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Capillary tube size, refrigerant, oil
I would like to discuss capillary tubes in regards to the following technical aspects:
1. Capillary tube size - diameter, length;
2. Refrigerant type;
3. Oil.
The technical aspects that come to mind are as follows (there will be many others):
a. Does each refrigerant have a certain cap tube 'sweet diameter'?
b. Cap tube noise levels;
c. Oil wetting, by refrigerant;
d. When does refrigerant plug-flow occur?
e. What size oil globule forms in each refrigerant (due wetting)?
f. How does the cap tube manage oil?
Basically, let's say, hypothetically, that you have a system that has been originally set up to use R-22 refrigerant. A new system is built, with compressor, filter-drier set up to use R-134a, but using the same diameter cap tube. What could reasonably be expected to happen?
If folks have practical experience in cap tubes, under different refrigerants & oils, I would very much like to hear your experiences.
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
desA
I would like to discuss capillary tubes in regards to the following technical aspects:
1. Capillary tube size - diameter, length;
2. Refrigerant type;
3. Oil.
The technical aspects that come to mind are as follows (there will be many others):
a. Does each refrigerant have a certain cap tube 'sweet diameter'?
b. Cap tube noise levels;
c. Oil wetting, by refrigerant;
d. When does refrigerant plug-flow occur?
e. What size oil globule forms in each refrigerant (due wetting)?
f. How does the cap tube manage oil?
Basically, let's say, hypothetically, that you have a system that has been originally set up to use R-22 refrigerant. A new system is built, with compressor, filter-drier set up to use R-134a, but using the same diameter cap tube. What could reasonably be expected to happen?
If folks have practical experience in cap tubes, under different refrigerants & oils, I would very much like to hear your experiences.
Well from my litle experience the R-22 'likes' the 1.25mm inner diameter.
The R-134A 'likes' the 1.0mm and in small wattage the 0.8mm.
However the capillary tubes dima selection has to do also with the Wattage of the system. Sorry for my poor english but changing the compressor NEEDS to change the capilary as well.
Also the R-22 has a reacher Condenser comparing R-134A , so there are other to consider.
A chip trick is to keep the condenser but change the fan with a smaller one or change the pitch...
Also the R-22 needs fan controllers (pressure switches) in order to work without problems.
R134A can use the old known klixons or as mentioned again depending on the system can have the fan motor constantly work
THe b,c,d I am not sure if have understood well - poor English- Anyway I wil try what I have ubderstood!
The noise has to do also with the quantity of refrigerant and correct setup of cap and system
Answering to your question what will happen...
I repeat I would be more specific If had the exact system.. Is it a refrigerator, a freezer or a A/C??
Also what is the length of current diam?
Actually there is a terrible BRAINSTORMING of what will happen:rolleyes::confused::confused:
Well you see the R134 works nearly the half Lbs of R-22 or even less. The correct HP for temp 10C ~ 12C is to have a 90Lbs ~ 110Lbs HP with the R-134A, BUT i think with the R22 cap the pressure will be lower. So you will think to charge with Refrigerant and will have the opposite results.. Actually will haveincreased the LP... This is one thought.
The 2nd thought if the current R22 cap has big Length (as I mentioned , depend on the system, so if it is a freezer WILL have bigger Length in order to have better evaporation) SO It might have the correct HP but the evaporation would not be correct and would not have the requested results...
Sorry for my LOOOONNNNNGGGGG TEXT...
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Re: Capillary tube size, refrigerant, oil
Ohhh !! Yes NOT forget...
Capillaries need tremendous RESEARCH... There are no books or programs to give you correct answers. Actually will give you a direction NOT the SOLUTION...
So EVERYONE NEEDS to experiment and try hard for the capillarie.
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Re: Capillary tube size, refrigerant, oil
Thanks for your posts 'aabbcc'. Some very interesting observations & thoughts.
Quote:
Well from my litle experience the R-22 'likes' the 1.25mm inner diameter.
The R-134A 'likes' the 1.0mm and in small wattage the 0.8mm.
However the capillary tubes dima selection has to do also with the Wattage of the system. Sorry for my poor english but changing the compressor NEEDS to change the capilary as well.
