CN117871451A - A system for measuring combustion temperature and monitoring flammable and explosive gases - Google Patents

Abstract

The invention discloses a system for measuring combustion temperature and monitoring combustible and explosive gas, which comprises: the FTA detector is provided with a hydrogen interface, and is connected with a hydrogen pipeline through the hydrogen interface, and the hydrogen pipeline provides hydrogen fuel for the FTA detector; the FTA detector is also provided with a sample gas interface, the FTA detector is connected with a sample gas pipeline through the sample gas interface, and the input end of the sample gas pipeline is provided with a sampling port; the gas sampling pipeline is provided with a three-way joint, the three-way joint is connected with a compressed air pipeline, the front section of the gas sampling pipeline is provided with an infrared monitoring probe, and the infrared monitoring probe is used for gas measurement. According to the invention, by adopting the combination of the FTA detector and the infrared monitoring probe, the LEL on-line monitoring of the combustible waste gas with different components is realized, and the monitoring can be performed under the condition of low oxygen content of the waste gas.

Description

A system for measuring combustion temperature and monitoring flammable and explosive gases

Technical Field

The invention relates to the technical field of gas monitoring, and in particular to a system for measuring combustion temperature and monitoring flammable and explosive gases.

Background technique

In the existing technology, the regenerative thermal oxidation furnace, or RTO furnace, is one of the waste gas treatment equipment with the highest purification efficiency for medium and low concentration waste gas. However, the incinerator device often uses open flames to work, which is prone to explosion accidents. Therefore, the waste gas concentration should be monitored in real time to prevent its concentration from exploding between the upper and lower explosion limits.

At present, most combustible gas monitoring systems use FID detectors, which use hydrogen flame as an ionization source to ionize organic matter and generate microcurrent to respond. FID detectors can meet the measurement of all organic waste gas concentrations.

However, there are some shortcomings in the current use of FID detectors:

1. The FID detector does not respond to inorganic combustible gases;

2. When the concentration of components is complex, the ratio concentration changes greatly. Due to the deviation of the FID response factor, the accuracy of measuring total hydrocarbons will be affected.

Therefore, the FID detector currently used in large quantities for combustible gas detection cannot be applied to environments with a large amount of combustible inorganic gases.

Secondly, the detector based on the flame temperature measurement principle has very strict requirements on oxygen concentration. When measuring in an environment with low oxygen concentration, the flame will be unstable and the flame temperature will deviate greatly. Therefore, it can only adapt to an environment with high oxygen concentration.

Therefore, seeking an LEL online monitoring system that can be used for all combustible gas measurements and meet the needs of low-oxygen environments has significant safety, environmental and economic effects.

Summary of the invention

The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

In view of the above problems existing in the existing system for measuring combustion temperature and monitoring flammable and explosive gases, the present invention is proposed.

Therefore, the purpose of the present invention is to provide a system for measuring combustion temperature and monitoring flammable and explosive gases, which realizes online LEL monitoring of combustible exhaust gases of different components by adopting an FTA detector and an infrared monitoring probe. This monitoring can be carried out when the oxygen content of the exhaust gas is low.

In order to solve the above technical problems, the present invention provides the following technical solutions: a system for measuring combustion temperature and monitoring flammable and explosive gases, comprising:

FTA detector, the FTA detector is provided with a hydrogen interface, through which the FTA detector is connected to a hydrogen pipeline, and the hydrogen pipeline provides hydrogen fuel for the FTA detector;

The FTA detector is also provided with a sample gas interface, the FTA detector is connected to a sample gas pipeline via the sample gas interface, and a sampling port is provided at the input end of the sample gas pipeline;

The sample gas pipeline is provided with a three-way joint, and the three-way joint is connected to a compressed air pipeline. The front section of the sample gas pipeline is provided with an infrared monitoring probe, and the infrared monitoring probe is used for gas measurement;

The sample gas pipeline is provided with a first filter and a first flame arrester, wherein the first filter is used to prevent impurities from entering the FTA detector; the first flame arrester is used to prevent hydrogen flame flashback and ensure safety;

The FTA detector is connected to an exhaust pipeline, and a second filter and a second flame arrester are arranged on the exhaust pipeline.

As a preferred solution of the system for measuring combustion temperature and monitoring flammable and explosive gases of the present invention, a negative pressure control module is provided at the rear end of the FTA detector, and the sample gas entering through the sampling port is extracted by the negative pressure control module.

As a preferred solution of the system for measuring combustion temperature and monitoring flammable and explosive gases described in the present invention, the negative pressure control module includes a flow limiting orifice, a pressure sensor and a jet pump connected to the outlet, the flow limiting orifice provides the vacuum required for the flow path by adjusting the orifice diameter, and the differential pressure sensor can send a pressure signal to an external control platform, and judge whether the flow path is blocked by judging the pressure change.

As a preferred solution of the system for measuring combustion temperature and monitoring flammable and explosive gases described in the present invention, the pressure sensor feeds back the sampling flow rate through pressure changes, and outputs an alarm when it exceeds the range. The FTA detector has good overall airtightness, and the inlet and outlet of the FTA detector can lead out pipelines to be connected to the pressure sensor and the jet pump. The jet pump provides negative pressure driving force for the FTA outlet.

