A radio frequency heating system with fluorescent temperature sensor and radio frequency heater

Abstract

The application discloses a radio frequency heating system with a fluorescent temperature sensor, comprising a radio frequency heating cavity, a fluorescent temperature measurement transmitter and a central control unit, wherein the central control unit is connected with the fluorescent temperature measurement transmitter; the radio frequency heating cavity is provided with a radio frequency heating container at the bottom, the radio frequency heating container contains fluorescent material with temperature-sensitive characteristics, the fluorescent material is excited by excitation light to generate fluorescence, and the radio frequency heating container and the fluorescent temperature measurement transmitter have a light path; the fluorescent temperature measurement transmitter comprises a light emitting device and a driving circuit thereof for generating excitation light, a photoelectric conversion device for receiving fluorescence, and a signal processing output circuit for processing the output signal of the photoelectric conversion device; and the central control unit is used for feedback control of the radio frequency heating system according to the temperature measured by the fluorescent temperature sensor. The application can realize accurate measurement and heating control of the temperature of a heated object.

Description

Technical Field

[0001] This invention belongs to the field of temperature measurement and control technology, specifically relating to a radio frequency heating system with a fluorescent temperature sensor and a radio frequency heater. Background Technology

[0002] Radio frequency (RF) is a type of high-frequency alternating electromagnetic wave with a frequency range of 300kHz-300GHz, including medium wave, short wave, meter wave, and microwave. When RF penetrates the interior of an object, it excites the migration of ions within the object, converting electrical energy into heat energy, ultimately heating the object. RF heating methods are widely used in food processing, treatment of human diseases, catalytic reactions, and other fields. Their essence lies in the strong absorption of RF energy by the medium. For example, an RF heater is one such example; it utilizes the absorption of microwave energy by water molecules to heat the object being heated.

[0003] Conventional temperature sensors, such as thermocouples and resistance temperature detectors (RTDs), are made of conductive metallic materials. These conductive materials generate induced currents under high-frequency electromagnetic fields. Based on the principle of electromagnetic induction, this leads to discharge or a rise in temperature, severely interfering with temperature measurements and causing significant errors or making stable temperature measurements impossible. Infrared thermometry can also be used for temperature measurement in radio frequency environments, but it has limitations. The measured temperature point must be within the visible range of the infrared sensor, and infrared thermometry can only measure the surface temperature of objects. The accuracy of infrared thermometry is affected by the emissivity of the object's surface material; different materials result in different infrared emissivity and thus different measured temperature values. Fluorescence thermometry overcomes some of these shortcomings. During measurement, a fluorescent material is placed on the surface of the object. An excitation light source is input from the other end of an optical fiber, transmitted through the fiber to the head to activate the fluorescent material. After the excitation light pulse, the afterglow of the fluorescent material is extracted through the original optical fiber. By filtering the spectrum and measuring the afterglow time constant, the temperature of the object can be calculated. Summary of the Invention

[0004] To address the technical deficiencies of existing technologies, the present invention aims to provide a radio frequency heating system with a fluorescence temperature sensor, comprising: a radio frequency heating cavity, a fluorescence temperature transmitter, and a central control unit, wherein the central control unit is connected to the fluorescence temperature transmitter.

[0005] The bottom of the radio frequency heating cavity is provided with a radio frequency heating container, which contains a fluorescent material with temperature-sensitive properties. The fluorescent material is excited by excitation light to produce fluorescence. There is a conductive optical path between the radio frequency heating container and the fluorescence temperature transmitter.

[0006] The fluorescence temperature transmitter includes a light-emitting device for generating the excitation light and its driving circuit, a photoelectric conversion device for receiving the fluorescence, and a signal processing output circuit for processing the output signal of the photoelectric conversion device.

[0007] The central control unit is used to perform feedback control of the radio frequency heating system based on the temperature measured by the fluorescent temperature sensor.

[0008] Preferably, the fluorescence temperature transmitter is located below the radio frequency heating container and uses space to transmit the optical signal of the conductive optical path.

[0009] Preferably, it further includes an optical waveguide for transmitting optical signals between the radio frequency heating container and the fluorescence temperature transmitter, the optical waveguide being made of a light-guiding material with optical guiding properties.

[0010] Preferably, the radio frequency heating cavity includes a radio frequency generator for generating radio frequency energy and a radio frequency waveguide for conducting the radio frequency energy.

[0011] Preferably, the radio frequency heating container is made of the fluorescent material.

