Flue gas humidity measuring device and method

Abstract

The invention discloses a flue gas humidity measuring device and method, and relates to the field of flue gas measurement, and the flue gas humidity measuring device comprises a cooler, a parameter measuring device and a processor; the cooler is used for condensing a part of water vapor in the entering flue gas to obtain saturated flue gas; the parameter measuring device is used for measuring flue gas parameter values; the flue gas parameter values comprise a first temperature, a first pressure and a first volume flow rate of flue gas at an inlet of the cooler, and a second temperature, a second pressure and a second volume flow rate of flue gas at an outlet of the cooler; the processor is connected with the parameter measuring device; the processor is used for calculating the volume flow rate of water vapor in the saturated flue gas according to the second pressure and calculating the volume concentration of water vapor at the inlet of the cooler according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter value; the volume concentration of the water vapor at the inlet of the cooler is used for representing the humidity content of the flue gas in the flue, and the application is wide in application range and convenient to use.

Description

Technical Field

[0001] The present application relates to the field of flue gas measurement, and particularly to a flue gas humidity measurement device and method. Background Art

[0002] Currently, the mainstream humidity measurement methods usually refer to the standard of "GB / T11605 - 2005 Humidity Measurement Method". The commonly used humidity measurement methods include: the expansion method, the dry and wet bulb method, the condensation dew point method, the lithium chloride dew point method, the resistance capacitance method, the electrolysis method, the gravimetric method, etc. These commonly used humidity measurement methods all have limitations in their applicable ranges, resulting in inconvenient use. Therefore, how to provide a flue gas humidity measurement solution with a wide applicable range has become an urgent problem to be solved currently. Summary of the Invention

[0003] The purpose of the present application is to provide a flue gas humidity measurement device and method to expand the applicable range and facilitate use.

[0004] To achieve the above purpose, the present application provides the following solutions:

[0005] In a first aspect, the present application provides a flue gas humidity measurement device, including: a cooler, a parameter measurement device, and a processor;

[0006] The inlet of the cooler is used to communicate with one end of the flue, and the outlet of the cooler is used to communicate with the other end of the flue; the cooler is used to condense a part of the water vapor in the incoming flue gas to obtain saturated flue gas; the saturated flue gas returns to the flue;

[0007] The parameter measurement device is used to measure flue gas parameter values; the flue gas parameter values include: the first temperature of the flue gas at the inlet of the cooler, the second temperature of the flue gas at the outlet of the cooler, the first pressure of the flue gas at the inlet of the cooler, the second pressure of the flue gas at the outlet of the cooler, the first volume flow rate of the flue gas at the inlet of the cooler, and the second volume flow rate of the flue gas at the outlet of the cooler;

[0008] The processor is connected to the parameter measurement device; the processor is used to calculate the volume flow rate of water vapor in the saturated flue gas according to the second pressure, and calculate the volume concentration of water vapor at the inlet of the cooler according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter values; the volume concentration of water vapor at the inlet of the cooler is used to characterize the humidity content of the flue gas in the flue.

[0009] Optionally, the flue gas humidity measurement device further includes: an electric heater;

[0010] The inlet of the cooler communicates with one end of the flue through the electric heater; the electric heater is used to heat the flue gas entering from the flue to a set temperature range so that the droplets in the flue gas are vaporized into water vapor, and the heated flue gas enters the cooler.

[0011] Optionally, the processor includes:

[0012] A flue gas saturation humidity calculation unit for calculating the flue gas saturation humidity according to the second pressure and the saturation pressure of water at the second temperature;

[0013] A saturated flue gas water vapor flow calculation unit for calculating the volume flow of water vapor in the saturated flue gas according to the flue gas saturation humidity and the specific volume of water vapor at the second temperature and the second pressure;

[0014] An outlet dry flue gas flow calculation unit for calculating the dry flue gas flow at the outlet of the cooler according to the second volume flow and the volume flow of water vapor in the saturated flue gas;

[0015] An inlet dry flue gas flow calculation unit for calculating the dry flue gas flow at the inlet of the cooler according to the dry flue gas flow at the outlet of the cooler, the first temperature, the second temperature, the first pressure and the second pressure;

[0016] An inlet water vapor volume flow calculation unit for calculating the volume flow of water vapor at the inlet of the cooler according to the first volume flow and the dry flue gas flow at the inlet of the cooler;

[0017] A water vapor volume concentration calculation unit for calculating the water vapor volume concentration at the inlet of the cooler according to the volume flow of water vapor at the inlet of the cooler and the first volume flow.

