A sintering system air leakage online detection method and system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUNAN CHANGTIAN AUTOMATION ENG CO LTD
- Filing Date
- 2022-12-02
- Publication Date
- 2026-07-03
Smart Images
Figure CN115979543B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of sintering technology, and in particular to an online detection method and system for air leakage in sintering systems. Background Technology
[0002] Air leakage in the sintering system mainly refers to the air below the material level on the sintering trolley entering the main exhaust pipe through various leakage points instead of passing through the material surface under the action of the exhaust fan. Air leakage not only increases the energy consumption of the main exhaust fan and reduces the yield and quality of sintered ore, but also adversely affects the recovery and utilization of waste heat from sintering flue gas.
[0003] In sintering production, air leakage in the sintering machine has a significant impact on the yield, quality, and energy consumption per ton of sinter. Increased air leakage reduces the effective airflow of the sintering machine, lowers productivity, and increases production costs. Currently, the most advanced sintering systems in China can achieve an air leakage rate of less than 20%, while those of general levels can reach around 40%. However, due to factors such as equipment scale, process conditions, and operational management levels, some sintering machines still have air leakage rates exceeding 50%, severely hindering the advancement of sintering technology. Research has found that a 10% reduction in the air leakage rate of the sintering machine can increase sinter production by approximately 6%, reduce electricity consumption by 2 kWh per ton of sinter, reduce coke powder by 1.0 kg, and improve the yield of finished sinter by 1.5% to 2.0%. Therefore, reducing the air leakage rate of the sintering system is crucial for sintering production.
[0004] The difficulty in testing the air leakage rate of a sintering machine lies in the fact that the air volume entering through the sintering material layer on the sintering trolley cannot be directly and accurately measured, and must be obtained indirectly. Currently, there are three main indirect methods for detecting air leakage in the sintering machine trolley and air box section: the static sealing method, the heat conservation method, and the oxygen balance method. The static sealing method ignores the differences in the size of the air leakage openings between the sintering machine trolley during movement and the static process, as well as the differences in flue gas density and air density. This is the source of error in the testing principle of this method. The method is difficult to implement: it involves two stages—sintering machine production testing and static sealing testing—resulting in a long testing cycle. Specifically, the pressure, temperature, and flow rate of the main exhaust duct (or main exhaust pipe) of the sintering machine are tested first, and then the static sealing test is conducted after the sintering machine is under maintenance. Static sealing requires approximately one day of testing time from the sintering plant, making it difficult to secure. Static sealing requires estimating the number of open trolleys and sealing the lower beams of these trolleys to the bellows section beams to prevent air leakage. Simultaneously, all trolleys on the closed bellows sections must be sealed, and the sealed trolleys cannot move. During the static sealing test, the total pressure of the main exhaust duct of the sintering machine needs to be adjusted to approximately equal to that during production by adjusting the damper opening of the main exhaust fan. If the total pressure cannot be increased, the number of open bellows sections needs to be reduced. Therefore, this method requires close cooperation from the sintering plant, making it difficult and time-consuming. The heat conservation method measures the composition and temperature of the sintering flue gas during sintering machine production. However, it must also consider the heat exchange between the sintering machine, the bellows section, and branch pipes and the outside environment. Since the heat exchange between these components is difficult to determine precisely, estimations are often used. Furthermore, the flue gas composition is complex, with each component requiring a specific gas sensor; generally, only the main components are detected, making the accuracy of the test results difficult to evaluate. The oxygen balance method indirectly obtains the air leakage rate by measuring the oxygen concentration of the flue gas before and after the sintering machine's bellows section system. However, existing oxygen balance methods have low evaluation accuracy.
[0005] Therefore, it is necessary to propose an online detection method and system for air leakage in sintering systems to address the aforementioned deficiencies. Summary of the Invention
[0006] The main objective of this invention is to provide an online detection method and system for air leakage in sintering systems, aiming to solve the technical problem that it is difficult to measure air leakage in sintering systems online in the prior art.
