An on-line analysis system applied to a coke oven gas production line

Abstract

The application relates to an online analysis system applied to a coke oven gas production line, which comprises a sampling module, a pretreatment module, a chromatographic analysis module and an oxygen analysis module. The sampling module is used for continuously collecting sample gas; the pretreatment module comprises a steady flow filtering unit and a rapid loop unit; the steady flow filtering unit is used for pressure reduction and filtration of the sample gas; the chromatographic analysis module comprises a chromatographic analyzer and a first flowmeter; the chromatographic analyzer is connected with the steady flow filtering unit; the first flowmeter is connected between the chromatographic analyzer and the steady flow filtering unit; the oxygen analysis module comprises an oxygen analyzer and a second flowmeter; the oxygen analyzer is connected with the steady flow filtering unit; the second flowmeter is connected between the oxygen analyzer and the steady flow filtering unit; the remaining sample gas in the steady flow filtering unit which is not output to the chromatographic analyzer and the oxygen analyzer is returned to the coke oven gas production line through the rapid loop unit. The application can improve the stability and result accuracy of the online analysis system and reduce the system maintenance cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coke oven gas analysis, in particular to an online analysis system applied to a coke oven gas production line. BACKGROUND

[0002] Coke oven gas is a byproduct generated in the coking process, and its main components include hydrogen, methane, carbon monoxide, carbon dioxide, nitrogen, and a small amount of hydrogen sulfide, ammonia, etc. At present, the coke oven gas analysis system mainly relies on the traditional offline analysis method, which needs to collect the coke oven gas sample and send it to the laboratory for analysis. This method not only takes a long time, but also has poor real-time performance of the analysis results. In addition, the offline analysis method usually needs to use a large amount of chemical reagents, which causes certain pollution to the environment, and the operation process is complicated, requiring high professional skills of the operator.

[0003] With the increasing demand for automation and intelligentization in industrial production, the traditional offline analysis method has been difficult to meet the needs of modern coke oven gas production lines, so the online analysis system has emerged as the times require. The online analysis system is a device that can collect, analyze and feedback data of coke oven gas in real time on the coke oven gas production line. However, the existing online analysis system still has many problems in real-time performance, safety and stability. Since the coke oven gas contains dust, tar, naphthalene and other substances, it is easy to cause blockage of the sampling pipeline, thereby directly affecting the operation stability and safety of the online analysis system. To solve this problem, the existing technology usually uses multiple sets of pretreatment equipment to clean and adsorb the sample gas after sampling. However, on the one hand, the sample gas passes through multiple pretreatment steps before entering the analyzer, which makes the gas detection data lag, cannot guarantee the real-time performance of the online analysis system, and also prolongs the gas residence time and increases the gas condensation amount. On the other hand, too many pretreatment steps make the system too complex, increase the maintenance cost and the probability of failure of the system, and affect the stability and safety of the system.

[0004] Therefore, it is a technical problem to be solved in the current coke oven gas analysis field to develop an online analysis system with high safety, high stability and low maintenance cost. SUMMARY

[0005] In order to improve the stability of the online analysis system and the accuracy of the analysis results, and reduce the maintenance cost of the system, the present application provides an online analysis system applied to a coke oven gas production line.

[0006] The online analysis system applied to a coke oven gas production line provided by the present application adopts the following technical scheme:

[0007] An online analysis system applied to a coke oven gas production line, comprising:

[0008] a sampling module for connecting to the coke oven gas production line and collecting sample gas;

[0009] a pretreatment module, the pretreatment module comprising a steady flow filtering unit and a fast loop unit; the steady flow filtering unit is connected to the sampling module, for reducing the pressure of the sample gas and filtering water and particulate matters in the sample gas before output; the fast loop unit is used to connect the steady flow filtering unit and the coke oven gas production line;

[0010] a chromatographic analysis module, the chromatographic analysis module comprising a chromatographic analyzer and a first flow meter; the chromatographic analyzer is connected to the steady flow filtering unit via the first flow meter; the first flow meter is used to limit the sample gas flow rate output from the steady flow filtering unit to the chromatographic analyzer;

[0011] an oxygen analysis module, the oxygen analysis module comprising an oxygen analyzer and a second flow meter; the oxygen analyzer is connected to the steady flow filtering unit via the second flow meter; the second flow meter is used to limit the sample gas flow rate output from the steady flow filtering unit to the oxygen analyzer; the remaining sample gas in the steady flow filtering unit that is not output to the chromatographic analyzer and the oxygen analyzer is returned to the coke oven gas production line through the fast loop unit.

[0012] By adopting the above technical solution, when the coke oven gas needs to be analyzed online, the sampling module collects sample gas in the coke oven gas production line at a high flow rate and then outputs the sample gas to the pretreatment module. The steady flow filtering unit in the pretreatment module filters water and particulate matters in the sample gas, and then the sample gas is input to the fast loop unit, the chromatographic analysis module, and the oxygen analysis module. The chromatographic analysis module analyzes the components of H2, N2, CH4, CnHm, etc. in the sample gas, and the oxygen analysis module analyzes the oxygen content in the sample gas. Due to the existence of the first flow meter and the second flow meter, the flow rate of the sample gas entering the chromatographic analysis module and the oxygen analysis module is limited, and the excess sample gas output from the steady flow filtering unit is returned to the coke oven gas production line through the fast loop unit. Thus, while meeting the input requirements of the chromatographic analysis module and the oxygen analysis module, the flow rate and flow velocity of the sample gas are maintained at a high level, the residence time of the sample gas in the transmission pipeline is greatly shortened, the condensation amount of the sample gas and the plugging probability of the transmission pipeline are reduced. The stability and safety of the entire system are improved, and the maintenance cost of the system is reduced. Moreover, the pretreatment steps of the system are simple, the residence of the sample gas in the transmission pipeline is reduced, and the real-time and accuracy of the analysis results are ensured.