A good starting point. So you're saying that R-134a typically 'prefers' a smaller diameter cap tube, than R-22, for instance.
Quote:
The noise has to do also with the quantity of refrigerant and correct setup of cap and system
So, quantity of refrigerant & correct cap tube diameter/length.
Quote:
I repeat I would be more specific If had the exact system.. Is it a refrigerator, a freezer or a A/C??
Also what is the length of current diam?
This is an air-to-water heat-pump.
Quote:
Well you see the R134 works nearly the half Lbs of R-22 or even less. The correct HP for temp 10C ~ 12C is to have a 90Lbs ~ 110Lbs HP with the R-134A, BUT i think with the R22 cap the pressure will be lower. So you will think to charge with Refrigerant and will have the opposite results.. Actually will haveincreased the LP... This is one thought.
So, with a system originally designed for R-22, the R-134a equivalent system would require far less refrigerant charge. Interesting observation.
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Re: Capillary tube size, refrigerant, oil
The reason I introduced the R-22/R-134a aspect for the particular machine, is that I suspect that this is how the current machine was developed.
The evap & coil condenser were originally set up for R-22. The compressor was replaced by an R-134a equivalent. The cap tube selection still remains a mystery, but, seems to be close to a 'standard' requirement for the compressor operating at the rated performance of Te,sat=7.2'C, Tc,at=54.4'C , for the inner diameter of 1.3973mm.
The odd thing about this setup, is that, under colder ambient weather conditions, the capillary & evaporator expansion noise seems to increase a great deal. This happens across the charge range, from low, to high.
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Re: Capillary tube size, refrigerant, oil
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
Toosh
Thanks, Toosh - much obliged. I'm reading through it now. :)
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Re: Capillary tube size, refrigerant, oil
A Google search for "capillary tube r134a R22" brings up links to a number of interesting scientific papers, which can be downloaded free-of-charge.
Quite a broad spectrum of interesting information amongst these.
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Re: Capillary tube size, refrigerant, oil
There are adiabatic & diabatic capillary tubes.
A question:
What are the implications of an adiabatic capillary tube, on the way it is, or should be installed?
Remembering that the definition of the term adiabatic is:
Quote:
ad·i·a·bat·ic [àddee ə báttik, àydee ə báttik, ày dī ə báttik]
adjective
without change in heat: describes a thermodynamic process that happens without loss or gain of heat
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
desA
There are adiabatic & diabatic capillary tubes.
A question:
What are the implications of an adiabatic capillary tube, on the way it is, or should be installed?
Remembering that the definition of the term adiabatic is:
I would assume that a cap tube is adiabatic unless soldered to the suction line.
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
Gary
I would assume that a cap tube is adiabatic unless soldered to the suction line.
The diabatic one seems to be the cap tube soldered onto the suction line, according to the article Toosh refered to.
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Re: Capillary tube size, refrigerant, oil
As I recall, a cap tube should not exceed 4 feet in length.
If the chosen diameter requires more than 4 foot, then a smaller diameter should be chosen.
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Re: Capillary tube size, refrigerant, oil
http://www.cubigel.com/java/X?cgi=cu...rmaciontecnica
The Cubigel compressor website has some very useful comparative information on various capillary tubes. Some, for R-134a go up to 5.50 m (2mm ID).
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
desA
Hmmm... maybe it was 4 meters... been a while. :)
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Re: Capillary tube size, refrigerant, oil
Quote:
A question:
What are the implications of an
adiabatic capillary tube, on the way it is, or should be installed?
Remembering that the definition of the term adiabatic is:
Quote:
Quote:ad·i·a·bat·ic [àddee ə báttik, àydee ə báttik, ày dī ə báttik]
adjective
without change in heat: describes a thermodynamic process that happens without loss or gain of heat
Progressing the term adiabatic little further. For no loss, or gain of heat, does this imply that an adiabatic capillary tube should be insulated?
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Re: Capillary tube size, refrigerant, oil
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Re: Capillary tube size, refrigerant, oil
Well I was trying to find this thread as I am new to this forum and lack of Positioning (LOL).
Well I have carefully read all the above and also the very interesting sites the pther memebrs posted about the formulas and cap diameters.
