Cooling System..

Discussion in 'The Projects Forum' started by jjuurreell, Sep 10, 2012.

  1. jjuurreell

    Thread Starter New Member

    Sep 9, 2012
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    can someone tell me what is the cooling system used in water dispenser? any links or info will help! THANKS!
     
  2. BSomer

    Member

    Dec 28, 2011
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    It could be either a thermoelectric (peltier) cooler or phase-change (freon compressor) cooler. It kind of depends on the type of "water dispenser" / "water cooler" you are looking at. The kind with a large water bottle sitting on top of it will usually be thermoelectric, where as the kind that mount to a wall and have a water line from the building is generally a phase change system.

    Here...
     
  3. debe

    Well-Known Member

    Sep 21, 2010
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    All the watercoolers Ive worked on use a refrigeration compressor to cool the water. Peltier devices just dont cut it for that sort of cooling.
     
  4. jjuurreell

    Thread Starter New Member

    Sep 9, 2012
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    we are about to use a cooling system for cocktail dispenser ..

    so which is more cheaper ? and more advisable to use ?

    thermoelectric (peltier) cooler
    phase-change (freon compressor) cooler
    refrigeration compressor

    thanks for the help fellas! :)
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
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    Unless your school has something ready made phase-change system or refrigeration compressor system. This is way to complex for a student project in electronics. The peltier solution may be doable for a student project. Remember this is a student project. Not something that are going to be produced and sold. I think your group are making a very common error made by students. Namely heavy over engineering/specification. Try to make a list of need to have and nice to have. Make the need to have list as short and simple as possible. Then discuss this list with your teacher. If your teacher approve the need to have list. Then solve all the problem on the need to have list. If you still have some time left. Go for the nice to have list. Then it comes to grading. It is much better to have something that you can prove are working. Instead of a lot of cool design ideas that only work on the paper. Trust me on this one. I have a lot experience both as teacher and student at university level
     
  6. jjuurreell

    Thread Starter New Member

    Sep 9, 2012
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    im sorry about that , but as of now, we have no other choice. since this is the only approved proposal in my group. we are fully aware that the project is somewhat difficult to make, but just what i have said. we have no other choice. we cant propose anymore. and we are about to defend the title at the end of the month. so please, if you have any advice or any answer to the question, please lend us your help. we cant afford to back off at this point of time and we need to graduate at the end of the school year.
     
  7. wayneh

    Expert

    Sep 9, 2010
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    What is? The title topic? You need to design (and make?) a water cooler?

    Building a vapor recompression (conventional) refrigeration unit would be quite difficult, and even your colleagues in chemical engineering would not be likely to try that. TEC is your only viable choice. But you'll be disappointed at how horribly inefficient it is.

    You might consider making a water cooler for situations where the conventional approach is simply not possible. For instance, something small to use in a car could make sense, or maybe something for camping.
     
  8. jjuurreell

    Thread Starter New Member

    Sep 9, 2012
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    Automated Cocktail Mixer and Dispenser..

    well the existing project doesnt have the cooling system so we decide to put a cooling system on to the project.
     
  9. t06afre

    AAC Fanatic!

    May 11, 2009
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    And now 20 days. Before the deadline, Your group finds out that this is way more complicated than expected. And you are still discussing however to use PIC or Arduoino. Ouch...You need to stop discussing and start to do something. It is better to have something to show than nothing at all. Just curious then did your group receive this assignment
     
  10. wayneh

    Expert

    Sep 9, 2010
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    Got it, thanks.

    So, how much cooling capacity do you need? I mean, do you need to cool a drink from ambient to ice cold in the brief time while the drink is mixed (high instantaneous cooling capacity), or can you pre-chill your ingredients?

    I love an ice-cold drink, so if I was doing this, I'd look to place all the liquor inventory in a freezer. A human would have to restock the freezer, presumably with warm booze. So you'd need enough cooling capacity to keep the freezer cold.

    If you want a fully "on demand" system, where the temperature of each drink is adjusted to a specification from ingredients at ambient, that'd be very cool but it will be more challenging.

    One think you need to know about a TEC is that they produce a lot of heat for each unit of heat they move. At their rated capacity, it may be 9 units of power consumed for 1 moved, with 10 units requiring dissipation on the hot side of the TEC. So you need to dissipate 10 for just one moved from the cool side. These numbers get much better - down to 2 dissipated for each one removed - if you run the TEC at much lower levels, but then you need more TEC modules for a given amount of cooling.
     
  11. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Here's an off the wall response. My fridge has a cold water dispenser and the water comes out pretty cold, colder then the sink, and they both have the same supply.

    Once repairing the water lines after a kitteh attack I discovered the water is chilled inside the fridge compartment by the simple method of 20 feet or so of coiled plastic hose being inside the fridge door. Holds enough water inline to fill the typical cold glass.

    Just a thought if your you have a fridge at the bar and your needs exceeds your budget.
     
  12. jjuurreell

    Thread Starter New Member

    Sep 9, 2012
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    Its still a title defense .. we dont need to show anything.. just the research we made and what are we going to do about it on the next semester .. we are doing something here, we are trying our best to finish the task. we will make the project on the next semester.. we just need information as of now .. details , ideas .. advice from the experts .. not discouragement .. thank you!
     
  13. jjuurreell

    Thread Starter New Member

    Sep 9, 2012
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    thanks! i think we need to pre-chill our ingredients before serving.. do you think we can make it ice cold ? well, its not necessary to make it ice cold in our project. we just need to make it cold (even a little cold will do) even if it is not ice cold.

    thanks for the TEC info, i have to research more about it .. :)
     
  14. jjuurreell

    Thread Starter New Member

    Sep 9, 2012
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    good idea .. but i think this will not work on us. we have 7 different beverages on this project.. so we need 7 20 feet coiled plastic hose to be put inside the fridge.. but you are right, we are trying not to spend to much.. so this kind of idea really help us.

    anyway, thanks for the info ..
     
  15. wayneh

    Expert

    Sep 9, 2010
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    You know, I think a cold block near the end of the process could help. You need a large, cold, thermal mass - like a block of metal or a brine bath - that you can draw the mixed drink thru, using a heat exchanger such as a coil of tubing. This would average out the need for cooling and you wouldn't need nearly as much instantaneous cooling capacity. Still needs to keep up on average, though.

    While you're at it, you should research static mixers. It's harder to mix some liquors than you might think. Try kahlua in vodka some time. Static mixers convert pump energy to mixing energy without moving parts. You can get them very small and inexpensive, for lab scale work. They're a great way to get inline mixing so you don't need a stirred chamber with another motor. You'll see a pressure drop going thru a static mixer - the mixing energy has to come from somewhere. A static mixer in a brine bath might be a pretty good heat exchanger.
     
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