CN115452882A - Device and method for measuring bulk temperature of sample in microwave field - Google Patents
Device and method for measuring bulk temperature of sample in microwave field Download PDFInfo
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- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
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Abstract
The invention relates to a device and a method for measuring the temperature of a sample body phase in a microwave field, which comprises a container and a reactor which are arranged in a microwave generator, wherein the reactor penetrates through the container, a platform for bearing a sample is arranged in the reactor, the side wall of the reactor or the position right above the platform faces an infrared temperature measuring device, an opening at the bottom of the reactor is connected with a test tube, a thermocouple temperature measuring device is arranged in the test tube and is connected with a transmission device and a power device, and the power device and the transmission device drive the thermocouple temperature measuring device to extend into or move out of the sample along the opening at the bottom of the reactor; the opening at the bottom of the reactor is also provided with an optical fiber temperature measuring device. The device is used for obtaining the infrared surface temperature-temperature reduction curve of the sample and reversely pushing to obtain the bulk temperature of the sample, and the infrared surface temperature is jointly corrected in two modes of direct temperature measurement of the optical fiber, so that the accurate measurement of the bulk temperature of the sample in the microwave field is realized.
Description
Technical Field
The invention relates to the technical field of microwave chemistry, in particular to a device and a method for measuring the bulk temperature of a sample in a microwave field.
Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
The microwave is electromagnetic wave with frequency of 300MHz-300GHz and wavelength of 1mm-1m, and has the advantages of high frequency, short wavelength, penetration to ionized layer, etc. Microwaves are used as transmission media and heating energy sources, can intensify molecular motion, improve molecular average energy, change chemical kinetics, reaction activation energy and chemical reaction paths, and are widely applied to various chemical fields from inorganic reaction to organic reaction, from pharmaceutical chemical industry to food processing, and from simple molecular reaction to complex biochemical reaction.
Microwave effects on chemical reactions have thermal and non-thermal effects. The microwave thermal effect refers to that under the action of electric moment, polar molecules and ions rotate and oscillate at high frequency along with the periodic change of the positive pole and the negative pole of a microwave field, so that absorbed microwave energy is converted into kinetic energy, and the kinetic energy is converted into heat energy due to mutual collision and friction among the molecules, so that the temperature of a system is raised. Microwave non-thermal effects refer to special effects that cannot be explained by temperature changes. The temperature of the sample in the microwave field is measured, and the method can be used for researching the opposite unified relation between the thermal effect and the non-thermal effect of the microwave.
For the measurement of the temperature of a sample in a microwave field, optical fiber temperature measurement, thermocouple temperature measurement and infrared temperature measurement are generally used at present, but the three methods have defects respectively. For optical fiber temperature measurement, the long-term temperature measurement range of common high-temperature-resistant optical fibers is-20 ℃ to +300 ℃, and when the long-term temperature measurement exceeds 300 ℃, an optical fiber sensor is easy to damage and is limited by the cost and difficult to apply on a large scale; for thermocouple temperature measurement, the microwave generates skin effect and eddy current effect on the surface of the metal sheath of the thermocouple and may generate 'point discharge', thereby affecting the temperature measurement precision and even damaging the thermocouple; for infrared thermometry, which measures the surface temperature of a sample or reactor, there is a temperature gradient between the bulk and the surface of the sample in the microwave heating mode, especially a large temperature gradient at high temperature. Therefore, the measurement of the bulk temperature of the sample in the microwave field is difficult to realize by the conventional measurement method.
Disclosure of Invention
In order to solve the technical problems in the background art, the invention provides a device and a method for measuring the bulk phase temperature of a sample in a microwave field, wherein the bulk phase temperature of the sample and the direct temperature measurement of a low-temperature section (0-300 ℃) optical fiber are obtained by backward pushing a cooling curve to jointly correct the infrared surface temperature so as to realize the online accurate measurement of the bulk phase temperature of the sample in the microwave field.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a device for measuring the bulk temperature of a sample in a microwave field, which comprises a container and a reactor, wherein the container and the reactor are arranged in a microwave generator, the reactor penetrates through the container, a platform for bearing the sample is arranged in the reactor, the side wall of the reactor or the position right above the platform faces an infrared temperature measuring device, an opening at the bottom of the reactor is connected with a test tube, a thermocouple temperature measuring device is arranged in the test tube and is connected with a transmission device and a power device, and the power device and the transmission device drive the thermocouple temperature measuring device to extend into or move out of the sample along the opening at the bottom of the reactor; the opening at the bottom of the reactor is also provided with an optical fiber temperature measuring device.
