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Re: Carters Widget Revealed!
if i understand yr diagram you want to add this to a standard system i dont think it will work all the time on a standard system because by reducing the pressure after the condenser before the reciever you are loosing omff or energy that the higher pressure liquid has you are then fillin a reciever with fluid at a low pressure which you are then putting to a tev evap and then trying to suck it out with a sort of venturi effect and increase pressure with a higher pressure sub cooled vapour i think it will work if instead of a reciever you use a vessle for liquid similar to an expansion tank take yr vapour feed off the top of that put the tev and evap below the condenser and reciever vessle using the effect of gravity and that all fluids find there own level and move yr widget closer to evap does that make any sense ?
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Re: Carters Widget Revealed!
have just had the penny drop big style yr basically squirting higher pressure vapour at the compressor causing a sucking vacume effect to increase the velocity of the gas leaving the evap so causing less work done by comp bloody genius :) and the part yr gonna fit is like you say very basic wow think u just re invented the wheel
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Re: Carters Widget Revealed!
As I read & re-read through this very interesting thread, I keep wondering about a few niggles going on in my engineering 'gut':
1. The ejector/motive device will be governed my a momentum interchange between the two fluids.
2. Momentum = mass*velocity = density*volume flowrate*velocity
3. Could the pressure drop in the motive device cause back pressure into the separation tank?
4. Would the liquid flash into the separation tank?
5. A niggly feeling of system feedback driven backwards from the motive device into the liquid circuit.
6. Expectation of some level of system 'bouncing'.
Niggles - can't quite put my finger on them. Will try to set up some simulations to play with gas/liquid dynamics.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
desA
As I read & re-read through this very interesting thread, I keep wondering about a few niggles going on in my engineering 'gut':
1. The ejector/motive device will be governed my a momentum interchange between the two fluids.
2. Momentum = mass*velocity = density*volume flowrate*velocity
3. Could the pressure drop in the motive device cause back pressure into the separation tank?
4. Would the liquid flash into the separation tank?
5. A niggly feeling of system feedback driven backwards from the motive device into the liquid circuit.
6. Expectation of some level of system 'bouncing'.
Niggles - can't quite put my finger on them. Will try to set up some simulations to play with gas/liquid dynamics.
Good Evening DesA
Your thread has started again,
http://www.refrigeration-engineer.co...s-Nothing-Else)
I have cut & pasted relevant comments for 'Mad' last night & will add this to it now
the rest of us can still play here, - too much banter/off topic
Regards chillerman
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
Good Evening DesA
Your thread has started again,
http://www.refrigeration-engineer.co...s-Nothing-Else)
I have cut & pasted relevant comments for 'Mad' last night & will add this to it now
the rest of us can still play here, - too much banter/off topic
Regards chillerman
Hey Chillerman, very nice job you did. I just asked in the Mod sextion - sextion, type error but a good one - how we can print a whole thread spread over several pages. You filtered out the chit-chat which is needed in such a conversations, especially at night to stay awake.
Chillerman, why should this book not be something for you. After what I've read from you..Certainly it is something for you. I will search once if I can't find it in a pdf version. I also have other ebooks regarding Thermodynamics.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
Peter_1
Hey Chillerman, very nice job you did. I just asked in the Mod sextion - sextion, type error but a good one - how we can print a whole thread spread over several pages. You filtered out the chit-chat which is needed in such a conversations, especially at night to stay awake.
Chillerman, why should this book not be something for you. After what I've read from you..Certainly it is something for you. I will search once if I can't find it in a pdf version. I also have other ebooks regarding Thermodynamics.
That's good, Thanks Peter
I have just noticed I have missed an important contribution from 'Tayters', will have to add it
Thankyou for the vote of confidence with the book, that encourage's me even more,
R's chillerman
sextion;)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
simon@parker
have just had the penny drop big style yr basically squirting higher pressure vapour at the compressor causing a sucking vacume effect to increase the velocity of the gas leaving the evap so causing less work done by comp bloody genius :) and the part yr gonna fit is like you say very basic wow think u just re invented the wheel
Well done, now get your think cap on.