[0012] Preferably, the fluorescent material is distributed on the surface of the radio frequency heating container.

[0013] Preferably, one end of the optical waveguide extends into the inner cavity of the radio frequency heating cavity and communicates with the bottom of the radio frequency heating container, while the other end is connected to the fluorescence temperature transmitter.

[0014] Preferably, the driving circuit of the light-emitting device controls the light output mode of the excitation light by controlling any one or more of the light intensity, frequency, wavelength or waveform of the excitation light.

[0015] The present invention also provides an radio frequency heater for heating an article, characterized in that it includes the radio frequency heating system with a fluorescent temperature sensor as described in the present invention, wherein the central control unit of the radio frequency heating system with the fluorescent temperature sensor is connected to the control panel of the radio frequency heater.

[0016] This invention configures a fluorescence temperature measuring device in a radio frequency heating container system and uses the fluorescence temperature measurement method to achieve non-contact temperature measurement of the heated item by utilizing the temperature characteristics of fluorescence. It can accurately detect the temperature of the item to be heated in the radio frequency heating container and perform temperature control. Attached Figure Description

[0017] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0018] Figure 1 The diagram illustrates a specific embodiment of the present invention, specifically a schematic diagram of a radio frequency heating system with a fluorescent temperature sensor. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described below in conjunction with the accompanying drawings and embodiments.

[0020] Those skilled in the art will understand that the radio frequency heating system utilizes optical waveguide coupling or spatial optical coupling based on the temperature characteristics of fluorescence, thereby detaching the electronic components of the temperature sensor from the temperature measurement site and avoiding the radio frequency environment; by using the radio frequency heating container itself as the temperature detection point, the traditional temperature probe is eliminated, making it more convenient and natural to use.

[0021] Figure 1 This diagram illustrates a specific embodiment of the present invention, specifically a schematic diagram of a radio frequency heating system with a fluorescence temperature sensor. Specifically, the radio frequency heating system with a fluorescence temperature sensor includes a radio frequency heating cavity, an optical waveguide 1, a radio frequency heating container 2, a fluorescence temperature transmitter 3, and a central control unit (not shown in the diagram). The radio frequency heating cavity heats an item placed within it via radio frequency heating. The optical waveguide 1 is used to transmit optical signals and can be designed with any shape and length as needed. The fluorescence temperature transmitter can detect the heating temperature within the radio frequency heating cavity. Further details will be discussed in subsequent embodiments. Figure 1 A more detailed explanation follows. Furthermore, the central control unit can employ a combination of a digital signal processor, a special-purpose integrated circuit, a field-programmable gate array (FPGA) or other programmable logic devices, hardware components (such as registers and FIFOs), a processor executing a series of firmware instructions, and programming software to control the present invention.

[0022] An radio frequency heating container 2 is placed at the bottom of the radio frequency heating cavity, which is used to hold the object to be heated. The radio frequency heating cavity includes an upper accommodating part for holding the object to be heated, which is preferably made of a high-temperature resistant food-grade material. The bottom of the radio frequency heating container 2 can be fixedly or detachably fixedly installed at the bottom of the radio frequency heating cavity. Further, the central control unit is connected to the fluorescence temperature transmitter 3 to perform feedback control of the radio frequency heating system based on the temperature measurement results of the fluorescence temperature sensor. It should be noted that the radio frequency heating container 2 and the fluorescence temperature transmitter 3 are spatially independent. Figure 1In the preferred embodiment shown, the radio frequency heating container 2 is placed at the bottom of the heating cavity; the fluorescence temperature transmitter 3 is fixedly disposed outside the radio frequency heating cavity. Further, the radio frequency heating container 2 contains a fluorescent material with temperature-sensitive properties, which is excited by excitation light to produce fluorescence. Those skilled in the art understand that fluorescent materials, after being excited by light of a certain wavelength (stimulated spectrum), emit fluorescent energy. After the excitation is removed, the persistence of the fluorescence afterglow depends on the characteristics of the fluorescent material, including factors such as ambient temperature. This excited fluorescence typically decays exponentially; the decay time constant is called the fluorescence lifetime or fluorescence afterglow time. The fluorescence lifetime varies under different ambient temperatures. Therefore, by measuring the length of the fluorescence lifetime, the temperature at the location of the fluorescent material can be determined. Further, a conductive optical path exists between the radio frequency heating container 2 and the fluorescence temperature transmitter 3 to realize the transmission of optical signals between the radio frequency heating container 2 and the fluorescence temperature transmitter 3. In this invention, the radio frequency heating container 2 is in direct contact with the object being heated, thereby sensing the object's temperature information. The radio frequency heating container 2 serves as both a container and a temperature probe. Further, as... Figure 1 As shown, the optical path transmits the fluorescent signal containing the temperature information of the heated item detected by the radio frequency heating container 2 through the optical waveguide 1. The fluorescent temperature transmitter 3 demodulates the fluorescent signal into an electrical signal and finally realizes digital output. More specifically, it will be described in more detail in the following embodiments, and will not be repeated here.