The microwave generator comprises a microwave generating chamber, a shell of the microwave generating chamber is connected with the water circulation sealing device, and a magnetron is arranged in the microwave generating chamber; the microwave oven is also provided with a microwave detector, and the microwave detector detects whether the microwave in the environment outside the microwave chamber exceeds the standard or not.
Quartz wool is arranged in the space between the interior of the container and the outer wall of the reactor.
The reactor has a gas outlet and a gas inlet, which extend to the outside of the microwave generator, respectively, for introducing inert gas.
The infrared temperature measuring device, the optical fiber temperature measuring device and the thermocouple temperature measuring device are all connected with a temperature display.
The infrared temperature measuring device is provided with an infrared temperature measuring sensor, no quartz glass is blocked between the infrared temperature measuring sensor and the sample and faces the surface of the sample, and the infrared surface temperature of the sample is obtained.
The optical fiber temperature measuring device is provided with an optical fiber temperature measuring sensor, and the optical fiber temperature measuring sensor extends into the sample along the opening at the bottom of the reactor to obtain the optical fiber bulk temperature of the sample.
The thermocouple temperature measuring device is provided with a thermocouple, the thermocouple extends into the sample along the opening at the bottom of the reactor under the driving of the power device and the transmission device to obtain the temperature of the sample changing along with time, and the bulk phase stable temperature of the sample when the time is zero is obtained through back pushing.
The container is a quartz container, the reactor is a quartz reactor, the platform is a porous quartz platform, and the test tube is a quartz test tube.
The second aspect of the present invention provides the method for measuring the bulk temperature of the sample in the microwave field, comprising the following steps:
loading a sample into a platform in a reactor, introducing inert gas, starting a water circulation sealing device, heating by a microwave generator, and testing two groups of temperature data;
a set of data, a test tube containing a thermocouple is inserted into the opening at the bottom of the reactor in advance, and an infrared temperature measuring device is used for obtaining the surface stable temperature T when the sample is heated by microwave in a set time period 1 When the microwave generator is turned off, the power device and the transmission device are utilized to drive the thermocouple to extend into the sample, the temperature of the sample changing along with time is obtained, and the polynomial fitting is used for reversely pushing the temperature until the time is zero, so that the bulk phase stable temperature T of the sample during microwave heating is obtained 2 ；
After the sample is cooled to room temperature, the microwave heating power is changed according to the test requirements to obtain a plurality of groups of corresponding cooling and inverse-pushing body phase temperatures T 2 Infrared surface temperature T 1 The data pair of (1);
the optical fiber sensor in the optical fiber temperature measuring device is inserted into the center of the sample from the opening at the bottom of the reactor to obtain the bulk temperature and the infrared surface temperature of the optical fiber within a set time period;
turning off the microwave generator, and after the sample is cooled to room temperature, changing the microwave heating power according to the test requirements to obtain a plurality of groups of corresponding fiber bulk temperature and infrared surface temperature data pairs;
and averaging the two groups of surface temperature-bulk phase temperature data, obtaining a relational expression of the surface temperature and the bulk phase temperature of the sample in the microwave field through a fitting equation after linear fitting, and realizing the measurement of the bulk phase temperature of the sample through the relational expression.
Compared with the prior art, the above one or more technical schemes have the following beneficial effects:
1. the device is used for obtaining the infrared surface temperature-temperature reduction curve of the sample and reversely pushing to obtain the bulk temperature of the sample, and the infrared surface temperature is jointly corrected in two modes of direct temperature measurement of the optical fiber, so that the accurate measurement of the bulk temperature of the sample in the microwave field is realized.