[0013] Optionally, the steady flow filtering unit comprises a first filter, a first pressure reducing valve and a second filter; an input end of the first filter is communicated with the sampling module, an output end of the first filter is communicated with an input end of the first pressure reducing valve, and the first filter is used for filtering particulate matters in the sample gas; an output end of the first pressure reducing valve is communicated with an input end of the second filter, and the second filter is used for filtering water and particulate matters in the sample gas; a main output end of the second filter is connected with the first flow meter and the second flow meter; the fast loop unit comprises a return pipe and a one-way valve; the return pipe is used for communicating a bypass output end of the second filter with the coke oven gas production line, and the one-way valve is arranged on the return pipe and is used for allowing the second filter to output to the coke oven gas production line in one direction.

[0014] By adopting the above technical solution, the first filter preliminarily filters particulate matters in the sample gas, prevents the particulate matters from entering subsequent components to cause damage to the components or blockage of the pipeline, the first pressure reducing valve reduces the pressure of the collected sample gas, ensures that the subsequent components work under appropriate pressure, and guarantees the safety of the system, the second filter filters water and particulate matters in the sample gas, further purifies the sample gas, avoids that the water and particulate matters in the sample gas cause damage to the chromatographic analyzer and the oxygen analyzer, and improves the accuracy of subsequent analysis. The return pipe of the fast loop unit can return the remaining sample gas to the low-pressure area of the coke oven gas production line, avoids waste, and makes the system form a cycle, and the arrangement of the one-way valve can prevent the coke oven gas production line from reversely inputting the sample gas into the steady flow filtering unit through the return pipe in an accident, and cause system failure or equipment damage.

[0015] Optionally, the chromatographic analysis module further comprises a third filter, a carrier gas input pipe, a first calibration unit and a first purging unit; the third filter is connected between the first flow meter and the chromatographic analyzer, and is used for filtering particulate matters in the sample gas; the carrier gas input pipe is used for connecting a first carrier gas input end of the chromatographic analyzer; the first calibration unit is connected with the chromatographic analyzer and is used for calibrating the chromatographic analyzer; and the first purging unit is used for purging the inside of the shell of the chromatographic analyzer.

[0016] By adopting the above technical solution, the third filter further filters micro-particles in the sample gas, avoids that the particles cause damage or blockage to the chromatographic analyzer, and improves the service life and analysis accuracy of the chromatographic analyzer. The carrier gas input pipe connects an external carrier gas bottle and a first carrier gas input end of the chromatographic analyzer, can provide carrier gas for the chromatographic analyzer, and ensures that the chromatographic analysis is normally performed. The first calibration unit can provide calibration for the chromatographic analyzer when the chromatographic analyzer has a deviation after being used for a long time, ensures the accuracy and reliability of the chromatographic analysis result. The first purging unit purges the inside of the shell of the chromatographic analyzer, makes the inside of the chromatographic analyzer always be under positive pressure, prevents combustible gas from entering the shell of the chromatographic analyzer, and improves the safety of the system.

[0017] Optionally, the first calibration unit comprises a first three-way control valve and a chromatographic calibration gas input pipe; three ports of the first three-way control valve are connected with a main output end of the second filter, an input end of the first flow meter and the chromatographic calibration gas input pipe respectively; the first purging unit comprises an instrument air input pipe and a fourth filter, and the instrument air input pipe is communicated with a purging gas input end and a second carrier gas input end of the chromatographic analyzer; the fourth filter is arranged on the instrument air input pipe.

[0018] By using the above technical scheme, when the chromatographic analyzer produces deviation, the standard gas with known component content is injected into the chromatographic analyzer through the first three-way control valve to perform calibration analysis, so as to ensure the accuracy and reliability of the analysis result of the chromatographic analyzer. The instrument air input pipe in the first purging unit not only can input air into the chromatographic analyzer to ensure that the chromatographic analyzer is always under positive pressure, so as to prevent combustible gas from entering the chromatographic analyzer to contact the electrical components and cause explosion; but also can be used as combustion-supporting gas to assist the combustion of hydrogen gas output by the carrier gas input pipe by using oxygen contained in the air, so as to ensure the normal operation of the chromatographic analysis. The fourth filter filters the air input from the instrument air input pipe, improves the cleanliness of the air, prevents impurities in the air from entering the chromatographic analyzer to damage the components, and thus improves the stability and safety of the system operation.

[0019] Optionally, the oxygen analysis module further comprises a second pressure reducing valve, a fifth filter, a second calibration unit and a second purging unit; the second pressure reducing valve is connected between the second filter and the second flow meter, and is used to limit the gas pressure of the sample gas output from the second filter to the second flow meter; the fifth filter is connected between the second flow meter and the oxygen analyzer, and is used to filter particulate matters in the sample gas; the second calibration unit is connected with the oxygen analyzer, and is used to calibrate the oxygen analyzer and input carrier gas into the oxygen analyzer; and the second purging unit is used to purge the inside of the shell of the oxygen analyzer.

[0020] By using the above technical scheme, the second pressure reducing valve can further reduce the gas pressure of the sample gas input into the oxygen analyzer, and improve the stability of the gas pressure of the sample gas. The fifth filter further filters the small particles in the sample gas, avoids damage or blockage of the oxygen analyzer caused by the particles, and improves the service life and analysis accuracy of the oxygen analyzer. The carrier gas input pipe is connected with an external carrier gas bottle and a first carrier gas input end of the chromatographic analyzer, can provide carrier gas for the chromatographic analyzer, and ensures the normal operation of the chromatographic analysis. The second calibration unit can provide calibration for the oxygen analyzer when the oxygen analyzer produces deviation after being used for a long time, and ensures the accuracy and reliability of the oxygen analysis result. The second purging unit purges the inside of the shell of the oxygen analyzer, so that the inside of the oxygen analyzer is always under positive pressure, prevents combustible gas from entering the shell of the oxygen analyzer, and improves the safety of the system.

