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  1. #1
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    saturated conditions in a receiver tank PROVE ME WRONG



    hello all,
    My name is Ryan im from Australia Sydney. I have been in the trade 10 years.
    I am in the process of trying to figure out if the fluid in a receiver tank,is in a saturated state.
    I have read a lot of forums on the subject and would like to get your feedback on my theory.
    based on my observations on a low temp rack in a supermarket.
    best example to use for this theory.
    R404a,
    ambient on roof where condensor is 73.4F/23C
    SCP set@190psi/Approx 84.2 F/29 C
    minimal fluctuation at time of testing, 188psi to 192psi - correct fan cycling maintained by E2 controller
    plant room temp where receiver is 68F/ 20C (in a underground car park)
    liquid temp entering tank at, 77F/25C (6inches from inlet) (constant temp with small fluctuations approx 1/2 a kelvin)
    liquid temp leaving 78F/ 25.5C (6inchs from outlet)
    pressure drop across tank from inlet to outlet 1 psi AND
    inlet to start of drier core shell 1.2 psi (approx 1 and 1/2 ft away from outlet of tank WITH VERTICAL RISE)
    pressures taken with calibrated fieldpiece gauges and cross checked contact probes,(against other sensors) which are insulated from abmient air.
    only one out of 4 compressor running fully loaded
    horizontal receiver tank, liquid enters from top, leaves at bottom (capacity approx 300 liters)
    subcooled 5K
    receiver tank sglass locations- middle of the vessel
    liquid level in tank sglass, half full, fluctuations between the bottom of sglass and half full (i can always see the liquid.)
    top of tank is slightly hotter than bottom by 1/2 Kelvin

    i think the state of the fluid is subcooled at the bottom (bulk liquid) and at the head or interface of liquid to vapour (also above this interface) its in a theoretical saturated vapour state with nonequilibrium conditions occurring.
    Thus the rise and fall of the liquid in the tank is not only from TXV opening and closing due to loads but also from the rate at which evaporation and condensation occurs.

    I think this state occurs NOT by the increase of energy into the subcooled liquid
    (ie we add sensible heat to a subcooled liquid to become a liquid with no subcooling, then add latent to cause a phase change to begin to a saturated liquid then saturated vapour)
    but by the simpler process of evaporation, of a fluid in a closed/dynamic system with constantly uneven molecular kinetic energy levels occuring at the top of the liquid.
    mostly from the liquid entering the tank causing different waves or splash patterns and the minor fluctuation of pressures and temps.
    I would love to hear what you all think as everyone i ask here in Australia just thinks im an idiot for looking in to it too much. (The funny thing is i work for the largest refrigeration company in Australia.)



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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    All sounds good what you say as it is a mixture in receiver. So what's the question?

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    basically what state is the vapour above the subcooled liquid.
    sorry in most forums people say its superheated vapour at the top followed by saturated interface then subcooled liquid i am trying to get someone to give there arguments on the point of the superheated vapour level,

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Question would be-
    Is this possible that a subcooled liquid @25C at a given pressure 190psi ( PT chart says 190psi=29C )
    forms a vapour which has a temperature well below its corresponding PT chart reference

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    http://icemeister.net/files/valves/S...Cold%20WAR.pdf

    Also, check the March 2010 issue for the follow up. I have the pdf on my computer but is too large to upload on the forum, I can e-mail it if you can't find it online. Some great info there.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    did u read my post the temp AT the top of the tank was only 26C not 29C IT DID NOT EQUAL THE SATURATED TEMP OF THE PRESSURE, it should be 29C

    i think these are the lines in the pdf you wanted me to read-

    (It is simple: we will have 110F at the liquid and vapor interface, but the refrigerant liquid immediately below the interface will be at 100F. The 110F saturation temperature will only be found at the interface, and with the vapor above the interface.

