阅读说明：本技术 一种不用放射源的煤炭发热量在线测量装置及其方法 (Online coal calorific value measuring device without radioactive source and method thereof ) 是由 李世星 吴涛 万伟龙 刘红永 王毅哲 于 2019-09-25 设计创作，主要内容包括：本发明属于煤炭的发热量在线测量技术领域,具体涉及一种不用放射源的煤炭发热量在线测量装置及其方法。本发明的测量方法采用微波雷达天线、低噪声探测器、近红外探头、信号处理器、信号放大器、上位机、下位机等构成测量硬件；利用微波雷达天线测得煤炭的水分,利用低噪声放大器测得煤炭的灰分,通过公式Q<Sup>f</Sup><Sub>DW</Sub>＝K<Sub>o</Sub>-86W<Sup>f</Sup>-92A<Sup>f</Sup>计算得到待测煤炭的发热量。不需要人为添加放射源,对环境安全没有任何影响；有效降低经典噪声、放大光信号和直接表征光信号的下交分量起伏量,具有无辐射、在线、安全、快速精确测量的特点。(The invention belongs to the technical field of on-line measurement of calorific value of coal, and particularly relates to an on-line measurement device and method for calorific value of coal without a radioactive source. The measuring method adopts a microwave radar antenna, a low-noise detector, a near-infrared probe, a signal processor, a signal amplifier, an upper computer, a lower computer and the like to form measuring hardware; measuring the moisture content of coal by using a microwave radar antenna, measuring the ash content of the coal by using a low noise amplifier, and obtaining the moisture content of the coal by using a formula Q f DW ＝K o ‑86W f ‑92A f And calculating to obtain the calorific value of the coal to be detected. The radioactive source is not needed to be added artificially, and the environmental safety is not influenced; effectively reduces the classical noise, amplifies the optical signal and directly represents the fluctuation of the lower-alternating component of the optical signal, and has the advantages of no radiation, online, safety,And the characteristic of rapid and accurate measurement.)

1. An on-line measuring device for coal calorific capacity without using radioactive sources is characterized in that: comprises a structural support (1), a microwave signal generator (3), a microwave signal operation processing unit (3-1), a signal processor (5), a lower computer (7), an upper computer (8) and a coal conveying belt (9); the structure support (1) is a frame structure, the top and the periphery of the structure support (1) are provided with a shell (1-1), the microwave signal generator (3), the microwave signal operation processing unit (3-1), the signal processor (5) and the lower computer (7) are all arranged on a bracket on the side surface of the structural bracket (1), the upper computer (8) is arranged outside the structural bracket (1), the coal conveying belt (9) is arranged in the structural support (1), a microwave radar antenna a (2) and a low-noise detector (4) are arranged below the coal conveying belt (9), a microwave radar antenna b (2-1) and 3-5 groups of near infrared probes (6) are arranged above the coal conveying belt (9), the microwave radar antenna a (2) and the microwave radar antenna b (2-1) are respectively connected with the microwave signal generator (3) through microwave communication cables; the low-noise detector (4) is connected with the signal processor (5) through a signal amplifier (10); the microwave signal operation processing unit (3-1) and the signal processor (5) are respectively and electrically connected with the lower computer (7); the lower computer (7) is electrically connected with the upper computer (8).

2. The device for on-line measurement of calorific value of coal without using radioactive source as claimed in claim 1, wherein: and a photoelectric converter (11) is also electrically connected between the signal amplifier (10) and the low-noise detector (4).

3. The device for on-line measurement of calorific value of coal without using radioactive source as claimed in claim 1, wherein: the microwave signal operation processing unit (3-1) is used for comparing energy attenuation and phase shift generated after the microwave penetrates through the coal to be detected, comparing a microwave tangent angle of the coal and a microwave tangent angle of water molecules in the coal, and calculating to obtain the water content in the coal;

the low-noise detector (4) is used for receiving ionizing radiation pulse signals emitted by trace radioactive elements contained in coal to be detected;

the 3-5 groups of near infrared probes (6) are used for measuring the volume of coal on the coal conveying belt (9) in real time; wherein three near infrared probes (6) are in a group and are uniformly distributed along the cross section direction of the coal conveying belt (9).

