Converter flue gas recovery method and system

Abstract

The present invention provides a converter flue gas recovery method and system, which are applied in a converter flue gas recovery system, wherein the system comprises: a first recovery cup valve, a release cup valve and a second recovery cup valve; the method comprises: when the converter starts smelting, obtaining the O2 concentration and the CO concentration in the flue gas; controlling the switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve according to the O2 and CO concentrations in the flue gas, so as to grade and recover flue gases of different concentrations; wherein the first recovery cup valve is used to recover flue gases with high CO concentrations, the second recovery cup valve is used to recover flue gases with low CO concentrations, and the release valve is used to release flue gases with high O2 concentrations; in this way, in different stages of converter smelting, converter flue gases of different CO concentrations can be graded and recovered according to the O2 concentration and CO concentration in the flue gas, so as to avoid energy waste; at the same time, the potential safety hazard caused by mixed recovery of converter flue gases of different CO concentrations can also be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of converter flue gas recovery, and in particular to a converter flue gas recovery method and system. Background Art

[0002] Oxygen converter steelmaking is the main steelmaking process in my country, accounting for about 90% of my country's steel production.

[0003] Generally speaking, there are two main technologies for converter flue gas purification and recovery, one is the wet process (OG process) technology, and the other is the dry process technology. Among them, the dry process technology has the advantages of high degree of flue gas purification, no secondary pollution, energy saving, and small footprint. Now it is adopted by more and more steel companies.

[0004] At present, when recovering flue gas, it is impossible to grade and recover CO of different concentration levels. For example, if the user needs flue gas with a high CO concentration, the flue gas with a low CO concentration will be released, resulting in a waste of energy. On the other hand, if the flue gas with a low CO concentration is mixed with the flue gas with a high CO concentration for recovery, the CO concentration of the mixed flue gas will be reduced, resulting in an increase in the oxygen content in the flue gas, which poses a safety hazard. Summary of the invention

[0005] In view of the problems existing in the prior art, the embodiments of the present invention provide a converter flue gas recovery method and system to solve or partially solve the technical problem that converter flue gas with different CO concentrations cannot be graded for recovery, resulting in energy waste and safety hazards.

[0006] In a first aspect of the present invention, a converter flue gas recovery method is provided, the method is applied in a converter flue gas recovery system, the system comprising: a first recovery cup valve, a venting cup valve and a second recovery cup valve; the method comprises:

[0007] During converter smelting, obtain the O2 concentration and CO concentration in the flue gas;

[0008] The switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled accordingly according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations; wherein the first recovery cup valve is used to recover flue gas with high CO concentration, the second recovery cup valve is used to recover flue gas with low CO concentration, the release valve is used to release flue gas with high O2 concentration, the first recovery pipeline is connected to the first recovery cup valve, and the second recovery pipeline is connected to the second recovery cup valve.

[0009] In the above scheme, the switch states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas, so as to grade and recover flue gas of different concentrations, including:

[0010] If it is determined that the O2 concentration in the flue gas is less than or equal to the first O2 concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the first recovery cup valve are controlled to be closed, and the second recovery cup valve is controlled to be opened, so that the second recovery cup valve can be used to recover flue gas with low CO concentration.

[0011] In the above scheme, the switch states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas, so as to grade and recover flue gas of different concentrations, including:

[0012] If it is determined that the O2 concentration in the flue gas is less than the second O2 concentration threshold and the CO concentration is greater than or equal to the CO concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the second recovery cup valve are controlled to be closed, and the first recovery cup valve is controlled to be opened, so as to use the first recovery cup valve to recover flue gas with high CO concentration.

[0013] In the above scheme, the switch states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas, so as to grade and recover flue gas of different concentrations, including:

[0014] If it is determined that the O2 concentration in the flue gas is greater than or equal to the second O2 concentration threshold and less than the first O2 concentration threshold and it is determined that the gas tank pressure is greater than or equal to the second recovery pipeline pressure; or,

[0015] If it is determined that the CO concentration in the flue gas is less than the CO concentration threshold and it is determined that the gas tank pressure is greater than or equal to the second recovery pipeline pressure, the release cup valve and the first recovery cup valve are controlled to be closed, and the second recovery cup valve is controlled to be opened, so that the second recovery cup valve can be used to recover flue gas with low CO concentration.