[0021] Optionally, the second calibration unit comprises a reference gas input pipe, a range gas input pipe, a pneumatic valve, a second three-way control valve and a third three-way control valve; the reference gas input end of the oxygen analyzer is communicated with the reference gas input pipe, the pneumatic valve is connected between the fifth filter and the oxygen analyzer, and is used for controlling the on-off of the sample gas input into the oxygen analyzer; the pneumatic control end of the pneumatic valve is communicated with the reference gas input pipe; the first port and the second port of the second three-way control valve are connected with the main output end of the second filter and the input end of the second pressure reducing valve respectively, the first port and the second port of the third three-way control valve are connected with the reference gas input pipe and the range gas input pipe respectively, and the third port of the second three-way control valve is connected with the third port of the third three-way control valve.

[0022] By adopting the technical scheme, the pneumatic valve can be opened only when the reference gas is output, and the sample gas can enter the oxygen analyzer. The problems of distortion of the measurement result of the oxygen analyzer and poisoning damage of the sensor caused by the sample gas entering the oxygen analyzer alone are prevented, explosion caused by the high combustible component concentration in the coke oven gas and contact of the oxygen analyzer with the components are avoided, and the stability and safety of the system operation are improved. Meanwhile, when the oxygen analyzer is used for a long time and deviation occurs, the reference gas with zero oxygen content and the range gas with a known oxygen content are input into the oxygen analyzer through switching of the second three-way control valve and the third three-way control valve, the maximum value and the minimum value of the oxygen content detection of the oxygen analyzer are calibrated, and the accuracy and reliability of the analysis result of the oxygen analyzer are ensured.

[0023] Optionally, the second calibration unit comprises a reference gas input pipe, a range gas input pipe, a pneumatic valve, a second three-way control valve and a third three-way control valve; the reference gas input end of the oxygen analyzer is communicated with the reference gas input pipe, the pneumatic valve is connected between the fifth filter and the oxygen analyzer, and is used for controlling the on-off of the sample gas input into the oxygen analyzer; the pneumatic control end of the pneumatic valve is communicated with the reference gas input pipe; the first port and the second port of the second three-way control valve are connected with the main output end of the second filter and the input end of the second pressure reducing valve respectively, the first port and the second port of the third three-way control valve are connected with the reference gas input pipe and the range gas input pipe respectively, and the third port of the second three-way control valve is connected with the third port of the third three-way control valve.

[0024] By adopting the technical scheme, the inert gas output by the inert gas input pipe is used to purge the inside of the shell of the oxygen analyzer, so that the inside of the oxygen analyzer is always under positive pressure, and explosion caused by combustible gas entering the oxygen analyzer and contacting with electrical components is prevented. Meanwhile, the purger can detect the combustible gas content in the waste gas output by the oxygen analyzer after being purged, and can give an early warning in time when the combustible gas content is abnormal, so that the safety of the system is further improved. In addition, the third pressure reducing valve is arranged on the inert gas input pipe, so that the gas pressure output by the inert gas input pipe to the purger can be limited, the gas pressure of the inert gas entering the purger is stable, the purging process is more stable and reliable, and the stable operation of the oxygen analyzer is ensured.

[0025] Optionally, the system further comprises a discharge module, the discharge module comprises a discharge pipe, a flame arrester and a first control valve; the discharge pipe is provided with an atmospheric discharge port and a condensate discharge port, the waste gas output end of the chromatographic analyzer and the waste gas output end of the oxygen analyzer are both communicated with the discharge pipe; the flame arrester is arranged at the atmospheric discharge port; the first control valve is arranged at the condensate discharge port; the bypass output end of the second filter is connected with a liquid storage tank, the output end of the liquid storage tank is connected with a second control valve, and the end of the second control valve away from the liquid storage tank is communicated with the discharge pipe.

[0026] By adopting the technical scheme, the waste gas generated after the sample gas is analyzed by the chromatographic analyzer and the oxygen analyzer is output into the discharge pipe and discharged through the atmospheric discharge port, and the condensate generated by the condensation of the waste gas is collected by the discharge pipe and discharged through the condensate discharge port. The flame arrester can prevent safety accidents such as backfire during the discharge of the waste gas, and improve the safety of the system. The first control valve facilitates the control of the discharge of the condensate. The liquid storage tank can collect the waste liquid generated by the filtration of the second filter and discharged from the bypass output end thereof, and the second control valve can control the opening and closing of the discharge of the liquid in the liquid storage tank, so that the waste liquid is collected and then discharged in a centralized manner, the discharge process of the entire online analysis system is more orderly and efficient, the influence of the discharge problem on the stability and safety of the system is reduced, and the maintenance cost of the system is reduced.

[0027] Optionally, the system further comprises a cabinet, the pretreatment module, the chromatographic analysis module, the oxygen analysis module and the discharge module are all installed in the cabinet; the cabinet is provided with a heater.

[0028] By adopting the technical scheme, the pretreatment module, the chromatographic analysis module, the oxygen analysis module and the discharge module are installed in the cabinet, which is conducive to integrated arrangement and facilitates management and maintenance; the heater arranged in the cabinet can prevent the condensation of water in the gas in the system, ensure the stable operation of the system in a suitable temperature environment, and further improve the stability and safety of the system.

[0029] Optionally, the sampling module comprises a sampling probe, a gate valve and a heat tracing pipe; one end of the sampling probe is connected to a coke oven gas output pipe of a coke oven gas production line, and the other end is connected to the gate valve; one end of the heat tracing pipe is connected to the gate valve away from the sampling probe, and the other end is connected to the steady flow filtering unit.

[0030] By adopting the above technical solution, the sampling probe can collect sample gas from the coke oven gas output pipe; the gate valve can control the on-off of the sample gas flow, so as to cut off the sample gas input during system maintenance; the heat tracing pipe can prevent condensation and other problems caused by temperature change during sample gas transmission, ensuring stable delivery of sample gas to the steady flow filtering unit, and further improving the stability and safety of the system.