    "Yes, we do need energy to create the 110F interface, but it is already being supplied by the 273 psig pressure. Enthalpy,or the amount of energy in the refrigerant, is the sum of both internal energy and the work created by pressure multiplied by the refrigerant volume.)

    this energy YOU TALK OF (above) is not creating a sensible heat reading of 3k at the top of the tank to be seen/recorded.
    as you should agree to cause a phase change of a subcooled liquid you must first add sensible heat to the subcooled liquid (ie add thermal energy which causes a rise in temp on a digital probe due to the higher vibration or collision rate of molecules)
    this temp reading must match the value on a PT chart for the given pressure, then you add latent heat measured in kj/kg to cause a phase change to occur. all of which wont happen if the bulk of the liquid is not at (for my example 29C).
    as long as there is one drop of liquid in that saturated state the temp of the liquid and vapour will remain the same ie still be extactly what the PT chart says for the pressure.
    so if that pdf was correct the temp recored at the top of the tank should be much higher than 26C
    please note i did write the interface is in a theoretical saturated vapour state with nonequilibrium conditions occurring"

    so i write again could evaporation have caused this CONDITION TO OCCUR please dont send me a pdf from sporlan.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Do you have a liquid seal between drain of condenser & inlet of liquid receiver?

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    no the liquid falls through the vapour into the liquid when first entering the receiver

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    but yes at the drain to the inlet i assume based on subcooling values it has a full column of liquid

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    A very interesting topic
    A couple of things to think about you are using a R4xxx refrigerant so what abiut glide
    Also you are see a solid head of liquid in your reciever so stratified layers can allow for differences in liquid temp at the outlet the bottom and the surface area also consider the possibility of vapour super cooling
    Also your temp measurements are likely to be the cooler if measured on the surface of the pipe influenced by location ambient
    Many factors come into play with a free drain cond and how it enters the reciever

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Hot goes to cold & higher pressure to lower pressure, so I see it possible that a mixture of (in this case) subcooled liquid, saturated gas & some superheated gas enters receiver due to pressure/temp differences. If you have a "p" or "u" trap in liquid drain it may be less prone to this because of the liquid seal. Inside the liquid receiver vapour may still be changing its state being cooled by sub cooled liquid, ambient etc. I think probably no answer will satisfy you but raising these questions is good, as it gets you thinking. So assuming you do get satisfied by someone, what will it prove at the end of the day? Will it assist you in troubleshooting/analysing systems as intrigued on what the deal is. Sorry I'm more on the practical side & best to think basic first then go from there.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by mad fridgie View Post
    A very interesting topic
    A couple of things to think about you are using a R4xxx refrigerant so what abiut glide
    Also you are see a solid head of liquid in your reciever so stratified layers can allow for differences in liquid temp at the outlet the bottom and the surface area also consider the possibility of vapour super cooling
    Also your temp measurements are likely to be the cooler if measured on the surface of the pipe influenced by location ambient
    Many factors come into play with a free drain cond and how it enters the reciever
    good points, approx glide 0.5 K at 29C, can you explain "supercooling of a vapour" i would have to do some research to be sure but i can only remember "supercooling of a liquid" is where liquid can exist below its freezing point.
    also i had considered the fact that it might not be TRUE r404a anymore over the last 10 years of operation numerous leaks have happened some of which are bound to be in evap coils and condensor coils (saturated state) and the chemical composition could have been changed and as the system holds 300kg if the leak was say, 60kg in this coil then 80 in that coil ect ect could that not change the composition greatly.
    r507 only needs 4% r134a in it, to change it from r507 to r404a
    example
    R507 AT 46 SCT 299 PSI
    R404A AT 46 SCT 289psi ( bubble temp 45.8 dew temp 46.1)only 0.3 degress glide
    SO ADDING 4% R134A CAUSES A 10 PSI DIFF AT THE SAME TEMP on a PT chart
    AND AT THAT SCALE ON A PT CHART .....THIS IS 1.5 K

    r125is also found in varying % rates in a lot of the r400 series so losing a large part of that % in r404a could also create some sort of new refrigerant which isnt subcooled at the tested pressures and temps, that idea is all little out there but its not impossible
    also no one ever vacs out a system in a supermarket rack (not in oz anyways) so air could also be present within the composition