Rememeber that the high pressure vapour, would be classed as intermidiate pressure vapour, so not to confuse it with the normal discharge pressure.
The intermediate vapour is that would just normally be wasted in standard refrigeration system. So the smarts is the combination of more than one principle and the simplistic nature of the device if we can resolve both the theorectical, then the practical issus.
On very large systems it could be more complex to achieve optiumum across the whole working range. (modulating everything)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
desA
As I read & re-read through this very interesting thread, I keep wondering about a few niggles going on in my engineering 'gut':
1. The ejector/motive device will be governed my a momentum interchange between the two fluids.
2. Momentum = mass*velocity = density*volume flowrate*velocity
3. Could the pressure drop in the motive device cause back pressure into the separation tank?
4. Would the liquid flash into the separation tank?
5. A niggly feeling of system feedback driven backwards from the motive device into the liquid circuit.
6. Expectation of some level of system 'bouncing'.
Niggles - can't quite put my finger on them. Will try to set up some simulations to play with gas/liquid dynamics.
Now we are thinking.
Firstly we have to consider that end results is time based, and built up over time.
You have covered this by stating that the system in its self could be a negative feedback system. (when we first start, mass flow is very low, does it continue to fall or will it rise, and then where is equalibrium reached.)
The main question (ignore the system as a whole for a while) is what would be the pressure/temperature of the two combine vapour streams? ( evap outlet and the intermediate vessel vapour outlet) (the vapour that would enter the normal compressor is the combination), or i should say best possible result.
At this stage I would have to presume (wrightly or wrongly) that the streams properties are at saturation.
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Re: Carters Widget Revealed!
have noticed in the time i have been doin refrigeration that the theory never quite matches practical because the system always in constant modulation it comes down to gut feeling and engineers judgement that is why it is considered black magic when we get it right :)
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Re: Carters Widget Revealed!
Gents
If I miss something that needs posting on the facts page, please give me a nudge
With the - #number
Trying to keep up & hopefully not missed nothing else yet
R's chillerman (or MF's - Receptionist !) ;) (without the skirt)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
simon@parker
have noticed in the time i have been doin refrigeration that the theory never quite matches practical because the system always in constant modulation it comes down to gut feeling and engineers judgement that is why it is considered black magic when we get it right :)
I do have I saying "the best design engineer is a serviceman, and the best serviceman is a design engineer"
What i am saying here is that even though we are in the same field , each has their own set of skills and when combined make for an excellent combination.
If you can understand why the theory, never quite matches, then it will feel less like black magic. I hope you are learning from thread (widget or no widget)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
Gents
If I miss something that needs posting on the facts page, please give me a nudge
With the - #number
Trying to keep up & hopefully not missed nothing else yet
R's chillerman (or MF's - Receptionist !) ;) (without the skirt)
You told me you had a skirt and lovely legs, uhhhhhh
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
You told me you had a skirt and lovely legs, uhhhhhh
Hollow sparrow legs ! deffo no skirt !
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
I do have I saying "the best design engineer is a serviceman, and the best serviceman is a design engineer"
What i am saying here is that even though we are in the same field , each has their own set of skills and when combined make for an excellent combination.
If you can understand why the theory, never quite matches, then it will feel less like black magic. I hope you are learning from thread (widget or no widget)
lol i meant when i fix something and explain to customer they get this blank look am guessing if it had been in medievil times i would have been burned at the stake :) i suppose i am quite lucky can spend time looking at kit and work out how its supposed to work then go and set it how it will work thats why am thinking way i am bout yr widget still a dam good idea and am no good at the mathes so cant help there am a field guy always will be :)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
simon@parker
lol i meant when i fix something and explain to customer they get this blank look am guessing if it had been in medievil times i would have been burned at the stake :) i suppose i am quite lucky can spend time looking at kit and work out how its supposed to work then go and set it how it will work thats why am thinking way i am bout yr widget still a dam good idea and am no good at the mathes so cant help there am a field guy always will be :)
A bit of advice.
