 31, fuel waste heat boiler 32, second high-temperature flue gas dust collector 33, fourth valve 34, second flue gas desulfurization and denitrification device 35, second induced draft fan 36, third valve 41, high-temperature chimney 42, combustion-supporting gas supply system 50, desalted water supply system 60. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field based on this application belong to the scope of protection of the present invention.

[0041] The main purpose of the embodiment of this scheme is to provide a heat recovery system for high-temperature flue gas from a heat recovery coke oven, so that the heat recovery system for high-temperature flue gas from a heat recovery coke oven can provide stable power generation and reduce the impact on the power grid.

[0042] To this end, the present application proposes a heat recovery system for high-temperature flue gas from a heat recovery coke oven.

[0043] The heat recovery system for high-temperature flue gas from a heat recovery coke oven provided by the present application, in addition to the heat recovery coke oven system that provides steam for the power generation system, is additionally provided with a fuel combustion system that provides controllable steam. When the amount of high-temperature flue gas from the coke oven is insufficient, steam is supplemented through the fuel combustion system to meet the needs of the power generation system. When the high-temperature flue gas from the coke oven is excessive, the steam of the fuel combustion system is reduced to meet the needs of the generator set.

[0044] Figure 1 FIG. 1 is a schematic diagram of a heat recovery system for high-temperature flue gas from a coke oven according to an embodiment of the present invention. Figure 1 As shown, the heat recovery system for high-temperature flue gas from a heat recovery coke oven includes: a power generation system, a heat recovery coke oven system, a fuel combustion system and a high-temperature flue gas dissipation system.

[0045] The power generation system includes a generator set 11; the heat recovery coke oven system includes a heat recovery coke oven 21 and a coke oven waste heat boiler 22, the high-temperature flue gas generated by the heat recovery coke oven 21 provides heat for the coke oven waste heat boiler 22, so that the coke oven waste heat boiler 22 generates a first steam to generate electricity for the generator set 11; the fuel combustion system includes a fuel combustion chamber 31 and a fuel waste heat boiler 32, the fuel combustion chamber 31 has a fuel regulator, and the fuel combustion chamber 31 is controlled by the fuel regulator to provide controllable heat for the fuel waste heat boiler 32, so that the fuel waste heat boiler 32 generates a controllable second steam to generate electricity for the generator set 11; the high-temperature flue gas dissipation system is used to discharge high-temperature flue gas from the heat recovery coke oven 21.

[0046] The high-temperature flue gas generated by the heat recovery coke oven 21 can be directly generated by burning the raw coal gas generated during the coking process. Specifically, the high-temperature flue gas generated by the direct combustion of the raw coal gas first supplies the heat required for heating the heat recovery coke oven 21 itself, and the remaining heat is used to heat the coke oven waste heat boiler 22.

[0047] The heat recovery system for high-temperature flue gas from a heat recovery coke oven 21 provided in an embodiment of the present invention comprises a power generation system, a heat recovery coke oven system, a fuel combustion system and a high-temperature flue gas dissipation system. The heat recovery coke oven system comprises a heat recovery coke oven 21 and a coke oven waste heat boiler 22, wherein the high-temperature flue gas generated by the heat recovery coke oven 21 provides heat for the coke oven waste heat boiler 22, so that the coke oven waste heat boiler 22 generates a first steam to generate electricity for the generator set 11; the fuel combustion system comprises a fuel combustion chamber 31 and a fuel waste heat boiler 32, wherein the fuel combustion chamber 31 has a fuel regulator, and the fuel combustion chamber 31 is controlled by the fuel regulator to provide controllable heat to the fuel waste heat boiler 32, so that the fuel waste heat boiler 32 generates a controllable second steam to generate electricity for the generator set 11; the fuel combustion system comprises a fuel combustion chamber 31 and a fuel waste heat boiler 32, wherein the fuel combustion chamber 31 has a fuel regulator, and the fuel combustion chamber 31 is controlled by the fuel regulator to provide controllable heat to the fuel waste heat boiler 32, so that the fuel waste heat boiler 32 generates a controllable second steam to generate electricity for the generator set 11. The generator set 11 generates electricity; in the embodiment of the present application, when the high-temperature flue gas generated by the heat recovery coke oven 21 is unstable and the first steam amount generated by the coke oven waste heat boiler 22 is unstable, the fuel regulator of the fuel combustion chamber 31 can be adjusted to control the fuel combustion chamber 31 to provide controllable heat for the fuel waste heat boiler 32, and the fuel waste heat boiler 32 generates a controllable second steam amount that complements the fluctuating first steam amount, thereby providing a relatively stable total steam amount for the generator set 11, so that the generator set 11 can output a relatively stable amount of power generation and reduce the impact on the power grid.

