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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
We are just about here.
Do you know what, a venturi, jet compressor, ejector or condell mover is?
basically a device that has a motive force (a high(er) pressure feed), a suction port (lowest pressure) and an outlet pressure (which is the sum of the motive and suction mass streams) medium pressure
I know how a ram air jet compressor works,
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Re: Carters Widget Revealed!
The vapour from the vessel becomes the motive force (highest pressure)
The vapour exiting the evaporator enters the suction port (lowest pressure)
The combined flow leave the devices and enters the compressor.(medium pressure)
effectivly we have a 2 stage compression system.
The suction of the compressor would be higher than if it came just from the suction.
The compressor mass flow would increase (higher inlet pressure)
So the total system mass flow would increase, including increased liquid mass flow through the evaporator.
Carter Widget (simplified)
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Re: Carters Widget Revealed!
O.k. Stay of execution for now. Saturated vapour but not to the point of liquid to compressor. Has to be higher pressure than evap. outlet so it can be throttled down. Seperate line supplied to compressor?
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mikeref
O.k. Stay of execution for now. Saturated vapour but not to the point of liquid to compressor. Has to be higher pressure than evap. outlet so it can be throttled down. Seperate line supplied to compressor?
No it goes through a device like a "venturi" for ease of desription and mixes together.
Ok another way of looking at.
You have 2 closed buckets, each has the same refrigerant in it, but at 2 completly different pressures/temperatures (saturation) High and Low. If there was a pipe between the 2 buckets and valve. If we opened the valve what would happen to the pressures inside the 2 buckets?
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Re: Carters Widget Revealed!
So (if I am understanding this correctl) the mass flow is increased to the widget by removing the vapour (same as push/pull recovery of a system)
The increase in mass increases the compressors mass flow rate
Which in turn increases system mass flow rate
????????
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Re: Carters Widget Revealed!
Have to equalise, high to low and initially the higher pressure bucket would turn cooler till equalisation established.
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Re: Carters Widget Revealed!
Damn, C.m. are you connected to IBM, or on speed?
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
So (if I am understanding this correctl) the mass flow is increased to the widget by removing the vapour (same as push/pull recovery of a system)
The increase in mass increases the compressors mass flow rate
Which in turn increases system mass flow rate
????????
Yes basically, but it is a "non steady state" system to start (it does not happen instantly) until it reaches equalibrium, and is a circular calculation (no start or end), which does make hard to understand.
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Re: Carters Widget Revealed!
Try this very basic device.
A piece of 7/8 pipe 6' long, stick your oxy/act tip in on end (middlish if possible) leave this end still open to the air, turn on oxygen (really you should use nitrogen to be safe) but it is the tip that is important. (motive force)
What you should see is that air is pulled into the pipe at one end (suction) and quite alot flow coming out of the other end. ( alot more flow that just the oxygen flowing from the tip)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mikeref
Damn, C.m. are you connected to IBM, or on speed?
Mozilla 6, sssssshhhhhh, im trying to learn
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
MikeHolm
Mozilla 6, sssssshhhhhh, im trying to learn
O.K. Zip! mouth closed, eyes glued. ;).
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mikeref
Damn, C.m. are you connected to IBM, or on speed?
Evening Mike
No, Just I have been hanging onto MF's every last word for days now:)
Quote:
Originally Posted by
mad fridgie
Yes basically, but it is a "non steady state" system to start (it does not happen instantly) until it reaches equalibrium, and is a circular calculation (no start or end), which does make hard to understand.
If I am following this part correctly, you need to wait for the system to settle (balance out/equalibrium) to achieve maximum gains in efficiency/flow rates & a constantly changing load(evaporater), de-stabilises the performance of the widget, hence further research & developent is required to fine tune performance. ???
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Re: Carters Widget Revealed!
This is a great suspense novel. Too bad i'm a 32 bit guy in a 64 bit world.
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Re: Carters Widget Revealed!
We used to install one pipe heating systems with a venturi on the return up to the mains pipe. There was a good amount of suction on the branch but the flow rate before the first tee equalled tthat after the second tee (venturi). It was an equalized loop (pressure)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
Evening Mike
No, Just I have been hanging onto MF's every last word for days now:)
If I am following this part correctly, you need to wait for the system to settle (balance out/equalibrium) to achieve maximum gains in efficiency/flow rates & a constantly changing load(evaporater), de-stabilises the performance of the widget, hence further research & developent is required to fine tune performance. ???
I am no specalist in venturi or the like ( i know nothing about them) only possible application. The question then comes down to what would the actual properties be of the outlet of the widget (The inlet to the compressor), When we move away from perfect design (which as we all know happens on every system) what then would be the effects on the system.
there are other possible beneifts as well. (or maybe)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
Try this very basic device.