[0031] In summary, the present application has the following beneficial technical effects:

[0032] 1. When online analysis of coke oven gas is required, the sampling module continuously collects sample gas in the coke oven gas production line at a large flow rate and then outputs it to the pretreatment module. The steady flow filtering unit in the pretreatment module filters the water and particulate matter in the sample gas, and then inputs the sample gas into the fast loop unit, the chromatographic analysis module and the oxygen analysis module. The chromatographic analysis module analyzes the components of H2, N2, CH4, CnHm, etc. in the sample gas, and the oxygen analysis module analyzes the oxygen content in the sample gas. Due to the presence of the first flow meter and the second flow meter, the flow rate of the sample gas entering the chromatographic analysis module and the oxygen analysis module is limited, and the excess sample gas output from the steady flow filtering unit is returned to the coke oven gas production line through the fast loop unit. Thus, while meeting the input requirements of the chromatographic analysis module and the oxygen analysis module, the flow rate and flow velocity of the sample gas are maintained at a high level, greatly reducing the residence time of the sample gas in the transmission pipeline, reducing the condensation amount of the sample gas and the blockage probability of the transmission pipeline. The stability and safety of the entire system are improved, and the system maintenance cost is reduced. Moreover, the entire pretreatment process of the system is simple, the residence of the sample gas in the transmission pipeline is reduced, and the real-time and accuracy of the analysis results are ensured.

[0033] 2. The first filter preliminarily filters the particulate matter in the sample gas, preventing the particulate matter from entering the subsequent components and causing damage or pipeline blockage; the first pressure reducing valve reduces the pressure of the collected sample gas, ensuring that the subsequent components work at a suitable pressure and ensuring the safety of the system; the second filter filters the water and particulate matter in the sample gas, further purifying the sample gas, avoiding damage to the chromatographic analyzer and the oxygen analyzer caused by water and particulate matter in the sample gas, and improving the accuracy of subsequent analysis. The return pipe of the fast loop unit can return the remaining sample gas to the low-pressure area of the coke oven gas production line, avoiding waste and forming a circulation system; the one-way valve prevents the coke oven gas production line from inputting sample gas in the reverse direction into the steady flow filtering unit through the return pipe in an accidental situation, causing system failure or equipment damage.

[0034] 3. Only when the reference gas output, the pneumatic valve can be opened, sample gas can enter the oxygen analyzer. Prevents sample gas alone into the oxygen analyzer, resulting in distortion of the oxygen analyzer measurement results and sensor poisoning damage problems occur; avoid the high concentration of combustible components in the coke oven gas and the contact of the oxygen analyzer components to produce an explosion, thereby improving the stability and safety of the system operation. At the same time, when the oxygen analyzer is used for a long time, the oxygen content of the reference gas is zero and the oxygen content of the range gas is a known value. The second three-way control valve and the third three-way control valve are switched to input the oxygen analyzer, calibrate the maximum oxygen content detection and the minimum oxygen content detection of the oxygen analyzer, and ensure the accuracy and reliability of the oxygen analyzer analysis results. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is the schematic diagram of the embodiment of the present application.

[0036] Figure 2 is the schematic diagram of the inside of the cabinet of the embodiment of the present application.

[0037] Figure 3 is mainly to show the internal structure of the cabinet.

[0038] BRIEF DESCRIPTION OF DRAWINGS: 100, coke oven gas production line; 1, sampling module; 11, sampling probe; 12, gate valve; 13, heat tracing pipe; 2, pretreatment module; 21, steady flow filter unit; 211, first filter; 212, first pressure reducing valve; 213, second filter; 22, fast loop unit; 221, backfeed pipe; 222, check valve; 223, safety valve; 3, chromatographic analysis module; 31, chromatographic analyzer; 32, first flowmeter; 33, third filter; 34, carrier gas input pipe; 35, first calibration unit; 351, first three-way control valve; 352, chromatographic calibration gas input pipe; 36, first purge unit; 361, instrument air input pipe; 362, fourth filter; 4, oxygen analysis module; 41, oxygen analyzer; 42, second flowmeter; 43, second pressure reducing valve; 44, fifth filter; 45, second calibration unit; 451, reference gas input pipe; 452, range gas input pipe; 453, pneumatic valve; 454, second three-way control valve; 455, third three-way control valve; 46, second purge unit; 461, purger; 462, inert gas input pipe; 463, third pressure reducing valve; 5, discharge module; 51, discharge pipe; 511, atmospheric discharge port; 512, condensate discharge port; 52, flame arrester; 53, first control valve; 54, liquid storage tank; 55, second control valve; 6, cabinet; 7, heater. DETAILED DESCRIPTION

[0039] The present application is further described in detail below. Figures 1-3 The present application is further described in detail below.

[0040] The embodiment of the present application discloses an online analysis system applied to a coke oven gas production line.

[0041] With reference to Figure 1 and Figure 2 In the embodiment, the online analysis system comprises a sampling module 1, a pretreatment module 2, a chromatographic analysis module 3, an oxygen analysis module 4, a discharge module 5 and a cabinet 6. The sampling module 1 is used for connecting the coke oven gas production line 100 and collecting sample gas.

[0042] The pretreatment module 2 comprises a steady flow filtration unit 21 and a fast loop unit 22. The steady flow filtration unit 21 is connected with the sampling module 1 and is used for reducing the pressure of the sample gas and filtering water and particulate matters in the sample gas before outputting. The fast loop unit 22 is used for connecting the steady flow filtration unit 21 and the coke oven gas production line 100.

[0043] The chromatographic analysis module 3 comprises a chromatographic analyzer 31 and a first flow meter 32. The chromatographic analyzer 31 is connected with the steady flow filtration unit 21 via the first flow meter 32. The first flow meter 32 is used for limiting the sample gas flow output from the steady flow filtration unit 21 to the chromatographic analyzer 31.

[0044] The oxygen analysis module 4 comprises an oxygen analyzer 41 and a second flow meter 42. The oxygen analyzer 41 is connected with the steady flow filtration unit 21 via the second flow meter 42. The second flow meter 42 is used for limiting the sample gas flow output from the steady flow filtration unit 21 to the oxygen analyzer 41. The remaining sample gas in the steady flow filtration unit 21 which is not output to the chromatographic analyzer 31 and the oxygen analyzer 41 is returned to the coke oven gas production line 100 through the fast loop unit 22.