[0007] To achieve the above objectives, the present invention provides an online method for detecting air leakage in a sintering system, comprising the following steps: obtaining the exhaust volume flow rate Q of the target gas in the air box branch pipe on the first side of the air box section i. 11-i Obtain the exhaust gas pressure P of the bellows branch pipe on the first side of bellows section i. 11-i Obtain the exhaust gas temperature T of the first side of the bellows branch pipe of bellows section i. 11-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the first side of bellows section i.11-i ; Obtain the exhaust volume flow rate Q of the target gas in the second side of the bellows branch pipe of bellows section i. 12-i Obtain the exhaust gas pressure P of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the exhaust gas temperature T of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the second side of bellows section i. 12 -i; Mark the gas discharged from the lower end of the grate at the bottom of the sintering trolley corresponding to wind box segment i as the actual effective intake air, and obtain the gas concentration C of the target gas in the actual effective intake air. 3-i ; Use formula
[0008] Calculate the air leakage rate of section i of the bellows.
[0009] Furthermore, using the formula
[0010]
[0011] Calculate and obtain the air leakage Q of the wind box section i under standard conditions. ki T 标 For 273.15K, P 标 The value is 101.325 kPa.
[0012] Furthermore, using the formula
[0013] Calculate and obtain the actual effective air intake volume Q of the bellows section i under standard conditions. 进-i .
[0014] Furthermore, using the formula Calculate the total effective air intake Q of all wind box sections in the sintering system under standard conditions. 有效进-标 , where M is the total number of bellows sections, M is greater than 1 and M is an integer.
[0015] Furthermore, using the formula
[0016]
[0017] Calculate the total air leakage Q of all branch pipes from the bellows branch pipes to the main exhaust pipe under standard conditions. 支管-漏-标 , where P 主排-i Q represents the gas pressure in the corresponding main exhaust pipe. 主排-i T represents the gas flow rate of the corresponding main exhaust pipe. 主排-i This indicates the gas temperature of the corresponding main exhaust pipe.
[0018] Furthermore, using the formula
[0019]
[0020] Calculate the total air leakage Q of the electrostatic precipitator under standard conditions. 漏-电除尘 ,in equal P 主抽 Q represents the gas pressure in the main extraction pipe. 主抽 T represents the gas flow rate of the main extraction pipe. 主抽 This indicates the gas temperature in the main extraction pipe.
[0021] Furthermore, using the formula Calculate the total air leakage rate of the sintering system.
[0022] The present invention also provides an online air leakage detection system for a sintering system, comprising a flue gas composition detection device and a processing unit, wherein the flue gas composition detection device is used to obtain the exhaust volume flow rate Q of the target gas in the exhaust branch pipe on the first side of the wind box section i. 11-i Obtain the exhaust gas pressure P of the bellows branch pipe on the first side of bellows section i. 11-i Obtain the exhaust gas temperature T of the first side of the bellows branch pipe of bellows section i. 11-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the first side of bellows section i. 11-i ; Obtain the exhaust volume flow rate Q of the target gas in the second side of the bellows branch pipe of bellows section i. 12-i Obtain the exhaust gas pressure P of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the exhaust gas temperature T of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the second side of bellows section i. 12-i The gas discharged from the lower end of the grate at the bottom of the sintering trolley corresponding to section i of the marked wind box is the actual effective air intake. The gas concentration C of the target gas in the actual effective air intake is obtained. 3-i The gas leaking into section i of the bellows from the outside is designated as ambient air leakage. The gas concentration C of the target gas in the ambient air leakage is then obtained. 2-i ;
[0023] The processing unit is used to employ formulas
[0024] Calculate and obtain the air leakage rate K of section i of the bellows. i .