2. And (3) inserting a thermocouple into the sample to obtain temperature change reduced along with time while the microwave heating is turned off, obtaining the stable temperature when the time is zero through backward pushing, namely obtaining the bulk phase stable temperature of the sample during the microwave heating, wherein the temperature corresponds to the infrared surface temperature and is matched with the bulk phase temperature directly measured by the optical fiber, and after linear fitting, realizing the combined correction of the infrared surface temperature.
3. The method of the combined correction is simple, the cost is low, powerful support is provided for the theoretical research of microwave non-thermal effect, and the method is helpful for disclosing the internal mechanism of microwave for improving the chemical reaction rate and strengthening the material synthesis.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are included to illustrate an exemplary embodiment of the invention and not to limit the invention.
FIG. 1 is a schematic diagram of a sample bulk temperature measurement device according to one or more embodiments of the present invention;
FIG. 2 is a graph of temperature calibration of a reduced temperature push-back thermocouple measurement provided in accordance with one or more embodiments of the present invention;
FIG. 3 is a schematic diagram of a combination of direct temperature measurement and temperature reduction and reverse temperature measurement to correct surface temperature for one or more embodiments of the present invention;
in the figure: 1-temperature display, 2-infrared temperature sensor, 3-quartz reactor, 4-microwave generator, 5-quartz container, 6-quartz cotton, 7-sample bed layer, 8-quartz test tube, 9-porous quartz platform, 10-magnetron, 11-thermocouple, 12-transmission device, 13-power device, 14-water circulation sealing device, 15-optical fiber sensor and 16-microwave detector.
Detailed Description
The invention is further described with reference to the following figures and examples.
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
As described in the background art, it is difficult to measure the bulk temperature of a sample in a microwave field by using three common measurement modes, i.e., optical fiber temperature measurement, thermocouple temperature measurement and infrared temperature measurement.
Therefore, the following embodiments provide a device and a method for measuring the bulk temperature of a sample in a microwave field, which jointly correct the infrared surface temperature by two technologies of obtaining the bulk temperature of the sample and direct temperature measurement of the low-temperature section (0-300 ℃) by backward pushing of a cooling curve, so as to realize the online accurate measurement of the bulk temperature of the sample in the microwave field.
The first embodiment is as follows:
as shown in fig. 1, a device for measuring the bulk temperature of a sample in a microwave field comprises a container and a reactor arranged in a microwave generator, wherein the reactor penetrates through the container, a platform for bearing the sample is arranged in the reactor, an infrared temperature measuring device is arranged right above the platform or on the side wall of the reactor, an opening at the bottom of the reactor is connected with a test tube, a thermocouple temperature measuring device is arranged in the test tube and is connected with a transmission device and a power device, and the power device and the transmission device drive the thermocouple temperature measuring device to extend into or move out of the sample along the opening at the bottom of the reactor; an opening at the bottom of the reactor is also provided with an optical fiber temperature measuring device.
The microwave generator comprises a microwave generating chamber, a shell of the microwave generating chamber is connected with the water circulation sealing device, and a magnetron is arranged in the microwave generating chamber; the microwave oven is also provided with a microwave detector, and the microwave detector detects whether the microwave in the environment outside the microwave chamber exceeds the standard or not.
Quartz wool is arranged in the space between the interior of the container and the outer wall of the reactor.
The container is a quartz container, the reactor is a quartz reactor, the platform is a porous quartz platform, and the test tube is a quartz test tube.
The reactor has a gas outlet and a gas inlet, which extend to the outside of the microwave generator, respectively, for introducing inert gas.
The infrared temperature measuring device, the optical fiber temperature measuring device and the thermocouple temperature measuring device are all connected with a temperature display.
In this embodiment, the quartz container 5 is opened at its top and at its bottom with the same size as the outer diameter of the quartz reactor 3 so that the quartz reactor 3 can pass through. The quartz cotton 6 is arranged in the quartz container 5, so that the heat dissipation of the sample can be reduced, the energy is saved, and the consumption is reduced. Meanwhile, for the cooling reverse-pushing method, the heat-insulating structure can effectively improve the accuracy of the temperature obtained by reverse pushing.
