An externally heated gas mass flowmeter sensor

Abstract

An outer heating type gas mass flowmeter sensor relates to the technical field of gas flow measurement. In order to solve the problem that the existing mass flowmeter needs to connect the vibrating tube into the main metal pipeline, if the gas flowing in the pipeline is corrosive and radioactive, the vibrating tube has fatigue stress limitation due to the vibrating state of the vibrating tube, the vibrating tube is corroded by the gas, and the mass flowmeter has the problems of poor reliability and low service life. The gas mass flowmeter sensor has the advantages that the service life is long because there is no material loss in the detection process, compared with other flow measurement methods, except for ultrasonic flowmeters and coriolis mass flowmeters, the metal pipeline structure is not damaged, the reliability of the mass flowmeter is improved, and the range ratio is large; and compared with the ultrasonic flowmeter and the coriolis mass flowmeter, the technical scheme is more sensitive to small flow gas measurement and has a low lower limit of measurement. The utility model is suitable for measuring the mass flow of gas.

Description

Technical Field

[0001] This utility model relates to the field of gas flow measurement technology, specifically to an externally heated gas mass flow meter sensor. Background Technology

[0002] In industrial production, it is often necessary to measure the flow rate of gas in metal pipes. Typical flow measurement instruments involve installing a sensor inside or connected to the metal pipe to pick up gas flow information and then converting it into a corresponding electrical signal. Of course, different measurement principles result in different sensors and different electrical signals. This requires openings in the pipe wall of the metal pipe to install the sensor components. When measuring the flow rate of high-pressure, high-temperature, highly corrosive, radioactive, leak-prone, or highly hazardous gases, this reduces the strength and protection level of the metal pipe.

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

[0004] Ultrasonic flow meter: It measures the flow rate of gas in a metal pipe by applying ultrasonic waves to the outside of the pipe. Currently, it mainly measures the gas velocity in the metal pipe by measuring the time difference of ultrasonic wave propagation.

[0005] Coriolis mass flow meter: It detects the mass flow rate of gas flowing through the tube by measuring the phase difference formed at different parts of the U-shaped tube after the gas flows through two U-shaped tubes vibrating at the same frequency.

[0006] In summary, existing mass flow meters require the vibrating tube to be connected to the main metal pipeline. If the gas flowing inside the pipeline is corrosive or radioactive, the vibrating tube will be under fatigue stress due to its vibration state, and the gas will corrode the vibrating tube, resulting in poor reliability and short lifespan of the mass flow meter. Utility Model Content

[0007] This invention addresses the problem that existing mass flow meters require the vibrating tube to be connected to the main metal pipeline. If the gas flowing inside the pipeline is corrosive or radioactive, the vibrating tube experiences fatigue stress due to its vibration, leading to gas corrosion and consequently, poor reliability and short lifespan. Therefore, this invention proposes an externally heated gas mass flow meter sensor.

[0008] This utility model discloses an externally heated gas mass flow meter sensor, which comprises a flange 1, a temperature sensor 2, a metal pipe 3, an insulating layer 4, and a platinum wire resistor 5.

[0009] 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.

[0010] Furthermore, 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.

[0011] Furthermore, the metal heat insulation box 8 is detachably connected to the outer surface of the metal pipe 3;

[0012] Furthermore, the platinum wire resistor 5 is fixed to the insulating layer 4 by a fixing adhesive layer 6;

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

[0014] Furthermore, 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.

[0015] Furthermore, the cross-sectional diameter of the platinum wire in the platinum wire resistor 5 is 0.05mm~0.06mm;

[0016] Furthermore, in use, the flow meter sensor is connected to the main pipeline being measured. The flanges 1 at both ends of the metal pipe 3 are connected to the measuring ports of the main pipeline being measured. When the platinum wire resistance 5 is energized, it will be heated. The degree of heating is related to the magnitude of the current. Under certain thermal conductivity conditions, it is also related to the mass flow rate of the gas in the metal pipe 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 of the gas flowing in the pipe. The temperature of the gas flowing in the metal pipe 3 is detected by the temperature sensor. Thus, when the gas molecules flowing in the pipe come into contact with the pipe wall near the platinum wire resistance 5, they carry away a portion of the heat generated by the electric heating of the platinum wire resistance 5. The mass flow rate is proportional to the number of molecules in contact with the pipe wall. Macroscopically, this manifests as a change in the heat loss and temperature of the platinum wire. Based on the model established by the heat transfer theory and the calibration data, the mass flow rate of the gas in the metal pipe can be determined.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] This invention overcomes the shortcomings of the prior art. The gas mass flow meter sensor with this structure described in this invention has a long service life because there is no material loss during the detection process. Compared with other flow measurement methods, except for ultrasonic flow meters and Coriolis mass flow meters, it does not damage the metal pipe structure, improves the reliability of the mass flow meter, can withstand high temperatures above 600℃, and has a large range ratio. Furthermore, compared with ultrasonic flow meters and Coriolis mass flow meters, the technical solution of this invention is more sensitive and has a lower measurement limit when measuring small flow rates of gas. Attached Figure Description

[0019] Figure 1 This is a front view of an externally heated gas mass flow meter sensor according to this utility model;

[0020] Figure 2 This is a partial cross-sectional view of an externally heated gas mass flow meter sensor according to this utility model. Detailed Implementation

[0021] Specific implementation method one: Combining Figure 1 and Figure 2 This embodiment describes an externally heated gas mass flow meter sensor, which comprises a flange 1, a temperature sensor 2, a metal pipe 3, an insulating layer 4, and a platinum wire resistor 5.