[0016] In the above scheme, the switch states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas, so as to grade and recover flue gas of different concentrations, including:

[0017] If it is determined that the O2 concentration in the flue gas is greater than the first O2 concentration threshold, the release cup valve is controlled to open, and the first recovery cup valve and the second recovery cup valve are controlled to close, so that the purified flue gas is discharged into the atmosphere by using the release cup valve.

[0018] In the above solution, the first O2 concentration threshold is 2-3%, the second O2 concentration threshold is 0.5-1%, and the CO concentration threshold is 30-35%.

[0019] A second aspect of the present invention provides a converter fume recovery system, the system comprising: a first recovery cup valve, a venting cup valve, a second recovery cup valve and a controller; wherein:

[0020] The controller is used to obtain the O2 concentration and CO concentration in the flue gas during converter smelting;

[0021] The switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled accordingly according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations; wherein the first recovery cup valve is used to recover flue gas with high CO concentration, the second recovery cup valve is used to recover flue gas with low CO concentration, the release valve is used to release flue gas with high O2 concentration, the first recovery pipeline is connected to the first recovery cup valve, and the second recovery pipeline is connected to the second recovery cup valve.

[0022] In the above solution, the system further includes: a fan; and the controller is further used for:

[0023] The flue pressure is collected, and if it is determined that the flue pressure is a negative value, the rotation speed of the fan is reduced.

[0024] In the above solution, the controller is specifically used for:

[0025] If it is determined that the O2 concentration in the flue gas is less than or equal to the first O2 concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the first recovery cup valve are controlled to be closed, and the second recovery cup valve is controlled to be opened, so that the second recovery cup valve can be used to recover flue gas with low CO concentration.

[0026] In the above solution, the controller is specifically used for:

[0027] If it is determined that the O2 concentration in the flue gas is less than the second O2 concentration threshold and the CO concentration is greater than or equal to the CO concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the second recovery cup valve are controlled to be closed, and the first recovery cup valve is controlled to be opened, so as to use the first recovery cup valve to recover flue gas with high CO concentration.

[0028] The present invention provides a converter flue gas recovery method and system, which are applied in a converter flue gas recovery system, wherein the system comprises: a first recovery cup valve, a release cup valve and a second recovery cup valve; the method comprises: when the converter starts smelting, obtaining the O2 concentration and CO concentration in the flue gas; controlling the switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas, so as to grade and recover flue gas of different concentrations; wherein the first recovery cup valve is used to recover flue gas with high CO concentration, the second recovery cup valve is used to recover flue gas with low CO concentration, and the release valve is used to release flue gas with high O2 concentration; in this way, in different stages of converter smelting, converter flue gas of different CO concentrations can be graded and recovered according to the O2 concentration and CO concentration in the flue gas, so as to avoid energy waste; at the same time, the potential safety hazard caused by mixed recovery of converter flue gas of different CO concentrations can also be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0030] In the attached picture:

[0031] Figure 1 A schematic structural diagram of a converter fume recovery system according to an embodiment of the present invention is shown;

[0032] Figure 2 A schematic flow chart of a converter flue gas recovery method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0034] In order to better understand the technical solution of this embodiment, the converter flue gas recovery system is first introduced here. Figure 1 As shown, the system includes: a first recovery cup valve V R1 , Diffusion cup valve V E And the second recovery cup valve V R2 ;

[0035] First recovery cup valve V R1 It is connected to the first end of the first recovery pipeline, the second end of the first recovery pipeline is connected to the high calorific value gas holder 11, and the third end of the first recovery pipeline is connected to the main gas pipeline; wherein the high calorific value gas holder can be a converter gas holder.

[0036] Relief cup valve V E The first end of the discharge pipe is connected to the discharge tower 12, and the third end of the discharge pipe is connected to the main gas pipeline.

[0037] Second recovery cup valve V R2 It is connected to the first end of the second recovery pipeline, the second end of the second recovery pipeline is connected to the low calorific value gas holder 13, and the third end of the second recovery pipeline is connected to the main gas pipeline; wherein the low calorific value gas holder can be a blast furnace gas holder.

