A measurement method based on CO2 concentration value to compensate humidity concentration value

Abstract

The present invention discloses a measurement method based on CO2 concentration value compensation humidity concentration value, comprising the following steps: Step 1, introducing carbon dioxide standard gas with a concentration value of 15% into the humidity analyzer, and recording the humidity concentration value C stably measured by the instrument at this time. x , get the compensation coefficient. The humidity analyzer is an instrument for measuring the humidity value of industrial waste gas based on the limiting current method principle; Step 2, according to the fuel type of the sample gas to be tested, obtain the maximum value C of the carbon dioxide concentration in the sample gas to be tested. max , C max is an empirical value; step three, introducing the sample gas to be tested into the humidity analyzer, measuring the real-time oxygen concentration through the dry oxygen electrode of the humidity analyzer, and then calculating the carbon dioxide concentration through the inversion formula. Step four, reading the humidity value measured by the wet oxygen electrode of the humidity analyzer is HY, and then calculating the accurate humidity concentration value through the compensation formula. The method of the present invention is simple and effective, and can effectively overcome the problem of carbon dioxide interference in measuring humidity values ​​based on the limiting current method principle.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial waste gas emission detection, and specifically relates to a measurement method based on CO2 concentration value compensation humidity concentration value. Background Art

[0002] At present, the domestic online monitoring industry for pollution source emissions requires the detection of flue gas humidity concentration, and the mainstream detection methods are mainly limiting current method and resistance-capacitance method; among them, the limiting current method has been widely promoted and applied in the industry because it is more suitable for high-temperature conditions and can measure oxygen concentration at the same time. The principle of the limiting current method is mainly to use a zirconia dual-electrode sensor to measure the dry oxygen value and the wet oxygen value at the same time, and then calculate the wet oxygen and dry oxygen to obtain the humidity content value; in the limiting current method, the wet oxygen electrode voltage is generally set to 1 to 1.5 volts, which can simultaneously excite oxygen, water vapor, carbon dioxide and other oxygen-containing gases in the flue gas to pump oxygen; then by comparing with the signal of the dry oxygen electrode, the influence of oxygen can be deducted, and the concentration value detected at this time includes water vapor and carbon dioxide components. How to deduct the interference of carbon dioxide on humidity measurement has become an urgent problem to be solved. Summary of the invention

[0003] The object of the present invention is to provide a measurement method for compensating a humidity concentration value based on a CO2 concentration value.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A method for measuring a humidity concentration value based on a CO2 concentration value compensation comprises the following steps:

[0006] Step 1: Introduce 15% carbon dioxide standard gas into the humidity analyzer and record the humidity concentration value C that the instrument stably measures. x , and get the compensation coefficient The humidity analyzer is an instrument for measuring the humidity value of industrial waste gas based on the limiting current method principle;

[0007] Step 2: According to the fuel type of the sample gas to be tested, obtain the maximum value C of the carbon dioxide concentration in the sample gas to be tested. max , C max is the experience value;

[0008] Step 3: Pass the sample gas to be tested into the humidity analyzer, and measure the real-time oxygen concentration through the dry oxygen electrode of the humidity analyzer. Then the carbon dioxide concentration is calculated by the inversion formula The inversion formula is

[0009] Step 4: Read the humidity value measured by the wet oxygen electrode of the humidity analyzer as HY, and then calculate the accurate humidity concentration value through the compensation formula The compensation formula is:

[0010] The method of the present invention is suitable for detecting oxygen and humidity concentrations by the limiting current method. It mainly obtains the carbon dioxide concentration in the flue gas by inverting the measured oxygen concentration, thereby deducting the influence of carbon dioxide in the humidity measurement and obtaining an accurate humidity concentration value.

[0011] The present invention further illustrates that in step 2, the maximum value of the carbon dioxide concentration C max Determine according to the following table:

[0012]

[0013] Advantages of the present invention:

[0014] The method of the present invention is simple and effective, and can effectively overcome the problem that when an instrument for measuring the humidity value of industrial waste gas based on the limiting current method is used, carbon dioxide interferes with humidity measurement. The method of the present invention obtains the carbon dioxide concentration in the flue gas by inverting the measured oxygen concentration, thereby deducting the influence of carbon dioxide in the humidity measurement and obtaining an accurate humidity concentration value. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with specific embodiments.