[0018] Optionally, the parameter measurement device includes: a temperature measurement device, a flow measurement device and a pressure measurement device; the temperature measurement device includes: a first thermometer and a second thermometer; the flow measurement device includes: a first flowmeter and a second flowmeter; the pressure measurement device includes: a first pressure gauge and a second pressure gauge;

[0019] The first thermometer, the first flowmeter and the first pressure gauge are arranged at the inlet of the cooler; the second thermometer, the second flowmeter and the second pressure gauge are arranged at the outlet of the cooler; the first thermometer is used to measure the first temperature; the first flowmeter is used to measure the first volume flow; the first pressure gauge is used to measure the first pressure; the second thermometer is used to measure the second temperature; the second flowmeter is used to measure the second volume flow; the second pressure gauge is used to measure the second pressure.

[0020] Optionally, the flue gas humidity measuring device further comprises: a filtering device; the filtering device includes a first filter cloth and a second filter cloth; the first filter cloth is disposed at the inlet of the cooler; the second filter cloth is disposed at the outlet of the cooler.

[0021] Optionally, the flue gas humidity measuring device further comprises: a fan; the outlet of the cooler is communicated with the other end of the flue through the fan; the fan is used for pumping the saturated flue gas into the flue.

[0022] Optionally, the cooler is a water cooler; the temperature of the water in the water cooler is less than or equal to 10°C.

[0023] Optionally, the set temperature range is 120°C to 130°C.

[0024] In a second aspect, the present application provides a method for measuring flue gas humidity, the method for measuring flue gas humidity is used for the above-mentioned flue gas humidity measuring device, and the method for measuring flue gas humidity includes:

[0025] Obtaining flue gas parameter values; the flue gas parameter values include: the first temperature of the flue gas at the inlet of the cooler, the second temperature of the flue gas at the outlet of the cooler, the first pressure of the flue gas at the inlet of the cooler, the second pressure of the flue gas at the outlet of the cooler, the first volume flow rate of the flue gas at the inlet of the cooler, and the second volume flow rate of the flue gas at the outlet of the cooler;

[0026] Calculating the volume flow rate of water vapor in the saturated flue gas according to the second pressure, and calculating the volume concentration of water vapor at the inlet of the cooler according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter values; the saturated flue gas is obtained by condensing a part of the water vapor in the incoming flue gas by the cooler; the volume concentration of water vapor at the inlet of the cooler is used to characterize the humidity content of the flue gas in the flue.

[0027] Optionally, calculating the volume flow rate of water vapor in the saturated flue gas according to the second pressure, and calculating the volume concentration of water vapor at the inlet of the cooler according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter values, specifically includes:

[0028] Calculating the saturated humidity of the flue gas according to the second pressure and the saturated pressure of water at the second temperature;

[0029] Calculating the volume flow rate of water vapor in the saturated flue gas according to the saturated humidity of the flue gas and the specific volume of water vapor at the second temperature and the second pressure;

[0030] Calculating the dry flue gas flow rate at the outlet of the cooler according to the second volume flow rate and the volume flow rate of water vapor in the saturated flue gas;

[0031] Calculate the dry flue gas flow rate at the inlet of the cooler based on the dry flue gas flow rate, the first temperature, the second temperature, the first pressure, and the second pressure at the outlet of the cooler;

[0032] Calculate the water vapor volume flow rate at the inlet of the cooler based on the first volume flow rate and the dry flue gas flow rate at the inlet of the cooler;

[0033] Calculate the water vapor volume concentration at the inlet of the cooler based on the water vapor volume flow rate and the first volume flow rate at the inlet of the cooler.