[0048] In this embodiment, the amount and temperature of high-temperature flue gas generated by the heat recovery coke oven 21 are mainly caused by the volatile matter of coking coal and the change of coking time. The heat recovery coke oven 21 is in normal production. It is assumed that the coke oven waste heat boiler 22 is under rated working conditions. Within unit time T, the amount of first steam generated is Q1, and the fuel waste heat boiler 32 is under rated working conditions. The amount of second steam generated is Q2. The amount of steam output by the heat recovery coke oven system and the fuel combustion system to the turbine unit of the generator set 11 for power generation is Q. Q = f1*Q1+f2*Q2, where f1 is the coefficient of variation of the steam amount of the coke oven waste heat boiler 22, f1 = 1-0.7, and f2 is the coefficient of variation of the steam amount of the fuel waste heat boiler 32, f2 = 1-0.4. When the coke oven waste heat boiler 22 fails, f1 = 0, f2 = 1, and the amount of steam provided by Q2 can meet the stable power generation output.

[0049] After calculation, the online power generation can configure the steam turbine unit according to the steam volume of 1.6*Q1. Within the unit time T, the Q required by the steam turbine unit is Q=Q1+0.4Q2, which is mainly provided by the coke oven waste heat boiler 22 and supplemented by the fuel waste heat boiler 32. The rated load of the fuel waste heat boiler Q2 is 1.4*Q1, that is, Q2=1.4*Q1. When the heat recovery coke oven 21 is in normal production, the fuel waste heat boiler 32 produces steam at the rated load of Q2*40%, and the power generation that can be obtained is stable. The online power deviation is within the range allowed by the trading rules.

[0050] In some embodiments, the heat recovery coke oven system further includes a first high-temperature flue gas dust collector 23, a first valve 24, and a second valve 25; the inlet of the first high-temperature flue gas dust collector 23 is connected to the flue gas outlet of the heat recovery coke oven 21, and the outlet of the first high-temperature flue gas dust collector 23 is respectively connected to the coke oven waste heat boiler 22 and the first flue gas outlet of the fuel combustion chamber 31, so that the high-temperature flue gas generated by the heat recovery coke oven 21 can provide heat to the coke oven waste heat boiler 22 and the fuel combustion chamber 31 respectively; the first valve 24 is arranged between the first high-temperature flue gas dust collector 23 and the coke oven waste heat boiler 22, and is used to turn on and off the high-temperature flue gas generated by the heat recovery coke oven 21 for the heat supply to the coke oven waste heat boiler 22; the second valve 25 is arranged between the first high-temperature flue gas dust collector 23 and the first flue gas outlet of the fuel combustion chamber 31, and is used to turn on and off the high-temperature flue gas generated by the heat recovery coke oven 21 for the heat supply to the fuel combustion chamber 31. By switching the first valve 24, the high-temperature flue gas can be connected or shut off to the coke oven waste heat boiler 22. By switching the second valve 25 , the high-temperature flue gas can be connected or blocked from passing to the fuel combustion chamber 31 .

[0051] The first high-temperature flue gas dust collector 23 can use gravity dust removal or cyclone dust removal technology to remove dust from the high-temperature flue gas generated by the heat recovery coke oven 21.

[0052] When the heat recovery coke oven 21 is in a low-load state and the high-temperature flue gas produced is insufficient, the first valve 24 is opened and the second valve 25 is closed. The fuel regulator can be controlled to increase the fuel provided to the fuel combustion chamber 31 and increase the heat provided to the fuel waste heat boiler 32. The high-temperature flue gas generated by the fuel combustion chamber 31 exchanges heat with the fuel waste heat boiler 32, and the second water vapor generated by the heat exchange of the fuel waste heat boiler 32 enters the water vapor main pipe to supplement the water vapor required for full load of the generator set 11.

[0053] When the heat recovery coke oven 21 is in an overproduction state and generates excess high-temperature flue gas, the first valve 24 is opened and the second valve 25 is opened, so that the fuel regulator can be controlled to reduce the fuel provided to the fuel combustion chamber 31 and the heat provided to the fuel waste heat boiler 32. The high-temperature flue gas generated by the fuel combustion chamber 31 merges with the high-temperature flue gas generated by the heat recovery coke oven 21 and exchanges heat with the fuel waste heat boiler 32. The second water vapor generated by the heat exchange of the fuel waste heat boiler 32 enters the water vapor main pipe to balance the water vapor required for the full load of the generator set 11.

