Head Equation for the Expander/Turbine
Head Equation for the Expander/Turbine
(OP)
Please elaborate the HEAD ESTIMATION EQUATION for the expansion of the gas through Expander/turbine?
The similar equation for the compressor is in attachment;
Can some body help me similar equation for the TURBINE/EXPANDER??? Any reference please?
Regards
The similar equation for the compressor is in attachment;
Can some body help me similar equation for the TURBINE/EXPANDER??? Any reference please?
Regards





RE: Head Equation for the Expander/Turbine
1) Fluid flow rate
2) Isentropic enthalpy change of the fluid
3) Expander efficiency
Multiplying these 3 gives you the actual extracted power.
See the thread http://www.eng-tips.com/viewthread.cfm?qid=377170 and the attachment.
Dejan IVANOVIC
Process Engineer, MSChE
RE: Head Equation for the Expander/Turbine
Dejan IVANOVIC
Process Engineer, MSChE
RE: Head Equation for the Expander/Turbine
I have to convert the Pressure ratio in maps in to head term to be used in Aspen Hysys as it takes only head instead of pressure ratio
RE: Head Equation for the Expander/Turbine
RE: Head Equation for the Expander/Turbine
Dejan IVANOVIC
Process Engineer, MSChE
RE: Head Equation for the Expander/Turbine
RE: Head Equation for the Expander/Turbine
RE: Head Equation for the Expander/Turbine
with your software you can possibly solve a turbine from a thermodynamic point of view on specific points (I do something equivalent in Excel with Prode library) but analysis of dynamic response would require more data and more complex models,
there are specific software tools or perhaps you may define a procedure in Matlab or a similar tool..
RE: Head Equation for the Expander/Turbine
Yes I have turbine inlet and turbine outlet temperature. The inlet flow rate and gas composition is defined.MY problem is well defined and degree of freedom is zero at the moment. The solution is there.
The Only question at the moment is to plug the series of volume flow rate vs head. And for head estimation I need an equation? Please specify this equation????
RE: Head Equation for the Expander/Turbine
can't you convert by taking in account density ?
Make sure about the units for head
RE: Head Equation for the Expander/Turbine
My modeling tool require performance map data in terms of volume flow rate vs head for different speeds. For this purpose I require head equation as a function of pressure ratio.
The similar equation for the compressor is;
H = {k/k-1}[ZRT][(p2/p1)^(k-1/k) -1] please see the attachment for full equation of compressor.
If you have similar equation for turbine please specify???
RE: Head Equation for the Expander/Turbine
why do you wish to enter that value ?
RE: Head Equation for the Expander/Turbine
to reduce the number of inputs which results in more better control during dynamic modelling.
But how gas law helps me to estimate the HEAD for expander????
Have you seen the compressor head equation in attachment of my last reply? I need similar equation.
RE: Head Equation for the Expander/Turbine
if you have (see your previous post) a series (dP vs. flow) of operating points, use these (with proper conversions, taking in account density, when required) as inputs in your software
RE: Head Equation for the Expander/Turbine
I have to convert the available Pressure ratio in to head?
For which I require head as a function of Pressure ratio?
RE: Head Equation for the Expander/Turbine
It is also possible to do this calc manually to get an approximate value for head; see Perry Chem Engg Handbook, 6th edn, chapter on process machinery, expanders subsection. This subsection is retained in the 7th edn also at page 29-46.
RE: Head Equation for the Expander/Turbine
Many thanks for the reference.
The equation available in the Perry's 6th or 7th edition is quite generic and does not account the k = cp/cv.
Also the separate simulation of expander to estimate the head and then use it in gas turbine is last option in my mind as data is quite lengthy.
RE: Head Equation for the Expander/Turbine
If you are running on Pro II, using a controller unit operation will speed up the trial and error for isentropic efficiency. The same facility would be possible with the adjust operation in Hysis.