Well before 2 years I did set up a system with 5.5Hp compressor LOW and been able to set uo 14 pieces capillary tubes into one evaporator refrigerant R404A, which is really busting ba**s.
I can say I have read all the thermodynamics (even some times is Korean language LOL) Well anyway I can say from my little experience the formulas and adiabatics CAN ONLY give you a very small indication of what will the system needs.
Concerning the minimum of 4ft of length I disagree as there many set ups from domestic refrigerators to industrial refrigerators with more than 3.5meters or even 5meters of capillary...
Concerning the noise during cols days, well you should use a pressostat switch so it could stop the fan motors to turn when the LP is less 32Lbrs and start again at 42 ~ 45 Lbrs.... So in R22 the fluid would expand and would not have the noise and the same time more efficiency of the system...
Now the R134A with 5.5metres LENGTH and 1.3mm I can say with sure it is not a winner.
Let;s make it a little bit more difficult..
Well I would use a 1.mm cap size and about 3meters of length... But the capilarries would be 2 pieces...
Then you will have better boiling of fluid and enough quantity for the evaporator...
Cappilaries must be of the same size 2x3mmxΦ1.0mm
And lastly something that will help you...
Increasing Length of capilary = decreasing evaporation Temp and of course decreasing the LP.
Decreasing Length of Capilary = increasing the evaporation Temp and of course increasing the LP..
As the increasing and decreasing of the LP, there are many parameters you could twist, change or upgrade as the capilary will perform differently from 10C ~ 40C...
When working wih capilary MUST increase or decreas 10cm maximum of the length in each attempt to make the system to balance.
The MAIN TARGET is to have BALANCE in all the ambient Temperatures... It can be done and this is the magic of the capilary...;)
Just my 2cents.
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Re: Capillary tube size, refrigerant, oil
How can someone correct his post?
Well due my worp speed typing (LOL) please consider the following ammendment (LOL)
Capilaries 2pcs x 3meterLength x Φ1.0mm.
Also the pressostat I mentioned for the R22 should be installed in the High Pressure. But you should be interested for thr Low Pressure.
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
aabbcc
How can someone correct his post?
Well due my worp speed typing (LOL) please consider the following ammendment (LOL)
Capilaries 2pcs x 3meterLength x Φ1.0mm.
Also the pressostat I mentioned for the R22 should be installed in the High Pressure. But you should be interested for thr Low Pressure.
Hi aabbcc, there is an edit button when you make a post just click it and your post will come back
Toosh
ps welcome to the form
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
Toosh
That's a great find, Toosh - much obliged. :)
Take a look at the rest of the articles on that link - may be a few more useful articles there.
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
desA
That's a great find, Toosh - much obliged. :)
Take a look at the rest of the articles on that link - may be a few more useful articles there.
Hi Des, here is a good experiment
http://spectrum.library.concordia.ca/194/1/NQ25924.pdf
Toosh
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
Toosh
Another great find. Keep them coming. :D
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
aabbcc
Well before 2 years I did set up a system with 5.5Hp compressor LOW and been able to set uo 14 pieces capillary tubes into one evaporator refrigerant R404A, which is really busting ba**s.
Wow. That must have been something to try & balance.
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I can say I have read all the thermodynamics (even some times is Korean language LOL) Well anyway I can say from my little experience the formulas and adiabatics CAN ONLY give you a very small indication of what will the system needs.
Fair comment.
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Concerning the minimum of 4ft of length I disagree as there many set ups from domestic refrigerators to industrial refrigerators with more than 3.5meters or even 5meters of capillary...
True. There are some at Cubigel, for R-134a, at 5.5m.
Quote:
Concerning the noise during cols days, well you should use a pressostat switch so it could stop the fan motors to turn when the LP is less 32Lbrs and start again at 42 ~ 45 Lbrs.... So in R22 the fluid would expand and would not have the noise and the same time more efficiency of the system...
Interesting idea. If you turn off the evaporator fan, surely Te,sat will continue to drop lower? Perhaps stop at a certain value & then re-start if the system pulls down too low?
I've seen the evap fan turned off on a european specification heat-pump operating at low temperatures. Interesting.