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by RANGER1 View Post
    Hot goes to cold & higher pressure to lower pressure, so I see it possible that a mixture of (in this case) subcooled liquid, saturated gas & some superheated gas enters receiver
    i can record superheated vapour temps where were they?
    Last edited by frank; 17-07-2013 at 09:38 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    also the starting point for a staurated vapour temp

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    sorry saturated liquid temp would be correct

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Supercooling of vapour think of a cloud
    Also i suspect yoi are measuring the temp on the surface of the receiver which if like in nz will be a thick wall so the your temp will read cooler than the internal vapour temp which reduces the actual difference
    You could have non condensesables sitting in the top of the receiver

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Air or non condensables could be seen as sub cooling as the SCT is not the true value anymore. You state 25c in 25.5c out & 20c ambient in car park. Top of liquid receiver is lower that SCT. Assume no non condensables in system, then 25c liquid receiver gives heat to 20c ambient, sub cooled liquid will have some temp difference of gas in receiver so it would have a driving force to condense vapour in receiver. Subcooled liquid & gas entering receiver (gas being a mixture of saturated vapour at SCT & or cooler gas being cooled by subcooled liquid). Basically a big mixture in a mildly turbulent environment. Hot going to cold with a reasonably steady SCT/pressure. If system off then different values again.ou would also have more accurate reading on outside surface of receiver where the liquid is present, compared to vapour space. Also any fluctuations in condensing pressure would change everything with the small fluctuations in pressure when you take readings. At the end of the day what will we determine from the result of our theories?

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by RANGER1 View Post
    Subcooled liquid & gas entering receiver (gas being a mixture of saturated vapour at SCT & or cooler gas being cooled by subcooled liquid).
    PLEASE EXPLIAN - & or cooler gas being cooled by subcooled liquid
    (once the vapour/gas is cooled below SCT it is a liquid.)

    please explain where this mix of a subcooled liquid and gas (gas being a mixture of saturated vapour at SCT) is being created.
    especially if i have a column of subcooled liquid leaving a condensor. and ambient conditions are lower than the liquids temp.
    id agree if the condensor produced a saturated liquid leaving it,(there would still be vapour in the fluid) but clearly it isnt, and you have neglected to factor in 2 other phase changes have occured to produce a subcoled liquid at 4k
    subcooled liquid/saturated liquid/complete saturated fluid(equilibrium exists)/saturated vapour/superheated vapour

    knowing this, to say we have a "saturated vapour at SCT" in any part of a subcooled liquid, is in fact highly unlikely. near impossible, as the liquid simply would not be subcooled how could it be, if latent heat energy still exists in any part of the fluid.
    its not like certain molecules of the vapour at a given pressure and temp, choose to condense become a saturated liquid then subcool while others choose to stay in a saturated vapour state the whole time. it happens to the bulk of the fluid at a given pressure and temp.

    for the record i do think gaseous bubbles are present in subcooled liquids but thats a whole other discussion

    you also wrote....
    Also any fluctuations in condensing pressure would change everything with the small fluctuations in pressure when you take readings.

    only if i had a saturated liquid entering the tank or a 0.5k subcooled liquid
    ,ie as the pressure increased the liquid would lean more towards a subcooled state(still be same temp though) and as it decreased the liquid would lean more towards a saturated liquid/vapour state (when this option occurs this would change the temp to its new corresponding pressure/temp realtionship)
    ANYWAYS i had 4k subcooling

    as for what i want to learn.......
    i want to learn if my thoughts, which are, that a subcooled liquid is simply evaporating into a gaseous phase in a receiver tank AND THE GAS IS NOT SATURATED with the evaporating substance is correct.

    once again i wrote its in a theoretical saturated vapour state with nonequilibrium conditions, by which i mean i dont know what else to call it.....

    Thats all. pretty simply really, just because no one has come up with this answer before doesnt mean it anit true
    Last edited by frank; 17-07-2013 at 09:40 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    dynamic system it is a crap shoot as it is dynamic, you can have bubbles of super heated gas in with the sub cooled liquid as it rushes through the condenser, this is why we can see bubbles in a sight glass yet the system is perfectly charged, in essence we can think of a sight glass as a micro receiver.

    in a vertical sight glass we have liquid on the bottom some slight gas at the top when running (this is for sake of argument we may or may not have a small amount of vapour pending on the velocity of fluid, sub cooling and so fourth)

    when the gas liquid mix hits the higher volume of the sight glass it drops in velocity yet pressure remain stable, at this point gravity comes into play, the bubbles rise to the surface and join the gas cloud where it will stratify based on weight and temp, as will the working fluid to a lesser extent.