[0038] Continue to refer Figure 1 The system further includes: a fan 14 and a controller 15; the fan 14 is used to blow gas and oxygen into the main gas pipeline; the controller 15 is used to:

[0039] When the converter starts smelting, the O2 concentration and CO concentration in the flue gas are obtained;

[0040] The first recovery cup valve V is controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas. R1 , Diffusion cup valve V E And the second recovery cup valve V R2 The switch state of the first recovery cup valve V R1 Used to recover flue gas with high CO concentration, the second recovery cup valve V R2 Used to recover flue gas with low CO concentration, vent cup valve V E Used to release flue gas with high O2 concentration, the first recovery pipeline is connected to the first recovery cup valve, and the second recovery pipeline is connected to the second recovery cup valve.

[0041] In one embodiment, the controller 15 is specifically configured to:

[0042] If it is determined that the O2 concentration in the flue gas is less than or equal to the first O2 concentration threshold and the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the venting cup valve V is controlled.E And the first recovery cup valve V R1 Close and control the second recovery cup valve V R2 Open to recover flue gas with low CO concentration using the second recovery cup valve.

[0043] In one embodiment, the controller 15 is specifically configured to:

[0044] If it is determined that the O2 concentration in the flue gas is less than the second O2 concentration threshold and the CO concentration is greater than or equal to the CO concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve V is controlled. E And the second recovery cup valve V R2 Close, control the first recovery cup valve V R1 Open to use the first recovery cup valve V R1 Recover flue gas with high CO concentration.

[0045] Specifically, the controller 15 collects the gas tank pressure PU1 (gas main pressure), the first recovery pipeline pressure PU2, and the second recovery pipeline pressure PU3 in real time; when PU1>PU2, the first recovery cup valve V R1 Open; if PU1≤PU2, the recovery cup valve V is not allowed R1 When PU1>PU3, the recovery cup valve V is allowed to R2 Open; if PU1≤PU3, the recovery cup valve V is not allowed R2 Turn on.

[0046] Therefore, the controller 15 controls the first recovery cup valve V according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure, and second recovery pipeline pressure in the flue gas. R1 , Diffusion cup valve V E And the second recovery cup valve V R2 The specific strategy of adjusting the switching state to perform graded recovery of flue gas of different concentrations will be described in detail in the subsequent method embodiments, so it will not be repeated here.

[0047] In one embodiment, the controller 15 is further configured to:

[0048] The pressure of the flue 16 is collected, and if it is determined that the flue pressure is a negative value, the rotation speed of the fan 14 is reduced.

[0049] Based on the same inventive concept as the above-mentioned embodiment, this embodiment also provides a converter flue gas recovery method, which is applied to the above-mentioned converter flue gas recovery system, such as Figure 2 As shown, the method comprises the following steps:

[0050] S210, when the converter is smelting, obtaining the O2 concentration and CO concentration in the flue gas;

[0051] At different stages of converter smelting, the O2 concentration and CO concentration in the flue gas are different. In order to avoid waste of resources, this embodiment will grade the flue gas containing different CO concentrations for corresponding applications in different scenarios.

[0052] Therefore, during the converter smelting process, it is necessary to obtain the O2 concentration and CO concentration in the flue gas.

[0053] S212, according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure, and second recovery pipeline pressure in the flue gas, the switching states of the first recovery cup valve, the release cup valve, and the second recovery cup valve are correspondingly controlled to perform graded recovery of flue gas of different concentrations; wherein, the first recovery cup valve is used to recover flue gas with high CO concentration, the second recovery cup valve is used to recover flue gas with low CO concentration, and the release valve is used to release flue gas with high O2 concentration.

[0054] In one embodiment, the switch states of the first recovery cup valve, the release cup valve, and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure, and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations, including:

[0055] If it is determined that the O2 concentration in the flue gas is less than or equal to the first O2 concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the first recovery cup valve are controlled to be closed, and the second recovery cup valve is controlled to be opened, so that the second recovery cup valve can be used to recover flue gas with low CO concentration.

[0056] The first O2 concentration threshold may be 2-3%, and may also be set based on actual conditions, which is not limited here.