In this embodiment, the microwave frequency output by the microwave generator 4 is 2.45GHz, the power is adjustable, the range is 0-1000W, and the microwave power is detected by the microwave detector 16.
Preferably, a water-cooled magnetron is selected to prevent damage due to insufficient heat dissipation from the magnetron 10.
In this embodiment, the infrared temperature measuring device is installed right above the quartz reaction tube, and directly aligns to the surface of the sample without being blocked by quartz glass with the bed material, so as to measure the surface temperature of the sample.
It should be noted that, the infrared temperature measuring device can also horizontally measure the temperature of the tube wall of the quartz tube, and the temperature of the sample body phase is accurately measured by correcting the temperature.
In the embodiment, the infrared temperature sensor 2 of the infrared temperature measuring device is positioned right above the quartz reactor 3.
In this embodiment, the water circulation sealing device 14 is enclosed outside the metal housing of the microwave generator 4, and is used for absorbing microwaves and preventing the microwaves from leaking into the environment.
In this embodiment, when the microwave heating is stopped, the motor (power device 13) is started, and the thermocouple is accurately added to the geometric center of the sample by fixing the transmission rod (transmission device 12) and the quartz test tube, so as to detect the real-time change of the bulk temperature of the sample.
The device is characterized in that inert gas is introduced after a sample is loaded into a platform in a reactor, a microwave generator is started to perform heating, and two groups of temperature data are tested in the period;
a set of data, which utilizes an infrared temperature measuring device to obtain the surface stable temperature T when the sample in a set time period is heated by microwave 1 When the microwave generator is closed, the power device and the transmission device are utilized to drive the thermocouple to extend into the sample, the temperature of the sample changing along with time is obtained, the inverse pushing is carried out until the time is zero through polynomial fitting, and the phase stable temperature T of the sample during microwave heating is obtained 2 ；
After the sample is cooled to room temperature, the microwave heating power is changed according to the test requirements to obtain a plurality of groups of cooling inverse-thrust phase temperatures T 2 Infrared surface temperature T 1 The data pair of (1);
the optical fiber sensor in the optical fiber temperature measuring device is inserted into the center of the sample from the bottom opening of the reactor to obtain the bulk temperature and the infrared surface temperature of the optical fiber within a set time period;
and (3) turning off the microwave generator, and after the sample is cooled to room temperature, changing the microwave heating power according to the test requirements to obtain a set of corresponding fiber bulk temperature and infrared surface temperature data pairs.
The sample surface temperature measured on line by the infrared sensor is corrected by combining two modes of backward deducing the sample bulk temperature and direct temperature measurement of the low-temperature section optical fiber through the cooling curve, so that a relational expression between the bulk temperature and the surface temperature is established, and the sample bulk temperature is measured on line.
Example two:
based on the method for measuring the bulk temperature of the sample by the measuring device in the embodiment, the method for measuring the temperature of the infrared surface by adopting the online temperature measurement method for correcting the temperature of the infrared surface by combining temperature reduction, reverse-push temperature measurement and optical fiber direct temperature measurement comprises the following steps of:
loading a sample into a platform in a reactor, introducing inert gas, starting a water circulation sealing device, heating by a microwave generator, and testing two groups of temperature data;
a set of data, a test tube containing a thermocouple is inserted into the opening at the bottom of the reactor in advance, and an infrared temperature measuring device is used for obtaining the surface stable temperature T when the sample is heated by microwave in a set time period 1 When the microwave generator is closed, the power device and the transmission device are utilized to drive the thermocouple to extend into the sample, the temperature of the sample changing along with time is obtained, the inverse pushing is carried out until the time is zero through polynomial fitting, and the phase stable temperature T of the sample during microwave heating is obtained 2 ；
After the sample is cooled to room temperature, the microwave heating power is changed according to the test requirements to obtain a plurality of groups of corresponding cooling and inverse-pushing body phase temperatures T 2 Infrared surface temperature T 1 The data pair of (1);
the optical fiber sensor in the optical fiber temperature measuring device is inserted into the center of the sample from the opening at the bottom of the reactor to obtain the bulk temperature and the infrared surface temperature of the optical fiber within a set time period;
and (3) turning off the microwave generator, and after the sample is cooled to room temperature, changing the microwave heating power according to the test requirements to obtain a plurality of groups of corresponding fiber bulk temperature and infrared surface temperature data pairs.
