Snow liquid water content measuring device and method
The snow liquid water content measurement device using calorimetry, which calculates the snow liquid water content using a constant temperature system and heating wire, solves the problems of low accuracy and difficulty in traceability of existing equipment, and realizes high-accuracy snow liquid water content measurement and calibration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING CHANGCHENG INST OF METROLOGY & MEASUREMENT AVIATION IND CORP OF CHINA
- Filing Date
- 2025-12-16
- Publication Date
- 2026-04-10
AI Technical Summary
Existing snow liquid water content measurement equipment has low accuracy and cannot be effectively traced and calibrated, and its operation is cumbersome.
A calorimetric snow liquid water content measurement device is used, which includes a constant temperature system, an insulation system, a measuring chamber, a reference chamber, a heating wire, a temperature measuring module, and a temperature control module. The snow liquid water content is calculated by calculating the voltage and current across the heating wire, combined with the specific heat capacity of water, the specific heat capacity of ice, and the latent heat of ice melting.
It achieves highly accurate measurement and calibration of snow liquid water content, simplifies the operation process, and improves the reliability of the measurement.
Smart Images
Figure CN121830786A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of thermal metrology and testing technology, and particularly relates to a device and method for measuring the liquid water content of snow. Background Technology
[0002] In the natural environment, snow is water existing in a crystalline state in the atmosphere. Tiny water droplets accumulating in the atmosphere are cooled by cold air to form supercooled droplets. The water vapor in the air becomes supersaturated, and under the influence of low temperatures, these supercooled droplets can form tiny ice crystal nuclei. Subsequently, water vapor continues to grow on these nuclei, forming various types of snow crystals. Snow quality can be divided into dry snow and wet snow, and the key parameter characterizing dry and wet snow is the snow liquid water content. Snow liquid water content refers to the amount of liquid water in snow; it is the proportion of liquid water in a unit mass of snow and is a key indicator for quantifying the dryness or wetness of snow. Conventional methods for measuring snow liquid water content rely on the relationship between liquid water content, density, and dielectric constant. The accuracy of liquid water content measuring instruments based on this principle depends mainly on the dielectric constant and snow density. These instruments measure the snow dielectric constant using a resonance method, and then require manual input of the snow density parameter to obtain the snow liquid water content value. This resonance-based snow liquid water content measuring device is not only cumbersome to operate and has low accuracy, but also lacks traceability and calibration. Summary of the Invention
[0003] To address the aforementioned problems, this invention discloses a device and method for measuring the liquid water content of snow. This method is based on calorimetry to measure the liquid water content of snow. The device includes a constant temperature system, a measuring chamber, a reference chamber, a temperature measuring module, and a temperature control module.
[0004] This invention achieves high-accuracy measurement of snow liquid water content. The snow liquid water content measuring device based on calorimetry can be traced back to resistance and voltage by individual parameters, providing technical support for effectively solving the traceability and calibration problems of snow liquid water content measuring instruments.
[0005] The first aspect of this invention discloses a device for measuring the liquid water content of snow. The device includes: a constant temperature system, an insulation system, a measuring chamber, a reference chamber, a heating wire, a temperature measuring module, and a temperature control module; wherein: the measuring chamber and the reference chamber are located inside the constant temperature system; the insulation system is wrapped around the outside of the constant temperature system; the heating wire is wound around the outside of the constant temperature system and the insulation system respectively; the temperature measuring module is arranged inside the measuring chamber and the reference chamber, outside the constant temperature system, and outside the insulation system; and the temperature control module is used to control the temperature of the device.
[0006] The top of the insulation system is designed with an insulation plug.
[0007] The temperature of the insulation system is kept consistent with the temperature of the cavity.
[0008] The device controls five heating wires: one around the cavity, one at the bottom of the cavity, one around the insulation screen, one at the bottom of the insulation screen, and one on the protective layer of the insulation screen. By controlling the output of the five heating wires in real time, the temperature of the insulation screen is made consistent with the temperature of the cavity.
[0009] The insulation system achieves insulation through zero temperature difference. It uses a heating wire to heat the measuring chamber and the sample. By calculating the voltage and current at both ends of the heating wire, the power generated by the heating wire is obtained in real time. The heating amount is calculated by time integration, and the liquid water content value is obtained from the relationship between the heating amount and the liquid water content.
