PUMP and CALCULATION of operating point

Tutorials software mecaflux, Cavitation, saturated vapor ,efficiency,Examples pressure drop

 

 

pump calculation software

The pumps are machines allow the fluid flow (liquid or gas) in a network using a certain amount of energy supplied by a motor.

The characteristics of flow and pressure pump, allow to establish an operating curve pump compared with losses of charges and the gradient of the network.

Comparing the curve of the pump and allows the network to find operating point pump system network.

If the fluid is a liquid , beware to avoid cavitation of suction pipe and pump .

There are many types of pumps :

example of positive displacement pumps

positive displacement pumps

examples of turbo pumps

The types of pumps

The types of pumps are numerous and related to the flow, the density of fluid and pressure to generate to achieve the desired flowrate.

The types of pumps are numerous and related to the flow, the density of fluid and pressure to generate to achieve the desired flowrate

To sizing and calculate the operating point of pump , we must know the network parameters. these parameters are:  -The flow volume m3 / s

-The saturation vapor pressure fluid if a liquid (Assesses the risk of cavitation) .

-The suction height. (if liquid)

-The discharge head . (if liquid)

-The pressure tank sucked (should be added or subtracted from the height)

-The pressure tank discharge (should be added or subtracted from the height)

-The pressure losses in the suction section and discharge section: " pressure drop of elements "And" Head losses of pipes "

-The efficiency of Your Pump (for calculations of energy consumption and engine power)

-The NPSH (Net Positive Suction Head) required for your pump. (assesses the risk of cavitation)

example of Manufacturer pump's curve , pressure versus flowrate

example of Manufacturer pump's curve , pressure versus flowrate

Sample curves of pressure head versus flow of pumps coupled in parallel or in series in Editor pumps of mecaflux

pressure head versus flow of pumps coupled in parallel or in series
 

With MECAFLUXPUMP CALCULATION SOFTWARE

  • Calculate the operating point and Size of a pump versus the pressure drop of the network

Calculate the operating point and Size of a pump versus the pressure drop of the network

  1. you calculated the pressure losses of various elements of your most disadvantaged network's section.(the other sections will be equipped with valves or other accessories to balance the pressure drop).
  2. you saved your network Inventory losses
  3. you've already entered curves pumps in the editor Pump or you enter a curve (6 points of pressure versus flowrate)

If you have a network in the inventory of losses while editing, it will be tested by default, if you want to test a saved network, click on "load a network".

If your network is open ,select "Open network" ,and enter the height .

You are now ready to Calculate the operating point and Size of a pump versus the pressure drop of the network.

You can check the "Quick Search" to display only the operating point in small size chart and move quickly from one pump to another with your editor and run the experiment:

or run a full scan testing:

 

Operating point of the pump coupled in parallel , in series or alone.

 

Controlling the risk of cavitation, and calculate the power of the pump versus a given flow

 - Select tab systems and pumps turbines and :

(In this tab you can also explore the parameters of a turbine)

Controlling the risk of cavitation, and calculate the power of the pump versus a given flow

 

  • Enter - flowrate in Network: 0.006 m3/sec

  • Enter - density and fluid temperature: 1000Kg/m3 and 20 ° C (this determines the pressure saturated vapor Water for other fluids you should uncheck "water" and fill the vapor pressure-saturation of your fluid)

  • "Enter the temperature and the altitude

  • Enter - suction Attention in this scheme the pump is located below the suction tank (pump load, the fluid drops) must therefore be a high negative: -3 m

    This deserves explanation:

    to identify, think about the pump and the effort it will provide for circulating the fluid:

    • -if the fluid goes down, it removes Labor , so the height (dimension between the axis of pump and tank surface) is negative. (down = negative sign)

    • -if the fluid must go up it adds work to the pump so the height (dimension between the axis of pump and tank surface) is positive. (sign up = positive)

  • Enter - discharge height, if the discharge reservoir is above the fluid pump , the value is positive: 7 meters

  • -Enter either:

    • the efficiency of your pump (0.8 is an average efficiency)the efficiency of your pump (0.8 is an average efficiency) for the energy absorbed by the pump shaft in KW . For electrical consumption of the pump motor you must enter the efficiency with the performance of the electric motor (0.5 is an average efficiency for a pump body and motor)

    • Thepower consumption at the the pump shaft (efficiency pump), or motor output (you will return the entire "motor-pump body")

  • - Click on view and the results sheet summarizes your network

 

pump does not have cavitation

In this part of the results sheet,

we see that the pump does not have cavitation and it consumes 0.99 kW for yield 0.8

 

 

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 mis à jour le 10 /2009

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