[0023] Furthermore, the optical waveguide 1 is made of a material with good light-guiding properties, preferably a material with high-temperature resistance and electrical insulation properties. For example... Figure 1 As shown, one end of the optical waveguide 1 is connected to the fluorescence temperature transmitter 3, and the other end is fixed to the bottom of the radio frequency heating container 2, preferably at the center of the bottom and facing the bottom of the radio frequency heating container 2, so as to transmit excitation light and fluorescence signals. It should be noted that the optical waveguide 1 can be made into various shapes and arranged arbitrarily according to actual conditions. In other embodiments, the optical waveguide 1 can also be omitted as an intermediary, and space can be used as a conducting optical path for direct transmission of optical signals between the radio frequency heating container 2 and the fluorescence temperature transmitter 3.

[0024] Furthermore, the fluorescence temperature transmitter 3 includes a light-emitting device for generating excitation light and its driving circuit, a photoelectric conversion device for receiving fluorescence, and a signal processing output circuit for processing the output signal of the photoelectric conversion device. The light-emitting device is preferably a light-emitting diode (LED), and the photoelectric conversion device is preferably a photodiode. Specifically, the fluorescence temperature sensor of the present invention operates as follows: the light-emitting device, driven by its driving circuit, converts electrical energy into light energy to emit the excitation light, which then irradiates the bottom of the radio frequency heating container 2 through the conductive optical path. The fluorescent material contained in the radio frequency heating container 2 fluoresces under the irradiation of the excitation light, and the fluorescence is transmitted from one end of the optical waveguide 1 through the optical waveguide 1, and then from the other end of the optical waveguide 1 to the photoelectric conversion device, generating a corresponding electrical signal. This electrical signal contains temperature information about the location of the fluorescent material. Therefore, by utilizing the temperature characteristics of the fluorescent material, the temperature is accurately calculated through the signal processing output circuit.

[0025] Those skilled in the art will understand that, by using the optical waveguide 1 as a transmission medium for optical signals, and taking advantage of the arbitrary shape and arrangement of the optical waveguide 1 itself, the position of the fluorescence temperature transmitter 3 is not limited to the bottom or side of the radio frequency heater; the fluorescence temperature transmitter 3 can be placed at any position outside the radio frequency heating cavity. The central control unit, connected to the temperature transmitter 3, enables precise temperature measurement and feedback control of the heated object using the fluorescence thermometry method, and outputs and displays the results through corresponding output devices.

[0026] Furthermore, the bottom of the radio frequency heating container 2 contains a temperature-sensitive material capable of generating fluorescence. In use, it is placed above the light guide port of the optical waveguide 1 at the bottom of the radio frequency heating cavity to receive excitation light, generate fluorescence, and transmit temperature signals. It should be noted that the radio frequency heating container 2 does not need to be attached to the optical waveguide 1, as the light signal can be well conducted in the air. The radio frequency heating container 2 can be made in various sizes and shapes according to actual needs. In another specific variation, when the radio frequency heating system with the fluorescent temperature sensor does not have the optical waveguide 1, the fluorescent temperature transmitter 3 is preferably placed below the radio frequency heating container 2. The light-emitting device and photoelectric conversion device of the fluorescent temperature transmitter 3 achieve optical path communication with the bottom of the radio frequency heating container 2, allowing the light signal to be transmitted spatially.

[0027] Furthermore, the radio frequency heating cavity specifically includes a radio frequency generator for generating radio frequency energy and a radio frequency waveguide for conducting the radio frequency energy, thereby realizing radio frequency heating using the radio frequency heating container. Those skilled in the art will understand that the temperature-sensitive material at the bottom of the radio frequency heating container 2 can be, but is not limited to, fluorescent temperature-sensitive materials such as ruby ​​or alexandrite. It should be noted that the radio frequency heating container 2 can be entirely prepared using the aforementioned temperature-sensitive fluorescent material, resulting in a uniform distribution of the fluorescent material throughout the radio frequency heating container 2; furthermore, the radio frequency heating container 2 can also contain the fluorescent material only in certain areas. Preferably, the fluorescent material is uniformly distributed on the surface of the radio frequency heating container; more preferably, the fluorescent material is concentrated on the bottom surface of the radio frequency heating container 2.