[0057] In one embodiment, the switch states of the first recovery cup valve, the release cup valve, and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure, and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations, including:

[0058] If it is determined that the O2 concentration in the flue gas is less than the second O2 concentration threshold and the CO concentration is greater than or equal to the CO concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the second recovery cup valve are controlled to be closed, and the first recovery cup valve is controlled to be opened, so that the first recovery cup valve can be used to recover flue gas with high CO concentration.

[0059] The second O2 concentration threshold is 0.5-1%, and the CO concentration threshold is 30-35%. They can also be set based on actual conditions and are not limited here.

[0060] In one embodiment, the switch states of the first recovery cup valve, the relief cup valve, and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure, and second recovery pipeline pressure in the flue gas, so as to perform graded recovery of flue gas of different concentrations, including:

[0061] If it is determined that the O2 concentration in the flue gas is greater than or equal to the second O2 concentration threshold and less than the first O2 concentration threshold and the gas tank pressure is greater than or equal to the second recovery pipeline pressure; or,

[0062] If it is determined that the CO concentration in the flue gas is less than the CO concentration threshold and the gas tank pressure is greater than or equal to the second recovery pipeline pressure, the venting cup valve and the first recovery cup valve are controlled to close, and the second recovery cup valve is controlled to open, so that the second recovery cup valve can be used to recover flue gas with low CO concentration.

[0063] In one embodiment, the switch states of the first recovery cup valve, the release cup valve, and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure, and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations, including:

[0064] If it is determined that the O2 concentration in the flue gas is greater than the first O2 concentration threshold, the vent cup valve is controlled to open, and the first recovery cup valve and the second recovery cup valve are controlled to close, so that the purified flue gas (flue gas with high oxygen content) can be discharged into the atmosphere through the vent tower using the vent cup valve.

[0065] In this way, the CO flue gas generated during the converter smelting process is recycled into the low calorific value gas tank and the high calorific value gas tank according to different concentrations, which improves the energy utilization efficiency of the converter gas and effectively avoids the problem of increased oxygen content in the mixed gas (increased oxygen content can easily cause explosion), thereby reducing production safety risks.

[0066] In practical applications, when the converter flue gas is recovered using the recovery method and recovery system provided in the above embodiment, the implementation process is as follows:

[0067] For heat 1, the heat starts blowing and the cup valve V is vented. E Open, recovery cup valve V R1 and V R2 Close; when the O2 concentration in the flue gas reaches 2% after blowing for 2 minutes and 40 seconds, the vent cup valve V E Close and open the second recovery cup valve V R2 , the first recovery cup valve V R1 Still closed.

[0068] At 4 minutes and 5 seconds after blowing, the CO concentration in the flue gas reaches 35%, and the O2 concentration in the flue gas is 0.122%. Close the second recovery cup valve VR2 , and at the same time open the first recovery cup valve V R1 At this time, the cup valve V E The flue gas is still closed and this part of the flue gas is recycled into the high calorific value gas tank. After that, the CO content in the flue gas continued to rise, reaching a maximum of 57%.

[0069] At the end of blowing, the secondary gun is measured. The blowing oxygen flow rate decreases, and the CO concentration in the flue gas also decreases. At 13 minutes and 8 seconds after blowing, the CO concentration in the flue gas drops to less than 35%, and the O2 concentration in the flue gas is 0.085%. At this time, the first recovery cup valve V is closed. R1 , and at the same time open the second recovery cup valve V R2 At this time, the cup valve V E Still in the closed state; this part of the flue gas is recovered to the low calorific value gas tank.

[0070] As the blowing oxygen flow reaches the valley value, the CO concentration in the flue gas also reaches the valley value, and then the blowing oxygen flow automatically returns to the peak value. The CO in the flue gas also gradually increases with the increase of the blowing oxygen flow. When the CO in the flue gas reaches 35% again, the O2 content in the flue gas is 0.078%. At this time, close the second recovery cup valve V R2 , and at the same time open the first recovery cup valve V R1 , and this part of the flue gas is recovered to the high calorific value gas tank. At this time, the diffuser valve V E Still closed.