And averaging the two groups of surface temperature-bulk phase temperature data pairs respectively, obtaining a fitting equation after linear fitting, obtaining a relational expression of the surface temperature and the bulk phase temperature of the sample in the microwave field, and realizing the measurement of the bulk phase temperature of the sample through the relational expression.
Specifically, the method comprises the following steps:
(1) Putting a certain amount of sample on a quartz cotton platform in a quartz reactor, connecting inert gas to an inlet of a quartz tube, connecting an infrared sensor right above the quartz tube, positioning a thermocouple below the quartz tube outside a microwave heater in place, starting a water circulation device outside the microwave generator, starting an inert gas cylinder, introducing inert gas with a certain flow, setting microwave heating power after airflow is stable, and starting microwave heating. After heating for a certain time and infrared temperature is stabilized, recording temperature value T 1 Turning off microwave heating, simultaneously turning on a thermocouple transmission device below the microwave heater to rapidly insert a thermocouple to the center position of the sample, recording the change of the thermocouple temperature along with time to obtain a relation curve of the thermocouple temperature after microwave heating is stopped and time, and reversely pushing the relation curve to zero time through polynomial fitting to obtain the phase stability temperature T of the sample during microwave heating 2 . After the temperature of the sample is reduced to room temperature, changing the microwave heating power, and obtaining a plurality of groups of T through the other steps 1 -T 2 。
(2) The optical fiber temperature measurement in the microwave field comprises the following steps: before starting microwave heating, the sample bulk temperature was measured by inserting a fiber optic sensor into the bottom of a quartz cuvette to correct the sample surface temperature for infrared measurement. And recording the infrared surface temperature and the optical fiber bulk temperature of the obtained sample in the same way as the other specific steps. And each power of temperature reduction reverse-pushing temperature measurement and optical fiber direct temperature measurement is subjected to temperature measurement for at least three times, so that the repeatability of experimental data is ensured.
(3) And averaging the temperature of each group of body phase and the surface temperature respectively measured by the three-time cooling back-push measurement and the optical fiber direct measurement, and performing linear fitting to obtain a fitting equation, thereby realizing the online accurate measurement of the body phase temperature of the sample.
It should be noted that the upper limit of the selected optical fiber temperature measurement is limited by 300 ℃, the sample type should be reasonably selected, and the microwave radiation power should be reasonably set to avoid the damage of the optical fiber due to the overtemperature of the sample during the temperature measurement process.
Furthermore, the kind of substance and its dielectric characteristics all have a certain influence on the amount of heat generated by the substance absorbing microwaves in the microwave field, which depends mainly on its dielectric loss factor, i.e. the microwave has the characteristic of selectively heating the substance. The microwave absorption capacity of the substance with large dielectric loss factor is strong, otherwise, the microwave absorption capacity is weak.
Further, the sample is active carbon, siC or Al 2 O 3 、Fe 2 O 3 One or more substances in the material.
Further, the inert gas is a compressed gas, and the gas includes one or more of nitrogen, argon and helium. The pressure of the gas after decompression is 0.1-1 MPa, and the gas flow is 20-200 mL/min.
Further, in order to ensure the accuracy of the phase temperature obtained by back-pushing, the difference between the time corresponding to the first selected thermocouple temperature and the microwave stopping time should be less than 20s.
Further, the cooling curve polynomial fit should be low standard deviation, R 2 >0.9999。
In some embodiments, the sample is pretreated to remove surface and pore internal impurity components before thermometry.
In some embodiments, the sample pre-treatment step is: washing with deionized water and anhydrous ethanol for 3 times, drying at 120 deg.C for 12h 2 Calcining for 1h at 850 ℃ under the atmosphere.
