The Thermal Flow Measuring Principle

Поделиться
HTML-код
  • Опубликовано: 13 июл 2009
  • eh.digital/2RmBcS2 - Illustration of the thermal flow measuring principle.
  • НаукаНаука

Комментарии • 40

  • @redapproves1330
    @redapproves1330 7 лет назад +15

    Don't know when I'll ever need a flow measuring system, but when that time comes, pretty sure E+H will come to mind. Also thanks for making these well explained videos; they sparked something in me with a desire to study physics.

  • @kunjal96
    @kunjal96 8 лет назад +11

    great animation ....concept clear in just 4 min..great great video ...keep it up.. you had done tremendous job.

  • @borntosurvive1624
    @borntosurvive1624 8 лет назад +14

    this look so great for all physical student and so weird for otherwise people

  • @ZsoltPinters
    @ZsoltPinters 7 лет назад +2

    Awesome animation, thanks!

  • @bhavanisridhar5704
    @bhavanisridhar5704 2 года назад +1

    Awesome. Keep rocking.

  • @egoisticrayyan433
    @egoisticrayyan433 3 года назад +1

    11years since it was uploaded
    NICE !

  • @binoymanaat9571
    @binoymanaat9571 5 лет назад +1

    VERY NICELY EXPLAINED ....THANKS A LOT...........

  • @mareysaad6597
    @mareysaad6597 5 месяцев назад +1

    How exciting ❤

  • @ajaydarji689
    @ajaydarji689 8 лет назад +2

    Very good explanation with the animation.
    It is useful for the principal understanding....
    Thank You

  • @udaynarayanpan6704
    @udaynarayanpan6704 Год назад +1

    Transcript of the video:
    Inside thermal flowmeters there are two temperature sensors protruding into the measuring tube. They are known at Pt100 resistance thermometers. One of these temperature sensors measures the actual gas temperature as a reference regardless of the flow velocity. The second temperature sensor is heated constantly via electrical energy, so that a predefine temperature difference is maintained between the two sensors-for example 10 degrees. If there is no flow, the differential temperature between the two sensors does not change. As soon as the fluid begins to flow in the measuring tube, heat is drawn from the heated temperature sensor by the gas flowing pass. The heat then is carried off by the flow. The corresponding colling effect is measured and compensated immediately by adding more heating current. As a result the temperature difference is continuously maintained. The heating current required to maintain the temperature difference is proportional to the cooling effect and therefore is a direct measure for the mass flow in the pipe. The greater the flow velocity-and therefore the additional cooling of the heater sensor-the greater the heating current required. An alternative adaption of the principle keeps the heater current at a constant value and then measures the change in temperature differential. But how is the heat actually transferred from the heated temperature sensor to the gas flowing past? This sequence shows that the heat is transferred by the gas molecules themselves. When the gas flows past, the molecules absorb tiny heat packet and carry them along with the flow. The faster the gas flows, the more often they absorb the heat. The heat transfer also depends on the density of the gas because at a higher pressure- or a lower temperature - there are more gas molecules in the pipeline. The greater number of molecules results in more contact with the heated sensor, meaning increased cooling and thus increased heating current flow. And finally, the heat transfer is also affected by the thermal properties of the gas. For example at the same mass flow, the high thermal conductivity of hydrogen-shown here in green-causes cooling that is 100 times greater than with air. For a precise measurement, it’s therefore important that the specif properties of the gas are known and are consistence. Flow measurements using the thermal principle is also possible in large pipe and ducts. There are meter types, designed specially for this application. They can be inserted directly into the pipe via a standard process connection. It is important that the required insertion depth be respected so that the measurements is carried out at the correct point. For that reason it is essential to program the actual internal pipe diameter for all insertion meter. Correct insertion also applies for rectangular and square ducting often found in factory or building air circulation system.

    • @endresshauser
      @endresshauser  Год назад

      Thank you for your comment. To see the complete transcript, please enable the subtitles/closed captions function of this video or open the transcript pane by clicking on the three dots and “show transcript”.

  • @jaykesapalaran5434
    @jaykesapalaran5434 Год назад +1

    Amazing tutorial using aNimation. Perfect..

  • @Heating.vn-girl
    @Heating.vn-girl 2 года назад +1

    very good video.