[0071] At 13 minutes and 59 seconds, the blowing is over and the gun is lifted. The O2 concentration in the flue gas is 0.078%, and the CO concentration in the flue gas is 44%. Although the O2 concentration in the flue gas is not greater than the first O2 concentration threshold, since the blowing is over at this time, in order to prevent the gas from flowing back from the gas tank, the V E The release cup valve (equivalent to the release and gun lifting action are interlocked, once the gun lifting action is detected, the release cup valve will be opened), close the first recovery cup valve V R1 , the second recovery cup valve V R2 Still closed.

[0072] Finally, the amount of low calorific value gas recovered by this furnace was 22.81Nm 3 / t, the average CO concentration of low calorific value gas is 19.55%, and the average O2 concentration of low calorific value gas is 0.36%; the amount of high calorific value gas recovered in this furnace is 105.96Nm 3 / t, the average CO concentration of high calorific value gas is 52.59%, and the average O2 concentration of high calorific value gas is 0.085%; if low calorific value gas and high calorific value gas are mixed and recycled, the average O2 concentration of the mixed gas is 0.134%, which is 36.24% higher than that of high calorific value gas when recycled alone. The energy efficiency of converter gas of this furnace is improved by 7.41%.

[0073] For heat 2, when the heat starts blowing, the vent cup valve V E Open the first recovery cup valve V R1 and the second recovery cup valve V R2 closure.

[0074] When blowing reaches 2 minutes and 51 seconds, the O2 concentration in the flue gas reaches 2%, and the venting cup valve V E Close and open the second recovery cup valve V R2 , the first recovery cup valve V R1 Still closed.

[0075] At 3 minutes and 49 seconds after blowing, the CO concentration in the flue gas reaches 35%, and the O2 concentration in the flue gas is 0.191%. Close the second recovery cup valve V R2 , and at the same time open the first recovery cup valve V R1 At this time, the cup valve V E The CO content in the flue gas continued to rise, reaching a maximum of 59%.

[0076] At the end of blowing, the secondary gun is measured. The blowing oxygen flow rate decreases, and the CO concentration in the flue gas also decreases. At 14 minutes and 14 seconds after blowing, the CO concentration in the flue gas is lower than 35%, and the O2 concentration in the flue gas is 0.13%. At this time, the first recovery cup valve V is closed. R1 , while turning on V R2 Recover the cup valve, and release the cup valve V E Still closed.

[0077] As the blowing oxygen flow reaches the valley value, the CO concentration in the flue gas also reaches the valley value, and then the blowing oxygen flow automatically returns to the peak value. The CO in the flue gas also gradually increases with the increase of the blowing oxygen flow. When the CO in the flue gas reaches 35% again, the O2 content in the flue gas is 0.052%. At this time, close the second recovery cup valve V R2 , and at the same time open the first recovery cup valve V R1 At this time, the cup valve V E Still closed.

[0078] At 13 minutes and 59 seconds, the blowing is finished and the gun is lifted. The O2 concentration in the flue gas is 0.052%, and the CO concentration in the flue gas is 50%. At this time, the bulk cup valve V is opened. E , close the first recovery cup valve V R1, the second recovery cup valve V R2 Still closed.

[0079] Finally, the amount of low calorific value gas recovered by this furnace was 19.35Nm 3 / t, the average CO concentration of low calorific value gas is 22.42%, and the average O2 concentration of low calorific value gas is 0.255%; the amount of high calorific value gas recovered in this furnace is 105.131Nm 3 / t, the average CO concentration of high calorific value gas is 53.70%, and the average O2 concentration of high calorific value gas is 0.052%; if low calorific value gas and high calorific value gas are mixed and recycled, the average O2 concentration of the mixed gas is 0.084%, which is 37.77% higher than that of high calorific value gas when recycled alone. The energy efficiency of converter gas of this furnace is improved by 7.13%.

[0080] For heat 3, when the heat starts blowing, the vent cup valve V E Open the first recovery cup valve V R1 and the second recovery cup valve V R2 Close; when the O2 concentration in the flue gas reaches 2% after blowing for 2 minutes and 45 seconds, the vent cup valve V E Close and open the second recovery cup valve V R2 , recovery cup valve V R1 Still closed.