[0034] According to the specific embodiments provided in this application, the following technical effects are disclosed in this application:

[0035] This application provides a flue gas humidity measurement device and method. The flue gas humidity measurement device includes a cooler, a parameter measurement device, and a processor. The cooler is used to condense a part of the water vapor in the incoming flue gas to obtain saturated flue gas. The parameter measurement device is used to measure the temperature, pressure, and volume flow rate of the flue gas at the inlet and outlet of the cooler. The processor is used to calculate the water vapor volume concentration at the inlet of the cooler according to the data measured by the parameter measurement device, so as to realize the measurement of the humidity content of the flue gas in the flue. This application has no restrictions on the measurement environment, has a wide application range, is easy to use, and has low cost. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a structural block diagram of a flue gas humidity measurement device provided in an embodiment of this application;

[0038] Figure 2 It is a structural schematic diagram of a flue gas humidity measurement device provided in another embodiment of this application.

[0039] Reference numerals: Inlet of the cooler - 1, Outlet of the cooler - 2, Temperature measurement device - 3, Flow rate measurement device - 4, Pressure measurement device - 5, Filter device - 6, Fan - 7. Detailed Embodiments

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0041] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0042] First, several related technologies of the humidity measurement method will be introduced.

[0043] Measurement principle of the expansion method: Utilize the characteristic that the length of materials such as hair changes with humidity to directly indicate the relative humidity value. Application scope: Applicable to the measurement of indoor environmental temperature and humidity in laboratories, computer rooms, warehouses, factories, etc. The disadvantages of this method are: prone to drift, and its sensitivity will be lost if used for a long time at a certain humidity; slow response, and transportation or vibration will damage its performance; cannot be used below 0°C.

[0044] Measurement principle of the dry and wet bulb method: Use two thermometers with the same type and size. One is used as the dry bulb thermometer, and the bulb of the other is wrapped with a layer of clean gauze and kept moist with distilled water as the wet bulb thermometer. The difference between the dry bulb temperature and the wet bulb temperature depends on the relative humidity of the ambient air at that time. Therefore, the relative humidity of the air can be obtained by using the dry bulb temperature and the wet bulb temperature. Application scope: The dry and wet bulb hygrometer is a basic measurement method, which can accurately measure the moisture content of flue gas below 100°C, but is not suitable for measuring flue gas above 100°C and positive pressure flue gas. This method is currently mostly used as a reference method and is measured synchronously with instrument detection to achieve on-site calibration. The disadvantages of this method are: when the wet bulb temperature is below 0°C, above 100°C, or the measured flue gas is under positive pressure, it is difficult to obtain reliable results. There are many factors affecting the measurement results (for example, wind speed, radiation, etc.), and high requirements are imposed on experimental personnel and the environment.

[0045] Measurement principle of the cold mirror dew point meter: Gases with different moisture contents will condense on the mirror surface at different temperatures. The dew layer is detected by photoelectric detection technology and the dew point temperature is measured. The cold mirror dew point meter adopts a direct measurement method. On the premise of ensuring accurate dew detection, high efficiency of mirror surface refrigeration, and precise measurement of the dew point temperature, this type of dew point meter can be used as a standard dew point meter. Application scope: The cold mirror dew point meter has a wide measurement range, and its measurement range has reached -95°C to 70°C, and the measurement accuracy reaches ±0.1°C to ±0.5°C, which can meet most measurement requirements. The disadvantages of this method are: relatively high price; high requirements for operators, and large instrument maintenance workload; there is supercooled water in the range of -20°C to 0°C, and it is necessary to pay attention to distinguishing supercooled water and frost.

[0046] Measurement principle of capacitive humidity measuring instrument: The basic principle of the capacitive humidity measuring instrument is to measure trace moisture based on a flat capacitive temperature sensor. The moisture content (volume fraction) in the gas is linearly related to the logarithm of the sensor capacitance. Scope of application: Suitable for on-line monitoring. Under the conditions of -10°C to 80°C, the measurement range of the capacitive humidity measuring instrument is 0%RH to 100%RH. Disadvantages of this method: This method is an indirect measurement, and operation at a higher temperature will cause drift; when the measured medium is a corrosive gas (such as NH 3 , SO 3 , Cl 2 ), it must be calibrated regularly to overcome aging, hysteresis and pollution, and it is not recommended to use; generally speaking, compared with the resistive on-line humidity measuring instrument, the accuracy is slightly lower.