[0025] The online air leakage detection method and system for sintering systems provided by this invention have the following beneficial effects:
[0026] The online air leakage detection method for sintering systems provided by this invention involves sampling at a measuring point located at the lower end of the grate bars at the bottom of the sintering trolley, and then analyzing the gas concentration C of the target gas in the actual effective intake air. 3-i By sampling at measuring points set at the air leak locations, the gas concentration C of the target gas in the leaked environment can be obtained through analysis. 2-i By sampling at the inflow point of the bellows branch pipe on the first side of bellows section i, the exhaust volume flow rate Q of the target gas in the bellows branch pipe on the first side of bellows section i can be obtained through analysis. 11-i The exhaust gas pressure P of the first side of the bellows branch pipe of bellows section i was obtained through analysis. 11-i The exhaust gas temperature T of the first side of the bellows branch pipe of bellows section i was obtained by analysis. 11 -i, the gas concentration C of the target gas in the first side of the bellows branch pipe located in bellows section i is obtained through analysis. 11-i By sampling at the inflow point of the bellows branch pipe on the second side of bellows section i, the exhaust volume flow rate Q of the target gas in the bellows branch pipe on the second side of bellows section i can be obtained through analysis. 12-i Then, the exhaust gas pressure P of the second side of the bellows branch pipe of bellows section i is analyzed. 12-i Furthermore, the exhaust gas temperature T of the second side of the bellows branch pipe of bellows section i is analyzed. 12-i Furthermore, the gas concentration C of the target gas in the bellows branch pipe located on the second side of bellows section i is analyzed. 12-i Then, the air leakage rate K of the bellows section i is calculated using the formula. i This enabled the online determination of the air leakage rate of bellows section i. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0028] Figure 1 This is one of the overall structural schematic diagrams of the sintering system in one embodiment of the present invention;
[0029] Figure 2 This is a second schematic diagram of the overall structure of the sintering system in one embodiment of the present invention;
[0030] Figure 3 Figure 1 A schematic diagram of the connected bellows section in the middle;
[0031] Figure 4This is a flowchart of an online air leakage detection method for a sintering system according to one embodiment of the present invention;
[0032] Figure 5 A schematic diagram illustrating the principle of localized air leakage convergence;
[0033] Figure 6 This is a schematic diagram illustrating the principle of an online air leakage detection method for a sintering system according to one embodiment of the present invention;
[0034] Figure 7 This is a schematic diagram of the online air leakage detection system for a sintering system according to one embodiment of the present invention;
[0035] Figure 8 yes Figure 7 A schematic diagram of the flue gas composition detection device.
[0036] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0037] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0039] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.
[0040] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.
[0041] like Figure 1 As shown, a 360m 2A 450m² sintering machine typically has 23 sets of air box sections. Each air box section is connected to the corresponding main exhaust pipe via two opposing air box branch pipes. The exhaust pipe is also commonly referred to as the main exhaust pipe. The main exhaust pipes located below the air box sections are divided into two series: exhaust pipe #1 and exhaust pipe #2. Each exhaust pipe is equipped with one main exhaust fan, for a total of two main exhaust fans. The upper part of the air box branch pipe connects to the corresponding air box section, and the lower part inserts into the corresponding exhaust pipe. Specifically, the branch pipes of the wind box sections W1, W3, W5, W7, W9, W11, W13, W15, W17, W19, and W23 enter the No. 1 main exhaust pipe; the branch pipes of the wind box sections W2, W4, W6, W8, W10, W12, W14, W16, W18, and W22 go to the No. 2 exhaust pipe; the branch pipes of the wind box sections W20 and W21 are designed to be switchable, and can be selected to enter the No. 1 or No. 2 main exhaust pipe according to the need for air volume balance. The switching valve is switched by an electric flue gas switching valve.
[0042] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 6 The study found that the main air leaks in the sintering system are located in the following three places: Firstly, because the trolley is constantly moving during production, and there may be lateral air leaks in each air box section i, there is air leakage between the trolley and each air box section i (under the suction effect, air below the material level of the sintering trolley does not pass through the material surface but enters the main exhaust pipe through each leak point); secondly, each air box section i is connected to the corresponding main exhaust pipe through its two lateral air box branch pipes, and there is air leakage between the air box branch pipes of each air box section i and the main exhaust pipe; thirdly, the exhaust pipe is connected to the electrostatic precipitator and the suction pipe, and there is air leakage at the connection between the exhaust pipe and the electrostatic precipitator.