[0010] When the device performs a snow liquid water content test: it measures the baseline heat value of the empty measuring chamber, adds a certain mass of water into the measuring chamber, heats the water to raise its temperature to a specific temperature, and obtains the required initial heat; it lowers the water temperature to the initial temperature, weighs a certain mass of snow, adds the weighed snow to the existing water in the measuring chamber, raises the temperature to a certain temperature, and maintains the same temperature rise as when there is only water. At this time, the total heating amount of the heating wire is obtained by measuring the voltage and current values at both ends of the heating wire; based on the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change value, the relationship between the snow liquid water content and the total heating amount, the value of the snow liquid water content is calculated.
[0011] The second aspect of this invention discloses a method for measuring the liquid water content of snow. The method utilizes the apparatus described in the first aspect to perform the snow liquid water content measurement. Specifically, the method includes: measuring the baseline heat value of an empty measuring cavity; adding a certain mass of water to the measuring cavity; heating the water to raise its temperature to a specific temperature to obtain the required initial heat; lowering the water temperature to the initial temperature; weighing a certain mass of snow; adding the weighed snow to the existing water in the measuring cavity to raise the temperature to a certain level, with the temperature rise being consistent with the temperature rise when only water is present; obtaining the total heating amount of the heating wire through the voltage and current values at both ends of the heating wire; and calculating the value of the snow liquid water content based on the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change value, and the relationship between the snow liquid water content and the total heating amount.
[0012] In summary, this invention addresses the problems of low accuracy and inability to effectively trace and calibrate snow liquid water content measurement equipment by proposing a calorimetric-based snow liquid water content measurement device and method, which can meet the requirements for high-accuracy snow liquid water content measurement and calibration. Attached Figure Description
[0013] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the snow liquid water content measuring device according to an embodiment of the present invention. Detailed Implementation
[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0016] This invention proposes a device and method for measuring the liquid water content of snow, belonging to the field of thermal metrology and testing technology. This invention addresses the problems of low accuracy and inability to effectively trace and calibrate snow liquid water content measuring equipment, and can meet the requirements for high-accuracy snow liquid water content measurement and calibration.
[0017] The device consists of a constant temperature system, an insulation system, a measuring chamber, a reference chamber, a temperature measurement module, and a temperature control module. The measuring chamber and reference chamber are housed within the constant temperature system, which provides a stable temperature environment for them. The insulation system isolates them from external temperature changes, achieving a thermal insulation effect. The measuring chamber holds the snow sample to be tested, and the temperature measurement module measures the temperature of various parts of the measuring and reference chambers. The temperature control module controls the temperature of different parts. The device uses calorimetry. First, it achieves insulation through zero temperature difference. A heating wire heats the measuring chamber and sample, neglecting other heat losses. By calculating the voltage and current across the heating wire, the power generated by the heating wire is obtained in real time. Through time integration, the heating amount is calculated, and the liquid water content can be obtained from the relationship between the heating amount and the liquid water content.
[0018] The first aspect of this invention discloses a device for measuring the liquid water content of snow. The device includes: a constant temperature system, an insulation system, a measuring chamber, a reference chamber, a heating wire, a temperature measuring module, and a temperature control module; wherein: the measuring chamber and the reference chamber are located inside the constant temperature system; the insulation system is wrapped around the outside of the constant temperature system; the heating wire is wound around the outside of the constant temperature system and the insulation system respectively; the temperature measuring module is arranged inside the measuring chamber and the reference chamber, outside the constant temperature system, and outside the insulation system; and the temperature control module is used to control the temperature of the device.
[0019] The top of the insulation system is designed with an insulation plug.
[0020] The temperature of the insulation system is kept consistent with the temperature of the cavity.
[0021] The device controls five heating wires: one around the cavity, one at the bottom of the cavity, one around the insulation screen, one at the bottom of the insulation screen, and one on the protective layer of the insulation screen. By controlling the output of the five heating wires in real time, the temperature of the insulation screen is made consistent with the temperature of the cavity.