[0045] Thus, when the coke oven gas needs to be analyzed online, the sampling module 1 continuously collects the sample gas in the coke oven gas production line 100 at a large flow rate and then outputs the sample gas to the pretreatment module 2. The sample gas is simply filtered by the steady flow filtering unit 21 in the pretreatment module 2, and then the sample gas is input to the rapid loop unit 22, the chromatographic analysis module 3, and the oxygen analysis module 4. The chromatographic analysis module 3 analyzes the components of H2, N2, CH4, CnHm, and other elements in the sample gas, and the oxygen analysis module 4 analyzes the oxygen content in the sample gas. Due to the presence of the first flow meter 32 and the second flow meter 42, the flow rate of the sample gas entering the chromatographic analysis module 3 and the oxygen analysis module 4 is limited, and the excess sample gas output from the steady flow filtering unit 21 is returned to the coke oven gas production line 100 through the rapid loop unit 22. Thus, while meeting the input requirements of the chromatographic analysis module 3 and the oxygen analysis module 4, the flow rate and flow velocity of the sample gas are maintained at a high level, the residence time of the sample gas in the transmission pipeline is greatly shortened, the condensation amount of the sample gas is reduced, and the probability of pipeline blockage is reduced. The stability and safety of the entire system are improved, and the maintenance cost of the system is reduced. Moreover, the entire pretreatment process of the system is simple, the residence of the sample gas in the transmission pipeline is reduced, and the real-time and accuracy of the analysis results are ensured.

[0046] Referring to Figure 1 and Figure 2 In the present embodiment, the sampling module includes a sampling probe 11, a gate valve 12, and a heat tracing pipe 13. The sampling probe 11 is usually made of a high-temperature-resistant and corrosion-resistant metal material, such as stainless steel. One end of the sampling probe 11 is connected to the coke oven gas output pipe of the coke oven gas production line 100 and is used to insert into the coke oven gas pipeline to collect sample gas, and the other end is connected to the gate valve 12. The gate valve 12 can control the on-off of sampling, which facilitates the cutting off of sample gas input during system maintenance and repair.

[0047] One end of the heat tracing pipe 13 is connected to the end of the gate valve 12 away from the sampling probe 11, and the other end is connected to the steady flow filtering unit 21. The heat tracing pipe 13 can be electrically heated or steam heated to prevent water in the sample gas from condensing during transmission and to ensure stable delivery of the sample gas to the steady flow filtering unit 21. The heat tracing pipe 13 can also be replaced by other pipes with heat preservation function, such as ordinary pipes wrapped with heat preservation materials.

[0048] Referring to Figure 2 and Figure 3In the embodiment, the steady flow filtering unit 21 comprises a first filter 211, a first pressure reducing valve 212 and a second filter 213. The first filter 211 is generally a filter screen, the input end of which is connected to the end of the heat tracing pipe 13 away from the gate valve 12, and the output end of which is connected to the input end of the first pressure reducing valve 212. The filter screen of the first filter 211 can be selected according to the need to filter larger particles such as dust in the sample gas, so as to prevent the particles from entering the subsequent components and causing damage to the components or blocking the pipeline.

[0049] The output end of the first pressure reducing valve 212 is connected to the input end of the second filter 213, and the first pressure reducing valve 212 can reduce the pressure of the sample gas to a suitable range to ensure the safe operation of the subsequent equipment. The main output end of the second filter 213 is connected to the input end of the first flow meter 32 and the input end of the second flow meter 42. The second filter 213 can be a composite filter that can filter both water and remaining particles in the sample gas, so as to further purify the sample gas and avoid the water and particles in the sample gas from damaging the chromatographic analyzer 31 and the oxygen analyzer 41, thereby improving the accuracy of the subsequent analysis.

[0050] The rapid loop unit 22 comprises a return pipe 221, a one-way valve 222 and a safety valve 223. The return pipe 221 is connected to the bypass output end of the second filter 213 and the low-pressure area of the coke oven gas production line 100, so as to return the remaining sample gas that has not been output to the chromatographic analyzer 31 and the oxygen analyzer 41 to the low-pressure area of the coke oven gas production line 100, thereby avoiding waste and forming a cycle of the system. The one-way valve 222 is arranged on the return pipe 221. The one-way valve 222 is generally a spring-type one-way valve, which is used to output the sample gas from the second filter 213 to the coke oven gas production line 100 in one direction, so as to prevent the coke oven gas production line 100 from inputting the sample gas in the reverse direction through the return pipe 221 to the steady flow filtering unit 21 in an unexpected situation, thereby causing system failure or equipment damage. The input end of the safety valve 223 is connected to the output end of the first pressure reducing valve 212, and the output end of the safety valve 223 is connected to the return pipe 221,

[0051] It should be noted that the main output end of the second filter 213 outputs the sample gas that is further filtered by the second filter 213, and the bypass output end of the second filter 213 outputs the sample gas that is not filtered by the second filter 213 and the waste liquid generated by the second filter 213.

[0052] Referring to Figure 2 and Figure 3 In the embodiment, the chromatographic analysis module 3 further comprises a third filter 33, a carrier gas input pipe 34, a first calibration unit 35 and a first purge unit 36.

[0053] The third filter 33 is generally a high-precision filter screen, and is connected between the first flow meter 32 and the chromatographic analyzer 31. The input end of the third filter 33 is connected to the output end of the first flow meter 32, and the output end of the third filter 33 is connected to the sample gas output end of the chromatographic analyzer 31. The third filter 33 is used to further filter the small particles in the sample gas, prevent the particles from entering the chromatographic analyzer 31 to damage the internal components, and improve the service life and analysis accuracy of the chromatographic analyzer 31. The carrier gas input pipe 34 is connected to an external carrier gas cylinder and the first carrier gas input end of the chromatographic analyzer 31, and provides carrier gas for the chromatographic analyzer 31 to ensure that the chromatographic analysis is normally performed.