[0043] Please refer to Figure 4 This invention provides an online method for detecting air leakage in a sintering system, comprising the following steps: obtaining the exhaust volume flow rate Q of the target gas in the air box branch pipe on the first side of the air box section i. 11-i Obtain the exhaust gas pressure P of the bellows branch pipe on the first side of bellows section i. 11-i Obtain the exhaust gas temperature T of the first side of the bellows branch pipe of bellows section i. 11-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the first side of bellows section i. 11-i ; Obtain the exhaust volume flow rate Q of the target gas in the second side of the bellows branch pipe of bellows section i. 12-i Obtain the exhaust gas pressure P of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the exhaust gas temperature T of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the second side of bellows section i. 12-iThe gas discharged from the lower end of the grate at the bottom of the sintering trolley corresponding to section i of the marked wind box is the actual effective air intake. The gas concentration C of the target gas in the actual effective air intake is obtained. 3-i The gas leaking into section i of the bellows from the outside is designated as ambient air leakage. The gas concentration C of the target gas in the ambient air leakage is then obtained. 2-i ; Use formula
[0044] Calculate the air leakage rate of section i of the bellows.
[0045] Optionally, in this invention, the gas discharged from the lower end of the grate at the bottom of the sintering trolley corresponding to the marked wind box section i is the actual effective intake air, and the volumetric flow rate Q of the target gas in the actual effective intake air is obtained. 3-i Actual effective intake gas pressure P 3-i Actual effective intake gas temperature T 3-i And the gas concentration C of the target gas 3-i The gas leaking into the external section i of the bellows is designated as ambient air leakage. The volumetric flow rate Q of the target gas in the ambient air leakage is then obtained. 2-i The gas pressure P of the leaking air in the environment 2-i The temperature T of the gas leaking into the environment 2-i And the gas concentration C of the target gas 2-i .
[0046] The online air leakage detection method for sintering systems provided by this invention involves sampling at a measuring point located at the lower end of the grate bars at the bottom of the sintering trolley, and then analyzing the gas concentration C of the target gas in the actual effective intake air. 3-i By sampling at measuring points set at the air leak locations, the gas concentration C of the target gas in the leaked environment can be obtained through analysis. 2-i By sampling at the inflow point of the bellows branch pipe on the first side of bellows section i, the exhaust volume flow rate Q of the target gas in the bellows branch pipe on the first side of bellows section i can be obtained through analysis. 11-i The exhaust gas pressure P of the first side of the bellows branch pipe of bellows section i was obtained through analysis. 11-i The exhaust gas temperature T of the first side of the bellows branch pipe of bellows section i was obtained by analysis. 11-i The gas concentration C of the target gas in the first side of the bellows branch pipe located in bellows section i was obtained through analysis. 11-i By sampling at the inflow point of the bellows branch pipe on the second side of bellows section i, the exhaust volume flow rate Q of the target gas in the bellows branch pipe on the second side of bellows section i can be obtained through analysis. 12-i Then, the exhaust gas pressure P of the second side of the bellows branch pipe of bellows section i is analyzed. 12-i Furthermore, the exhaust gas temperature T of the second side of the bellows branch pipe of bellows section i is analyzed. 12-iFurthermore, the gas concentration C of the target gas in the bellows branch pipe located on the second side of bellows section i is analyzed. 12-i Then, the air leakage rate K of the bellows section i is calculated using the formula. i This enabled the online determination of the air leakage rate of bellows section i.
[0047] Understandably, the target gas is at least one of oxygen, carbon dioxide, and carbon monoxide.
[0048] Furthermore, in order to obtain the leakage air volume Q of the target gas in the wind box section i under standard conditions... ki Using formula
[0049]
[0050] Calculate and obtain the air leakage Q of the wind box section i under standard conditions. k-i T 标 For 273.15K, P 标 The value is 101.325 kPa.
[0051] Furthermore, in order to obtain the effective air intake volume of the target gas in wind box section i under standard conditions, the formula is adopted.
[0052] Calculate and obtain the effective air intake Q of the bellows section i under standard conditions. 进-i .
[0053] Furthermore, in order to obtain the total effective air intake of all wind box sections of the sintering system under standard conditions, Calculate the total effective air intake Q of all wind box sections in the sintering system under standard conditions. 有效进-标 Where M is greater than i, M is an integer, and its size usually varies depending on the area of the sintering machine, such as 180m². 2 There are 18 small sintering machines, each with a capacity of 600m³. 2 The large sintering machine will have 28 wind box sections, 360m in this embodiment. 2 The number of air box sections (M) in the sintering machine is 23. For sintering machines with smaller areas, there are fewer flues, with only one exhaust pipe, which does not affect the calculation of the air leakage rate.