Please do not undersell yourself!
you are already on the way to being a design engineer, just by showing interest and giving your thoughts.
If you have not be taught the nicities of the industry, then how are you expected to know.
Without relealising you more than likely design plenty. have you ever changed a compressor that was not quite the same size of the original (say a bit bigger), youl be thinking lower suction pressures, high cond pressures, well in many cases that is what a design engineer does when selectiong equipment.
All check the posts that seem to have a ding dong about them, this where good information is provided to prove points.
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Re: Carters Widget Revealed!
i start mumbling crap too because normally im checking out boooobies whilst justifying my site visit!haha
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
desA
As I read & re-read through this very interesting thread, I keep wondering about a few niggles going on in my engineering 'gut':
1. The ejector/motive device will be governed my a momentum interchange between the two fluids.
2. Momentum = mass*velocity = density*volume flowrate*velocity
3. Could the pressure drop in the motive device cause back pressure into the separation tank?
4. Would the liquid flash into the separation tank?
5. A niggly feeling of system feedback driven backwards from the motive device into the liquid circuit.
6. Expectation of some level of system 'bouncing'.
Niggles - can't quite put my finger on them. Will try to set up some simulations to play with gas/liquid dynamics.
(Time to read for a minute)
Hi DesA/Mad Fridgie
3. could a NRV be used in the line to prevent feedback ???
my first thought would be resistance/flow ???
But if thats the case - larger pipework to NRV + larger NRV - would this then balance out ???
R's chillerman
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
desA
As I read & re-read through this very interesting thread, I keep wondering about a few niggles going on in my engineering 'gut':
1. The ejector/motive device will be governed my a momentum interchange between the two fluids.
2. Momentum = mass*velocity = density*volume flowrate*velocity
3. Could the pressure drop in the motive device cause back pressure into the separation tank?
4. Would the liquid flash into the separation tank?
5. A niggly feeling of system feedback driven backwards from the motive device into the liquid circuit.
6. Expectation of some level of system 'bouncing'.
Niggles - can't quite put my finger on them. Will try to set up some simulations to play with gas/liquid dynamics.
3. only if the nozzle is to small and chokes (other wise no, unless there is some for of reverse shockwave), this would balance itself out, as the pressure would increase reduce the flash gas and increase thre liquid flow through the evap expansion device (this also comes down how we control the pressure in the vessel, up stream or down stream)
4. the vessel is at reduced pressure than the liquid line (for design purposes) if the liquid is highly sub cooled or a pressure close to that of the vessel the amount of flash gas will reduce, "this would normall indicate the system is running very efficiently anyway, and has been considered in the practical application"
5. Could be a possibilty as at the start the evap would be very starved, give low compressor mass flow, so lo flash gas. (can be resolved easily with a simple widget by-pass)
6. Likely to be abit of instability, can live with this (fairly normal for most refrigeration system, example pressure controlled cycling condensing fans)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
(Time to read for a minute)
Hi DesA/Mad Fridgie
3. could a NRV be used in the line to prevent feedback ???
my first thought would be resistance/flow ???
But if thats the case - larger pipework to NRV + larger NRV - would this then balance out ???
R's chillerman
Not really an issue, if we had a reverse pressure wave, then installation of a simple muffler type device would resolve this issie
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
Not really an issue, if we had a reverse pressure wave, then installation of a simple muffler type device would resolve this issie
I see above, now, if only waited afew minutes more, thanks
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
install monkey
i start mumbling crap too because normally im checking out boooobies whilst justifying my site visit!haha
While i was pointing out a problem on a fridge to a young house wife one day, she bent over, with the low cut top to get a closer look at the situation and my eyes had no-where else to go except down her shirt. made out i had something in my eye:eek:..Mike.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mikeref
While i was pointing out a problem on a fridge to a young house wife one day, she bent over, with the low cut top to get a closer look at the situation and my eyes had no-where else to go except down her shirt. made out i had something in my eye:eek:..Mike.