[0022] 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.

[0023] In this specific embodiment, during use, the flow meter sensor is connected to the main pipeline being measured. The flanges 1 at both ends of the metal pipe 3 are connected to the measuring ports of the main pipeline being measured. When the platinum wire resistance 5 is energized, it will be heated. The degree of heating is related to the magnitude of the current. Under certain thermal conductivity conditions, it is also related to the mass flow rate of the gas in the metal pipe 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 of the gas flowing in the pipe. The temperature of the gas flowing in the metal pipe 3 is detected by the temperature sensor. Thus, when the gas molecules flowing in the pipe come into contact with the pipe wall near the platinum wire resistance 5, they carry away a portion of the heat generated by the electric heating of the platinum wire resistance 5. The mass flow rate is proportional to the number of molecules in contact with the pipe wall. Macroscopically, this manifests as a change in the heat loss and temperature of the platinum wire. Based on the model established by the heat transfer theory and the calibration data, the mass flow rate of the gas in the metal pipe can be determined.

[0024] Specific Implementation Method Two: Combining Figure 1 and Figure 2 This embodiment further defines the sensor described in Specific Embodiment 1. In this embodiment, an externally heated gas mass flow meter sensor is provided, wherein a metal heat insulation box 8 is fitted onto the insulating layer 4 at the other end of the outer surface of the metal pipe 3.

[0025] In this specific embodiment, 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. This prevents the platinum wire resistance 5 from being heated after being energized, thus preventing heat from dissipating to the outside.

[0026] Specific implementation method three: Combining Figure 1 and Figure 2 This embodiment further defines the sensor described in Specific Embodiment Two. In this embodiment, an externally heated gas mass flow meter sensor is provided, wherein the metal insulation box 8 is detachably connected to the outer surface of the metal pipe 3.

[0027] Specific implementation method four: Combination Figure 1 and Figure 2 This embodiment further defines the sensor described in Specific Embodiment Two. In this embodiment, an externally heated gas mass flow meter sensor is provided, wherein the platinum wire resistor 5 and the insulating layer 4 are fixed by a fixing adhesive layer 6.

[0028] Specific Implementation Method Five: Combining Figure 1 and Figure 2 This embodiment further defines the sensor described in Specific Embodiment Four. In this embodiment, an externally heated gas mass flow meter sensor is provided, wherein the interior of the metal heat insulation box 8 is filled with a large amount of heat insulation material 7.

[0029] Specific Implementation Method Six: Combination Figure 1 and Figure 2 This embodiment further defines the sensor described in Specific Embodiment Five. In this embodiment, 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.

[0030] Specific implementation method seven: Combination Figure 1 and Figure 2 This embodiment further defines the sensor described in Specific Embodiment Six. In this embodiment, the platinum wire in the platinum wire resistor 5 has a cross-sectional diameter of 0.05mm to 0.06mm.

[0031] Working principle

[0032] In use, the flow meter sensor is connected to the main pipeline being measured. The flanges 1 at both ends of the metal pipe 3 are connected to the measuring ports of the main pipeline. When the platinum wire resistance 5 is energized, it will be heated. The degree of heating is related to the magnitude of the current. Under certain thermal conductivity conditions, it is also related to the mass flow rate of the gas in the metal pipe 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 of the gas flowing in the pipe. The temperature of the gas flowing in the metal pipe 3 is detected by the temperature sensor. Thus, when the gas molecules flowing in the pipe come into contact with the pipe wall near the platinum wire resistance 5, they carry away a portion of the heat generated by the electric heating of the platinum wire resistance 5. The mass flow rate is proportional to the number of molecules in contact with the pipe wall. Macroscopically, this manifests as a change in the heat loss and temperature of the platinum wire. Based on the model established by the heat transfer theory and the calibration data, the mass flow rate of the gas in the metal pipe can be determined.

Claims

1. An externally heated gas mass flow meter sensor characterized by: 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. An externally heated gas mass flow meter sensor according to claim 1, wherein: 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. An externally heated gas mass flow meter sensor according to claim 2, wherein: The metal heat insulation box (8) is detachably connected to the outer surface of the metal pipe (3).

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

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

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

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