    Turbulence will mix our fluid and gas phases to a certain extent, so what we see is an average of our sub-cooled working fluid.

    So in the end so long as the txv's are getting a solid column of sub-cooled liquid we are all good, trying to map out the exact thing happening just over complicates things albeit interesting.
    Last edited by The MG Pony; 14-07-2013 at 06:35 PM.
    Now in Redvers Sask.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Oh old MG how I have grown to love our little chats don't worry I will respond tooniht I've gotta go fix some household fridges today if I get stuck can I send you a quick e-mail

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    cute, very cute, how ever this topic has given me motivation to build an acrylic receiver with embedded k-type thermal junctions every inch and make a small system to actually run it, aut to yield interesting results providing I can scare up the required materials.
    Now in Redvers Sask.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Good idea here's an email I sent to myself so I
    could find there number quicly
    notice the date
    From: "Ryan Sharp" Date: Jul 11, 2013 9:17 PM Subject: To: "Ryan Sharp" <
    ACRYLIC Material Safety data sheet Hazards Identification
    I also plan on making a whole system oout of acrylic tube and all
    fYI go onto ebay and u can buy special adhievse tape which can hold 700psi its from uk ebay
    Last edited by frank; 17-07-2013 at 09:43 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by The MG Pony View Post
    dynamic system it is a crap shoot as it is dynamic........
    There's your answer. The PT (and PH) charts represent states of equilibrium. You might approach stasis in a pipe, but this is a 300 liter tank at 50% capacity with phase change and different modes of heat transfer in the top and bottom halves of the receiver.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    .

    Subcooling crops up about twice a year and each debate,
    interestingly covers the same information and I enjoy reading
    debates.

    This was my response the last time and I still stand by it now.

    Liquid that is subcooled is not in contact with the vapour.

    The trouble with subcooling is it is not as straight forward as that,
    even at degree level there is debate about how subcooled liquid flows
    through a system.

    I can explain it in layman's terms and it works for me, ask me to go deeper
    though and my brain freezes up because it does not work on pure science.

    So my understanding of liquid is.

    Subcoold liquid can be in contact with vapour if it is flowing.
    The second it becomes stationary it is saturated and the reason
    is because the flowing liquid has temperature levels in it. As liquid
    flows through a pipe it flows in thermoclimes? (thermocline?), basically
    it flows at different temps through the pipe and therefore it can still be
    classified as subcooled because the liquid is below the saturation temp.

    It is a lot more complicated than that but that works for me.

    Regards

    Rob
    .. ... -. .----. - / -- --- .-. ... . / -.-. --- -.. . / --. --- --- -..

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    im uploading to youtube tonight big pony ill post a link for u tomorrow night,

    its a video of real life running conditions i think u will like it......

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    please watch me.............http://www.youtube.com/watch?v=yqWgasIzh40

    So can you "big pony" please explain to me how the sub cooled liquid still has any superheated vapour present?

    now I realise you said (this is for sake of argument we may or may not have a small amount of vapour pending on the velocity of fluid, sub cooling and so forth)

    so when you apply that logic to this situation (i.e. liquid line was sized for all 4 donks running at design conditions) and then I dramatically reduce the velocity by only allowing 1 donk to run and we see the whole sglass full of voids in the liquid but achieve lower liquid temps do u still think its superheated vapour in that fluid.