4. The device for on-line measurement of calorific value of coal without using radioactive source as claimed in claim 1, wherein: the signal processor (5) is used for filtering noise and interference outside the signal frequency range of target elements including thorium, radium, uranium, potassium and rubidium to be detected, performing energy level analysis on the frequency, wavelength and energy peak of characteristic ionizing radiation pulse signals emitted by various trace radioactive elements including thorium, radium, uranium, potassium and rubidium contained in coal, and quantitatively analyzing the total pulse counting quantity of the five elements including thorium, radium, uranium, potassium and rubidium and the single element pulse counting quantity of the five elements according to the energy level comparison analysis result.

5. The device for on-line measurement of calorific value of coal without using radioactive source according to claim 1 or 4, wherein: the signal processor (5) is a DSP chip.

6. The device for on-line measurement of calorific value of coal without using radioactive source as claimed in claim 1, wherein: the lower computer (7) is a BOXPC embedded industrial personal computer, and the upper computer (8) is a Siemens KA61EA type PLC;

the microwave signal operation processing unit (3-1) is a PCB printed board which is composed of microwave devices such as a power divider, a coupler, an amplifier and a constant temperature crystal oscillator and is used for detecting microwave signal attenuation and phase shift parameters.

7. The device for on-line measurement of calorific value of coal without using radioactive source as claimed in claim 1, wherein: the device adopts the high-voltage stabilized power supply made of low-voltage transistors, and the voltage stabilizing coefficient is S _ V which is 0.05%.

8. An on-line measurement method for the calorific value of coal without using a radioactive source is characterized in that: the method comprises the following steps:

step 1, a microwave signal generator (3) is electrified and generates microwaves;

step 2, transmitting a microwave signal through a microwave radar antenna a (2), and receiving the signal through a microwave radar antenna b (2-1) after the microwave signal penetrates through coal to be detected;

step 3, comparing energy attenuation and phase shift generated after the microwaves penetrate through the coal to be detected by the microwave signal operation processing unit (3-1), simultaneously comparing a microwave tangent angle of the coal and a microwave tangent angle of water molecules in the coal, and calculating to obtain the water content in the coal;

step 4, the low-noise detector (4) receives ionizing radiation pulse signals emitted by trace radioactive elements contained in the coal to be detected;

step 5, the ionizing radiation pulse signals are converted through a photoelectric converter (11) and then enter a signal amplifier (10) to be amplified step by step;

step 6, the amplified electric signals enter a signal processor (5), the signal processor (5) firstly filters noise and interference outside the signal frequency range of target elements including thorium, radium, uranium, potassium and rubidium to be detected, then carries out energy level analysis on the frequency, wavelength and energy peak of characteristic ionizing radiation pulse signals emitted by various trace radioactive elements including thorium, radium, uranium, potassium and rubidium contained in coal, and quantitatively analyzes the total pulse counting quantity of the thorium, radium, uranium, potassium and rubidium in the coal to be detected and the single element pulse counting quantity of the five elements according to the result of the energy level comparison analysis;

step 7, synchronously measuring the volume of coal on the coal conveying belt (9) through a near-infrared probe (6) arranged above the coal conveying belt (9), and transmitting a coal volume measurement signal and an analysis result of the signal processor (5) to a lower computer (7);

8, measuring by using a near-infrared probe (6) by using a lower computer (7) to obtain the instantaneous volume of coal to be detected on a belt, converting the total pulse counting quantity of the five elements of thorium, radium, uranium, potassium and rubidium obtained in the step 6 and the single element pulse counting quantity of the five elements into the total pulse counting quantity of a unit volume and the single element pulse counting quantity according to the instantaneous volume of the coal, then obtaining the specific contents of the thorium, radium, uranium, potassium and rubidium contained in the unit volume of the coal to be detected, and calculating to obtain the ash content value of the coal to be detected through the proportional relation between the specific contents of the thorium, the radium, the uranium, the potassium and the rubidium contained in the unit volume of the coal to be detected and the total content of inorganic matters in the coal;

step 9, substituting the obtained moisture value and ash value into a formula by the lower computer (7)

Q^f _DW＝K_o-86W^f-92A^f

In the formula: q^f _DW-the analytical basis lower calorific value of the fuel, kcal/kg;

W^f、A^f-fuelAnalyzing the contents of base water and ash in percentage by weight;

K_o-coefficients, in particular:

when A is^fWhen the weight percentage of the (B) is 37-44%, K_oIs 68.5;

when A is^fWhen the weight percentage of the component (A) is 44-48%, K_oIs 67.0;

when A is^fWhen the weight percentage of the component (A) is 48-55%, K_oIs 65.0;

when A is^fWhen the weight percentage of K is 55-60 percent_oIs 63.0;

when A is^fWhen the weight percentage of K is more than 60 percent_oIs 61.5;

step 10, generating heat quantity Q^f _DWDisplayed on the upper computer (8) through a communication cable.