[0054] Furthermore, in order to obtain the air leakage from all bellows branch pipes to the main exhaust pipe under standard conditions, the formula is used.
[0055]
[0056] Under standard conditions, the air leakage from all bellows branch pipes to the main exhaust pipe, where P 主排-iQ represents the gas pressure in the corresponding main exhaust pipe. 主排-i T represents the gas flow rate of the corresponding main exhaust pipe. 主排-i This represents the gas temperature of the corresponding main exhaust pipe. Understandably, the gas pressure of the main exhaust pipe is obtained by sampling at a measuring point set inside the main exhaust pipe, Q. 主排-i T represents the gas flow rate of the main exhaust pipe. 主排-i This indicates the gas temperature in the main exhaust pipe.
[0057] Furthermore, in order to obtain the air leakage rate of the electrostatic precipitator under standard conditions, the formula is used.
[0058] Calculate and obtain the air leakage of the electrostatic precipitator under standard conditions, where P 主抽 Q represents the gas pressure in the main extraction pipe. 主抽 T represents the gas flow rate of the main extraction pipe. 主抽 This indicates the gas temperature in the main extraction pipe. Understandably, the gas pressure in the main extraction pipe is obtained by sampling at measuring points located within the main extraction pipe. Q represents... 主抽 T represents the gas flow rate of the main extraction pipe. 主抽 This indicates the gas temperature in the main extraction pipe.
[0059] Furthermore, using the formula Calculate the total air leakage rate of the sintering system.
[0060] Optionally, in this invention, the total air leakage Q of the branch pipe can also be used as a reference. 支管-漏-标 The total air leakage Q of the electrostatic precipitator 漏-电除尘 The total air leakage of the sintering system is obtained by calculating the total air leakage of all wind box sections. The total air leakage of the system is equal to the total air leakage Q of the branch pipes. 支管-漏-标 The total air leakage Q of the electrostatic precipitator 漏-电除尘 And the sum of the total air leakage of all bellows sections.
[0061] Understandably, please refer to Figure 6 and Figure 7In this invention, a flue gas composition detection device is used to acquire gas samples from sampling points and analyze various states of the target gas. Optionally, since there are multiple data parameters to be detected, it is practically impossible to set up a detection device for each parameter. Therefore, a patrol-style sampling method or a manual patrol sampling method can be used, and the data is used for calculation after a set of data is detected. The online flue gas composition detection device mainly includes a sampling unit, a pretreatment unit, an analysis unit, and a control unit. The sampling unit mainly includes a sampling probe, a suction pump, and a sampling pipeline. The suction pump is used to ensure that the sampling pipeline has a certain air pressure to draw other gases into the detection device. The pretreatment unit and control unit are mainly used to perform a series of processes on the measured gas, such as dust removal, water removal, and pressure and flow control. They mainly include: a dust removal section, a water removal section, a pressure adjustment section, and a flow adjustment section. The analysis unit mainly completes the detection of CO2, CO, and O2 content in the sampled gas, and the analyzed gas is returned to the main flue.
[0062] Specifically, the present invention sets up multiple measuring points for obtaining flue gas. The first type of measuring point is located below the grate bar of the sintering machine trolley, the second type of measuring point is located at the wind box branch pipe of the wind box section of the sintering machine, the third measuring point is located inside the main flue, and the fourth measuring point is located at the inlet measuring hole of the main exhaust fan.
[0063] Please refer to this again. Figures 1 to 8 The technical concept of this invention is as follows:
[0064] The study investigated the layout of the measuring points: During normal production, measuring holes were installed on the horizontal flue at the inlet of each main exhaust fan; measuring holes were also installed on each main exhaust pipe; a set of measuring holes was selected for the trolley, the wind box section, and its wind box branch pipes: the effective air intake measuring points were determined to be the measuring points at the lower part of the trolley grate, the measuring points on the first side of the wind box section i, and the measuring points on the second side of the wind box section i. A microcomputer flue gas analyzer was used to analyze the total pressure, static pressure, flow rate, and temperature of the flue gas obtained through the measuring points.