For example:
(1) Sample preparation and tubing connections
Adding activated carbon particles in N 2 Calcining for 1h at 850 ℃ in the atmosphere, cooling to room temperature, taking out, grinding, sieving to 20-40 meshes, weighing 2g, placing on a quartz cotton platform of a quartz reactor, inserting into a microwave generator, sheathing quartz cotton thereon for heat preservation, connecting with an infrared sensor, connecting with an inert gas at an air inlet of the quartz reactor, and connecting with a quartz test tube and a thermocouple temperature measuring device at the bottom of the quartz reactor.
(2) Infrared surface temperature and cooling back-thrust phase temperature measurement
Starting the external water circulation device of the microwave generator and starting N 2 And (3) adjusting the pressure of the gas cylinder after the pressure reducing valve is adjusted to be 0.2MPa, setting the mass flow meter to be 100mL/min, starting a microwave generator after the flow is stabilized for 5min, and adjusting the microwave power to be 400W. At this time, the infrared temperature rapidly rises and gradually becomes stable, and the infrared temperature T is recorded after heating for 15min 1 =501 ℃. Immediately stopping microwave heating, simultaneously starting the motor 13, rapidly inserting a thermocouple into the geometric center of the sample bed, recording the change of the temperature of the thermocouple along with time, and performing polynomial Fitting on cooling scattering points, wherein the result is shown in figure 2, the origin Data in figure 2 is a point formed by Original Data, and the Curve Fitting is a fitted Curve.
The bulk temperature of the bed at the time of microwave stop is T 2 ＝T 0,Fit =728 ℃, fit R 2 =0.99997. Respectively adjusting the microwave power to 100, 200, 600, 800 and 1000W after the sample is cooled to room temperature, and respectively obtaining a plurality of groups of T according to the method 1 -T 2 。
(3) Sample replacement and pipe connection
Mixing Al 2 O 3 The pellets are washed for 3 times by deionized water and absolute ethyl alcohol and then are placed in a drying box for drying for 12 hours at 120 ℃ so as to remove surface impurities. 2g of the solution is weighed and placed on a quartz reactor platform, and other steps are the same as the step (1).
(4) Infrared surface temperature and optical fiber bulk temperature measurement
And (3) measuring the bulk temperature of the sample through an optical fiber, recording the infrared surface temperature after the sample is heated by 50W microwaves for 15min and the bulk temperature measured by the optical fiber, closing a microwave generator after the measurement is finished, respectively adjusting the microwave power to be 100, 150, 200, 250 and 300W to record the bulk temperature and the surface temperature after the sample is cooled to the room temperature, and the other steps are the same as the step (2).
(5) Temperature correction
As shown in fig. 3, a plurality of sets of surface temperature T1-bulk temperature T2 data points are averaged and subjected to linear fitting to obtain a fitting equation: y =1.45x-7.66,r 2 =0.99984. By simulatingThe resultant equation corrects the infrared surface temperature, and the online measurement of the sample bulk temperature in the microwave field can be realized.
The process can realize the online measurement of the bulk phase temperature of the sample in the microwave field, provides powerful support for the theoretical research of microwave non-thermal effect, and is favorable for disclosing the inherent mechanism of microwave for improving the chemical reaction rate and strengthening the material synthesis.
The sample surface temperature measured on line by the infrared sensor is corrected in a mode of reversely deducing the sample bulk temperature through the cooling curve and directly measuring the temperature of the low-temperature section optical fiber, so that a relational expression of the bulk temperature and the surface temperature is established, and the sample bulk temperature is measured on line.
The method is simple, low in cost and wide in temperature measuring range, and is favorable for further popularization of the temperature on-line measuring technology in the microwave field.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A sample bulk temperature measuring device in a microwave field is characterized in that: the device comprises a container and a reactor which are arranged in a microwave generator, wherein the reactor penetrates through the container, a platform for bearing a sample is arranged in the reactor, an infrared temperature measuring device is arranged right above the platform or on the side wall of the reactor, an opening at the bottom of the reactor is connected with a test tube, a thermocouple temperature measuring device is arranged in the test tube, the thermocouple temperature measuring device is connected with a transmission device and a power device, and the power device and the transmission device drive the thermocouple temperature measuring device to extend into or move out of the sample along the opening at the bottom of the reactor; the opening at the bottom of the reactor is also provided with an optical fiber temperature measuring device.