Its best to open the freezer door and ask them to smell the coldness-and hey presto monkey fingers!!!!haha
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Re: Carters Widget Revealed!
Not one to blow my own trumpet but i built a particle collider in my kitchen using pipe cleaners and squirty washing up bottles!haha
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Re: Carters Widget Revealed!
MF, at a given point, the amount of flash will partially be determined by the surface area and insulation of the "vessel" be it a pipe or a tank and the exterior temp around the vessel and the boundary (surface) area between liquid/gas. If the the vessel is long and thin like a low loss header there will be more surface area but less liquid/gas boundary area.
Will this aid in producing a higher quality gas? I assume the above factors will help to determine the quantity of usable flash gas to be injected. What it seems to me is we are looking at a steam boiler (sort of)
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Re: Carters Widget Revealed!
Fellows, i try very hard to keep the boooobies/legs etc out of my working life. In this way I am an abject failure. only problem is i seem to work for a lot of lesbians. DUUHHH
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Re: Carters Widget Revealed!
Should i have put #184 in the other post?
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
MikeHolm
MF, at a given point, the amount of flash will partially be determined by the surface area and insulation of the "vessel" be it a pipe or a tank and the exterior temp around the vessel and the boundary (surface) area between liquid/gas. If the the vessel is long and thin like a low loss header there will be more surface area but less liquid/gas boundary area.
Will this aid in producing a higher quality gas? I assume the above factors will help to determine the quantity of usable flash gas to be injected. What it seems to me is we are looking at a steam boiler (sort of)
You are correct this have to be considered in the vessel design.
First we have to seperate the liquid and vapour , so first we have slow down the exit velocity leaving expansion device (squirt effect), (could be baffle or gause, or can use it to aid seperation centrifugal force) then we have to ensure the internal velocity is low enough the gravity will actually allow the liquid to drop out, and suspose the height also becomes important to give enough time for it to happen.
the actual boundry layer between the mass of liquid and vapour is always being broken due to the falling droplets. as vapour and liquid at saturation no energy exchange occurs, but you may get a reverse action to the drops failing "splash back"
Now in heat ingress to the vessel, if in the example the vessell was not insulated, the we would likely be superheating the vapour prior to the exit, and adding a slight amount of energy in the liquid causing slightly more flash gas to drive the TVR.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
MikeHolm
Should i have put #184 in the other post?
yes, but my secartary will sort it. lol (the one with the legs)
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Re: Carters Widget Revealed!
So far, the simulations are showing up a few interesting leads to pursue (the ejector pull/momentum dynamics haven't yet been modeled):
1. The AEV seems to be required to generate a flash, otherwise the vessel stays as liquid only, with no vapour feed stream to the ejector.
1A. Practically some flash could be caused by small pipe changes/blockages as well.
2. If the liquid line is split (remains as liquid) - one part to TXV/evap, then the other part flashing on its way to the ejector - could create a sizable vapour speed/momentum to the ejector.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
desA
So far, the simulations are showing up a few interesting leads to pursue (the ejector pull/momentum dynamics haven't yet been modeled):
1. The AEV seems to be required to generate a flash, otherwise the vessel stays as liquid only, with no vapour feed stream to the ejector.
1A. Practically some flash could be caused by small pipe changes/blockages as well.
2. If the liquid line is split (remains as liquid) - one part to TXV/evap, then the other part flashing on its way to the ejector - could create a sizable vapour speed/momentum to the ejector.
1 yes AEV or similar is always required.