[0047] Measurement principle of resistive-capacitive humidity measuring instrument: The equivalent circuit of the resistive-capacitive humidity sensor is a parallel capacitor and resistor. The greater the moisture content, the greater the capacitance value and the smaller the resistance value. When the capacitance size is determined, the size of the sensing capacitor depends on the relative dielectric constant of the medium. The relative dielectric constant of the sample depends on the water content of the sample. The water content (volume fraction) in the sample gas is a function of the changes in the resistance and capacitance values of the resistive-capacitive humidity sensor. Scope of application: Suitable for on-line monitoring. Under the conditions of -10°C to 80°C, the measurement range of the capacitive humidity measuring instrument is 0%RH to 100%RH. Disadvantages of this method: This method is an indirect measurement and needs to be calibrated regularly; it is not suitable for low-humidity environments, and the sensitivity is lost when the relative humidity is lower than 15%RH; generally speaking, compared with the capacitive on-line humidity measuring instrument, the response is slightly slower.

[0048] Measurement principle of micro moisture analyzer by absorption electrolysis method: When the gas sample flows through a special-structured electrolytic cell, the contained water vapor is absorbed and electrolyzed by the P 2 O 5 film layer. When the absorption and electrolysis processes reach equilibrium, the electrolysis current is proportional to the water vapor content in the gas sample, so the humidity of the gas sample can be known by measuring the electrolysis current. Scope of application: The micro moisture analyzer by absorption electrolysis method can be used for a variety of inert gases and certain gases that do not react with P 2 O 5 . The measurement range is generally from 1 μL / L to 2000 μL / L and is widely used in low-humidity measurements. Disadvantages of this method: The service life of the electrolytic cell is limited and the use cost is relatively high; both high humidity and low humidity will shorten its service life, and the response is slow at low humidity; it cannot be used for certain corrosive gases and gases that can react with P 2 O 5 .

[0049] In view of the above problems, the present application provides a flue gas humidity measurement device and method, which have a wide application range, low cost and high accuracy.

[0050] In an exemplary embodiment, as Figure 1 shown, a flue gas humidity measurement device is provided, including: a cooler, a parameter measurement device and a processor.

[0051] The inlet of the cooler is used to communicate with one end of the flue, and the outlet of the cooler is used to communicate with the other end of the flue; the cooler is used to condense a part of the water vapor in the incoming flue gas to obtain saturated flue gas; the saturated flue gas flows back to the flue.

[0052] The parameter measurement device is used to measure the flue gas parameter values; the flue gas parameter values include: the first temperature of the flue gas at the inlet of the cooler, the second temperature of the flue gas at the outlet of the cooler, the first pressure of the flue gas at the inlet of the cooler, the second pressure of the flue gas at the outlet of the cooler, the first volume flow rate of the flue gas at the inlet of the cooler, and the second volume flow rate of the flue gas at the outlet of the cooler.

[0053] The processor is connected to the parameter measurement device; the processor is used to calculate the volume flow rate of the water vapor in the saturated flue gas according to the second pressure, and calculate the volume concentration of the water vapor at the inlet of the cooler according to the volume flow rate of the water vapor in the saturated flue gas and the flue gas parameter values; the volume concentration of the water vapor at the inlet of the cooler is used to characterize the humidity content of the flue gas in the flue.

[0054] The flue gas humidity measurement device of this embodiment condenses a part of the water vapor in the incoming flue gas by using a cooler to obtain saturated flue gas, and uses a parameter measurement device to measure the temperature, pressure and volume flow rate of the flue gas at the inlet and outlet of the cooler, so as to calculate the volume concentration of the water vapor at the inlet of the cooler, and realize the humidity content of the flue gas in the flue. This device has no limitation on the measurement environment, has a wide application range, is easy to use, and has low cost.

[0055] In another exemplary embodiment of the present application, referring to Figure 2 , the flue gas humidity measurement device further includes: an electric heater; the inlet 1 of the cooler is communicated with one end of the flue through the electric heater; the electric heater is used to heat the flue gas entering from the flue to a set temperature range to vaporize the liquid droplets in the flue gas into water vapor, and the heated flue gas enters the cooler. Wherein, the set temperature range can be 120°C to 130°C.

[0056] For the flue gas humidity measurement device of this embodiment, if the flue gas temperature is relatively high, the cooler can cool it down before measurement; if the flue gas temperature is relatively low and contains small droplets, the electric heater can vaporize it before measurement. Therefore, it is not only suitable for high-temperature measurement but also for low-temperature measurement. Thus, this embodiment can be applied even if there are tiny condensed water droplets in the flue gas, expanding the applicable temperature range.