9. The method for on-line measurement of calorific value of coal without using radioactive source as claimed in claim 8, wherein: the step 3 specifically comprises the following steps: the microwave signal operation processing unit (3-1) compares the energy attenuation and phase shift generated after the microwave penetrates through the coal to be detected, simultaneously compares the microwave tangent angle of the coal and the microwave tangent angle of the water molecules in the coal, and compares and calibrates the microwave tangent angle and the microwave tangent angle with the water value of the coal obtained by a laboratory through an oven method, thereby establishing a corresponding equation of the microwave energy attenuation and phase shift and the water content in the coal:

Y＝0.00000068*X*X+0.0004685*X+C

wherein Y is the moisture content in coal, X is the microwave attenuation, and C is the microwave phase shift cycle.

Technical Field

The invention belongs to the technical field of on-line measurement of calorific value of coal, and particularly relates to an on-line measurement device and method for calorific value of coal without a radioactive source.

Background

The issuance and implementation of the national energy conservation law put forward higher and stricter requirements on the energy consumption management mode and the energy consumption standard of the boiler of the thermal power plant. In addition, the efficiency of the unit participating in peak shaving in the power plant also has the phenomenon of increasing the coal consumption index of power generation, and a great deal of inconvenience is brought to the coal consumption examination and management work of the power plant. Therefore, the external coal supply and the internal combustion of the power plant are monitored in real time, and the boiler-by-boiler management of boiler energy consumption is realized. However, the traditional furnace fuel sampling and testing method has the problems of poor timeliness, insufficient sample representativeness, more man-made interference factors and the like, so that the requirement of calculating the power generation and supply coal consumption of each boiler with different capacity types by furnace measurement in a power plant cannot be met. In recent years, with the development of the concept of digital power plants, more and more thermal power plants are beginning to install on-line monitoring systems for fuel entering a furnace so as to better measure the coal consumption increase value accurately.

Currently, laboratories typically use calorimeters to measure the calorific value of coal. On-line measurement of the calorific value of coal is generally carried out by roughly calculating by using a dual-energy gamma ray absorption method and a simple empirical formula. The implementation mode is that two isotope radioactive sources Am241 and Cs137 respectively emit low-energy and medium-energy gamma rays to irradiate coal on a belt, and then the other side of the belt receives rays penetrating through the coal. Because the absorption efficiency of different substances in the coal to the rays with the two energies is different, particularly the absorption efficiency of heavy elements in the coal to low-energy gamma rays emitted by Am241 is far higher than that of other light elements in the coal, the grey value of the coal can be obtained by analyzing according to the intensity change before and after the two rays transmit the coal, and then the grey value is substituted into a simple empirical formula to calculate the approximate calorific value range of the coal. Because the dual-energy gamma ray absorption method has poor safety of the radioactive source, once the radioactive source is lost or leaked, the radioactive source can cause great harm to the environment or human bodies, so the radioactive source must be strictly managed, and great expense needs to be paid for the radioactive source every year in application; and the ash measurement precision of the dual-energy gamma-ray absorption method is easily influenced by the thickness change (flow change) of the coal bed, the change of the accumulation shape and the change of the ambient temperature and humidity, and the error of the calorific value of the coal calculated on the basis often exceeds 500 kilocalories, so that the measurement precision requirement of thermal power plants, metallurgical industries and the like on the calorific value of the coal can not be met. The calorimeter method has the advantages of low price and high accuracy, but requires a coal laboratory to be used as a special room for measuring the calorific capacity, and other test work cannot be carried out indoors; a curtain is prepared indoors to avoid direct sunlight; the temperature change is preferably not more than 1 ℃ in each measurement; the temperature difference in winter and summer is preferably not more than 15-30 ℃. Therefore, the conditioned person should prepare the air conditioning equipment; when the calorific value is measured by a calorimeter, strong ventilation and heat source radiation should be avoided in a room, and in short, in order to reduce the influence of environmental conditions on the calorific value measurement result, the calorific value measurement room should be kept relatively constant at room temperature as much as possible. The heat generation amount should not be measured when the room temperature is not constant. Therefore, the calorimeter has low measuring efficiency and is difficult to adapt to the modern production field.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide an on-line coal calorific value measuring device without a radioactive source and a method thereof. The measuring method of the invention does not need to artificially add radioactive sources, and has no influence on the environmental safety; the method comprises the following steps that a microwave radar antenna, a low-noise detector, a near-infrared probe, a signal processor, a signal amplifier, an upper computer, a lower computer and the like are adopted to form measurement hardware; the method effectively reduces the fluctuation quantity of the lower cross component of classical noise, amplified signal light and direct representation signal light, and has the characteristics of no radiation, online, safe, rapid and accurate measurement.