Quote:
Now the R134A with 5.5metres LENGTH and 1.3mm I can say with sure it is not a winner.
Let;s make it a little bit more difficult..
Well I would use a 1.mm cap size and about 3meters of length... But the capilarries would be 2 pieces...
Then you will have better boiling of fluid and enough quantity for the evaporator...
Cappilaries must be of the same size 2x3mxΦ1.0mm (corrected to suit later post)
This is interesting, indeed. Thanks for this. I have seen a few of these dual-capillary systems for R-134a fridges & even R-22 airconditioning systems.
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And lastly something that will help you...
Increasing Length of capilary = decreasing evaporation Temp and of course decreasing the LP.
Decreasing Length of Capilary = increasing the evaporation Temp and of course increasing the LP..
Ok. Good points to remember. Thank you.
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As the increasing and decreasing of the LP, there are many parameters you could twist, change or upgrade as the capilary will perform differently from 10C ~ 40C...
When working wih capilary MUST increase or decreas 10cm maximum of the length in each attempt to make the system to balance.
The MAIN TARGET is to have BALANCE in all the ambient Temperatures... It can be done and this is the magic of the capilary...;)
Just my 2cents.
Some excellent tips. Thanks you 'aabbcc'. :)
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Re: Capillary tube size, refrigerant, oil
Would it be possible to run two capillaries of different dimensions, to stage the flow across a wider range?
Say for instance, dia 1mm x 3m + dia 1.5mm x 5m?
Has any work been done on stretching the operating range in this way?
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
desA
Would it be possible to run two capillaries of different dimensions, to stage the flow across a wider range?
Say for instance, dia 1mm x 3m + dia 1.5mm x 5m?
Has any work been done on stretching the operating range in this way?
Well This will not work. Capillaries MUST be ALWAYS same diameter and Length...
Of course in case we need to have a perfectly balanced system and not just to have it work anyhow. I have tried this but never been able to adjust and set up a correct 'behaviour'...
Well I am trying to find a way to upload a photo with the evap of 14cap's
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2 Attachment(s)
Re: Capillary tube size, refrigerant, oil
Here is the evaporator with 14Capillary ...
Well It is a nightmare.
Now I am on a work with more cap's and then there is a project with some more and then........ (nightmare)
:rolleyes::rolleyes::confused::confused::confused:
Also a pressure switch for HP . You can find in the market...
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Re: Capillary tube size, refrigerant, oil
Oopss! I made them too small.
Wel I still CANNOT find the edit button.. As said am newbie here and cannot positioning yet...
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Re: Capillary tube size, refrigerant, oil
Still cannot find the EDIT as Toosh advised (thanks) . Maybe it is not allowed to newbies to edit their posts?
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Re: Capillary tube size, refrigerant, oil
^ That is quite a remarkable picture. :D
Can I ask why you are using so many capillaries, & not a TXV?
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
desA
^ That is quite a remarkable picture. :D
Can I ask why you are using so many capillaries, & not a TXV?
Because of the :
Efficiency
Cost
Efficiency Again - No Valve can match the cappilary in efficiency.
Rapid balance of the system
No malfunctions , No orifice
Well many more ...
And because I have tried the TXV's without having the same results.
But results for each one of us different ... So for me the capillary is the one. :D:D
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Re: Capillary tube size, refrigerant, oil
Well let's say you have a system that defrost's many times per hour.
So the buol of the Valve would be heated as well and would retain the valve close - Correct?
So until the system regains its 'position' the bulp will remain close. This might be from 2minutes up to 10minutes from working condition to working condition.
With the capillary you just switch ON. The system immediately sprays fluid in the evaporator and the 2minutes is a GAIN...
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Re: Capillary tube size, refrigerant, oil
I have just red you other thread with the capilary tube system and the really very interesting analysis you all guys made...
But really for science it is nice to experiment and 'play' . In the real orld unfortunatelly NO PROGRAM or CALCULATION is enough to direct you in the correct diameter and length.
Eventhough there are other parameters to twist or upgrade to a cap system in order to put it down the RIGHT WAY (LOL)
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
aabbcc
Because of the :
Efficiency
Cost
Efficiency Again - No Valve can match the cappilary in efficiency.