    Or could it just be gaseous bubbles forming to fill the void fraction created by the slow moving liquid. In a pipe which is too large.
    in my mind it is clearly not superheated nor saturated as that large amount of vapour would have surely caused a temp increase if it were saturated would it not.
    And how do we create vapour from a sub cool liquid we must add energy then we creates a saturated liquid then saturated vapour u no how the story goes..... And that’s in a static system or dynamic.
    the only other way I know how to cause vapour to occur without adding energy which can be recorded at some point is to.... what’s that word again "evaporate" the surface of the liquid.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Look at your own vid.
    The answer you look for is in the detail.
    Pressure, temps, mass flow, change and time.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by mad fridgie View Post
    Look at your own vid.
    The answer you look for is in the detail.
    Pressure, temps, mass flow, change and time.
    cant figure it out u tell me what state is the vapour in

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    saturated vapour

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    only a kiwi would come up with that.... you must be a mad man....mad fridgie

    a saturated vapour which exists below its saturation temp for that given pressure, IN A SUBCOOLED LIQUID and is being created by a changing flow rate. PLEASE..... oh yeah and instanly changes back to a subcooled liquid when the fluid is pumped quicker.... STOP IT....

    you should make your own PT chart up and just write nonsense on it.

    WHAT DOES EVERY PT CHART DISPLAY (FOR SINGLE COMPOUND REFRIGERANT) A SATURATED VAPOUR AT A PRESSURE AND TEMP.

    even though its a dynamic system bitzer/copeland any other compressor manufacturer any evap or cond manufacturer all know its a dynamic system and all provide constant pt charts for how the fluid acts inside those coils regardless of it being sattic or dynamic

    IF ANY THING you might say saturated liquid as the viods/vapour in the liquid are not affecting the fluids temp, IE IT AINT SATURATED FLUID YET and doesnt have a realtionship with a pressure and temp...
    but even this is wrong.....

    no one knows do they???????????
    where are you big pony........................ i need an intelligent answer.............


    you may all think im a **** but if someone could explain it or could clearly prove im wrong im sure someone would be putting me in my place.....

    Don't abuse other members... edited by Frank
    Last edited by frank; 23-07-2013 at 09:16 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by rjsinoz View Post
    only a kiwi would come up with that.... you must be a mad man....mad fridgie

    a saturated vapour which exists below its saturation temp for that given pressure, IN A SUBCOOLED LIQUID and is being created by a changing flow rate. PLEASE..... oh yeah and instanly changes back to a subcooled liquid when the fluid is pumped quicker.... STOP IT....

    you should make your own PT chart up and just write nonsense on it.

    WHAT DOES EVERY PT CHART DISPLAY (FOR SINGLE COMPOUND REFRIGERANT) A SATURATED VAPOUR AT A PRESSURE AND TEMP.

    even though its a dynamic system bitzer/copeland any other compressor manufacturer any evap or cond manufacturer all know its a dynamic system and all provide constant pt charts for how the fluid acts inside those coils regardless of it being sattic or dynamic

    IF ANY THING you might say saturated liquid as the viods/vapour in the liquid are not affecting the fluids temp, IE IT AINT SATURATED FLUID YET and doesnt have a realtionship with a pressure and temp...
    but even this is wrong.....

    no one knows do they???????????
    where are you big pony........................ i need an intelligent answer.............


    you may all think im a **** but if someone could explain it or could clearly prove im wrong im sure someone would be putting me in my place.....

    .......
    what temp is your liquid line, what influences this temp.
    This is not the same temp as what is within the pipe.

    Your drop 3 comps off, a pressure change occurs, due to reduced mass flow, lowering pressure. As seen in your vid

    The causing flashing, the flasher gas has a lower cp, than the liquid. The ambient then has a further influence on the pipe surface temp and thus the probe. Hence a lower pipe surface temp. As seen in your vid.

    Plus you do not know the pressure at the point at which you are measuring the temp. In your vid, the liquid flow is which way and then what does that give us.


    Get your head out of your bottom, then you might see what is happening
    Last edited by frank; 23-07-2013 at 09:18 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG


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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    vlcsnap-2013-07-21-22h39m20s240.jpg

    easy view

    get my head out of where......

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    hey i found my answer read this and thank

    Fundamentals_of_Fluid_Mechanics_Second_edition_ by GS Sawhney my answer.jpg

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by rjsinoz View Post
    hey i found my answer read this and thank

    Fundamentals_of_Fluid_Mechanics_Second_edition_ by GS Sawhney my answer.jpg
    That is not your answer,

    you can get localized low pressure areas, which do cause bubbles which need time to collapse, But that is not what you are seeing.