[0054] In addition, since the boiler system has a higher failure rate than the generator set 11, especially when the coke oven waste heat boiler 22 has a pipe burst or other failure, the coke oven waste heat boiler 22 needs to be shut down for fault handling. In the prior art, there is only one coke oven waste heat boiler 22, and the high-temperature flue gas generated by the heat recovery coke oven 21 needs to be released, and the generator set 11 needs to be shut down. In this solution, two boilers (coke oven waste heat boiler 22 and fuel waste heat boiler 32) are set up. When the coke oven waste heat boiler 22 has a pipe burst or other failure, the first valve 24 can be closed and the second valve 25 can be opened to introduce the high-temperature flue gas from the heat recovery coke oven 21 into the fuel waste heat boiler 32 to maintain the operation of the generator set 11 system.

[0055] In some embodiments, the high-temperature flue gas dissipation system includes: a third valve 41 and a high-temperature chimney 42; the high-temperature chimney 42 is connected to the outlet of the first high-temperature flue gas dust collector 23, and the third valve 41 is arranged between the high-temperature chimney 42 and the outlet of the first high-temperature flue gas dust collector 23, and is used to discharge high-temperature flue gas for the heat recovery coke oven 21. When the heat recovery coke oven 21 generates too much high-temperature flue gas, the third valve 41 can be opened to discharge the excess flue gas to the outside through the high-temperature chimney 42.

[0056] In some embodiments, the second valve 25 may be a double-directional valve. When the second valve 25 and the third valve 41 are opened at the same time, the smoke from the combustion chamber 31 may be discharged to the outside through the high-temperature chimney 42 .

[0057] In some embodiments, the fuel combustion system also includes: a second high-temperature flue gas dust collector 33 and a fourth valve 34; the inlet of the second high-temperature flue gas dust collector 33 is connected to the second flue gas outlet of the fuel combustion chamber 31 and the fuel waste heat boiler 32, so that the high-temperature flue gas generated by the fuel combustion chamber 31 can provide heat for the fuel waste heat boiler 32; the fourth valve 34 is arranged between the inlet of the second high-temperature flue gas dust collector 33 and the second flue gas outlet of the fuel combustion chamber 31, and is used to turn on and off the high-temperature flue gas generated by the fuel combustion chamber 31 to supply the fuel waste heat boiler 32.

[0058] The second high-temperature flue gas dust collector 33 can use gravity dust removal or cyclone dust removal technology to remove dust from the high-temperature flue gas generated by the fuel combustion chamber 31.

[0059] When the heat recovery coke oven 21 is in a low load state, or when the heat recovery coke oven 21 is in an overproduction state, the fourth valve 34 can be in an open state. When the fuel waste heat boiler 32 needs to be repaired, the fourth valve 34 is closed, the second valve 25 and the third valve 41 are opened, and the high-temperature flue gas of the fuel combustion chamber 31 can be discharged through the high-temperature chimney 42.

[0060] In some embodiments, the high temperature flue gas heat recovery system of the heat recovery coke oven 21 further includes: a combustion-supporting gas supply system 50 , which provides combustion-supporting gas to the heat recovery coke oven 21 and the fuel combustion chamber 31 .

[0061] In practice, the raw coal gas produced in the carbonization chamber does not need to be completely burned in the combustion chamber to meet the heat required for coking, so a certain amount of combustible gas remains in the high-temperature flue gas discharged from the combustion chamber.

[0062] In addition, since the heat recovery coke oven 21 is heated by burning its own raw gas to generate high-temperature flue gas, the temperature of the high-temperature flue gas is mainly achieved by adjusting the amount of combustion-supporting gas air. The temperature of the high-temperature flue gas has a great influence on the coking time and flue gas composition. Table 1 lists a group of high-temperature flue gas compositions at the bottom of the combustion chamber under different coking time conditions.

[0063] Table 1 High temperature flue gas composition

[0064] Coking time <![CDATA[H2(%)]]> <![CDATA[O2(%)]]> <![CDATA[N2(%)]]> <![CDATA[CH4(%)]]> CO(%) <![CDATA[CO2(%)]]> <![CDATA[H2O(%)]]> 28 hours 4.4 0.1 65.2 0.2 3.1 3.6 23.4 21 hours 2.89 0.29 65.98 0.9 3.27 8.04 18.6

[0065] From the data in Table 1, it can be seen that the hydrogen content in the high-temperature flue gas is relatively high, and there is a trend of increasing with the extension of the coking time. When the coking time is long, the hydrogen content is too high, and it is easy to produce safety hazards. For this reason, the combustible gas in the high-temperature flue gas can be burned out before entering the coke oven waste heat boiler 22. In some embodiments, the heat recovery coke oven system also includes: a secondary combustion chamber 26, which is arranged between the high-temperature flue gas outlet of the heat recovery coke oven 21 and the inlet of the first high-temperature flue gas dust collector 23, and is used for secondary combustion of the high-temperature flue gas generated by the heat recovery coke oven 21, so as to improve the heat recovery efficiency of the high-temperature flue gas of the heat recovery coke oven.