[0054] The first calibration unit 35 includes a first three-way control valve 351 and a chromatographic standard gas input pipe 352. The three ports of the first three-way control valve 351 are respectively connected to the main output end of the second filter 213, the input end of the first flow meter 32, and the chromatographic standard gas input pipe 352. By controlling the first three-way control valve 351, it can be switched whether the gas input into the chromatographic analyzer 31 is sample gas or chromatographic standard gas, so that when the chromatographic analyzer 31 is normally running, the carrier gas input ensures that the chromatographic analysis is normally performed. When the chromatographic analyzer 31 has been used for a long time and the accuracy deviates, the standard gas with known component content is injected into the chromatographic analyzer 31 for calibration analysis to ensure the accuracy and reliability of the analysis results of the chromatographic analyzer 31.

[0055] The first purge unit 36 includes an instrument air input pipe 361 and a fourth filter 362. The input end of the input pipe of the instrument air input pipe 361 is connected to an external air compressor to input air, and the output end of the instrument air input pipe 361 is connected to the purge gas input end and the second carrier gas input end of the chromatographic analyzer 31. By inputting air into the purge gas input end of the chromatographic analyzer 31, the inside of the shell of the chromatographic analyzer 31 is always under positive pressure, preventing combustible gas from entering the chromatographic analyzer 31 and contacting the electrical components to cause an explosion. By inputting air into the second carrier gas input end of the chromatographic analyzer 31 as combustion-supporting gas, the oxygen contained in the air is used to assist the combustion of hydrogen gas output by the carrier gas input pipe 34, ensuring that the chromatographic analysis is normally performed.

[0056] The fourth filter 362 is arranged on the instrument air input pipe 361 and is used to filter the air input from the instrument air input pipe 361, improve the cleanliness of the air, and prevent impurities in the air from entering the chromatographic analyzer 31 to damage the components, thereby improving the stability and safety of the system operation.

[0057] Referring to Figure 2 and Figure 3In the embodiment, the oxygen analysis module 4 further comprises a second pressure reducing valve 43, a fifth filter 44, a second calibration unit 45 and a second purging unit 46. The second pressure reducing valve 43 is connected between the second filter 213 and the second flow meter 42, for further limiting the sample gas pressure output from the second filter 213 to the second flow meter 42, improving the stability of the sample gas pressure, and ensuring the safe operation of the oxygen analyzer 41.

[0058] The fifth filter 44 is generally a high-precision mesh filter, and is connected between the second flow meter 42 and the oxygen analyzer 41, for further filtering the tiny particles in the sample gas, preventing the particles from entering the oxygen analyzer 41 and damaging the internal components, and improving the service life and analysis accuracy of the oxygen analyzer 41.

[0059] The second calibration unit 45 is connected to the oxygen analyzer 41 for calibrating the oxygen analyzer 41 and inputting carrier gas into the oxygen analyzer 41, and comprises a reference gas input pipe 451, a range gas input pipe 452, a pneumatic valve 453, a second three-way control valve 454 and a third three-way control valve 455.

[0060] The input end of the reference gas input pipe 451 is communicated with an external reference gas cylinder, and the output end of the reference gas input pipe 451 is communicated with the reference gas input end of the oxygen analyzer 41. The pneumatic valve 453 is connected between the fifth filter 44 and the oxygen analyzer 41, for controlling the on-off of the sample gas input into the oxygen analyzer 41. The input end of the fifth filter 44 is communicated with the output end of the second flow meter 42, the output end of the fifth filter 44 is communicated with the input end of the pneumatic valve 453, the output end of the pneumatic valve 453 is communicated with the sample gas input end of the oxygen analyzer 41, the pneumatic control end of the pneumatic valve 453 is communicated with the output end of the reference gas input pipe 451, and the input end of the reference gas input pipe 451 is communicated with an external reference gas cylinder.

[0061] The first port and the second port of the second three-way control valve 454 are respectively connected to the main output end of the second filter 213 and the input end of the second pressure reducing valve 43, the first port and the second port of the third three-way control valve 455 are respectively connected to the output ends of the reference gas input pipe 451 and the range gas input pipe 452, the input end of the range gas input pipe 452 is communicated with an external range gas cylinder, and the third port of the second three-way control valve 454 is connected to the third port of the third three-way control valve 455.

[0062] In this way, only when the reference gas is output, the pneumatic valve 453 can be opened, and the sample gas can enter the oxygen analyzer 41 from the sample gas input end of the oxygen analyzer 41. The problem of causing the oxygen analyzer 41 to measure the result to be distorted and the sensor to be damaged by the sample gas entering the oxygen analyzer 41 alone is prevented, thereby improving the stability and safety of the system operation. Meanwhile, when the oxygen analyzer 41 is used for a long time and deviates, the reference gas with zero oxygen content and the range gas with a known oxygen content are input into the oxygen analyzer 41 through the switching of the second three-way control valve 454 and the third three-way control valve 455, so as to calibrate the maximum value and the minimum value of the oxygen content detection of the oxygen analyzer 41, and ensure the accuracy and reliability of the analysis result of the oxygen analyzer 41.

[0063] The second purging unit 46 is used for purging the inside of the shell of the oxygen analyzer 41. The second purging unit 46 includes a purger 461, an inert gas input pipe 462, and a third pressure reducing valve 463. The input end of the inert gas input pipe 462 is communicated with an external inert gas cylinder. The input end of the purger 461 is communicated with the output end of the inert gas input pipe 462. The output end of the purger 461 is communicated with the purging gas input end of the oxygen analyzer 41. The purging gas output end of the oxygen analyzer 41 is communicated with the waste gas input end of the purger 461. The purger 461 can detect the combustible gas content in the gas output by the oxygen analyzer 41. The third pressure reducing valve 463 is arranged on the inert gas input pipe 462 and is used for limiting the gas pressure output by the inert gas input pipe 462 to the purger 461, so as to ensure that the inert gas pressure entering the purger 461 is stable.