    Your pics are steady steady state your vid was not, which showed pressure change "change being the magic word"

    Even though you show some insight into testing your testing methods are highly flawed for precise measurements along with your instrumentation.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    when you drop capacity the system will need to rebalance to the new level, it well could be super heated vapour that had been carried along to the point the capacity is droped, then it can flash feeding off the energy stored in the super heated bubbles to level off to a net 0 tempriture gain or loss.

    Now here we need to factor in laminar flow as well, the pipe will have closer to ambient fluid along the inside surface as the sub cooled liquid rushes by it with fairly low levels of interaction if no turbulance is disrupting this boundry layer (This is why an olval pipe condencer can out perform a conventional surpentine one of 3 times the size!)

    So on the reduced capacity it will consume any internal heat to flash off resulting in a net 0 tempriture change, these where the bubbles you saw, the reason is the condensor has less heat it needs to reject dropping head pressure by a bit. the reason the guages didn't see this is 1 digital guages are slow, 2 laminal flow and a boundry layer acts as a buffer between the fluid streams distorting the real world temp of the fluid refrigerent. so you are correct, there may been no superheated bubbles in this case rather the system simply rebalancing its self. sadly the guages are useles to me as even though I'm in Canada we still learn in imperial!

    to see the fluid temp accuretly you need a tool from ritchie that you can put the therm in physical contact with the fluid stream. this will cuas turbulance and break up boundry layers as well as measur the core of the fluid stream yeilding a truer messure of the temp.

    now I think I just confused my self, what is the question being posed here again?
    Now in Redvers Sask.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by rjsinoz View Post
    hey i found my answer read this and thank

    Fundamentals_of_Fluid_Mechanics_Second_edition_ by GS Sawhney my answer.jpg
    these all do come into play as well, the sight glass creats turbulance in the fluid flow and cuase shearing currents to form wich disrupts the flow in the core of the pipe. if you look it seems the bubbles start just below the sight glass if not further down.
    Now in Redvers Sask.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by rjsinoz View Post
    only a kiwi would come up with that.... you must be a mad man....mad fridgie

    a saturated vapour which exists below its saturation temp for that given pressure, IN A SUBCOOLED LIQUID and is being created by a changing flow rate. PLEASE..... oh yeah and instanly changes back to a subcooled liquid when the fluid is pumped quicker.... STOP IT....

    you should make your own PT chart up and just write nonsense on it.

    WHAT DOES EVERY PT CHART DISPLAY (FOR SINGLE COMPOUND REFRIGERANT) A SATURATED VAPOUR AT A PRESSURE AND TEMP.

    even though its a dynamic system bitzer/copeland any other compressor manufacturer any evap or cond manufacturer all know its a dynamic system and all provide constant pt charts for how the fluid acts inside those coils regardless of it being sattic or dynamic

    IF ANY THING you might say saturated liquid as the viods/vapour in the liquid are not affecting the fluids temp, IE IT AINT SATURATED FLUID YET and doesnt have a realtionship with a pressure and temp...
    but even this is wrong.....

    no one knows do they???????????
    where are you big pony........................ i need an intelligent answer.............


    you may all think im a **** but if someone could explain it or could clearly prove im wrong im sure someone would be putting me in my place.....

    .....

    A pt chart is only good for one snap shot of the system at that exact moment, any where ells it is meaningles! don't over read into what the pt chart is. when you factor in the fact turbulance in the fluid stream can create up to hundreds of pressur zones all differing up to and over a 1psi!
    Last edited by frank; 23-07-2013 at 09:20 PM.
    Now in Redvers Sask.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    No one can "prove" you wrong, only you can do that, all we can do is share our understanding, then you must either decide to agree or disagree then incorperate it into your mental modle of the system.
    Now in Redvers Sask.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by The MG Pony View Post
    A pt chart is only good for one snap shot of the system at that exact moment, any where ells it is meaningles! don't over read into what the pt chart is. when you factor in the fact turbulance in the fluid stream can create up to hundreds of pressur zones all differing up to and over a 1psi!
    PT charts are developed by taking data points under static conditions in a lab. The data points are then fed into a computer curve fitting algorithm from which intermediate data points can be interpolated. Again, you are right, they are meaningless in anything other than static conditions.