[0081] At 3 minutes and 41 seconds of blowing, the CO concentration in the flue gas reaches 35%, and the O2 concentration in the flue gas is 0.182%. Close the second recovery cup valve V R2 , and at the same time open the first recovery cup valve V R1 At this time, the cup valve V E Still in the closed state; thereafter the CO content in the flue gas continued to rise, reaching a maximum of 61%.

[0082] At the end of blowing, the auxiliary gun is measured. The blowing oxygen flow rate decreases, and the CO concentration in the flue gas also decreases. At 13 minutes and 17 seconds after blowing, the CO concentration in the flue gas is lower than 35%, and the O2 concentration in the flue gas is 0.087%. At this time, the first recovery cup valve V is closed. R1 , and at the same time open the second recovery cup valve V R2 , relief cup valve V E Still closed.

[0083] As the blowing oxygen flow rate reaches the valley value, the CO concentration in the flue gas also reaches the valley value, and then the blowing oxygen flow rate automatically returns to the peak value, and the CO in the flue gas also gradually increases with the increase of the blowing oxygen flow rate; blowing ends at 13 minutes and 59 seconds, and the gun is lifted. The O2 concentration in the flue gas is 0.339%, and the CO concentration in the flue gas is 20%. At this time, open V E Release the cup valve and close the second recovery cup valve V R2, the first recovery cup valve V R1 Still closed.

[0084] The final amount of low calorific value gas recovered by this furnace is 17.96Nm 3 / t, the average CO concentration of low calorific value gas is 23.31%, and the average O2 concentration of low calorific value gas is 0.373%; the amount of high calorific value gas recovered in this furnace is 105.96Nm 3 / t, the average CO concentration of high calorific value gas is 50.29%, and the average O2 concentration of high calorific value gas is 0.087%; if low calorific value gas and high calorific value gas are mixed and recovered, the average O2 concentration of the mixed gas is 0.129%, which is 32.31% higher than when high calorific value gas is recovered alone. The energy efficiency of converter gas of this furnace is improved by 7.28%.

[0085] For heat 4, the heat starts blowing and the cup valve V is vented. E Open the first recovery cup valve V R1 and the second recovery cup valve V R2 closure.

[0086] When the oxygen concentration in the flue gas reaches 2% after 2 minutes and 52 seconds of blowing, the venting cup valve V E Close and open the second recovery cup valve V R2 , the first recovery cup valve V R1 Still closed.

[0087] At 3 minutes and 43 seconds of blowing, the CO concentration in the flue gas reaches 35%, and the O2 concentration in the flue gas is 0.26%. Close the second recovery cup valve V R2 , and at the same time open the first recovery cup valve V R1 At this time, the cup valve V E Still in the closed state; thereafter the CO content in the flue gas continued to rise, reaching a maximum of 63%.

[0088] At the end of blowing, the auxiliary gun is measured. The blowing oxygen flow rate decreases, and the CO concentration in the flue gas also decreases. At 14 minutes and 8 seconds after blowing, the CO concentration in the flue gas is lower than 35%, and the O2 concentration in the flue gas is 0.052%. At this time, the first recovery cup valve V is closed. R1 , and at the same time open the second recovery cup valve V R2 At this time, the cup valve V E It is still in the closed state; as the blowing oxygen flow rate reaches the valley value, the CO concentration in the flue gas also reaches the valley value, after which the blowing oxygen flow rate automatically returns to the peak value, and the CO in the flue gas also gradually increases with the increase of the blowing oxygen flow rate.

[0089] At 13 minutes and 59 seconds, the blowing was finished and the gun was lifted. The oxygen content in the flue gas was 0.052% and the CO concentration in the flue gas was 22%. At this time, V ERelease the cup valve and close the second recovery cup valve V R2 , the first recovery cup valve V R1 Still closed.

[0090] Finally, the amount of low calorific value gas recovered by this furnace was 17.66Nm 3 / t, the average CO concentration of low calorific value gas is 23.53%, and the average O2 concentration of low calorific value gas is 0.278%; the amount of high calorific value gas recovered in this furnace is 105.13Nm 3 / t, the average CO concentration is 50.29%, and the average O2 concentration is 0.052%; if the low calorific value gas is mixed with the high calorific value gas for recycling, the average O2 concentration of the mixed gas is 0.084%, which is 38.45% higher than when the high calorific value gas is recycled alone. The energy efficiency of the converter gas of this furnace is improved by 7.29%.