[0064] In this way, the purger 461 uses the inert gas output by the inert gas input pipe 462 to purge the inside of the shell of the oxygen analyzer 41, so that the inside of the oxygen analyzer 41 is always under positive pressure, and the combustible gas is prevented from entering the oxygen analyzer 41 to contact the electrical components and cause explosion. Meanwhile, when the purger 461 detects that the combustible gas content in the waste gas output by the oxygen analyzer 41 after purging is abnormal, a timely warning can be given, and the safety of the system is further improved.

[0065] Referring to Figure 2 and Figure 3 In the embodiment, the exhaust module 5 includes an exhaust pipe 51, a flame arrester 52, and a first control valve 53. The exhaust pipe 51 is a stainless steel pipe arranged vertically. The top end and the bottom end of the exhaust pipe 51 are respectively provided with an atmospheric exhaust port 511 and a condensate discharge port 512. The waste gas output end of the chromatographic analyzer 31, the waste gas output end of the oxygen analyzer 41, and the waste gas output end of the purger 461 are all communicated with the exhaust pipe 51. The waste gas generated after the sample gas is analyzed by the chromatographic analyzer 31 and the oxygen analyzer 41 and the waste gas output by the purger 461 are all output into the exhaust pipe 51 and discharged through the atmospheric exhaust port 511. Meanwhile, the condensate generated by the condensation of the waste gas is collected by the exhaust pipe 51 and discharged through the condensate discharge port 512.

[0066] The flame arrester 52 is arranged at the atmosphere discharge port 511 of the discharge pipe 51 to prevent backfire of the discharged waste gas and improve the safety of the system. The first control valve 53 is arranged at the condensate discharge port 512 of the discharge pipe 51 to control the discharge of the condensate and realize periodic discharge of the condensate accumulated in the discharge pipe 51.

[0067] The bypass output end of the second filter 213 is further connected with a liquid storage tank 54, which is used to collect the waste liquid separated by the second filter 213. The output end of the liquid storage tank 54 is communicated with the discharge pipe 51, and a second control valve 55 is arranged between the output end of the liquid storage tank 54 and the discharge pipe 51 to facilitate control of the discharge of the liquid. The liquid storage tank 54 can be a visual liquid storage tank 54 to facilitate observation of the amount of waste liquid in the liquid storage tank 54.

[0068] Referring to Figure 2 and Figure 3 In the embodiment, the pretreatment module 2, the chromatographic analysis module 3, the oxygen analysis module 4 and the discharge module 5 are all arranged in the cabinet 6, which can protect and integrate the modules and facilitate management and maintenance. The cabinet 6 is provided with a heater 7, which can be an electric heater to ensure stable operation of the system in a suitable temperature environment, prevent condensation of water in the sample gas from affecting normal operation of the system, and further improve the stability and safety of the system.

[0069] The implementation principle of the online analysis system applied to the coke oven gas production line in the embodiment is as follows: when the coke oven gas needs to be analyzed online, the sampling module 1 continuously collects sample gas in the coke oven gas production line 100 at a large flow rate and then outputs the sample gas to the pretreatment module 2. The water and particulate matters in the sample gas are simply filtered by the steady flow filtering unit 21 in the pretreatment module 2, and then the sample gas is input to the rapid loop unit 22, the chromatographic analysis module 3 and the oxygen analysis module 4. The chromatographic analysis module 3 analyzes the components of H2, N2, CH4, CnHm and other elements in the sample gas, and the oxygen analysis module 4 analyzes the oxygen content in the sample gas. Due to the presence of the first flow meter 32 and the second flow meter 42, the flow rate of the sample gas entering the chromatographic analysis module 3 and the oxygen analysis module 4 is limited, and the excess sample gas output from the steady flow filtering unit 21 is returned to the coke oven gas production line 100 through the rapid loop unit 22. Thus, while meeting the input amount of the chromatographic analysis module 3 and the oxygen analysis module 4, the flow rate and flow speed of the sample gas are maintained at a high level, the residence time of the sample gas in the transmission pipeline is greatly shortened, and the condensation amount of the sample gas and the plugging probability of the transmission pipeline are reduced. The stability and safety of the entire system are improved, and the maintenance cost of the system is reduced. Moreover, the entire pretreatment step of the system is simple, the residence of the sample gas in the transmission pipeline is reduced, and the real-time and accuracy of the analysis results are ensured.