As a preferred solution of the system for measuring combustion temperature and monitoring flammable and explosive gases of the present invention, the second filter has a powerful filtering function to prevent impurities from clogging the flow limiting orifice plate, and the second flame arrester is used to prevent backfire.

As a preferred solution of the system for measuring combustion temperature and monitoring flammable and explosive gases described in the present invention, the infrared monitoring probe is installed before the sample gas and compressed air in the sampling pipeline are merged, and a separate measurement is performed on the gas with large response deviation in the gas components, thereby achieving temperature compensation for the FTA detector and improving measurement accuracy.

Beneficial effects of the present invention:

1. By using the FTA detector and the infrared monitoring probe, the LEL online monitoring of combustible waste gas with different components is realized. This monitoring can be carried out when the oxygen content of the waste gas is low. It overcomes the disadvantage that the FID detector has no response to inorganic combustible gases, and at the same time overcomes the problem of temperature deviation of the traditional FTA detector under low oxygen concentration. 2. The infrared monitoring probe makes temperature compensation for the FTA response deviation of individual gases, making the measurement more accurate. 3. The use of negative pressure injection shortens the response time and enhances safety. 4. The FTA detector has an advantage in the range of acceptance of sample flow fluctuations, which solves the problem that the FID detector must strictly control the injection volume.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

FIG. 1 is a schematic diagram of the system structure of the system for measuring combustion temperature and monitoring flammable and explosive gases according to the present invention.

Detailed ways

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

Referring to FIG. 1 , a system for measuring combustion temperature and monitoring flammable and explosive gases is provided, comprising:

FTA detector 1, FTA detector 1 is provided with a hydrogen interface, through which FTA detector 1 is connected to hydrogen pipeline 2, hydrogen pipeline 2 provides hydrogen fuel for FTA detector 1;

The FTA detector 1 is also provided with a sample gas interface, through which the FTA detector 1 is connected to a sample gas pipeline 3, and an input end of the sample gas pipeline 3 is provided with a sampling port 4;

A three-way joint is provided on the sample gas pipeline 3, and the three-way joint is connected to the compressed air pipeline 5. An infrared monitoring probe 14 is provided at the front section of the sample gas pipeline 3, and the infrared monitoring probe 14 is used for gas measurement. The infrared monitoring probe 14 is installed before the sample gas and the compressed air in the sampling pipeline merge, and performs separate measurement on the gas with large response deviation in the gas components, thereby realizing temperature compensation for the FTA detector and improving the measurement accuracy;

The sample gas pipeline 3 is provided with a first filter 6 and a first flame arrester 7. The first filter 6 is used to prevent impurities from entering the FTA detector 1; the first flame arrester 7 is used to prevent hydrogen flame flashback and ensure safety;

Specifically, the FTA detector 1 is connected to an exhaust pipeline 8 , and the exhaust pipeline 8 is provided with a second filter 9 and a second flame arrester 10 .

Among them, a negative pressure control module is arranged at the rear end of the FTA detector, and the sample gas entering through the sampling port 4 is extracted by the negative pressure control module. Specifically, the negative pressure control module includes a flow limiting orifice 11, a pressure sensor 12 and a jet pump 13 connected to the outlet. The flow limiting orifice 11 provides the vacuum required for the flow path by adjusting the orifice diameter. The differential pressure sensor 12 can send a pressure signal to an external control platform, and judge whether the flow path is blocked by judging the pressure change. The pressure sensor 12 feeds back the sample flow rate through the pressure change, and outputs an alarm when it exceeds the range. The FTA detector 1 has good overall air tightness, and the inlet and outlet of the FTA detector 1 can lead out pipelines to be connected to the pressure sensor 12 and the jet pump 13. The jet pump 13 provides negative pressure driving force for the FTA outlet.

The second filter 9 has a strong filtering function to prevent impurities from clogging the flow limiting orifice 11, and the second flame arrester 10 is used to prevent backfire.

In the present invention, the main components of the system are placed in the high temperature area of the column box, which can ensure that the sample is not distorted after entering the system and can obtain more accurate results.

In the present invention, the FTA detector 1 has a nozzle for combustion of hydrogen gas and sample gas.

In the present invention, the hydrogen fuel is controlled by a flow sensor to avoid fluctuations in the hydrogen flow caused by the pressure provided by the negative pressure module.

In the present invention, by adopting the FTA detector 1, online LEL monitoring of all combustible exhaust gases is achieved, the sensitivity and versatility of the detection process are enhanced, and the compressed air pipeline 5 overcomes the problems of unstable flame morphology and flame temperature under low oxygen concentration, thereby realizing LEL measurement of combustible exhaust gases under low oxygen concentration.

Specifically, the negative pressure control module provided at the outlet of the FTA detector 1 can extract the sample gas entering through the sampling port 4 .

In the present invention, the FTA detector 1 has a flame temperature measurement function, and the measuring tool involves a high-precision temperature measuring element.

