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Energy Conversion Systems

  1. Jun 10, 2006 #1
    To All:

    I would like to invite both members and visitors of the PhysicsForums.com Engineering (Mechanical and Aerospace Engineering) Forum to start a discussion on Energy Conversion Systems -- ask questions of interest, share knowledge and experience related to Energy Conversion Systems technical performance analysis, modeling, operation and commercialization issues.

    Also, everybody is welcome to contribute to the Energy Conversion Systems topic.


  2. jcsd
  3. Jun 10, 2006 #2


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    engware, usually here if anyone has a specific question to ask or piece of knowledge to share then they'll start a thread themselves.

    Are you after any particular information or do you just want to stimulate a discussion? If it's the latter, then I'd like to hear some views on whether people think gas turbines are going to gradually take slices of the electric power market from reciprocating engines.
  4. Jun 10, 2006 #3
    Hi there:

    I have to admit that I was trying to start/stimulate a general discussion.

    Let me get back to your question.

    In my opinion, the gas turbines should take over. However, not entirely.

    In some cases, the energy economics will be still in the favor of reciprocating engines.


    Last edited: Jun 10, 2006
  5. Jun 10, 2006 #4


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    Except that most gas-fired turbines were designed to be economical for gas at $2-3/million BTU. Now gas prices have increased to over $5/MMBTU. During September and December 2005, natural gas spiked over $15/MMBTU, and operating a gas fired plant meant losing money in some cases, unless one could find someone desparate to buy the power at high cost.

    Combined cycle plants, which have about 60% efficiency look attractive as long as the gas prices are not too high.

    What is the basis of this statement?
  6. Jun 10, 2006 #5
    Hi there:

    I agree with your post.

    However, the oil prices have also gone up recently.

    Even though we are talking about simple/basic and combined power cycles, with the help from renewable energy that can generate hydrogen when energy supply exceeds demand, one can get fuel at no and/or low cost.

    If such generated hydrogen gets used as the gas turbine or reciprocating engine fuel, then the energy economics picture changes -- it becomes a case of capital availability.


    Last edited: Jun 10, 2006
  7. Jun 20, 2006 #6
    Hello All:

    As I'm a Wanna Be in this and most fields I will try to keep my question as clear as possible.

    I have googled this to no avail....how does one convert the square meters of PV (Solar Panels/190Watt 24volt) by X qubic feet of H20 equals what in Hydrogen and O Volumes? (is there a simplified, if not crude formula)

    And why wouldn't ppl harness the Lightning with a 100x100x10 pool with a large honeycomb type anode?

    Also, does anybody have experience calculating +or- atmospheres under a man made vortex of water? And what PSI would be in optimal conditions?

    Thanks so much for any help.

    Last edited by a moderator: Jun 21, 2006
  8. Jun 22, 2006 #7


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    First of all, one must start with how much energy is required to break down water - which is an electrochemical problem. One should be able to find the energy in a chemistry book. Take the power and integrate over time to get energy - e.g. in kWh and then with that energy determine how many moles of H2O one can electrolyze. One must also know the efficiency of the solar to electric and electric to chemical conversion.


    Lightning represents large magnitudes of current, and would require huge electrodes and an appropriate system. Such a system is expensive, and the location of lightning strikes is relatively random, so tapping the energy on a reliable basis is unlikely.

    I don't really understand "+or- atmospheres under a man made vortex of water". The pressure will depend on the altitude (depth) within the atmosphere. At sea level, the atmosphere had a nominal pressure of about 14.7 psia, or 0.101325 MPa. The pressure will fluctuate slightly based on air temperature or composition (dry vs moist). Pressure will not be much more or less than 1 atm.
  9. Jun 23, 2006 #8

    I apologize for the simple questions...but I didn't take Physics in HS and didn't make it to a university.

    So, Hypothetically, if one were to build an 8' tall cylinder that one could mount on the bottom, an impellar to CREATE a vortex......

    How does one know what design would yield the most effecient vortex...i.e. consistant flow with minimal output from the impellar.
    ( I understand that the material will have friction and the water itself will have friction.)

    I understand that Nano CPU's are being designed with the electrons flowing through single file and as such removing friction/heat from the proccessors......Can the same outcome be designed into this format? Understanding yes that the electrons on the Nano CPU are coded in an atom by atom formation only allowing one to flow at a time. Still needed to be asked. Wanting to make the most efficient vortex possible.

    would the cylinder have a cone shape or.....:biggrin:
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