[0022] The insulation system achieves insulation through zero temperature difference. It uses a heating wire to heat the measuring chamber and the sample. By calculating the voltage and current at both ends of the heating wire, the power generated by the heating wire is obtained in real time. The heating amount is calculated by time integration, and the liquid water content value is obtained from the relationship between the heating amount and the liquid water content.
[0023] When the device performs a snow liquid water content test: it measures the baseline heat value of the empty measuring chamber, adds a certain mass of water into the measuring chamber, heats the water to raise its temperature to a specific temperature, and obtains the required initial heat; it lowers the water temperature to the initial temperature, weighs a certain mass of snow, adds the weighed snow to the existing water in the measuring chamber, raises the temperature to a certain temperature, and maintains the same temperature rise as when there is only water. At this time, the total heating amount of the heating wire is obtained by measuring the voltage and current values at both ends of the heating wire; based on the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change value, the relationship between the snow liquid water content and the total heating amount, the value of the snow liquid water content is calculated.
[0024] The second aspect of this invention discloses a method for measuring the liquid water content of snow. The method utilizes the apparatus described in the first aspect to perform the snow liquid water content measurement. Specifically, the method includes: measuring the baseline heat value of an empty measuring cavity; adding a certain mass of water to the measuring cavity; heating the water to raise its temperature to a specific temperature to obtain the required initial heat; lowering the water temperature to the initial temperature; weighing a certain mass of snow; adding the weighed snow to the existing water in the measuring cavity to raise the temperature to a certain level, with the temperature rise being consistent with the temperature rise when only water is present; obtaining the total heating amount of the heating wire through the voltage and current values at both ends of the heating wire; and calculating the value of the snow liquid water content based on the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change value, and the relationship between the snow liquid water content and the total heating amount.
[0025] Example 1: like Figure 1 As shown (1 is the cavity, 2 is the wire, 3 is the temperature sensor for temperature measurement, 4 is the temperature equalization layer to ensure uniform internal temperature, 5 is the insulation screen, 6 is the heating wire of the protective layer on the insulation screen, 7 is the heating furnace, 8 is the metal bracket, 9 is the insulation plug, and 10 is the protective sensor on the insulation screen), a calorimetric snow liquid water content measuring device consists of a constant temperature system, an insulation system, a measuring cavity, a reference cavity, a temperature measuring module, and a temperature control module. The measuring cavity and the reference cavity are placed in the constant temperature system, which provides a stable temperature environment for the measuring cavity and the reference cavity. The insulation system is used to isolate the influence of external temperature changes to achieve insulation effect. The measuring cavity is used to place the snow sample to be tested, and the temperature measuring module is used to measure the temperature values of various parts of the measuring cavity and the reference cavity. The temperature control module is used for temperature control of different parts. The measurement method of this device applies the principle of calorimetry. First, it achieves a thermal insulation effect by achieving zero temperature difference. Then, it uses a heating wire to heat the measuring chamber and the sample, ignoring other heat losses. By calculating the voltage and current across the heating wire, the power generated by the heating wire is obtained in real time. The heating amount is calculated by time integration, and the liquid water content value can be obtained from the relationship between the heating amount and the liquid water content.
[0026] The working process is as follows: When testing the liquid water content of snow, firstly, the baseline heat value of the empty measuring chamber is measured. Then, a certain mass of water is added to the measuring chamber, and the water is heated to a certain temperature to obtain the required initial heat. The water temperature is then lowered to the initial temperature. Next, a certain mass of snow is weighed and added to the existing water in the measuring chamber, raising the temperature to a certain level, with the temperature rise consistent with that when only water is present. At this point, the total heating amount of the heating wire is obtained by measuring the voltage and current values across the heating wire. Finally, based on the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change value, and the relationship between the liquid water content of snow and the total heating amount, the value of the liquid water content of snow can be calculated.
[0027] Example 2: When testing the liquid water content of snow, the baseline heat value of the empty measuring cavity is first measured. Then add a mass of m into the measuring cavity. w Water, heating water raises the water temperature To obtain the required amount of heat Then measure a certain mass of snow m s Adding the same mass of snow to the water in the measuring chamber also raises the temperature. At this point, the total heating amount Q of the heating wire is obtained through the voltage and current values. t Based on the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change, the liquid water content of snow, and the heating amount Q. t The relationship between these factors allows for the calculation of the liquid water content in snow.
