A method and device for identifying the state of liquid in a pot by measuring vibration

Abstract

The invention relates to a vibration measuring method and device for identifying the liquid state in a pot, comprising: a measuring rod or table top, a vibration sensor, an A / D sampling and analysis circuit module, the measuring rod or table top is in rigid contact with the pot, and the The vibration sensor is in close contact with the measuring rod or the table, and the A / D sampling and analysis circuit module is connected to the vibration sensor through a shielded wire; this method utilizes the principle that the pot is heated unevenly, and the internal liquid vibrates due to convective heat transfer movement and bubble rupture , the vibration signal of the pot is transmitted to the vibration sensor and then converted into an electrical signal. After signal conditioning, the A / D sampling analysis circuit module performs time domain / frequency domain conversion to generate amplitude-frequency characteristic values ​​and power spectrum values. The operation combination As the judgment basis value, the static judgment can be made by comparing the background value and the actual value when there is no liquid in the pot, or dynamically judge the liquid state in the pot according to the change trend of these values, including whether there is liquid in the pot, the degree of convection, and whether it is boiling or a specific intermediate state.

Description

technical field [0001] The invention relates to a liquid state detection technology in a pot, in particular to a vibration-measuring method and device for identifying the convective state of liquid in a pot, which are suitable for stoves Background technique [0002] At present, there is no method and device for the whole process of monitoring and judging whether there is liquid in the pot placed on it, the convection state and boiling state of the liquid after the liquid is heated, which will easily lead to empty burning / drying, overflow after boiling and For problems such as excessive boiling, refer to related technologies and patents, there are the following types of technical solutions for detecting dry burning and boiling: [0003] 1. Judgment of dry burning: Measure the temperature of the bottom of the pot through the temperature sensor attached to the bottom of the pot. If it exceeds the set value, it is considered dry burning. This technology can only judge whether ...

AI Technical Summary

Problems solved by technology

[0005] A. Measure the vibration characteristics produced by the liquid vaporization process during boiling. For example, the Chinese patent No. 200620025739.0 "Water Boiling Detection Device for Electromagnetic Cooker" uses the mechanical vibration generated by the vaporization of water droplets when water boils to identify, and can only identify single boiling state;

[0006] B. Judgment by measuring the audio characteristics when boiling, such as the publication numbers 201010607284.2 and 201020682133.9 Chinese patent "A Water Boiling Detection Device for Induction Cooker", which only judges the boiling characteristics in the audio domain, and cannot judge whether there is liquid, the degree of convection, and empty heating / burn dry and other features;

[0007] C. Measuring the infrared radiation of the pot, judging that the surface temperature of the pot and the infrared radiation value will not exceed a certain range when there is water in the pot. For example, the Chinese patent "Induction Heating Cooker" with patent number 201110398864.X discloses infrared sensor detection Boiling technology only recognizes a single state, and has certain restrictions on the scope of application of the pot

[0008] All the above technical solutions are only for a certain project, and have certain scope of application and limitations, such as not being able to identify dry boiling and boiling at the same time, whether there is water / oil in the pot, and whether the water / oil is boiling, etc., and not being able to identify the liquid in the pot degree of convection or boiling etc.

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