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  1. E

    Refrigeration question

    using R-22 for example...what my question means is that to design a refrigeration cycle u select the pieces according to capacity, but what makes sure they wil operate at a certain condensing temp and evap and not another?
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    Refrigeration question

    Hey All Suppose ur designing a refrigeration cycle. if u go to the market to choose parts for an 18000BTU/h circuit. The compressor has different ratings according to the entering temp and exit temp, then u have the thermal expansion valve which is also rated in BTU/hr depending on entry and...
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    Solar Water Heater

    ok point taken...but if u want to buy it? do u have an idea what it would cost?
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    Solar Water Heater

    Just curious...how much would it cost you to install a solar water heating system ($/Watt) where u live?
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    Evaporator terms

    well i got the book before u answer...its magnificent, what i was looking for all the way..thnx
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    Evaporator terms

    does dossat's book guide u through the whole evaporator and condenser designs?
  7. E

    Evaporator terms

    thank you, i will check the book out..
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    Evaporator terms

    thnx russ.. about the 10 tons, the performance of the heat exchanger lies in tubing, and gases flowing, and so and so...i felt its wierd that they rates the compressor as if it was the only defining principle in the heat exchanger. but i guess ur right.
  9. E

    Evaporator terms

    1.superheat Psig Saturated Temp Suction line temp superheat temp. 58 32 44 12 64 37 47 10 70 41 50 9 can some1 help me understand the ratings above.. Saturated temperature...
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    Design calculator for Condensers, evaporators, heat pumps

    ahh..thnx besides today i found another program something called evap-cond. i just have to test it with proven designs. definitely not gonna test it on CFD software :)
  11. E

    Design calculator for Condensers, evaporators, heat pumps

    i just finished downloading the package from rae-corp. they are asking for a password !! damn
  12. E

    Design calculator for Condensers, evaporators, heat pumps

    Hey guys Anyone knows a good calculator for condenser, evaporator, or heat pump design? common unknown parameters would be number of passes, or length of columns, depth or rows..... Thnks
  13. E

    Sound waves as energy?

    well passing cars can create huge pressure differentials like on highways, don't u think they could generate wind power to turn miniature wind turbines?
  14. E

    Heat loss from a pool

    yeah, but u always have to see that ur input heat compensates for the loss of heat from the surface of the pool. like if evaporation causes 10kW loss, and ur heater only compensates for 8kW..so ur water is gonna become cooler gradually
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    Heat loss from a pool

    Well i'm not sure about that, i think they are kind of experimental cause they are measured relative to one external air temperature. Besides newton's law of cooling doesn't allow us to measure the convection constants of air neither the radiation constants.
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    Heat loss from a pool

    yeah i found this website too:) thnx anyway. what i meant in temp leaving the pool is that after steady state is reached and my pool is heated, i need to maintain that heat. so when i have to reheat the water i'm taking it that this water leaves the pool to be reheated at 23 Celsius, do u think...
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    Heat loss from a pool

    thats a big difference between this value and the value given on the website !! and yes the pool is inside and heated (at least the first one)..my research is to design a heat exchanger for it. i have another question in that matter, if i want to calculate the temperature of the pool water...
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    Heat loss from a pool

    Hi all I found values for heat transfer from a pool on the following website: http://www.engineeringtoolbox.com/heat-loss-open-water-tanks-d_286.html can someone please tell me how reliable is this information? especially that they didn't mention free natural convection, or is it...
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    Globe valved ic engine

    i'd worry about backfire, uneven flow through the valve. just because some technology has advanced far doesn't mean its too late to try new ways. but i'm worried about backfire and even distribution inside the cylinder, cause theres no spraying control in such valves.
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    Sound waves as energy?

    well actually sound waves propagate through a medium via bumping molecules/atoms into each other. besides wave is a form of energy propagation. whether oscillatory or any other form.
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    Time for water to freeze in a pipe

    first of all it varies if u start from 45 or from 26..what i would do if it was a rotational repetitive cycle is to start from 45, and calculate heat loss according to the chosen increments. after each increment u can calculate the temperature the water has reached. then u start again. of course...
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    Sound waves as energy?

    well technically anything that moves can create energy, and sound waves create movement thus energy, but very small..
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    Which engineering field makes the most money?

    usually most engineers are paid the same. according to my observations engineers who get into business or management will get paid higher and will go further in modern day corporations. (my observations are limited to the middle east though)
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    Motors and batteries

    r u sure about that? i mean i know that the engine operates by varying its polarity on 1 side, and keeping it the same on the other. would be difficult to do that using AC, unless you r using a permanent magnet system ? what do u think?
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    Motors and batteries

    The battery probably won't hold not for any backup time u need like 10 of those batteries to have decent backup. An electric motor is usually DC driven cause from the way it works, if u put AC current on it, it will move back and forth thus staying in the same place and we don't want that to...
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