A piece of 7/8 pipe 6' long, stick your oxy/act tip in on end (middlish if possible) leave this end still open to the air, turn on oxygen (really you should use nitrogen to be safe) but it is the tip that is important. (motive force)
What you should see is that air is pulled into the pipe at one end (suction) and quite alot flow coming out of the other end. ( alot more flow that just the oxygen flowing from the tip)
Similar to how the oil is returned from the evaporator in a flooded phe system, high pressure vapour is driven down a pipe that is connected to the oil pipe and as it flows it pulls the oil into the vapour and the mixed vapour/oil then returns to the compressor/or oil reservoir
???
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Re: Carters Widget Revealed!
Sorry to cut in Terry, go on.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
Similar to how the oil is returned from the evaporator in a flooded phe system, high pressure vapour is driven down a pipe that is connected to the oil pipe and as it flows it pulls the oil into the vapour and the mixed vapour/oil then returns to the compressor/or oil reservoir
???
Basically "yes".
I am the first to know my limitions, and I am at this point now.
I have been talking to a number of true boffins (profs ect) all think is has the potential.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
MikeHolm
Sorry to cut in Terry, go on.
Absolutly no problem mike.
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Re: Carters Widget Revealed!
There must be a flaw in my methodology. Surely others must have looked at this simple system!
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
If I am following this part correctly, you need to wait for the system to settle (balance out/equalibrium) to achieve maximum gains in efficiency/flow rates & a constantly changing load(evaporater), de-stabilises the performance of the widget, hence further research & developent is required to fine tune performance. ???
Quote:
Originally Posted by
mad fridgie
I am no specalist in venturi or the like ( i know nothing about them) only possible application. The question then comes down to what would the actual properties be of the outlet of the widget (The inlet to the compressor), When we move away from perfect design (which as we all know happens on every system) what then would be the effects on the system.
there are other possible beneifts as well. (or maybe)
We need a clear feed of liquid coming from the condensor (at start up & fluctuating load this is not available) ???
If we start pulling vapour before we have this then we can slow the flow rather than increase it ???
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
If I am following this part correctly, you need to wait for the system to settle (balance out/equalibrium) to achieve maximum gains in efficiency/flow rates & a constantly changing load(evaporater), de-stabilises the performance of the widget, hence further research & developent is required to fine tune performance. ???
Quote:
Originally Posted by
mad fridgie
I am no specalist in venturi or the like ( i know nothing about them) only possible application. The question then comes down to what would the actual properties be of the outlet of the widget (The inlet to the compressor), When we move away from perfect design (which as we all know happens on every system) what then would be the effects on the system.
there are other possible beneifts as well. (or maybe)
Quote:
Originally Posted by
chillerman2006
We need a clear feed of liquid coming from the condensor (at start up & fluctuating load this is not available) ???
If we start pulling vapour before we have this then we can slow the flow rather than increase it ???
If correct the widget outlet to the compressor can be electronically controlled ???
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Re: Carters Widget Revealed!
Hi MF.
watching with interest. Industrial techs should pick it straight away, but I won't comment.
After our last meeting, how did things pan out
magoo
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Re: Carters Widget Revealed!
Since we are talking about high quality vapour and using that vapour to drive the venturi, and the suction or branch on the venturi will be at lower pressure, I am failing to see where the supply of vapour will come from to feed that branch (and therefore increase mass flow through the comp) IF you dont have a flash tank somewhere. Am I right is assuming that which will bypass the evap reduces the net refrig effect? I see some bypassing but don't know if the increased efficiency of the comp makes up for the loss in the evap.
Now my head is on the block
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Re: Carters Widget Revealed!
By the time I get one response in you guys are five ahead
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
MikeHolm
Since we are talking about high quality vapour and using that vapour to drive the venturi, and the suction or branch on the venturi will be at lower pressure, I am failing to see where the supply of vapour will come from to feed that branch (and therefore increase mass flow through the comp) IF you dont have a flash tank somewhere. Am I right is assuming that which will bypass the evap reduces the net refrig effect? I see some bypassing but don't know if the increased efficiency of the comp makes up for the loss in the evap.
Now my head is on the block
That is my understanding too, both die together:D there is a fine line
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Re: Carters Widget Revealed!