[0066] In some embodiments, the combustion-supporting gas supply system 50 also provides combustion-supporting gas to the secondary combustion chamber 26. By adjusting the amount of gas added to the secondary combustion chamber 26, the combustible gas is burned out and the heat of waste heat recovery is increased.

[0067] In some embodiments, the heat recovery coke oven system further includes: a first flue gas desulfurization and denitrification device 27, a first induced draft fan 28 and a chimney 29; the first flue gas desulfurization and denitrification device 27 is connected to the exhaust port of the coke oven waste heat boiler 22 and the chimney 29 respectively, and the first induced draft fan 28 is arranged between the exhaust port of the first flue gas desulfurization and denitrification device 27 and the chimney 29. The first flue gas desulfurization and denitrification device 27 can use dry or semi-dry desulfurization and denitrification technology to desulfurize and denitrify the flue gas discharged from the coke oven waste heat boiler 22. The first induced draft fan 28 is a wear-resistant fan to increase its service life.

[0068] In some embodiments, the fuel combustion system further includes: a second flue gas desulfurization and denitrification device 35 and a second induced draft fan 36; the second flue gas desulfurization and denitrification device 35 is connected to the exhaust port of the fuel waste heat boiler 32 and the chimney 29 respectively, and the second induced draft fan 36 is arranged between the exhaust port of the second flue gas desulfurization and denitrification device 35 and the chimney 29. The second flue gas desulfurization and denitrification device 35 can use dry or semi-dry desulfurization and denitrification technology to desulfurize and denitrify the flue gas discharged from the fuel waste heat boiler 32. The second induced draft fan 36 is a wear-resistant fan to increase its service life.

[0069] In some embodiments, the heat recovery system for high-temperature flue gas from the heat recovery coke oven 21 further includes: a desalted water supply system 60 for providing desalted water to the coke oven waste heat boiler 22 and the fuel waste heat boiler 32 .

[0070] In the embodiment of this scheme, a fuel combustion chamber 31 and a fuel waste heat boiler 32 are arranged next to the coke oven waste heat boiler 22, and the fuel combustion chamber 31 is connected to the coke oven waste heat boiler 22 and the fuel waste heat boiler 32 through valve control and the high-temperature flue gas pipeline. In this scheme, the high-temperature flue gas generated by burning fuel in the fuel combustion chamber 31 can be provided to the fuel waste heat boiler 32, and the fuel waste heat can also receive the high-temperature flue gas from the heat recovery coke oven 21.

[0071] When the amount of high-temperature flue gas from the heat recovery coke oven 21 is insufficient, the fuel combustion chamber 31 is used to supplement the heat, providing sufficient water vapor for the generator set 11 to meet the needs of the generator set 11. When the high-temperature flue gas from the heat recovery coke oven 21 is excessive, the fuel combustion is reduced, and the high-temperature flue gas from the heat recovery coke oven 21 is introduced into the fuel waste heat boiler 32 to stabilize the water vapor supply to the generator set 11 and meet the needs of the generator set 11.

[0072] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0073] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A heat recovery system for high temperature flue gas from a coke oven, characterized in that: include: A power generation system, comprising a generator set (11); A heat recovery coke oven system, comprising a heat recovery coke oven (21) and a coke oven waste heat boiler (22), wherein the high-temperature flue gas generated by the heat recovery coke oven (21) provides heat to the coke oven waste heat boiler (22), so that the coke oven waste heat boiler (22) generates first steam to generate electricity for the generator set (11); A fuel combustion system, comprising a fuel combustion chamber (31) and a fuel waste heat boiler (32), wherein the fuel combustion chamber (31) has a fuel regulator, and the fuel combustion chamber (31) is controlled by the fuel regulator to provide controllable heat to the fuel waste heat boiler (32), so that the fuel waste heat boiler (32) generates controllable second steam to generate electricity for the generator set (11); A high-temperature flue gas dissipation system is used to discharge high-temperature flue gas from the heat recovery coke oven (21).