    The study of thermodynamics involves years of learning basic rules, followed by more years of learning that the rules don't apply to the real world. Most of us never reach the second stage.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by mad fridgie View Post
    That is not your answer,

    you can get localized low pressure areas, which do cause bubbles which need time to collapse, But that is not what you are seeing.

    Your pics are steady steady state your vid was not, which showed pressure change "change being the magic word"

    Even though you show some insight into testing your testing methods are highly flawed for precise measurements along with your instrumentation.


    we all got sidetracked with my sglass vid anyways as i said in the vid that was for you big pony.
    THE QUESTION.jpg
    Last edited by frank; 23-07-2013 at 09:22 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by Doug30293 View Post
    PT charts are developed by taking data points under static conditions in a lab. The data points are then fed into a computer curve fitting algorithm from which intermediate data points can be interpolated. Again, you are right, they are meaningless in anything other than static conditions.

    The study of thermodynamics involves years of learning basic rules, followed by more years of learning that the rules don't apply to the real world. Most of us never reach the second stage.
    OK SOUNDS ABOUT RIGHT, LETS ALL CHUCK OUR PT CHARTS OUT THEN, THERE POINTLESS AS YOU ARE ALL TRYING TO SAY. ONLY GOOD FOR STATIC LAWS, JUST REFRIGERANT IN A BOTTLE.

    let me ask you all this how does everyone of you set a txv, thats right you all, pull your useless PT charts out dont you?????????

    or do you all just wind her in and out till things get cold, anyone....
    in fact wats the point of gauges while we are at it,what do we need them for the pressures we read are point less figures as the don’t really give us any true understanding of what the system is doing.
    How could they when the gas laws /refrence points we know are all just data points under static conditions in a lab.
    Its also good to know…. Then a computer (which was designed by a human who clearly had no understanding of the gas laws himself) calculates a curve fitting algorithm from which intermediate data points can be interpolated. BET that’s accurate then…..

    By the way has anyone of you actually stuck a probe in to the middle of an evap coil and turn the fans off…. Your temp is always very very close to the corresponding saturated temp/ pressure of the fluid within 0.1 to 0.5 K
    And what do you know a coil has turbulence from bends, conduction heat transfer from fins convection heat transfer from the fluid running along side the pipe, flow rates changing, all of which prove im the idiot for relying on a pt chart.
    THEY ARE NOT USELESS AND IF U THINK THEY ARE GET RID OF YOUR PT CHART AND JUST GUESS THINGS,
    YOUR QUOTE…..
    The study of thermodynamics involves years of learning basic rules, followed by more years of learning that the rules don't apply to the real world. Most of us never reach the second stage.
    PICK UP YOUR TOOLS investigate theory and cross refrence that to the real world
    As in one simply paragraph (about testing what temp the inside if an evap coil is with no fans, compared to your pressure/temp) ( which most of you will try tomorrow assuming your not office workers/engineers ) all your garabe about pt charts are pointless and how flow rates cause the subcooled liquid to contain saturated vapour or what ever has been said just sound stupid.
    Last edited by frank; 23-07-2013 at 09:37 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by The MG Pony View Post
    No one can "prove" you wrong, only you can do that, all we can do is share our understanding, then you must either decide to agree or disagree then incorperate it into your mental modle of the system.
    are you an engineer if no, what types of systems have you performed breakdown work on,

    not quotes from a office not the occasional stop in at site but breakdown work, you no at 2am with no wiring diagram no idea of what the last 5 idiots from the last 5 companys have done, you hopefully know what i mean, work in a scummy plant room or at the bottom of a pub/club or ****ty little butcher shop or supermarket, or anywhere you would find your normaly wrong designed and installed ref system.

    because you are very smart but are you also a good fridgey, very rarely you find people are both......