[0057] In another exemplary embodiment of the present application, still refer to Figure 2 , the parameter measurement device includes: a temperature measurement device 3, a flow measurement device 4, and a pressure measurement device 5; the temperature measurement device 3 includes: a first thermometer and a second thermometer; the flow measurement device 4 includes: a first flowmeter and a second flowmeter; the pressure measurement device 5 includes: a first pressure gauge and a second pressure gauge.

[0058] The first thermometer, the first flowmeter, and the first pressure gauge are arranged at the inlet 1 of the cooler; the second thermometer, the second flowmeter, and the second pressure gauge are arranged at the outlet 2 of the cooler; the first thermometer is used to measure the first temperature; the first flowmeter is used to measure the first volumetric flow rate; the first pressure gauge is used to measure the first pressure; the second thermometer is used to measure the second temperature; the second flowmeter is used to measure the second volumetric flow rate; the second pressure gauge is used to measure the second pressure.

[0059] In another exemplary embodiment of the present application, still refer to Figure 2 , the flue gas humidity measurement device further includes: a filtering device 6; the filtering device 6 includes a first filter cloth and a second filter cloth; the first filter cloth is arranged at the inlet 1 of the cooler; the second filter cloth is arranged at the outlet 2 of the cooler. The filtering device 6 is used to filter dust and droplets in the flue gas and can be replaced or cleaned regularly.

[0060] In another exemplary embodiment of the present application, still refer to Figure 2 , the flue gas humidity measurement device further includes: a fan 7; the outlet 2 of the cooler is communicated with the other end of the flue through the fan 7; the fan 7 is used to pump the saturated flue gas to the flue.

[0061] In another exemplary embodiment of the present application, the processor includes: a flue gas saturation humidity calculation unit, a saturated flue gas water vapor flow calculation unit, an outlet dry flue gas flow calculation unit, an inlet dry flue gas flow calculation unit, an inlet water vapor volumetric flow calculation unit, and a water vapor volume concentration calculation unit.

[0062] The flue gas saturation humidity calculation unit is used to calculate the flue gas saturation humidity according to the second pressure and the saturation pressure of water at the second temperature. Specifically, asFigure 2 As shown, assume that the volumetric flow rate of superheated steam in the flue gas at the inlet 1 of the cooler is V 1s and the dry flue gas flow rate is V 1g , then the first volumetric flow rate V 1 measured by the first flowmeter at this point is V 1s = V 1g + V 1g . Then the flue gas enters the cooler and is cooled to 30 - 40 °C using normal temperature water not higher than 30 °C. A part of the water vapor in the flue gas is condensed, and the flue gas at this point is saturated flue gas. The saturated humidity d 2 of the flue gas is calculated as follows:

[0063]

[0064] where d 2 is the saturated humidity of the flue gas at this point; p T2 is the saturated pressure of water at the second temperature; p 2 is the second pressure.

[0065] The saturated flue gas water vapor flow rate calculation unit is used to calculate the volumetric flow rate of water vapor in the saturated flue gas according to the saturated humidity of the flue gas and the specific volume of water vapor at the second temperature and the second pressure. The volumetric flow rate V 2s of water vapor in the saturated flue gas can be calculated using the following formula.

[0066]

[0067] where v 2 is the specific volume of water vapor at the second temperature and the second pressure.

[0068] The outlet dry flue gas flow rate calculation unit is used to calculate the dry flue gas flow rate at the outlet 2 of the cooler according to the second volumetric flow rate and the volumetric flow rate of water vapor in the saturated flue gas. Specifically, Figure 2 the measured flue gas volumetric flow rate at the outlet 2 of the cooler, i.e., the second volumetric flow rate, is V 2 , so the formula for calculating the dry flue gas flow rate V 2g at the outlet 2 of the cooler is: V 2g = V 2 – V 2s .