2. The heat recovery system for high-temperature flue gas from a coke oven according to claim 1, characterized in that: The heat recovery coke oven system further comprises a first high-temperature flue gas dust collector (23), a first valve (24) and a second valve (25); The inlet of the first high-temperature flue gas dust collector (23) is connected to the flue gas outlet of the heat recovery coke oven (21), and the outlet of the first high-temperature flue gas dust collector (23) is respectively connected to the first flue gas outlets of the coke oven waste heat boiler (22) and the fuel combustion chamber (31), so that the high-temperature flue gas generated by the heat recovery coke oven (21) can provide heat for the coke oven waste heat boiler (22) and the fuel combustion chamber (31); The first valve (24) is arranged between the first high-temperature flue gas dust collector (23) and the coke oven waste heat boiler (22), and is used to switch on and off the high-temperature flue gas generated by the heat recovery coke oven (21) for supplying heat to the coke oven waste heat boiler (22); The second valve (25) is arranged between the first high-temperature flue gas dust collector (23) and the first flue gas outlet of the fuel combustion chamber (31), and is used to switch on and off the high-temperature flue gas generated by the heat recovery coke oven (21) for supplying heat to the fuel combustion chamber (31).

3. The heat recovery system for high temperature flue gas from a coke oven according to claim 2, characterized in that: The high-temperature smoke dissipation system comprises: a third valve (41) and a high-temperature chimney (42); The high-temperature chimney (42) is connected to the outlet of the first high-temperature flue gas dust collector (23), and the third valve (41) is arranged between the high-temperature chimney (42) and the outlet of the first high-temperature flue gas dust collector (23) to discharge high-temperature flue gas for the heat recovery coke oven (21).

4. The heat recovery system for high-temperature flue gas from a heat recovery coke oven according to claim 3, characterized in that: The fuel combustion system further comprises: a second high-temperature flue gas dust collector (33) and a fourth valve (34); The inlet of the second high-temperature flue gas dust collector (33) is connected to the second flue gas outlet of the fuel combustion chamber (31) and the fuel waste heat boiler (32), so that the high-temperature flue gas generated by the fuel combustion chamber (31) can provide heat for the fuel waste heat boiler (32); The fourth valve (34) is arranged between the inlet of the second high-temperature flue gas dust collector (33) and the second flue gas outlet of the fuel combustion chamber (31), and is used to switch on and off the supply of the high-temperature flue gas generated by the fuel combustion chamber (31) to the fuel waste heat boiler (32).

5. The heat recovery system for high temperature flue gas from a coke oven according to claim 2, characterized in that: Also includes: The combustion-supporting gas supply system (50) provides combustion-supporting gas to the heat recovery coke oven (21) and the fuel combustion chamber (31).

6. The heat recovery system for high-temperature flue gas from a heat recovery coke oven according to claim 5, characterized in that: The heat recovery coke oven system further comprises: a secondary combustion chamber (26), wherein the secondary combustion chamber (26) is arranged between the high-temperature flue gas outlet of the heat recovery coke oven (21) and the inlet of the first high-temperature flue gas dust collector (23), and is used for secondary combustion of the high-temperature flue gas generated by the heat recovery coke oven (21).

7. The heat recovery system for high temperature flue gas from a heat recovery coke oven according to claim 2, characterized in that: The combustion-supporting gas supply system (50) also provides combustion-supporting gas to the secondary combustion chamber (26).

8. The heat recovery system for high temperature flue gas from a heat recovery coke oven according to claim 1, characterized in that: The heat recovery coke oven system further comprises: a first flue gas desulfurization and denitrification device (27), a first induced draft fan (28) and a chimney (29); The first flue gas desulfurization and denitrification device (27) is respectively connected to the exhaust port of the coke oven waste heat boiler (22) and the chimney (29), and the first induced draft fan (28) is arranged between the exhaust port of the first flue gas desulfurization and denitrification device (27) and the chimney (29).

9. The heat recovery system for high-temperature flue gas from a heat recovery coke oven according to claim 8, characterized in that: The fuel combustion system further comprises: a second flue gas desulfurization and denitrification device (35) and a second induced draft fan (36); The second flue gas desulfurization and denitrification device (35) is respectively connected to the exhaust port of the fuel waste heat boiler (32) and the chimney (29), and the second induced draft fan (36) is arranged between the exhaust port of the second flue gas desulfurization and denitrification device (35) and the chimney (29).

10. The heat recovery system for high-temperature flue gas from a heat recovery coke oven according to claim 1, characterized in that: Also includes: The desalted water supply system (60) provides desalted water to the coke oven waste heat boiler (22) and the fuel waste heat boiler (32).

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