External heating type gas mass flow meter sensor

Abstract

The invention discloses an external heating type gas mass flowmeter sensor, and relates to the technical field of gas flow measurement. The invention relates to a mass flow meter, and aims to solve the problems of poor reliability and short service life of the mass flow meter caused by fatigue stress limitation of a vibration pipe and corrosion of the vibration pipe due to the fact that the vibration pipe is in a vibration state under the condition that the vibration pipe needs to be connected into a main metal pipeline and gas flowing in the pipeline has corrosivity and radioactivity in the conventional mass flow meter. The gas mass flow meter sensor with the structure is long in service life due to no material loss in the detection process; compared with other flow measurement modes, except for the ultrasonic flowmeter and the Coriolis mass flowmeter, the structure of a metal pipeline is not damaged, the reliability of the mass flowmeter is improved, and the measuring range ratio is large; in addition, compared with an ultrasonic flowmeter and a Coriolis mass flowmeter, the technical scheme of the invention is more sensitive and low in measurement lower limit during measurement of small-flow gas. The gas mass flow measuring device is suitable for measuring the gas mass flow.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas flow measurement, in particular to an external heating type gas mass flow meter sensor. BACKGROUND

[0002] In industrial production, the flow of gas in metal pipes needs to be measured in many cases. Generally, the flow measuring instrument is installed in the metal pipe or communicates with the metal pipe to pick up the gas flow information and then convert it into corresponding electrical signals. Of course, different sensors have different measuring principles and different electrical signals. Thus, an opening is needed on the wall of the metal pipe, and the sensor components are installed. When measuring the flow of high-pressure, high-temperature, highly corrosive, radioactive, and hazardous gases, this will reduce the strength and protection level of the metal pipe.

[0003] Currently, ultrasonic flow meters and Coriolis mass flow meters are used to measure outside the pipe.

[0004] Ultrasonic flow meter: The ultrasonic flow meter measures the flow of gas in the metal pipe by applying ultrasonic waves outside the pipe. Currently, the time difference of ultrasonic wave propagation is mainly measured to measure the flow rate of gas in the metal pipe.

[0005] Coriolis mass flow meter: The Coriolis mass flow meter detects the phase difference formed at different positions of the U-shaped pipe after the gas flows through the two U-shaped pipes vibrating at the same frequency to detect the mass flow of the gas flowing through the pipe.

[0006] As described above, the existing mass flow meter requires the vibration pipe to be connected to the main metal pipe. If the gas flowing in the pipe is corrosive and radioactive, the vibration pipe will have fatigue stress limitations due to the vibration state, and the gas will corrode the vibration pipe, resulting in poor reliability and low service life of the mass flow meter. SUMMARY

[0007] The present application is to solve the problem of the existing mass flow meter, which requires the vibration pipe to be connected to the main metal pipe. If the gas flowing in the pipe is corrosive and radioactive, the vibration pipe will have fatigue stress limitations due to the vibration state, and the gas will corrode the vibration pipe, resulting in poor reliability and low service life of the mass flow meter. An external heating type gas mass flow meter sensor is proposed.

[0008] The external heating type gas mass flow meter sensor of the present application comprises a flange 1, a temperature sensor 2, a metal pipe 3, an insulating layer 4, and a platinum wire resistance 5.

[0009] The metal pipeline 3 is provided with a flange 1 at each end, and a sensor mounting port is formed on one end of the outer surface of the metal pipeline 3, and a temperature sensor 2 is mounted on the sensor mounting port; an insulation layer 4 is arranged on the other end of the outer surface of the metal pipeline 3 along the length direction, and a platinum wire resistance 5 is sleeved on the insulation layer 4 on the other end of the outer surface of the metal pipeline 3;

[0010] Further, the insulation layer 4 on the other end of the outer surface of the metal pipeline 3 is sleeved with a metal heat insulation box 8;

[0011] Further, the metal heat insulation box 8 is detachably connected with the outer surface of the metal pipeline 3;

[0012] Further, the platinum wire resistance 5 and the insulation layer 4 are fixed by a fixing adhesive layer 6;

[0013] Further, the metal heat insulation box 8 is filled with a large amount of heat insulation material 7;

[0014] Further, the heat insulation material 7 in the metal heat insulation box 8 is in full contact with the fixing adhesive layer 6 on the outer surface of the platinum wire resistance 5;