[0016] Example:

[0017] A method for measuring a humidity concentration value based on a CO2 concentration value compensation comprises the following steps:

[0018] Step 1: Introduce 15% carbon dioxide standard gas into the humidity analyzer and record the humidity concentration value C that the instrument stably measures. x , and get the compensation coefficient The humidity analyzer is an instrument for measuring the humidity value of industrial waste gas based on the limiting current method principle;

[0019] Step 2: According to the fuel type of the sample gas to be tested, obtain the maximum value C of the carbon dioxide concentration in the sample gas to be tested. max , C max is the experience value;

[0020] Step 3: Pass the sample gas to be tested into the humidity analyzer, and measure the real-time oxygen concentration through the dry oxygen electrode of the humidity analyzer. Then the carbon dioxide concentration is calculated by the inversion formula The inversion formula is

[0021] Step 4: Read the humidity value measured by the wet oxygen electrode of the humidity analyzer as HY, and then calculate the accurate humidity concentration value through the compensation formula The compensation formula is:

[0022] Application Example 1:

[0023] During factory calibration, a carbon dioxide standard gas with a concentration of 15% is introduced, and the humidity concentration value stably measured by the instrument is recorded as 9%, and the compensation coefficient is 0.6. The instrument is used for flue emission detection of boilers burning anthracite. Without considering compensation, the real-time measured oxygen concentration is 5.5%, and the humidity concentration is 14.3%. According to the properties of anthracite, when anthracite is effectively burned in the flue, the maximum concentration of carbon dioxide produced by combustion is about 20.2%. According to the measured oxygen concentration, the carbon dioxide concentration in the flue is inverted to be about 14.9% (calculated according to step three). At this time, the humidity value that needs to be compensated is 8.9%, and the final humidity concentration after compensation is 5.4%.

[0024] Application Example 2:

[0025] During factory calibration, a carbon dioxide standard gas with a concentration of 15% is introduced, and the humidity concentration value stably measured by the instrument is recorded as 9%, and the compensation coefficient is 0.6. The instrument is used for flue emission detection of boilers burning dry natural gas. Without considering compensation, the real-time measured oxygen concentration is 3.5% and the humidity concentration is 13.3%. According to the properties of natural gas, when natural gas is effectively burned in the flue, the maximum concentration of carbon dioxide produced by combustion is about 11.5%. According to the measured oxygen concentration, the carbon dioxide concentration in the flue is inverted to about 9.6% (calculated according to step three). At this time, the humidity value that needs to be compensated is 5.8%, and the final humidity concentration after compensation is 7.5%.

[0026] Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation of the present invention. For ordinary technicians in the relevant technical field, other different forms of changes or modifications can be made based on the above description; it is not necessary and impossible to list all the implementation methods here; and the obvious changes or modifications derived from them are still within the protection scope of the present invention.

Claims

1. A method for measuring humidity concentration value based on CO2 concentration value compensation, characterized in that The following steps are involved: Step 1: Introduce 15% carbon dioxide standard gas into the humidity analyzer and record the humidity concentration value C that the instrument stably measures. x , and get the compensation coefficient The humidity analyzer is an instrument for measuring the humidity value of industrial waste gas based on the limiting current method principle; Step 2: According to the fuel type of the sample gas to be tested, obtain the maximum value C of the carbon dioxide concentration in the sample gas to be tested. max ; The maximum value of the carbon dioxide concentration C max Determine according to the following table: Step 3: Pass the sample gas to be tested into the humidity analyzer, and measure the real-time oxygen concentration through the dry oxygen electrode of the humidity analyzer. Then the carbon dioxide concentration is calculated by the inversion formula The inversion formula is Step 4: Read the humidity value measured by the wet oxygen electrode of the humidity analyzer as HY, and then calculate the accurate humidity concentration value through the compensation formula The compensation formula is:

Images