In order to achieve the purpose, the invention adopts the technical scheme that: an on-line measuring device for the calorific value of coal without radioactive sources comprises a structural support, a microwave signal generator, a microwave signal operation processing unit, a signal processor, a lower computer, an upper computer and a coal conveying belt; the coal conveying belt is characterized in that the structural support is of a frame structure, shells are arranged at the top and around the structural support, the microwave signal generator, the microwave signal operation processing unit, the signal processor and the lower computer are all arranged on the support on the side face of the structural support, the upper computer is arranged outside the structural support, the coal conveying belt is arranged in the structural support, a microwave radar antenna a and a low-noise detector are arranged below the coal conveying belt, a microwave radar antenna b and 3-5 groups of near infrared probes are arranged above the coal conveying belt, and the microwave radar antenna a and the microwave radar antenna b are respectively connected with the microwave signal generator through microwave communication cables; the low-noise detector is connected with the signal processor through the signal amplifier; the microwave signal operation processing unit and the signal processor are respectively and electrically connected with the lower level machine; the lower computer is electrically connected with the upper computer.

And a photoelectric converter is electrically connected between the signal amplifier and the low-noise detector.

The microwave signal operation processing unit is used for comparing energy attenuation and phase shift generated after the microwave penetrates through the coal to be detected, comparing a microwave tangent angle of the coal and a microwave tangent angle of water molecules in the coal, and calculating to obtain the water content in the coal;

the low-noise detector is used for receiving ionizing radiation pulse signals emitted by trace radioactive elements contained in coal to be detected;

the 3-5 groups of near infrared probes are used for measuring the volume of coal on the coal conveying belt in real time; wherein, the three near infrared probes are in a group and are uniformly distributed along the cross section direction of the coal conveying belt.

The signal processor is used for filtering noise and interference outside the signal frequency range of target elements including thorium, radium, uranium, potassium and rubidium to be detected, performing energy level analysis on the frequency, wavelength and energy peak of characteristic ionizing radiation pulse signals emitted by various trace radioactive elements including thorium, radium, uranium, potassium and rubidium contained in coal, and quantitatively analyzing the total pulse counting quantity of the five elements including thorium, radium, uranium, potassium and rubidium in the coal to be detected and the single element pulse counting quantity of the five elements according to the energy level comparison analysis result.

The signal processor is a DSP chip.

The BOXPC embedded industrial personal computer is arranged at the lower computer, and the upper computer is a Siemens KA61EA type PLC;

the microwave signal operation processing unit is a PCB printed board which is composed of microwave devices such as a power divider, a coupler, an amplifier and a constant temperature crystal oscillator and is used for detecting microwave signal attenuation and phase shift parameters.

The on-line measuring device for the calorific value of the coal without the radioactive source adopts a high-voltage stabilized power supply manufactured by a low-voltage transistor, and the voltage stabilizing coefficient is 0.05 percent.

An on-line measurement method for calorific value of coal without using radioactive source comprises the following steps:

step 1, electrifying a microwave signal generator and generating microwaves;

step 2, transmitting a microwave signal through a microwave radar antenna a, and receiving the signal through a microwave radar antenna b after the microwave signal penetrates through coal to be detected;

step 3, comparing energy attenuation and phase shift generated after the microwaves penetrate through the coal to be detected by the microwave signal operation processing unit, simultaneously comparing a microwave tangent angle of the coal and a microwave tangent angle of water molecules in the coal, and calculating to obtain the water content in the coal;

step 4, the low-noise detector receives ionizing radiation pulse signals emitted by trace radioactive elements contained in the coal to be detected;

step 5, the ionizing radiation pulse signals are converted through a photoelectric converter and then enter a signal amplifier for gradual amplification;

step 6, the amplified electric signals enter a signal processor, the signal processor firstly filters noise and interference outside the signal frequency range of target elements including thorium, radium, uranium, potassium and rubidium to be detected, then carries out energy level analysis on the frequency, wavelength and energy peak of characteristic ionizing radiation pulse signals emitted by various trace radioactive elements including thorium, radium, uranium, potassium and rubidium contained in coal, and quantitatively analyzes the total pulse counting quantity of the thorium, radium, uranium, potassium and rubidium in the coal to be detected and the single element pulse counting quantity of each of the five elements according to the result of the energy level comparison analysis;