[0091] For heat 5: Start blowing, release cup valve V E Open the first recovery cup valve V R1 and the second recovery cup valve V R2 closure.

[0092] When the O2 concentration in the flue gas reaches 2% after blowing for 2 minutes and 30 seconds, the venting cup valve V E Close and open the second recovery cup valve V R2 , the first recovery cup valve V R1 Still closed.

[0093] At 4 minutes and 12 seconds of blowing, the CO concentration in the flue gas reaches 35%, and the O2 concentration in the flue gas is 0.095%. Close the second recovery cup valve V R2 , and at the same time open the first recovery cup valve V R1 At this time, the cup valve V E Still in the closed state; thereafter the CO content in the flue gas continued to rise, reaching a maximum of 69%.

[0094] At the end of blowing, the auxiliary gun is measured. The blowing oxygen flow rate decreases, and the CO concentration in the flue gas also decreases. At 13 minutes and 9 seconds after blowing, the CO concentration in the flue gas is lower than 35%, and the O2 concentration in the flue gas is 0.061%. At this time, the first recovery cup valve V is closed. R1 , and at the same time open the second recovery cup valve V R2 At this time, the cup valve V E Still closed.

[0095] As the blowing progressed, the CO concentration in the flue gas continued to decrease. At 13 minutes and 28 seconds after blowing, the blowing was completed and the gun was lifted. The oxygen content in the flue gas was 0.061%, and the CO concentration in the flue gas was 18%. At this time, V E Release the cup valve and close the second recovery cup valve V R2, the first recovery cup valve V R1 Still closed.

[0096] The amount of low calorific value gas recovered in this furnace is 24.22Nm 3 / t, the average CO concentration of low calorific value gas is 22.86%, and the average O2 concentration of low calorific value gas is 0.325%; the amount of high calorific value gas recovered in this furnace is 102.94Nm 3 / t, the average CO concentration of high calorific value gas is 60.33%, and the average O2 concentration of high calorific value gas is 0.061%; if low calorific value gas and high calorific value gas are mixed and recovered, the average O2 concentration of the mixed gas is 0.111%, which is 45.14% higher than when high calorific value gas is recovered alone. The energy efficiency of converter gas of this furnace is improved by 7.83%.

[0097] In summary, the recovery results of the above five furnaces can be shown in Table 1:

[0098] Table 1

[0099]

[0100] Through one or more embodiments of the present invention, the present invention has the following beneficial effects or advantages:

[0101] The present invention provides a converter flue gas recovery method and system, which are applied in a converter flue gas recovery system, wherein the system comprises: a first recovery cup valve, a release cup valve and a second recovery cup valve; the method comprises: when the converter starts smelting, obtaining the O2 concentration and the CO concentration in the flue gas; controlling the switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve according to the O2 and CO concentrations in the flue gas, so as to perform graded recovery of flue gases of different concentrations; wherein the first recovery cup valve is used to recover flue gases with high CO concentrations, the second recovery cup valve is used to recover flue gases with low CO concentrations, and the release valve is used to release flue gases with high O2 concentrations; in this way, in different stages of converter smelting, converter flue gases of different CO concentrations can be graded and recovered according to the O2 concentration and CO concentration in the flue gas, so as to avoid energy waste; at the same time, the potential safety hazard caused by the mixed recovery of converter flue gases of different CO concentrations can also be avoided.

[0102] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the present invention is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the present invention described herein, and the description of the above specific languages ​​is for disclosing the best mode of the present invention.

[0103] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0104] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the intention that the claimed invention requires more features than those explicitly recited in each claim. More specifically, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present invention.