[0069] The inlet dry flue gas flow rate calculation unit is used to calculate the dry flue gas flow rate at the inlet 1 of the cooler according to the dry flue gas flow rate at the outlet 2 of the cooler, the first temperature, the second temperature, the first pressure, and the second pressure. Specifically, according to the temperatures and pressures at the inlet 1 and the outlet 2 of the cooler, assuming the dry flue gas is an ideal gas, V 2gConvert to the volume when the temperature and pressure are equal to those at the inlet 1 of the cooler, i.e., the dry flue gas flow rate V at the inlet 1 of the cooler 1g The calculation formula is:

[0070]

[0071] Where, T 1 is the first temperature, T 2 is the second temperature, p 1 is the first pressure, p 2 is the second pressure.

[0072] The inlet water vapor volume flow rate calculation unit is used to calculate the water vapor volume flow rate at the inlet 1 of the cooler according to the first volume flow rate and the dry flue gas flow rate at the inlet 1 of the cooler. The water vapor volume flow rate V at the inlet 1 of the cooler 1s The calculation formula is: V 1s = V 1 – V 1g .

[0073] The water vapor volume concentration calculation unit is used to calculate the water vapor volume concentration at the inlet 1 of the cooler according to the water vapor volume flow rate at the inlet 1 of the cooler and the first volume flow rate. The water vapor volume concentration c at the inlet 1 of the cooler 1s The calculation formula is:

[0074]

[0075] In this embodiment, what the processor needs to directly obtain is the flue gas parameter value measured by the parameter measuring device.

[0076] In another exemplary embodiment of the present application, the cooler is a water cooler; the temperature of the water in the water cooler is less than or equal to 10°C.

[0077] In practical applications, a specific implementation of the above flue gas humidity measurement device is as follows: Drill two holes on the side wall of the boiler flue or other flue gas channels. One is the smoke extraction hole, and the other is the smoke return hole. The smoke extraction hole is connected to an electric heater, a cooler, and a fan 7 through a pipeline. The outlet of the fan 7 is connected to the smoke return hole through a pipeline. A filtering device 6, a temperature measurement device 3, a flow measurement device 4, and a pressure measurement device 5 are installed before and after the water cooler. The two filter cloths in the filtering device 6 are detachable for easy cleaning or replacement. The electric heater is used to heat the extracted flue gas to a temperature of 120 - 130 °C. In this way, if there are small droplets in the flue gas, they will be vaporized into water vapor. The cooler is used to cool it to 15 - 20 °C with constant temperature water not higher than 10 °C, and condense a part of the water vapor in the flue gas. A filter cloth is arranged on each side of the water cooler. The temperature measurement device 3 is used to detect the flue gas temperature at the inlet and outlet of the cooler. The flow measurement device 4 is used to detect the flue gas flow at the inlet and outlet of the cooler. The pressure measurement device 5 is used to detect the flue gas pressure at the inlet and outlet of the cooler.

[0078] Based on the same inventive concept, the embodiment of the present application also provides a flue gas humidity measurement method implemented by using the above-mentioned flue gas humidity measurement device. The solution provided by this flue gas humidity measurement method to solve the problem is similar to the solution described in the above flue gas humidity measurement device. Therefore, the specific limitations in one or more embodiments of the following flue gas humidity measurement methods can refer to the limitations on the flue gas humidity measurement device in the above text, and will not be repeated here.

[0079] In an exemplary embodiment, a flue gas humidity measurement method is provided. The flue gas humidity measurement method is used for the above-mentioned flue gas humidity measurement device, and the flue gas humidity measurement method includes:

[0080] (1) Obtain flue gas parameter values; the flue gas parameter values include: the first temperature of the flue gas at the inlet of the cooler, the second temperature of the flue gas at the outlet of the cooler, the first pressure of the flue gas at the inlet of the cooler, the second pressure of the flue gas at the outlet of the cooler, the first volume flow rate of the flue gas at the inlet of the cooler, and the second volume flow rate of the flue gas at the outlet of the cooler.

[0081] (2) Calculate the volume flow rate of water vapor in the saturated flue gas according to the second pressure, and calculate the volume concentration of water vapor at the inlet of the cooler according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter values; the saturated flue gas is obtained by condensing a part of the water vapor in the incoming flue gas by the cooler; the volume concentration of water vapor at the inlet of the cooler is used to characterize the humidity content of the flue gas in the flue. This step specifically includes:

[0082] Calculate the saturated humidity of the flue gas based on the second pressure and the saturated pressure of water at the second temperature.