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by The MG Pony View Post
    No one can "prove" you wrong, only you can do that, all we can do is share our understanding, then you must either decide to agree or disagree then incorperate it into your mental modle of the system.
    sure they can if.....
    example
    i say to you the stove is hot and you dont agree, so i shove your hand onto the stove and hold it there, you will soon agree with me that it is in fact hot and thats because i proved it.....

    another example
    if i tell you im hung like a horse and can **** any woman i want, cause im such a good looking bloke. the minute you saw me i would have proved that simply is not true.

    proving something is easy if you know the answer

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    *Face palms* some just can't see the forest for the tree's <_<

    step one: settle down take a deep breath

    step two: care fully read the whole thread even the stuff you wrote

    step three, let it sink in

    step 4: dwell on it

    step five come back here and let us know your epiphany!

    fyi last rig was in an old bar where they never closed the door and the thing living in the evap growled at you every time you went near the txv and the plant this green thing insisted on a tole! R-22, txv hunting evap freezes up under high humidity, core issue over loaded evap blocking up with water and we can see where it goes from there!
    Now in Redvers Sask.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by The MG Pony View Post
    *Face palms* some just can't see the forest for the tree's <_<



    fyi last rig was in an old bar where they never closed the door and the thing living in the evap growled at you every time you went near the txv and the plant this green thing insisted on a tole! R-22, txv hunting evap freezes up under high humidity, core issue over loaded evap blocking up with water and we can see where it goes from there!
    have you been at mad fridgeys house smoking the bong.....

    remember big pony digital probe in a evap coil no fans running big pony you gotta remember no fans running other wise it just wont work......
    oh yeah if you dont get very close temps to what you see on your gauges after a minute depending on the size of the coil, open the txv, its not set right

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    What can happen in receiver and what happens in the liquid line can be 2 different things. which one do you want to focus on.
    PT charts are based upon steady state conditions, and on average are applicable to run of the mill refrigeration.
    Because you are measuring averages, anything else then you are using the wrong tools and method.

    For example, you poxy clamp (resolution and accuracy piss poor, but good enough for a service engineer) with a half hearted attempt at insulation. What do you think your reaction time is going to be and what influence does the surround ambient have. Quite a lot.

    Why do you set an expansion valve? What is its purpose?

    Why do you need sub cooling (basic reason on a basic TEV system)

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    You have a sheet of metal, on one side is 30C air still and on the other is 20C air still. Which of the 2 temps is the metal sheet going to be.
    What is the reason for your answer.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    Quote Originally Posted by mad fridgie View Post
    You have a sheet of metal, on one side is 30C air still and on the other is 20C air still. Which of the 2 temps is the metal sheet going to be.
    What is the reason for your answer.
    I'm at q Work so quickly 30 degrees higher energy to loweefficehFgg

    Txv why we set? To maximize cooling capacity of
    evaporate coil ensure enough saturated liquid
    enters to achieve correct h eat transfer from product load while maintain a superbeated vapour at the end of the cool sond liquid doesn't enter comp why subcool to offset pressure drop from vertical lift or through drier and ensure full Colin of liquid
    Last edited by frank; 23-07-2013 at 09:28 PM.

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    Re: saturated conditions in a receiver tank PROVE ME WRONG

    [QUOTE=rjsinoz;282043]
    Quote Originally Posted by mad fridgie View Post
    You have a sheet of metal, on one side is 30C air still and on the other is 20C air still. Which of the 2 temps is the metal sheet going to be.
    What is the reason for your answer.[/QUOc
    I'm at q Work so quickly 30 degrees higher energy to loweefficehFgg

    Txv why we set? To maximize cooling capacity of
    evaporate coil ensure enough saturated liquid
    enters to achieve correct h eat transfer from product load while maintain a superbeated vapour at the end of the cool sond liquid doesn't enter comp why subcool to offset pressure drop from vertical lift or through drier and ensure full Colin of liquid
    Purpose creates adibatic flash ie pressure and temp match on those silly and unrealible or charts expect your one that's special cause you made it right mad manhow was that, as it was all while fault finding a hidden mp15

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