Rapid balance of the system
No malfunctions , No orifice
Well many more ...
Very interesting.
I'm finding the capillary to be very challenging. For small power systems, it's difficult to get a TXV anyway - they are also expensive. It is going to be worth the time & effort to get to understand these fascinating parts of our toolbox.
How do you see the cap tube working for a heat-pump, with the large spread in Tc,sat from cold to hot condition?
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
aabbcc
Eventhough there are other parameters to twist or upgrade to a cap system in order to put it down the RIGHT WAY (LOL)
Hahaha... I guess I know what you are getting at... :D
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
desA
Very interesting.
I'm finding the capillary to be very challenging. For small power systems, it's difficult to get a TXV anyway - they are also expensive. It is going to be worth the time & effort to get to understand these fascinating parts of our toolbox.
How do you see the cap tube working for a heat-pump, with the large spread in Tc,sat from cold to hot condition?
I have never tried to work capilary on a heat pump.
However my opinion is the target with the Cap is to make the LOW PRESSURE decreases as possible even in 40C work conditions. As mentioned before the Tcsaturation and/or superheats, subcooling and all the book of thermodynamics can be manipulated else way. As mentioned in previous posts for R22 and R404A this can be done with Presure switches to control the fan. Also the use of more capilaries instead of one, the quantity of refrigerant, a receiver , fan rpm, fan pitch, Diam of fan, condensing unit and many more...
What I am thinking now is that the Cap on a heat pump might and should work different since the system advantages from the HOT PLATE - not the cold.
So the more HP in the Hot plate (that in standard systems is the cold plate) the more of the benefit...
So we are talking for a smaller condenser and bigger in length capillary... Then wll need some more fluid in it, but will change the thermodynamics once more...
So you need a small receiver in order to store the excess of the refrigerant fluid.. Receiver can be a small filter of let say 60gram as the excess of refrigerant should only be a +25gr ~ 50gr.
I refer ,as have in mind an older htread of yours, to the system have in your lab and the rest of the members gave a fantastic analysis and manipulation of DANFOSS programs...
The noise you were listening it is because the system needed those 25~50 grams... BUT in a warmer weather you would have a problem... BUT WHO CARES as in warm weather the HEAT PUMP will be out of work...:D
Again sorry for my LONG TEXT..
I have tried NOT to enter in any formulas or calculation because I would make it with my Greek letter formulas and then we would LOST TO TRANSLATION and more important BECAUSE I STRONGLY believ that formulas CANNOT PREDICT CAPILLARIES...:eek::eek:
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Re: Capillary tube size, refrigerant, oil
Concerning the receiver . You need to make it by your own. You can cut a 3/8 dryer filter and take everything out. Then put the inlet pipe and the outlet pipe - the one will return to suction should be long and suck only gas not liguid... It is common to have liguid returns with a cap system...So you do need a long outlet pipe in the receiver.(sorry for my English Again I think you get the message).
Why the companies DO NOT DO this..
Well is all about the cost and of course they rush to put the product in the market...
For a small heat pump of 11000BTU or 14000BTU (I gues those are the number of what you have in your lab)
the less parts the better. Adn of course you will need to change it after a while...
Research with capillary is never enough and there is the fascination..
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
aabbcc
Well let's say you have a system that defrost's many times per hour.
So the buol of the Valve would be heated as well and would retain the valve close - Correct?
So until the system regains its 'position' the bulp will remain close. This might be from 2minutes up to 10minutes from working condition to working condition.
With the capillary you just switch ON. The system immediately sprays fluid in the evaporator and the 2minutes is a GAIN...
TEV will be open not closed.
A cap has its place, and indeed can equal a valve at a fixed point, "Optimum", but there are very few systems where all process variables are constant, thus keeping the system at optimum.
Practically a valve does allow for inperfection in design, as a cap needs to be right. For one off applications, the time spent optimising the cap, (cost) will be greater than the value of the valve installation.
I agree that present software is an aid to cap selection, no a fixed solution.
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
aabbcc
I have never tried to work capilary on a heat pump.
However my opinion is the target with the Cap is to make the LOW PRESSURE decreases as possible even in 40C work conditions.