[0083] Calculate the volume flow rate of water vapor in the saturated flue gas based on the saturated humidity of the flue gas and the specific volume of water vapor at the second temperature and the second pressure.

[0084] Calculate the dry flue gas flow rate at the outlet of the cooler based on the second volume flow rate and the volume flow rate of water vapor in the saturated flue gas.

[0085] Calculate the dry flue gas flow rate at the inlet of the cooler based on the dry flue gas flow rate at the outlet of the cooler, the first temperature, the second temperature, the first pressure, and the second pressure.

[0086] Calculate the volume flow rate of water vapor at the inlet of the cooler based on the first volume flow rate and the dry flue gas flow rate at the inlet of the cooler.

[0087] Calculate the volume concentration of water vapor at the inlet of the cooler based on the volume flow rate of water vapor at the inlet of the cooler and the first volume flow rate.

[0088] This application has the following advantages:

[0089] (1) There is no restriction on the environment to be measured, wide application range, convenient to use, and low cost.

[0090] (2) Wide applicable temperature range: The humidity of flue gas in the temperature range of 50 - 300 °C can be measured (the maximum flue gas temperature is determined according to the temperature resistance range of the installed filter cloth). When using this application, if the flue gas temperature is high, the water cooler can cool it down for measurement. If the flue gas temperature is low and contains small droplets, it can also be vaporized by electric heating for measurement. Therefore, it is applicable not only to high temperatures but also to low temperatures, further expanding the application range.

[0091] (3) Real-time online measurement can be achieved: After the data measured by the parameter measurement device is calculated by the processor, the humidity content in the flue gas can be calculated in real time, so real-time online measurement can be achieved.

[0092] (4) High precision: By selecting high-precision thermometers, pressure gauges, and flow meters, high-precision measurement of flue gas humidity can be achieved.

[0093] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as within the scope described in this specification.

[0094] In this article, specific examples are used to illustrate the principle and implementation of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application. At the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be construed as a limitation on this application.

Claims

1. A flue gas humidity measuring device, characterized in that: The smoke humidity measuring device comprises: a cooler, a parameter measuring device and a processor; The inlet of the cooler is used to communicate with one end of the flue, and the outlet of the cooler is used to communicate with the other end of the flue; the cooler is used to condense a part of the water vapor in the incoming flue gas to obtain saturated flue gas; the saturated flue gas flows back to the flue; The parameter measuring device is used to measure flue gas parameter values; the flue gas parameter values ​​include: a first temperature of the flue gas at the inlet of the cooler, a second temperature of the flue gas at the outlet of the cooler, a first pressure of the flue gas at the inlet of the cooler, a second pressure of the flue gas at the outlet of the cooler, a first volume flow rate of the flue gas at the inlet of the cooler, and a second volume flow rate of the flue gas at the outlet of the cooler; The processor is connected to the parameter measuring device; the processor is used to calculate the volume flow rate of water vapor in the saturated flue gas according to the second pressure, and calculate the volume concentration of water vapor at the inlet of the cooler according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter value; the volume concentration of water vapor at the inlet of the cooler is used to characterize the humidity content of the flue gas in the flue.

2. The smoke humidity measuring device according to claim 1, characterized in that: The smoke humidity measuring device further comprises: an electric heater; The inlet of the cooler is connected to one end of the flue through the electric heater; the electric heater is used to heat the flue gas entering from the flue to a set temperature range so that the droplets in the flue gas are vaporized into water vapor, and the heated flue gas enters the cooler.

3. The smoke humidity measuring device according to claim 1, characterized in that: The processor comprises: a flue gas saturation humidity calculation unit, configured to calculate the flue gas saturation humidity according to the second pressure and the saturation pressure of water at the second temperature; a saturated flue gas water vapor flow calculation unit, configured to calculate the volume flow of water vapor in the saturated flue gas according to the flue gas saturation humidity and the specific volume of water vapor at the second temperature and the second pressure; an outlet dry flue gas flow calculation unit, configured to calculate the dry flue gas flow at the outlet of the cooler according to the second volume flow and the volume flow of water vapor in the saturated flue gas; an inlet dry smoke flow calculation unit, configured to calculate the dry smoke flow at the inlet of the cooler according to the dry smoke flow at the outlet of the cooler, the first temperature, the second temperature, the first pressure, and the second pressure; an inlet water vapor volume flow calculation unit, used for calculating the water vapor volume flow at the inlet of the cooler according to the first volume flow and the dry flue gas flow at the inlet of the cooler; A water vapor volume concentration calculation unit is used to calculate the water vapor volume concentration at the inlet of the cooler according to the water vapor volume flow rate at the inlet of the cooler and the first volume flow rate.