[0065] First, the principle of calculating the leakage rate using the flue gas composition balance method is studied. The basic principle is that the concentration of a certain component changes due to the entry of external gas, and the leakage amount and leakage rate can be calculated from this.
[0066] Please refer to this again. Figure 5 Assuming that effective air intake enters manifold 1 through branch pipe 3, and ambient air leakage enters manifold 1 through branch pipe 2, according to the law of conservation of mass, the following conservation relationship exists:
[0067] The total airflow mass is conserved, meaning that the total amount of gas corresponding to the effective intake air Q3 and the ambient air leakage Q2 is equal to the total amount of gas in the confluence air Q1.
[0068]
[0069] The mass of a single gas component is conserved, meaning that the total amount of a certain gas component in the effective intake air Q3 and the gas component in the ambient leakage air Q2 is equal to the total amount of that gas component in the merged gas Q1.
[0070]
[0071] The parameters in the formula are explained as follows: P i —Pressure (Pa) of each gas component; Q i —Volume flow rate (L / min) of each gas component; T i —Temperature (K) of each gas component; C i —The concentration (%) of a certain gas component in each gas component.
[0072] The air leakage rate K in this local area is...
[0073]
[0074] The air leakage Q in this local area under standard conditions K for
[0075]
[0076] As shown in the above formula, solving for the local leakage rate requires measuring the concentration of a certain gas component in each part, while the leakage volume also requires measuring the pressure, flow rate, and temperature of a portion of the gas. This will be illustrated using an example of 23 wind box sections, two large flues, and two exhaust ducts.
[0077] Please refer to this again. Figure 6 , Figure 7 and Figure 8 Secondly, we studied the air leakage test scheme for the sintering machine. This time, we adopted the flue gas balance method and the comprehensive method of pipeline pressure, temperature and flow test.
[0078] Firstly, the study of air leakage in the electrostatic precipitator section: Air leakage in the electrostatic precipitator section is mainly due to insufficient sealing at the connections before and after the precipitator, allowing outside air to enter. The air leakage in this section can be directly measured by measuring the flow rate Q of the main exhaust duct during actual production. 主抽 The total flow rate Q of the main exhaust pipe 主排 Through the ideal gas equation of state: (Where R = 8.317 J / (mol·K)), the flow rate can be converted into the gas flow rate under standard conditions:
[0079] The air leakage rate for this section is expressed using the standard flow rate as follows:
[0080]
[0081] Right now
[0082] Secondly, the study of air leakage from the wind box branch pipe section (wind box branch pipe) to the main exhaust pipe: the measurement method is similar to the air leakage test of the electrostatic precipitator section. It should be noted that the air leakage of this section must be measured by measuring the flow rate on all wind box branch pipes, the flow rate Q_main_exhaust on the main exhaust pipe, and the sum of the flow rates on all wind box branch pipes ∑Q_main_exhaust. 支管 The difference is the air leakage of that section.
[0083] The air leakage rate for this section is expressed using the standard flow rate as follows:
[0084]
[0085] Please refer to this again. Figure 6 Thirdly, the air leakage from the trolley to each wind box branch pipe section (i.e., the air leakage of wind box section i) is crucial. During equipment production, the trolley moves continuously; and the opening of the branch pipe dampers in the wind box first increases and then decreases, resulting in completely different air intake conditions for each wind box section. Therefore, it is necessary to measure each wind box section individually. Taking any wind box section i# for experimental analysis, the gas discharged from the bottom of the trolley's grate is recorded as the effective air intake, while the air intake above the material is considered ambient air intake. Because combustion occurs in the material section, and substances are consumed and generated during the chemical reaction, the ambient air intake and effective air intake are not equal.
[0086] Satisfying the equation:
[0087]
[0088]
[0089] Combining the above two equations, we can obtain the air leakage rate K. i ,
[0090]
[0091] Corresponding standard condition air leakage Q ki for
[0092]
[0093] The effective air intake volume Q of this section of the trolley 进-i for
[0094]
[0095] Fourth, calculation of air leakage rate: The total exhaust volume in the actual production process is expressed as the standard flow rate as follows:
[0096]
[0097] The sum of the standard flow rates of all effective gases in the actual production process
[0098] The final total air leakage rate is:
[0099] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.