step 7, synchronously measuring the volume of the coal on the coal conveying belt through a near-infrared probe arranged above the coal conveying belt, and transmitting a coal volume measurement signal and an analysis result of a signal processor to a lower computer;

step 8, the lower computer measures by using a near infrared probe to obtain the instantaneous volume of coal to be detected on a belt, the total pulse counting quantity of the five elements of thorium, radium, uranium, potassium and rubidium obtained in the step 6 and the single element pulse counting quantity of the five elements are converted into the total pulse counting quantity of unit volume and the single element pulse counting quantity according to the instantaneous volume of the coal, then the specific content of the thorium, the radium, the uranium, the potassium and the rubidium contained in the unit volume of the coal to be detected is obtained, and the ash content of the coal to be detected is obtained through calculation according to the proportional relation between the specific content of the thorium, the radium, the uranium, the potassium and the rubidium contained in the unit volume of the coal to be detected and the total content of inorganic matters in the coal;

step 9, substituting the obtained moisture value and ash value into a formula by the lower computer

Q^f _DW＝K_o-86W^f-92A^f

In the formula: q^f _DW-the analytical basis lower calorific value of the fuel, kcal/kg;

W^f、A^fanalyzing the weight percentage content of the base moisture and ash in the fuel;

K_o-coefficients, in particular:

when A is^fWhen the weight percentage of the (B) is 37-44%, K_oIs 68.5;

when A is^fWhen the weight percentage of the component (A) is 44-48%, K_oIs 67.0;

when A is^fWhen the weight percentage of the component (A) is 48-55%, K_oIs 65.0;

when A is^fWhen the weight percentage of K is 55-60 percent_oIs 63.0;

when A is^fThe weight percentage content of the components is more than 60 percentWhen, K_oIs 61.5;

step 10, generating heat quantity Q^f _DWAnd displaying on the upper computer through the communication cable.

The step 3 specifically comprises the following steps: the microwave signal operation processing unit compares the energy attenuation and phase shift generated after the microwave penetrates through the coal to be detected, simultaneously compares the microwave tangent angle of the coal and the microwave tangent angle of water molecules in the coal, and compares and calibrates the microwave tangent angle with the coal moisture value obtained by a laboratory by adopting an oven method, thereby establishing a corresponding equation of the microwave energy attenuation and the phase shift with the moisture content in the coal:

Y＝0.00000068*X*X+0.0004685*X+C

wherein Y is the moisture content in coal, X is the microwave attenuation, and C is the microwave phase shift cycle.

The invention has the beneficial effects that: the invention detects the total moisture in the coal by energy attenuation and phase shift after the microwave penetrates the coal to be detected; the ash content information is obtained by detecting the proportion of thorium, radium, uranium, potassium, rubidium and other trace radioactive elements contained in coal relative to the whole inorganic matters in the coal. Trace radioactive elements are ubiquitous in nature, and a certain amount of natural radioactive elements (such as uranium, thorium, potassium and the like) exist in rocks and soil. Coal is no exception and the minerals (ash) in the coal burn contain more radioactive elements than the organic matter (volatiles). The radioactive elements can be regarded as a plurality of tiny radioactive sources, the fluctuation quantity of the lower-cross component of classical noise, amplified signal light and direct representation signal light is effectively reduced through the low-noise detector, and the coal ash content can be rapidly measured.

Drawings

FIG. 1 is a schematic structural diagram of a measuring device according to the present invention;

FIG. 2 is a flow chart of the operation of the measuring device of the present invention;

FIG. 3 is a comparison curve of measured value and tested value of the moisture of the coal belt according to the present invention;

FIG. 4 is a comparison graph of measured ash content and tested ash content of the coal conveying belt according to the present invention;

FIG. 5 is a comparison curve of measured value and tested value of calorific value of the coal belt;

in the figure: 1. a structural support; 1-1, a shell; 2. a microwave radar antenna a; 2-1, a microwave radar antenna b; 3. a microwave signal generator; 3-1, a microwave signal operation processing unit; 4. A low noise detector; 5. a signal processor; 6. a near-infrared probe; 7. a lower computer; 8. an upper computer; 9. a coal conveying belt; 10. a signal amplifier; 11. a photoelectric converter; 12. and (5) coal to be tested.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The invention can also have other various implementation forms and can be used for detecting the on-line and off-line heating quantity of coal. Various modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.