[0105] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition they may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0106] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

[0107] The various component embodiments of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all functions of some or all components in a gateway, proxy server, or system according to an embodiment of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0108] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

[0109] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0110] 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 modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A converter flue gas recovery method, characterized in that: The method is applied in a converter fume recovery system, the system comprising: a first recovery cup valve, a venting cup valve and a second recovery cup valve; the method comprises: During converter smelting, obtain the O2 concentration and CO concentration in the flue gas; The switch states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas, so as to grade and recover flue gas of different concentrations; wherein, the first recovery cup valve is used to recover flue gas with high CO concentration, the second recovery cup valve is used to recover flue gas with low CO concentration, the release valve is used to release flue gas with high O2 concentration, the first recovery pipeline is connected to the first recovery cup valve, and the second recovery pipeline is connected to the second recovery cup valve; wherein, The switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations, including: If it is determined that the O2 concentration in the flue gas is less than or equal to the first O2 concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the first recovery cup valve are controlled to be closed, and the second recovery cup valve is controlled to be opened, so as to use the second recovery cup valve to recover the flue gas with low CO concentration; The switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations, including: If it is determined that the O2 concentration in the flue gas is less than the second O2 concentration threshold and the CO concentration is greater than or equal to the CO concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the second recovery cup valve are controlled to be closed, and the first recovery cup valve is controlled to be opened, so as to use the first recovery cup valve to recover the flue gas with high CO concentration; The switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations, including: If it is determined that the O2 concentration in the flue gas is greater than or equal to the second O2 concentration threshold and less than the first O2 concentration threshold and it is determined that the gas tank pressure is greater than or equal to the second recovery pipeline pressure; or, If it is determined that the CO concentration in the flue gas is less than the CO concentration threshold and it is determined that the gas tank pressure is greater than or equal to the second recovery pipeline pressure, the release cup valve and the first recovery cup valve are controlled to be closed, and the second recovery cup valve is controlled to be opened, so that the second recovery cup valve can be used to recover flue gas with low CO concentration.

2. The method according to claim 1, characterized in that The switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations, including: If it is determined that the O2 concentration in the flue gas is greater than the first O2 concentration threshold, the release cup valve is controlled to open, and the first recovery cup valve and the second recovery cup valve are controlled to close, so that the purified flue gas is discharged into the atmosphere by using the release cup valve.

3. The method according to any one of claims 1, characterized in that The first O2 concentration threshold is 2-3%, the second O2 concentration threshold is 0.5-1%, and the CO concentration threshold is 30-35%.

4. A system for implementing the converter flue gas recovery method according to any one of claims 1 to 3, characterized in that: The system comprises: a first recovery cup valve, a release cup valve, a second recovery cup valve and a controller; wherein, The controller is used to obtain the O2 concentration and CO concentration in the flue gas during converter smelting; The switching states of the first recovery cup valve, the release cup valve and the second recovery cup valve are controlled accordingly according to the O2 concentration, CO concentration, gas tank pressure, first recovery pipeline pressure and second recovery pipeline pressure in the flue gas to perform graded recovery of flue gas of different concentrations; wherein the first recovery cup valve is used to recover flue gas with high CO concentration, the second recovery cup valve is used to recover flue gas with low CO concentration, the release valve is used to release flue gas with high O2 concentration, the first recovery pipeline is connected to the first recovery cup valve, and the second recovery pipeline is connected to the second recovery cup valve.

5. The system according to claim 4, characterized in that The system further comprises: a fan; and the controller is further used for: The flue pressure is collected, and if it is determined that the flue pressure is a negative value, the rotation speed of the fan is reduced.

6. The system according to claim 4, characterized in that The controller is specifically used for: If it is determined that the O2 concentration in the flue gas is less than or equal to the first O2 concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the first recovery cup valve are controlled to be closed, and the second recovery cup valve is controlled to be opened, so that the second recovery cup valve can be used to recover flue gas with low CO concentration.

7. The system according to claim 4, characterized in that The controller is specifically used for: If it is determined that the O2 concentration in the flue gas is less than the second O2 concentration threshold and the CO concentration is greater than or equal to the CO concentration threshold, and it is determined that the gas tank pressure is greater than or equal to the first recovery pipeline pressure, the release cup valve and the second recovery cup valve are controlled to be closed, and the first recovery cup valve is controlled to be opened, so as to use the first recovery cup valve to recover flue gas with high CO concentration.

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