  • @user-bo4mf4ll7o
    @user-bo4mf4ll7o Месяц назад

    Hello, Sir. I'm a teacher, and I find your videos incredibly beneficial for both my students and myself. I would appreciate it if you could provide clarification on whether the video producer permits its use for classroom teaching purposes. Additionally, are there any potential copyright issues that we should be aware of?

  • @TheRacoonChannel
    @TheRacoonChannel 9 лет назад +14

    Great animation and easy-to-grasp explanation, but ''tiny heat packets'' should be banned vocabulary :-)

    • @manandahalfx2
      @manandahalfx2 4 года назад

      You've never heard of the subatomic particles thermotons?

  • @aravindhs9988
    @aravindhs9988 4 года назад +2

    Great animation I really loved it... Can you please tell me how you can differentiate the cooling effect caused in the Pt 100, weather it is caused by change in density of the fluid or is it caused because of change in flow rate of the fluid.....

    • @arindamghatak
      @arindamghatak 2 года назад

      Difficult to calibrate the flowmeter based on fluid density and fluid velocity. Probably easier to calibrate the flowmeter based on fluid mass flow rate instead (m = PvAM/RT) where P = Gas Pressure, v = Gas velocity, A = Internal area of pipe, M = Molecular weight of gas, R = Gas constant and T = Temperature of gas. This encompass the cooling effects of both, the gas velocity and the gas pressure.

  • @fgttw
    @fgttw 14 лет назад +1

    Project Name:Power Protection Application - Generator + UPS + ATS

  • @user-yh6bn1dk6o
    @user-yh6bn1dk6o 7 месяцев назад

    Great video.
    To Calibrate a T-mass 65 to read CO2, should I input manually the operating pressure of 11.5 bar, the density of CO2 at 1 bar, 0°C to proper calculate the mass flow? Is it all or there are other parameters to set. Since the Meter comes from factory with settings for air.
    Thanks in advance.

    • @endresshauser
      @endresshauser  7 месяцев назад +1

      Thank you for your question. The t-mass 65 flowmeters, or the successor products t-mass 300/500, require the following information to calculate the mass flow:
      • The gas or gas mixture (selectable from a list of 22 single gases or mixtures, including CO2)
      • The (absolute) process pressure
      • The (preselected or customer-specific) reference conditions (when conversion to corrected volume is desired)
      • The pipe inner diameter (only for insertion version)
      Direct mass measurement with t-mass flowmeters doesn't require knowledge of the gas density for correct calculation of the mass flow. For the calculation of corrected volume, however, t-mass requires the reference density, which it computes based on the selected reference conditions. The default factory setting for t-mass is air. Customer-specific settings for other selectable gases can be ordered for preprogramming by the factory.

    • @user-yh6bn1dk6o
      @user-yh6bn1dk6o 7 месяцев назад

      @@endresshauser
      Thus, for CO2 mass measurement is enough to select CO2 in gas group and indicate process pressure, with pipe diameter.
      Thank you for your assistance.
      How can I perform the zero Test, because the flowmeter shows reading when downstream valve to the meter is closed.

  • @terrysarjoo4642
    @terrysarjoo4642 5 лет назад

    Mix the temperatures to get reads, heat cold flow. Water temperature and flow from pump will blend in.

    • @federicofacchinetti5019
      @federicofacchinetti5019 2 года назад

      This instrument is suitable for gases only, not for water or other liquids

  • @akshaydandile3426
    @akshaydandile3426 3 года назад

    How to make model of hot wire anemometer

  • @prasad10sunku
    @prasad10sunku 3 года назад +1

    Dear Sir,
    I am Sunku Prasad, a PhD student from IIT Guwahati, India, working in the area of high temperature thermal energy storage system. I want to know whether it is possible to design a thermal mass flow meter for measuring mass flow rate of molten salt. the molten salt is flowing in the pipe at a temperature of 400°C. The flow rate range is 2.5 lpm to 10 lpm.
    Kindly let me know the possibility of such device.
    Please share your contact to discuus further on this application.
    Thanking you
    Sincerely
    Sunku prasad

    • @endresshauser
      @endresshauser  3 года назад

      Dear Sir
      In theory, this is possible but you would have to heat the sensor to more than 400 °C requiring a lot of power. There are more suitable technologies available, however, like DP, vortex flowmeters and clamp-on ultrasonic flowmeters producing more accurate results. You can find out more about these technologies on our website eh.digital/2QGefe0

  • @hadibesharat9683
    @hadibesharat9683 2 года назад

    is Dt constant in measuring process? i mean dt shall be fixed in process with increasing or decreasing thermal current.