[0015] Further, the platinum wire in the platinum wire resistance 5 has a cross-sectional diameter of 0.05mm-0.06mm;

[0016] Further, in use, the flow meter sensor is connected to the measured main pipeline, the flanges 1 at the two ends of the metal pipeline 3 are connected with the measurement ports of the measured main pipeline, and the platinum wire resistance 5 is powered to be heated, and the heating degree is related to the current size, and under certain heat conduction conditions, is also related to the mass flow of the gas in the metal pipeline 3 and the temperature of the gas, after all, the temperature rise of the platinum wire resistance 5 heated by the current is based on the temperature rise of the gas flowing in the pipeline, and the temperature of the gas flowing in the metal pipeline 3 is detected by the temperature sensor, so that the gas molecules flowing in the pipeline contact the pipe wall near the platinum wire resistance 5 and take away a part of the heat generated by the electric heating of the platinum wire resistance 5, and the mass flow is proportional to the number of molecules contacting the pipe wall, and macroscopically, the heat loss and the temperature of the platinum wire change, and the model established according to the heat transfer theory and the calibration data can determine the mass flow of the gas in the metal pipeline.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] The gas mass flow meter sensor with the structure disclosed in the present application has a long service life because no material is lost during detection; compared with other flow measurement methods, except for ultrasonic flow meters and Coriolis mass flow meters, the structure does not damage the metal pipeline, improves the reliability of the mass flow meter, can withstand high temperature above 600 DEG C, and has a large range ratio; and compared with ultrasonic flow meters and Coriolis mass flow meters, the technical scheme of the present application is more sensitive to small flow gas measurement and has a low lower limit of measurement. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a front view of a gas mass flow meter sensor of the present application;

[0020] Figure 2 is a partial sectional view of a gas mass flow meter sensor of the present application. DETAILED DESCRIPTION

[0021] Specific implementation one: combining Figure 1 and Figure 2 The gas mass flow meter sensor described in the present embodiment comprises a flange 1, a temperature sensor 2, a metal pipeline 3, an insulation layer 4 and a platinum wire resistance 5.

[0022] The metal pipeline 3 is provided with a flange 1 at each end, the outer surface of the metal pipeline 3 is provided with a sensor mounting port at one end, the temperature sensor 2 is mounted on the sensor mounting port, the outer surface of the metal pipeline 3 is provided with an insulation layer 4 along the length direction at the other end, and the platinum wire resistance 5 is sleeved on the insulation layer 4 at the other end of the outer surface of the metal pipeline 3.

[0023] In use, the flow meter sensor is connected to the measured main pipeline, the flanges 1 at the two ends of the metal pipeline 3 are connected to the measurement ports of the measured main pipeline, the platinum wire resistance 5 is powered to be heated, the degree of heating is related to the current size, under certain heat conduction conditions, the mass flow of the gas in the metal pipeline 3 is also related to the temperature of the gas, and the temperature rise of the platinum wire resistance 5 heated by the current is based on the temperature of the gas flowing in the pipeline, the temperature of the gas flowing in the metal pipeline 3 is detected by the temperature sensor, so that the gas molecules flowing in the pipeline contact the pipe wall near the platinum wire resistance 5 and take away a part of the heat generated by the electric heating of the platinum wire resistance 5, the mass flow is proportional to the number of molecules contacting the pipe wall, and macroscopically, the heat loss and temperature of the platinum wire change, and the model established according to the heat transfer theory and the calibration data can determine the mass flow of the gas in the metal pipeline.

[0024] Specific implementation two: combining Figure 1 andFigure 2 The present embodiment is a further limitation of the sensor described in Embodiment One. The present embodiment is an outer heating type gas mass flow meter sensor, wherein the metal heat insulation box 8 is sleeved on the other end of the insulating layer 4 on the outer surface of the metal pipeline 3.

[0025] In the present embodiment, the metal heat insulation box 8 is sleeved on the other end of the insulating layer 4 on the outer surface of the metal pipeline 3, so that the platinum wire resistance 5 is prevented from being heated after being electrified and the heat is prevented from being dissipated to the outside.

[0026] Embodiment Three: Combination of Embodiments One and Two Figure 1 and Figure 2 The present embodiment is a further limitation of the sensor described in Embodiment Two. The present embodiment is an outer heating type gas mass flow meter sensor, wherein the metal heat insulation box 8 is detachably connected to the outer surface of the metal pipeline 3.