[0070] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: all equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. An online analysis system used in a coke oven gas production line, characterized in that: include: A sampling module (1) is used to connect to the coke oven gas production line (100) and collect sample gas; A pretreatment module (2), the pretreatment module (2) comprising a steady flow filter unit (21) and a fast loop unit (22); the steady flow filter unit (21) is connected to the sampling module (1) and is used to reduce the pressure of the sample gas and filter water and particulate matter in the sample gas before outputting it; the fast loop unit (22) is used to connect the steady flow filter unit (21) and the coke oven gas production line (100); A chromatographic analysis module (3), the chromatographic analysis module (3) comprising a chromatographic analyzer (31) and a first flow meter (32); the chromatographic analyzer (31) is connected to the steady flow filter unit (21) via the first flow meter (32); the first flow meter (32) is used to limit the flow rate of the sample gas output from the steady flow filter unit (21) to the chromatographic analyzer (31); An oxygen analysis module (4), the oxygen analysis module (4) comprising an oxygen analyzer (41) and a second flow meter (42); the oxygen analyzer (41) is connected to the steady flow filter unit (21) via the second flow meter (42); the second flow meter (42) is used to limit the flow of sample gas output from the steady flow filter unit (21) to the oxygen analyzer (41); the remaining sample gas in the steady flow filter unit (21) that is not output to the chromatographic analyzer (31) and the oxygen analyzer (41) is returned to the coke oven gas production line (100) through the fast loop unit (22); The steady flow filtering unit (21) comprises a first filter (211), a first pressure reducing valve (212) and a second filter (213); the input end of the first filter (211) is connected to the sampling module (1), the output end of the first filter (211) is connected to the input end of the first pressure reducing valve (212), and the first filter (211) is used to filter particulate matter in the sample gas; the output end of the first pressure reducing valve (212) is connected to the input end of the second filter (213), and the second filter (213) is used to filter water and particulate matter in the sample gas, and the main output end of the second filter (213) is connected to the first flow meter (32) and the second flow meter (42); The oxygen analysis module (4) further comprises a second pressure reducing valve (43), a fifth filter (44), a second calibration unit (45) and a second purge unit (46); the second pressure reducing valve (43) is connected between the second filter (213) and the second flow meter (42) and is used to limit the pressure of the sample gas output from the second filter (213) to the second flow meter (42); The fifth filter (44) is connected between the second flow meter (42) and the oxygen analyzer (41) and is used to filter particulate matter in the sample gas; the second calibration unit (45) is connected to the oxygen analyzer (41) and is used to calibrate the oxygen analyzer (41) and input carrier gas into the oxygen analyzer (41); the second purge unit (46) is used to purge the interior of the housing of the oxygen analyzer (41); The second calibration unit (45) includes a reference gas input pipe (451), a range gas input pipe (452), a pneumatic valve (453), a second three-way control valve (454) and a third three-way control valve (455); the reference gas input end of the oxygen analyzer (41) is connected to the reference gas input pipe (451), the pneumatic valve (453) is connected between the fifth filter (44) and the oxygen analyzer (41), and is used to control the on-off of the sample gas input to the oxygen analyzer (41). The pneumatic valve (453) is connected to the oxygen analyzer (41). The pneumatic control end is connected to the reference gas input pipe (451); the first port and the second port of the second three-way control valve (454) are respectively connected to the main output end of the second filter (213) and the input end of the second pressure reducing valve (43); the first port and the second port of the third three-way control valve (455) are respectively connected to the reference gas input pipe (451) and the range gas input pipe (452); and the third port of the second three-way control valve (454) is connected to the third port of the third three-way control valve (455).

2. The online analysis system for use in a coke oven gas production line according to claim 1, characterized in that: The fast loop unit (22) comprises a return pipe (221) and a one-way valve (222); the return pipe (221) is used to connect the bypass output end of the second filter (213) and the coke oven gas production line (100); the one-way valve (222) is arranged on the return pipe (221) to enable the second filter (213) to output one-way to the coke oven gas production line (100).

3. The online analysis system for use in a coke oven gas production line according to claim 2, characterized in that: The chromatographic analysis module (3) further comprises a third filter (33), a carrier gas input pipe (34), a first calibration unit (35) and a first purge unit (36); the third filter (33) is connected between the first flow meter (32) and the chromatographic analyzer (31) and is used to filter particulate matter in the sample gas; the carrier gas input pipe (34) is used to be connected to the first carrier gas input end of the chromatographic analyzer (31); the first calibration unit (35) is connected to the chromatographic analyzer (31) and is used to calibrate the chromatographic analyzer (31); and the first purge unit (36) is used to purge the interior of the housing of the chromatographic analyzer (31).

4. The online analysis system for use in a coke oven gas production line according to claim 3, characterized in that: The first calibration unit (35) includes a first three-way control valve (351) and a chromatographic calibration gas input pipe (352); the three ports of the first three-way control valve (351) are respectively connected to the main output end of the second filter (213), the input end of the first flow meter (32) and the chromatographic calibration gas input pipe (352); the first purge unit (36) includes an instrument air input pipe (361) and a fourth filter (362), the instrument air input pipe (361) is connected to the purge gas input end and the second carrier gas input end of the chromatographic analyzer (31); the fourth filter (362) is arranged on the instrument air input pipe (361).

5. The online analysis system for use in a coke oven gas production line according to claim 1, characterized in that: The second purge unit (46) includes a purge (461), an inert gas input pipe (462) and a third pressure reducing valve (463); the input end of the purge (461) is connected to the inert gas input pipe (462), the output end of the purge (461) is connected to the purge gas input end of the oxygen analyzer (41), the purge gas output end of the oxygen analyzer (41) is connected to the exhaust gas input end of the purge (461), and the purge (461) is capable of detecting the combustible gas content in the gas output by the oxygen analyzer (41); the third pressure reducing valve (463) is arranged on the inert gas input pipe (462) to limit the gas pressure output from the inert gas input pipe (462) to the purge (461).

6. The online analysis system for use in a coke oven gas production line according to claim 2, characterized in that: The invention also includes a discharge module (5), wherein the discharge module (5) includes a discharge pipe (51), a flame arrester (52) and a first control valve (53); the discharge pipe (51) is provided with an atmospheric discharge port (511) and a condensate discharge port (512); the exhaust gas output end of the chromatographic analyzer (31) and the exhaust gas output end of the oxygen analyzer (41) are both connected to the discharge pipe (51); the flame arrester (52) is arranged at the atmospheric discharge port (511); the first control valve (53) is arranged at the condensate discharge port (512); the bypass output end of the second filter (213) is connected to a liquid storage tank (54), the output end of the liquid storage tank (54) is connected to a second control valve (55), and the end of the second control valve (55) facing away from the liquid storage tank (54) is connected to the discharge pipe (51).

7. The online analysis system for use in a coke oven gas production line according to claim 6, characterized in that: It also includes a cabinet (6), wherein the pretreatment module (2), the chromatographic analysis module (3), the oxygen analysis module (4) and the exhaust module (5) are all installed in the cabinet (6); a heater is provided in the cabinet (6).

8. The online analysis system for use in a coke oven gas production line according to claim 1, characterized in that: The sampling module (1) comprises a sampling probe (11), a gate valve (12) and a heat tracing pipe (13); one end of the sampling probe (11) is connected to the coke oven gas output pipe of the coke oven gas production line (100), and the other end is connected to the gate valve (12); one end of the heat tracing pipe (13) is connected to the end of the gate valve (12) facing away from the sampling probe (11), and the other end is connected to the steady flow filter unit (21).

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