Claims
1. A method for online detection of air leakage in a sintering system, characterized in that, Includes the following steps: Obtain the exhaust volume flow rate Q of the target gas in the first side of the bellows branch pipe of bellows section i. 11-i Obtain the exhaust gas pressure P of the bellows branch pipe on the first side of bellows section i. 11-i Obtain the exhaust gas temperature T of the first side of the bellows branch pipe of bellows section i. 11-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the first side of bellows section i. 11-i ; Obtain the exhaust volume flow rate Q of the target gas in the second side of the bellows branch pipe of bellows section i. 12-i Obtain the exhaust gas pressure P of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the exhaust gas temperature T of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the second side of bellows section i. 12-i ; The gas discharged from the lower end of the grate at the bottom of the sintering trolley corresponding to section i of the marked wind box is the actual effective air intake. The gas concentration C of the target gas in the actual effective air intake is obtained. 3-i ; The gas leaking into the external section i of the bellows is designated as ambient air leakage. The gas concentration C of the target gas in the ambient air leakage is then obtained. 2-i ; Using formula Calculate the air leakage rate of section i of the bellows; the unit of gas pressure is... The unit of gas volumetric flow rate is The unit of gas temperature is The unit for gas concentration is %.
2. The online air leakage detection method for a sintering system according to claim 1, characterized in that, Using formula Calculate and obtain the air leakage of section i of the bellows under standard conditions. ,in It is 273.15K. The value is 101.325 kPa.
3. The online air leakage detection method for a sintering system according to claim 2, characterized in that, Using formula Calculate and obtain the actual effective air intake volume of bellows section i under standard conditions. .
4. The online air leakage detection method for a sintering system according to claim 3, characterized in that, Using formula Calculate the total effective air intake of all wind box sections of the sintering system under standard conditions. , where M is the total number of bellows sections, M is greater than 1 and M is an integer.
5. The online air leakage detection method for a sintering system according to claim 3, characterized in that, Using formula Calculate the total air leakage of all branch pipes from the bellows branch pipes to the main exhaust pipe under standard conditions. ,in This indicates the gas pressure in the corresponding main exhaust pipe. This indicates the gas flow rate of the corresponding main exhaust pipe. This represents the gas temperature of the corresponding main exhaust pipe, where M is the total number of bellows sections, M is greater than 1 and M is an integer.
6. The online air leakage detection method for a sintering system according to claim 5, characterized in that, Using formula Calculate the total air leakage of the electrostatic precipitator under standard conditions. ,in equal , This indicates the gas pressure in the main extraction pipe. This indicates the gas flow rate of the main extraction pipe. This indicates the gas temperature in the main extraction pipe.
7. The online air leakage detection method for a sintering system according to claim 6, characterized in that, Using formula Calculate the total air leakage rate of the sintering system.
8. An online air leakage detection system for a sintering system, comprising a flue gas composition detection device and a processing unit. The flue gas composition detection device is used to obtain the exhaust volume flow rate Q of the target gas in the first side of the wind box branch pipe of the wind box section i. 11-i Obtain the exhaust gas pressure P of the bellows branch pipe on the first side of bellows section i. 11-i Obtain the exhaust gas temperature T of the first side of the bellows branch pipe of bellows section i. 11-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the first side of bellows section i. 11-i ; Obtain the exhaust volume flow rate Q of the target gas in the second side of the bellows branch pipe of bellows section i. 12-i Obtain the exhaust gas pressure P of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the exhaust gas temperature T of the bellows branch pipe on the second side of bellows section i. 12-i Obtain the gas concentration C of the target gas in the bellows branch pipe on the second side of bellows section i. 12-i ; The gas discharged from the lower end of the grate at the bottom of the sintering trolley corresponding to section i of the marked wind box is the actual effective air intake. The gas concentration C of the target gas in the actual effective air intake is obtained. 3-i The gas leaking into section i of the bellows from the outside is designated as ambient air leakage. The gas concentration C of the target gas in the ambient air leakage is then obtained. 2-i ; The processing unit is used to employ formulas Calculate and obtain the air leakage rate of section i of the bellows. The unit of gas pressure is . The unit of gas volumetric flow rate is The unit of gas temperature is The unit for gas concentration is %.