[0027] Embodiment Four: Combination of Embodiments Two and Three Figure 1 and Figure 2 The present embodiment is a further limitation of the sensor described in Embodiment Two. The present embodiment is an outer heating type gas mass flow meter sensor, wherein the platinum wire resistance 5 is fixed to the insulating layer 4 through the fixed adhesive layer 6.

[0028] Embodiment Five: Combination of Embodiments Three and Four Figure 1 and Figure 2 The present embodiment is a further limitation of the sensor described in Embodiment Four. The present embodiment is an outer heating type gas mass flow meter sensor, wherein the metal heat insulation box 8 is filled with a large amount of heat insulation material 7.

[0029] Embodiment Six: Combination of Embodiments Four and Five Figure 1 and Figure 2 The present embodiment is a further limitation of the sensor described in Embodiment Five. The present embodiment is an outer heating type gas mass flow meter sensor, wherein the heat insulation material 7 in the metal heat insulation box 8 is in sufficient contact with the fixed adhesive layer 6 on the outer surface of the platinum wire resistance 5.

[0030] Embodiment Seven: Combination of Embodiments Five and Six Figure 1 and Figure 2 The present embodiment is a further limitation of the sensor described in Embodiment Six. The present embodiment is an outer heating type gas mass flow meter sensor, wherein the cross-sectional diameter of the platinum wire in the platinum wire resistance 5 is 0.05mm-0.06mm.

[0031] Working Principle

[0032] In use, the flow meter sensor is connected to the measured main pipeline, the flanges 1 at both ends of the metal pipeline 3 are connected to the measurement port of the measured main pipeline, and the platinum wire resistance 5 is powered to be heated. The degree of heating is related to the size of the current input, and under certain heat conduction conditions, it is also related to the mass flow of the gas in the metal pipeline 3 and the temperature of the gas. After all, the temperature rise of the platinum wire resistance 5 heated by the current is based on the temperature rise of the gas flowing in the pipe. The temperature of the gas flowing in the metal pipeline 3 is detected by the temperature sensor. In this way, the gas molecules flowing in the pipe contact the pipe wall near the platinum wire resistance 5 and take away a part of the heat generated by the electric heating of the platinum wire resistance 5. The mass flow is proportional to the number of molecules contacting the pipe wall, and macroscopically, the heat loss and temperature of the platinum wire will change. According to the model established by heat transfer theory and the calibration data, the mass flow of the gas in the metal pipeline can be determined.

Claims

1. An externally heated gas mass flow meter sensor, characterized in that: It includes a flange (1), a temperature sensor (2), a metal pipe (3), an insulation layer (4), and a platinum wire resistor (5). A flange (1) is provided at each end of the metal pipe (3). A sensor mounting port is machined on one end of the outer surface of the metal pipe (3), and a temperature sensor (2) is installed on the sensor mounting port. An insulating layer (4) is provided along the length of the other end of the outer surface of the metal pipe (3). A platinum wire resistor (5) is sleeved on the insulating layer (4) at the other end of the outer surface of the metal pipe (3).

2. The externally heated gas mass flow meter sensor according to claim 1, characterized in that: A metal heat insulation box (8) is fitted onto the insulation layer (4) at the other end of the outer surface of the metal pipe (3).

3. The externally heated gas mass flow meter sensor according to claim 2, characterized in that: The metal heat insulation box (8) is detachably connected to the outer surface of the metal pipe (3).

4. The externally heated gas mass flow meter sensor according to claim 2, characterized in that: The platinum wire resistor (5) and the insulating layer (4) are fixed by a fixing adhesive layer (6).

5. The externally heated gas mass flow meter sensor according to claim 4, characterized in that: The interior of the metal insulated box (8) is filled with a large amount of insulation material (7).

6. The externally heated gas mass flow meter sensor according to claim 5, characterized in that: The heat insulation material (7) inside the metal heat insulation box (8) is in full contact with the fixing adhesive layer (6) on the outer surface of the platinum wire resistor (5).

7. The externally heated gas mass flow meter sensor according to claim 6, characterized in that: The diameter of the platinum wire in the platinum wire resistor (5) is 0.05mm~0.06mm.

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