The idea is that the widget was to be quite simple (hence cheap) but yes could quite easily control with a sol valve and could also be made with proportinal control to keep optomised. (but we but the cart before the horse)
The very basic idea was the vessel was maintained at a constant pressure. (this makes sizeing the evap and expansion device easy) This gives us the oppotunity to allow the head pressure to fall, a lot lower that is presently classed as standard. ( so looking at the very big picture with lower head, we would get less flash gas, so the widget would not work as well, but we still maintain very high efficiency and system equalibrium) All the components could be produced as a single item, so installation would be very very similar to installing a suction accumulator with an internal liquid line heat exchanger. (Maybe with a removable nozzle orifice for different size systems, in a similar way we change the orifice size in an expansion valve)
I have but much thought and energy into this.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
chillerman2006
That is my understanding too, both die together:D there is a fine line
You mean i said something that made sense?? will wonders never cease
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Re: Carters Widget Revealed!
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
MikeHolm
Since we are talking about high quality vapour and using that vapour to drive the venturi, and the suction or branch on the venturi will be at lower pressure, I am failing to see where the supply of vapour will come from to feed that branch (and therefore increase mass flow through the comp) IF you dont have a flash tank somewhere. Am I right is assuming that which will bypass the evap reduces the net refrig effect? I see some bypassing but don't know if the increased efficiency of the comp makes up for the loss in the evap.
Now my head is on the block
You need to read from the start (there is reason behind my madness, in the way i started the thread) Yes there is a flash tank, or I called a vessel.
It is at pressure in the middle between normal evap pressure and cond pressure.
It is positioned in the liquid line between the cond outlet anf the TEV (expansion device) inlet.
The flash gas in the vessel is something that would normally occur just after the expansion valve prior to evap inlet, and has in energy terms very little benefit to the refrigeration system. how ever we do have to pump it around the whole system.
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
Gary
Not quite the same but I would say similar in some ways. thanks gedi master gary! (not seen that one)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
Gary
This does remind me a bit of the Philips ejector system used for DX over feed systems.
(very common on jester jenson plates sysems)
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Re: Carters Widget Revealed!
I understand that it is not desireable to have flash prior to the evap so i can see removing it before the TEV so am I to understand that the amount that would be moved through the device is only that amount that would normally flash prematurely and not try to get more than usual?
again head on chopping block
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Re: Carters Widget Revealed!
MF
I should have been more clear, I was agreeing, (with my limited understanding being) that the compressor has limited duty, and the more we take from the widget, the less can be taken from the evap/suction line ???
And my previous post ( if again I understand) if we start pulling vapour prior to a clear feed of liquid from the condensor, then would vapour be pulled through the condensor preventing/lowering the amount of refrigerant that is condensed ???
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Re: Carters Widget Revealed!
Perhaps a compounded cycle with inter-cooler.
magoo
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
Magoo
Perhaps a compounded cycle with inter-cooler.
magoo
Good Afternoon Magoo,
I have tried googling, no clear description, for the lessor knowledgeable (me) could you explain how it works please
R's chillerman
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Re: Carters Widget Revealed!
Mike first, yes we only take part of what would normally be produced in standard system. And practically has very little use (my first question) but in a normal system still has to be 100% transported around the whole system "energy in"
CM
The vapour leaving the widget (including the ejector) is combined with the flow from the evap. The vapour can only flow if there is sufficient flash gas coming from the condensor liquid, If for example the liquid was very highly sub cooled prior to the widget, then no flash would be produced in the vessel and very little flow would occur through the ejector. (the ejector has avery small hole, need good pressure to flow)
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
Magoo
Perhaps a compounded cycle with inter-cooler.
magoo
Effectively the widget is that (without the inter cooler)
also known as two stage (in one compression chamber, out of this one into a second compression chamber.)
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Re: Carters Widget Revealed!
Hi Chillerman,
the low stage piston/s suck from a low load and discharge into a vessel [ intercooler ] that condenses partiallly, the resultant vapour becomes the suction of the high stage pistons, which discharges to final condenser, the partial liquid formed in intercooler is regengerated to supply low load topped from high stage liquid. [ jet valve area ]
A short cycle description, you have two levels of evaporation and two levels of condensing. easy with screws / piston ratios with recips.
magoo
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Re: Carters Widget Revealed!
Quote:
Originally Posted by
mad fridgie
Mike first, yes we only take part of what would normally be produced in standard system. And practically has very little use (my first question) but in a normal system still has to be 100% transported around the whole system "energy in"
CM
The vapour leaving the widget (including the ejector) is combined with the flow from the evap. The vapour can only flow if there is sufficient flash gas coming from the condensor liquid, If for example the liquid was very highly sub cooled prior to the widget, then no flash would be produced in the vessel and very little flow would occur through the ejector. (the ejector has avery small hole, need good pressure to flow)
My mistake, this is not a design for a unit that employs subcooling, Got it cheers