[0028] Those skilled in the art will understand that the radio frequency heating system with a fluorescence temperature sensor of the present invention can be installed in radio frequency heaters of different models and types. By structurally and electrically connecting the radio frequency heater and the radio frequency heating system with the fluorescence temperature sensor, a radio frequency heater with temperature display and control functions is obtained. In use, the user places the radio frequency heating container 2 above the light guide port of the optical waveguide 1 at the bottom of the radio frequency heating cavity of the radio frequency heater, and simultaneously operates the corresponding control panel externally located on the surface of the radio frequency heater. The control panel is connected to the fluorescence temperature transmitter 3 through the central control unit, thereby enabling real-time measurement and control of the temperature of the object being measured. In such an embodiment, one end of the optical waveguide 1 extends into the inner cavity of the radio frequency heating cavity and communicates with the radio frequency heating container 2, while the other end is connected to the fluorescence temperature transmitter 3. In this invention, the driving circuit of the light-emitting device controls the light output mode of the excitation light by controlling at least one or more of the light intensity, frequency, wavelength, or waveform of the excitation light, which will not be elaborated here. Furthermore, the fluorescent temperature sensor of the radio frequency heater is also connected to the display device of the radio frequency heater. The display device can be an LCD screen, which can display the temperature measured by the fluorescent temperature sensor in real time, so as to facilitate users to obtain temperature information and control the microwave heating temperature in real time.

[0029] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A radio frequency heating system with a fluorescent temperature sensor, characterized in that, include: The system includes an radio frequency heating cavity, a fluorescence temperature transmitter, and a central control unit, wherein the central control unit is connected to the fluorescence temperature transmitter. The bottom of the radio frequency heating cavity is provided with a radio frequency heating container. The radio frequency heating container can be detachably installed at the bottom of the radio frequency heating cavity. It serves as both a container and a temperature probe. The radio frequency heating container contains a fluorescent material with temperature-sensitive properties. When in use, the fluorescent material is placed above the light guide port of the optical waveguide at the bottom of the radio frequency heating cavity and is excited by excitation light to generate fluorescence. There is a conductive optical path between the radio frequency heating container and the fluorescence temperature transmitter. The fluorescence temperature transmitter is disposed outside the radio frequency heating cavity. The fluorescence temperature transmitter includes a light-emitting device for generating the excitation light and its driving circuit, a photoelectric conversion device for receiving the fluorescence, and a signal processing output circuit for processing the output signal of the photoelectric conversion device. The central control unit is used to perform feedback control of the radio frequency heating system based on the temperature measured by the fluorescent temperature sensor.

2. The radio frequency heating system with a fluorescence temperature sensor according to claim 1, characterized in that, The fluorescence temperature transmitter is located below the radio frequency heating container and uses space to transmit the optical signal of the conductive optical path.

3. The radio frequency heating system with a fluorescence temperature sensor according to claim 1, characterized in that, It also includes an optical waveguide for transmitting optical signals between the radio frequency heating container and the fluorescence temperature transmitter, the optical waveguide being made of a light-guiding material with optical guiding properties.

4. The radio frequency heating system with a fluorescence temperature sensor according to any one of claims 1 to 3, characterized in that, The radio frequency heating cavity includes a radio frequency generator for generating radio frequency energy and a radio frequency waveguide for conducting the radio frequency energy.

5. The radio frequency heating system with a fluorescence temperature sensor according to claim 3, characterized in that, One end of the optical waveguide extends into the inner cavity of the radio frequency heating cavity and communicates with the bottom of the radio frequency heating container, while the other end is connected to the fluorescence temperature transmitter.

6. The radio frequency heating system with a fluorescence temperature sensor according to any one of claims 1 to 3, characterized in that, The driving circuit of the light-emitting device controls the light output mode of the excitation light by controlling any one or more of the light intensity, frequency, wavelength or waveform of the excitation light.

7. A radio frequency heater for heating articles, characterized in that, The radio frequency heating system includes the fluorescent temperature sensor according to any one of claims 1 to 6, wherein the central control unit of the radio frequency heating system with fluorescent temperature sensor is connected to the control panel of the radio frequency heater.

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