4. The smoke humidity measuring device according to claim 1, characterized in that: The parameter measuring device comprises: a temperature measuring device, a flow measuring device and a pressure measuring device; the temperature measuring device comprises: a first thermometer and a second thermometer; the flow measuring device comprises: a first flowmeter and a second flowmeter; the pressure measuring device comprises: a first pressure gauge and a second pressure gauge; The first thermometer, the first flowmeter and the first pressure gauge are arranged at the inlet of the cooler; the second thermometer, the second flowmeter and the second pressure gauge are arranged at the outlet of the cooler; the first thermometer is used to measure the first temperature; the first flowmeter is used to measure the first volume flow; the first pressure gauge is used to measure the first pressure; the second thermometer is used to measure the second temperature; the second flowmeter is used to measure the second volume flow; the second pressure gauge is used to measure the second pressure.

5. The smoke humidity measuring device according to claim 1, characterized in that: The smoke humidity measuring device further comprises: a filtering device; the filtering device comprises a first filter cloth and a second filter cloth; the first filter cloth is arranged at the inlet of the cooler; and the second filter cloth is arranged at the outlet of the cooler.

6. The smoke humidity measuring device according to claim 1, characterized in that: The flue gas humidity measuring device also includes: a fan; the outlet of the cooler is connected to the other end of the flue through the fan; the fan is used to draw the saturated flue gas into the flue.

7. The smoke humidity measuring device according to claim 1, characterized in that: The cooler is a water cooler; the temperature of water in the water cooler is less than or equal to 10°C.

8. The smoke humidity measuring device according to claim 2, characterized in that: The set temperature range is 120°C to 130°C.

9. A method for measuring flue gas humidity, characterized in that: The flue gas humidity measurement method is used for the flue gas humidity measurement device according to any one of claims 1 to 8, and the flue gas humidity measurement method comprises: Obtain flue gas parameter values; the flue gas parameter values ​​include: a first temperature of the flue gas at the inlet of the cooler, a second temperature of the flue gas at the outlet of the cooler, a first pressure of the flue gas at the inlet of the cooler, a second pressure of the flue gas at the outlet of the cooler, a first volume flow rate of the flue gas at the inlet of the cooler, and a second volume flow rate of the flue gas at the outlet of the cooler; The volume flow rate of water vapor in the saturated flue gas is calculated according to the second pressure, and the volume concentration of water vapor at the inlet of the cooler is calculated according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter value; the saturated flue gas is obtained by condensing a part of water vapor in the incoming flue gas by the cooler; the volume concentration of water vapor at the inlet of the cooler is used to characterize the humidity content of the flue gas in the flue.

10. The method for measuring flue gas humidity according to claim 9, characterized in that: Calculating the volume flow rate of water vapor in the saturated flue gas according to the second pressure, and calculating the volume concentration of water vapor at the inlet of the cooler according to the volume flow rate of water vapor in the saturated flue gas and the flue gas parameter value, specifically includes: calculating the saturated humidity of the flue gas according to the second pressure and the saturated pressure of water at the second temperature; Calculating the volume flow rate of water vapor in the saturated flue gas according to the saturated humidity of the flue gas and the specific volume of water vapor at the second temperature and the second pressure; Calculating the dry flue gas flow rate at the outlet of the cooler according to the second volume flow rate and the volume flow rate of water vapor in the saturated flue gas; Calculate the dry flue gas flow rate at the inlet of the cooler according to the dry flue gas flow rate at the outlet of the cooler, the first temperature, the second temperature, the first pressure and the second pressure; Calculating a water vapor volume flow rate at the inlet of the cooler according to the first volume flow rate and the dry flue gas flow rate at the inlet of the cooler; The water vapor volume concentration at the inlet of the cooler is calculated based on the water vapor volume flow rate at the inlet of the cooler and the first volume flow rate.

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