Specifically, the FTA detector 1 outputs a temperature signal through a high-precision temperature measuring element, and after proportional processing of the temperature signal, it can be applied to the analysis and monitoring of different gases.

Specifically, the high-precision temperature measurement element has the characteristics of fast response and fast output, meeting the response time required by the system.

Specifically, to meet standardization, high-precision temperature measurement elements and flame morphology must be unified.

In the present invention, corrosion-resistant stainless steel material is used, and Hastelloy is the preferred material, so that analysis and testing of gases with more complex working conditions and corrosiveness can be performed.

working principle:

Before monitoring, the combustible exhaust LEL online monitoring system needs to calculate the oxygen supplement air flow required for the compressed air pipeline according to the working conditions, and adjust the temperature output ratio by the dilution ratio.

Then, the injection volume range is calculated according to the working conditions and the calculated air flow provided by the compressed air circuit, and the alarm range of the pressure sensor 12 is determined by the injection volume range.

Then, the size of the flow restriction orifice 11 and the driving gas size required by the jet pump 13 are determined.

Then the hydrogen fuel enters the FTA detector 1 through the hydrogen pipeline at a certain flow rate, and at this time, zero gas and compressed air are introduced into the sampling pipeline to keep the flame stable for a certain period of time. Then the sample gas is introduced into the sampling port.

The FTA detector 1 has a temperature measurement function. After collecting the temperature signal, the FTA detector 1 converts it into the LEL value of the gas according to proportional processing.

To ensure the accuracy of the measurement results, the combustible waste gas LEL online monitoring system should be calibrated for zero point and range before the first sample measurement and after a period of periodic operation to ensure that the measured value can truly reflect the actual situation of the sample.

In the present invention, the zero point calibration is: using hydrocarbon-free air to perform zero point calibration on the system through the sampling port 4, and the pre-calibration data should be removed to ensure that the influence of sample residue on the zero point calibration is eliminated.

In the present invention, the range calibration is: using a certain concentration of ethylene to calibrate the system through the injection port 4, and the range calibration should be performed after the zero point calibration to ensure that the influence of sample residue on the range calibration is eliminated.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims (6)

1. A system for measuring combustion temperature to monitor a flammable and explosive gas, comprising:

the FTA detector (1), the FTA detector (1) is provided with a hydrogen interface, the FTA detector (1) is connected with a hydrogen pipeline (2) through the hydrogen interface, and the hydrogen pipeline (2) provides hydrogen fuel for the FTA detector (1);

the FTA detector (1) is also provided with a sample gas interface, the FTA detector (1) is connected with a sample gas pipeline (3) through the sample gas interface, and the input end of the sample gas pipeline (3) is provided with a sampling port (4);

the gas sampling pipeline (3) is provided with a three-way joint, the three-way joint is connected with a compressed air pipeline (5), the front section of the gas sampling pipeline (3) is provided with an infrared monitoring probe (14), and the infrared monitoring probe (14) is used for gas measurement;

a first filter (6) and a first flame arrester (7) are arranged on the sample gas pipeline (3), and the first filter (6) is used for preventing impurities from entering the FTA detector (1); the first flame arrester (7) is used for preventing the hydrogen flame from backfire and ensuring the safety;

the FTA detector (1) is connected with an exhaust pipeline (8), and the exhaust pipeline (8) is provided with a second filter (9) and a second flame arrester (10).

2. The system for measuring combustion temperature to monitor combustible explosive gases according to claim 1, wherein: the rear end of the FTA detector is provided with a negative pressure control module, and the negative pressure control module is used for extracting sample gas entering through a sampling port (4).

3. The system for measuring combustion temperature to monitor combustible explosive gases according to claim 2, wherein: the negative pressure control module comprises a flow limiting orifice plate (11), a pressure sensor (12) and a jet pump (13) communicated with an outlet, wherein the flow limiting orifice plate (11) provides vacuum degree required by a flow path by adjusting the diameter of the orifice plate, and the pressure difference sensor (12) can send a pressure signal to an external control platform to judge whether the flow path is blocked or not by judging pressure change.

4. A system for measuring combustion temperature to monitor combustible explosive gases in accordance with claim 3, wherein: the pressure sensor (12) feeds back the sample injection flow through pressure change, and the alarm is output when the pressure change exceeds the range, the whole air tightness of the FTA detector (1) is good, the inlet and the outlet of the FTA detector (1) can be led out of the pipeline to be connected with the pressure sensor (12) and the jet pump (13), and the jet pump (13) provides negative pressure driving force for the FTA outlet.

5. The system for measuring combustion temperature to monitor combustible explosive gases according to claim 1, wherein: the second filter (9) has a powerful filtering function and is used for preventing impurities from blocking the flow limiting orifice plate (11), and the second flame arrester (10) is used for preventing backfire.

6. The system for measuring combustion temperature to monitor combustible explosive gases according to claim 1, wherein: the infrared monitoring probe (14) is arranged before the sample gas and the compressed air in the sampling pipeline are converged, and the gas with large response deviation in the gas component is singly measured, so that the temperature compensation of the FTA detector is realized, and the measurement accuracy is improved.