    • @endresshauser
      @endresshauser  2 года назад

      Hello Hadi Besharat, yes that is correct, the differential temperature is constant during the measurement process.

  • @rajakannan4292
    @rajakannan4292 2 года назад

    Hi E+H team, is it possible to measure chlorine & hydrogen gas using this type of thermal mass flowmeter??
    What it's advantage over DP type flowmeter (which we are using in our plant) ??

    • @endresshauser
      @endresshauser  2 года назад

      Hello Raja Kannan
      Yes, thermal mass flowmeters can be used for measuring both chlorine and hydrogen gases. With potentially corrosive gases like chlorine, it is important to ensure that the gas remains dry and that suitable wetted parts materials are used. Thermal mass meters are frequently used for monitoring of hydrogen gas, where low flows are common and good repeatability is required.
      Thermal mass flowmeters offer a number of advantages over differential pressure flowmeters.
      Thermal mass
      1) provides a direct mass measurement
      2) is not density dependent and does not require p/T compensation
      3) delivers very high turndowns, typically 100:1, in some cases, up to 1000:1
      4) creates very small pressure drops compared to orifice plates, for example
      5) is extremely flexible in their application (a single type can be used to service various measuring points)
      6) requires limited engineering to size for an application
      7) has no issues with impulse lines (clogging or freezing, e.g.)
      8) is less sensitive to drift (that could result from the primary and secondary elements)
      Find out more about our thermal mass flowmeters Proline t-mass here: eh.digital/3rk4Iw4

  • @Quotila0
    @Quotila0 3 года назад

    Nice video. But I still didn't get how is temperature used to measure the flow. Like high and low? Not specific flow rate?

    • @endresshauser
      @endresshauser  3 года назад +1

      Dear Poulami Dutta, the thermal principle operates by monitoring the cooling effect of a gas stream as it passes over a
      heated transducer (PT100). Gas flowing through the sensing section passes over two PT 100 RTD transducers one of which is used
      conventionally as a temperature sensing device, while the other is used as a heater. The temperature sensor monitors the actual process values while the heater is maintained at a constant differential temperature above this by varying the power consumed by the sensor. The greater the mass flow, the greater the cooling effect and power required to maintain the differential temperature. The measured heater power is therefore a measure of the gas mass flowrate.

    • @vinayaksharma9538
      @vinayaksharma9538 2 года назад

      @@endresshauser Hi sir, I'm using the PT100 RTD sensor but it can only detect the temperature. I searched for the heated transducer one but didn't found anything. Can you please help me how to find the self heating PT100 sensor.
      Thank you

    • @engineerchokra9505
      @engineerchokra9505 Год назад

      @@vinayaksharma9538, the first one is measuring the actual gas temperature called reference temperature and 2nd one is both heater and temperature sensor which is creating a differential temperature which the transmitter has to maintain. The more number of molecules with the great velocity decreases the temperature of heater thus the transmitter will send more electrical signal to the heater to maintain the differential temperature. The measure heater power is actually a measure of mass flow rate

  • @EIRohitKumar
    @EIRohitKumar Год назад

    hi guys

  • @mohamedna6551
    @mohamedna6551 2 года назад

    فد شي ذكي وعبقري بس مالة داعي هواي اكو تطبيقات لل folw
    هذا استعراض افكار هههههههه

  • @aravindhs9988
    @aravindhs9988 4 года назад

    Great Animation really loved it. Can you please tell me how this can be used in measurement of natural gas? Will it affect the natural gas due to the heat transferred ?

    • @endresshauser
      @endresshauser  4 года назад +3

      Thank you for your question. With our devices, typically a relatively small temperature differential of 10K is used to regulate the heating element while in operation, so that the fluid (or more specifically its properties) remains unaffected. Of course, it is also ensured, through the conformance with safety and hazardous area norms, that in the case of flammable gases, even in the event of a sensor failure, that it cannot result in an ignition.