With a heat-pump, there is advantage in allowing the LP rise in a controlled way. If the LP s dropped, then compressor pressure-ratio will be stretched, resulting in high compressor discharge temperatures. There is a limit as to how high the discharge temp should be allowed to climb.
Quote:
As mentioned before the Tcsaturation and/or superheats, subcooling and all the book of thermodynamics can be manipulated else way. As mentioned in previous posts for R22 and R404A this can be done with Presure switches to control the fan.
For a heat pump, the equivalent of your LP manipulation techniques, would be at HP - by adjusting condenser performance eg. speed up water flow.
Quote:
Also the use of more capilaries instead of one, the quantity of refrigerant, a receiver , fan rpm, fan pitch, Diam of fan, condensing unit and many more...
Can you perhaps tell us more on your ideas here?
Quote:
What I am thinking now is that the Cap on a heat pump might and should work different since the system advantages from the HOT PLATE - not the cold.
So the more HP in the Hot plate (that in standard systems is the cold plate) the more of the benefit... So we are talking for a smaller condenser and bigger in length capillary...
Yes, the HP side needs to be worked with - but, don't raise the Tc,sat, as this will lower system COP. The condenser heat-transfer efficiency needs to be adjusted.
Quote:
Then wll need some more fluid in it, but will change the thermodynamics once more...
I'm interested in this comment & why you need more fluid. Is this because of increased cap tube length?
Quote:
So you need a small receiver in order to store the excess of the refrigerant fluid.. Receiver can be a small filter of let say 60gram as the excess of refrigerant should only be a +25gr ~ 50gr.
I refer ,as have in mind an older htread of yours, to the system have in your lab and the rest of the members gave a fantastic analysis and manipulation of DANFOSS programs...
The lab system has an inline filter-drier, as well as a small suction strainer, before the cap tube.
Quote:
The noise you were listening it is because the system needed those 25~50 grams... BUT in a warmer weather you would have a problem...
So, you feel that the noise was because the system was short of refrigerant? Can you perhaps explain this further?
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
aabbcc
Concerning the receiver . You need to make it by your own. You can cut a 3/8 dryer filter and take everything out. Then put the inlet pipe and the outlet pipe - the one will return to suction should be long and suck only gas not liguid... It is common to have liguid returns with a cap system...So you do need a long outlet pipe in the receiver.(sorry for my English Again I think you get the message).
It would be great if you could sketch this & attach the picture. (Upload your pic to www.tinypic.com, then link it in your RE post).
Quote:
Why the companies DO NOT DO this..
Well is all about the cost and of course they rush to put the product in the market...
For a small heat pump of 11000BTU or 14000BTU (I gues those are the number of what you have in your lab)
the less parts the better. Adn of course you will need to change it after a while...
Very true. Manufacturers seem to cut costs everywhere - sometimes in the wrong places, unfortunately.
Quote:
Research with capillary is never enough and there is the fascination..
Thanks so much for your input - it is very useful & interesting. :D
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Re: Capillary tube size, refrigerant, oil
Quote:
Originally Posted by
mad fridgie
TEV will be open not closed.
As I've read, it will be closed on system start, until sufficient SH has been reached, after which it will open.
Quote:
A cap has its place, and indeed can equal a valve at a fixed point, "Optimum", but there are very few systems where all process variables are constant, thus keeping the system at optimum.
Now, this is something the industry seems to have fixed in our heads regarding a cap tube. Is this actually true, though?
In other words, what process variables, or grouping of variables, needs to remain fixed, in order for a cap tube to work over a wider operating range? If both Te & Pc slide together, is there a group that remains relativley constant? Perhaps it is time we re-think a little more about cap tubes?
Quote:
Practically a valve does allow for inperfection in design, as a cap needs to be right. For one off applications, the time spent optimising the cap, (cost) will be greater than the value of the valve installation.
I agree that present software is an aid to cap selection, no a fixed solution.
Does the cap tube actually need to be 'perfect'? Perfect at what point in a system? Could a target point in the system be selected & used for nominal cap tube sizing? Does it really need all the laborious cut-&-try efforts we hear about in the received logic?