[0028] This includes: the heat required to heat existing water ΔQ w The amount of heat Q required to raise the temperature of liquid water in snow. w The amount of heat Q required to warm up ice in snow i The latent heat Q required for snow ice to melt into water h Based on the liquid water content of snow and Q t The relationship between them, namely: .
[0029] The liquid water content in the snow is f, and the mass of the liquid water in the snow is m. w ,but: .
[0030] From this, we can obtain: In the formula: c w —Specific heat capacity of water, in J / (kg·K); c i —Specific heat capacity of ice, in J / (kg·K); h—Latent heat of melting ice into water per unit mass, in J / kg; —Initially measured temperature, in K; —Temperature rise The final temperature was measured in Kelvin (K).
[0031] Therefore, the liquid water content f in snow can be determined as follows: In summary, this invention addresses the problems of low accuracy and inability to effectively trace and calibrate snow liquid water content measurement equipment by proposing a calorimetric-based snow liquid water content measurement device and method, which can meet the requirements for high-accuracy snow liquid water content measurement and calibration.
[0032] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A snow liquid water content measuring device, characterized by, The device comprises a constant temperature system, an adiabatic system, a measuring cavity, a reference cavity, a heating wire, a temperature measuring module, and a temperature control module. The measuring cavity and the reference cavity are placed inside the constant temperature system. The adiabatic system is wrapped outside the constant temperature system. The heating wire is wound around the constant temperature system and the adiabatic system. The temperature measuring module is arranged inside the measuring cavity and the reference cavity, outside the constant temperature system, and outside the adiabatic system. The temperature control module is used to control the temperature of the device.
2. A snow liquid water content measuring device according to claim 1, characterized in that The top of the adiabatic system is designed with an adiabatic plug.
3. A snow liquid water content measuring device according to claim 2, wherein The temperature of the adiabatic system is consistent with the temperature of the cavity.
4. A snow liquid water content measuring device according to claim 3, wherein The device controls five heating wires, which are respectively around the cavity, at the bottom of the cavity, around the adiabatic screen, at the bottom of the adiabatic screen, and on the protective layer of the adiabatic screen. By controlling the output of the five heating wires in real time, the temperature of the adiabatic screen is consistent with the temperature of the cavity.
5. A snow liquid water content measuring device according to claim 4, wherein The adiabatic system achieves the adiabatic effect through zero temperature difference. The heating wire is used to heat the measuring cavity and the sample. The power generated by the heating wire is obtained in real time by calculating the voltage and current at both ends of the heating wire. The heating amount is calculated by time integration. The liquid water content value is obtained from the relationship between the heating amount and the liquid water content.
6. A snow liquid water content measuring device according to claim 5, wherein When the device is used to test the liquid water content of snow, the baseline heat value of the empty measuring cavity is measured. A certain amount of water is added to the measuring cavity. The water is heated to a specific temperature. The initial heat required is obtained. The water temperature is lowered to the initial temperature. A certain amount of snow is weighed. The weighed snow is added to the water in the measuring cavity. The temperature is raised to a certain temperature. The temperature rise amplitude is consistent with that when only water is present. The total heating amount of the heating wire is obtained by the voltage and current values at both ends of the heating wire. The liquid water content of snow is calculated according to the relationship between the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change value, and the total heating amount. The method uses the device of any one of claims 1-5 to measure the liquid water content of snow. The method specifically comprises:
7. A method of measuring the snow liquid water content, characterized in that, The baseline heat value of the empty measuring cavity is measured. A certain amount of water is added to the measuring cavity. The water is heated to a specific temperature. The initial heat required is obtained. The water temperature is lowered to the initial temperature. A certain amount of snow is weighed. The weighed snow is added to the water in the measuring cavity. The temperature is raised to a certain temperature. The temperature rise amplitude is consistent with that when only water is present. The total heating amount of the heating wire is obtained by the voltage and current values at both ends of the heating wire. The liquid water content of snow is calculated according to the relationship between the specific heat capacity of water, the specific heat capacity of ice, the latent heat required for ice to melt into water, the temperature change value, and the total heating amount.