2. A device for measuring the bulk temperature of a sample in a microwave field according to claim 1, wherein: the microwave generator comprises a microwave generating chamber, a shell of the microwave generating chamber is connected with the water circulation sealing device, and a magnetron is arranged in the microwave generating chamber; the microwave oven is also provided with a microwave detector, and the microwave detector detects whether the microwave in the environment outside the microwave chamber exceeds the standard or not.
3. A device for measuring the bulk temperature of a sample in a microwave field according to claim 1, wherein: and quartz wool is arranged in the space between the interior of the container and the outer wall of the reactor.
4. A device for measuring the bulk temperature of a sample in a microwave field according to claim 1, wherein: the reactor is provided with a gas outlet and a gas inlet which respectively extend out of the outer side of the microwave generator and are used for introducing or leading out inert gas.
5. A device for measuring the bulk temperature of a sample in a microwave field according to claim 1, wherein: the infrared temperature measuring device, the optical fiber temperature measuring device and the thermocouple temperature measuring device are all connected with a temperature display.
6. A device for measuring the bulk temperature of a sample in a microwave field according to claim 5, wherein: the infrared temperature measuring device is provided with an infrared temperature measuring sensor, no quartz glass is blocked between the infrared temperature measuring sensor and the sample and the infrared temperature measuring sensor faces the surface of the sample, and the infrared temperature measuring device is used for obtaining the infrared surface temperature of the sample.
7. A device for measuring the bulk temperature of a sample in a microwave field according to claim 5, wherein: the optical fiber temperature measuring device is provided with an optical fiber temperature measuring sensor, and the optical fiber temperature measuring sensor extends into the sample along the opening at the bottom of the reactor to obtain the optical fiber bulk temperature of the sample.
8. A device for measuring the bulk temperature of a sample in a microwave field according to claim 5, wherein: the thermocouple temperature measuring device is provided with a thermocouple, the thermocouple extends into the sample along the opening at the bottom of the reactor under the driving of the power device and the transmission device to obtain the temperature of the sample along with the time change, and the bulk phase stable temperature of the sample when the time is zero is obtained through back pushing.
9. A device for measuring the bulk temperature of a sample in a microwave field according to claim 1, wherein: the container is a quartz container, the reactor is a quartz reactor, the platform is a porous quartz platform, and the test tube is a quartz test tube.
10. A method for realizing the measurement of the bulk temperature of a sample in a microwave field based on the device of any one of claims 1 to 9, which is characterized in that: the method comprises the following steps:
loading a sample into a platform in a reactor, introducing inert gas, starting a water circulation sealing device, heating by a microwave generator, and testing two groups of temperature data;
a group of data, a test tube containing a thermocouple is connected into an opening at the bottom of the reactor in advance, and an infrared temperature measuring device is utilized to obtain the surface stable temperature T when the sample is heated by microwave in a set time period 1 When the microwave generator is closed, the power device and the transmission device are utilized to drive the thermocouple to extend into the sample, the temperature of the sample changing along with time is obtained, the inverse pushing is carried out until the time is zero through polynomial fitting, and the phase stable temperature T of the sample during microwave heating is obtained 2 ；
After the sample is cooled to room temperature, the microwave heating power is changed according to the test requirements, and a plurality of groups of corresponding cooling inverse-pushing body phase temperatures T are obtained 2 Infrared surface temperature T 1 The data pair of (1);
the optical fiber sensor in the optical fiber temperature measuring device is inserted into the center of the sample from the opening at the bottom of the reactor to obtain the bulk temperature and the infrared surface temperature of the optical fiber within a set time period;
turning off the microwave generator, and after the sample is cooled to room temperature, changing the microwave heating power according to the test requirements to obtain a plurality of groups of corresponding fiber bulk temperature and infrared surface temperature data pairs;
and averaging the two groups of surface temperature-bulk phase temperature data, obtaining a relational expression of the surface temperature and the bulk phase temperature of the sample in the microwave field through a fitting equation after linear fitting, and realizing the measurement of the bulk phase temperature of the sample through the relational expression.
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