2 Unless you change the conditions of the liquid entering the TEV at the evap all you a have done is reduce the mass flow to the evap, reducing net cooling, then on the other side, will the expanding liquid, pulling in the evap vapour, lift the suction pressure to the compressor enough to increase the compressor mass first to equal the original short fall and secondary to increase the mass flow to make it a increase the net cooling over a standard so that the system becomes commercially viable. (it is somehat similar to know what will be the outlet pressure and temperature of the TVR/ejector orcompressor inlet
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
You are correct this have to be considered in the vessel design.
First we have to seperate the liquid and vapour , so first we have slow down the exit velocity leaving expansion device (squirt effect), (could be baffle or gause, or can use it to aid seperation centrifugal force) then we have to ensure the internal velocity is low enough the gravity will actually allow the liquid to drop out, and suspose the height also becomes important to give enough time for it to happen.
the actual boundry layer between the mass of liquid and vapour is always being broken due to the falling droplets. as vapour and liquid at saturation no energy exchange occurs, but you may get a reverse action to the drops failing "splash back"
Now in heat ingress to the vessel, if in the example the vessell was not insulated, the we would likely be superheating the vapour prior to the exit, and adding a slight amount of energy in the liquid causing slightly more flash gas to drive the TVR.
I was under the assumption that the vessel was between the condenser and the TXV. If not, won't there be a lot more flash (due to lower pressure) in the vessel then desired. In other words, work that can be done in the evap is being re-routed to the TVR.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
MikeHolm
I was under the assumption that the vessel was between the condenser and the TXV. If not, won't there be a lot more flash (due to lower pressure) in the vessel then desired. In other words, work that can be done in the evap is being re-routed to the TVR.
The flash gas does not do any work in the evap (energy) (very start of the thread).
The vessel is at sn intermediate pressure, and is between cond and TXV
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
yes, but my secartary will sort it. lol (the one with the legs)
Only just see this, I'll do it as soon as I finish your coffee & get back with your bacon butties ! Boss
Gents if I missed pasteing a post that you's want moving over to the facts or something that needs moving of the facts please give me a nudge #1 facts is now massive so time to start #3
If You Have an Hour or so to spare it really reads well, so well I think its time to place your cv's up there as well as this could be a carsberg team ! Keep it coming !
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Re: Carters Widget Revealed!
ive reviewed the concept the design spec ,the fundmentals also the logic and expected outputs and cost savings and i have a query over the widget.-what colour is it???
i hope i posted this on the right thread or ill have ur administrator removing this haha
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
install monkey
ive reviewed the concept the design spec ,the fundmentals also the logic and expected outputs and cost savings and i have a query over the widget.-what colour is it???
i hope i posted this on the right thread or ill have ur administrator removing this haha
Haha I'll ask the boss when he gets back if he has navy blue with pink spots as we know you like to be different !
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
Haha I'll ask the boss when he gets back if he has navy blue with pink spots as we know you like to be different !
i asked if i could buy a beta version to tinker with-mf has lost a sale! have u got one in ur filing cabinet?
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
install monkey
ive reviewed the concept the design spec ,the fundmentals also the logic and expected outputs and cost savings and i have a query over the widget.-what colour is it???
i hope i posted this on the right thread or ill have ur administrator removing this haha
well if we are now talking colours i want stealth black please with a silver go faster stripe :) lol
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
simon@parker
well if we are now talking colours i want stealth black please with a silver go faster stripe :) lol
which way do you want the stripe??
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mikeref
While i was pointing out a problem on a young house wife one day, she bent over, with the low cut top to get a closer look at the situation and my eyes hands no-where else to go except down her skirt. made out i had something in my pocket:eek:..Mike.
Evening Mike,
What was the problem with this house wife & what did you find in her skirt ? ;)
And what was in your pocket Mate ? :D
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Re: Carters Widget Revealed!
I thought red was the go faster colour