What would it take to build a cryogenic cooler?

[sdumper]

why dont you take a deep breath plan something, buy your parts and then come back here once your ready to build it.

No one wants to follow links nor do your design and homework for you. This is a complex build your planning and its obvious your in way over your head.

[eligray]

why dont you take a deep breath plan something, buy your parts and then come back here once your ready to build it.

No one wants to follow links nor do your design and homework for you. This is a complex build your planning and its obvious your in way over your head.

I want to articulate my agreement with this statement, but he's already blown off identical posts about two dozen times

[quintus]

He is just a kid running around...

[wdrzal]

I didn't look at the patent info for 2 reasons. first something doe NOT have to work to get a patent,just needs to be a unique idea. 2 if it does work it falls under patent laws and you can't copy the design unless the patent is expired.

[Shingoshi]

I didn't look at the patent info for 2 reasons. first something doe NOT have to work to get a patent,just needs to be a unique idea. 2 if it does work it falls under patent laws and you can't copy the design unless the patent is expired.

One of the main benefits of patent studies, is to provide a guide post for the advancement of new work. If what you said here were true, there would be no legal right of one person to cite the work of another (and their patent) as the basis of their own new work. Anyone looking at the background of patents will quickly see that most patents are derivative works, and not in the least bit original, as in something that was never done before. In many cases, the new works represent modifications and subsequent advancements of the older preexisting patents.

And it doesn't make any sense to talk about being barred from doing something which isn't possible. The real point is to examine explore and develop new ideas based on the good ideas of others.

Shingoshi

[Shingoshi]

I'm now awaiting the delivery of two "York p015-03288-004 2 ton Compressor Matsua ptac" purchased from Ebay. These should settle any concerns for me about the ability to hold any load thrown at them. Thanks to a post by [XC] gomeler in another thread, I now have the idea of using both of these units in tandem. I believe they will have all of the necessary ports required for any of the interconnected lubrication issues without modification/alteration. I will then be using the smaller Rechi compressors strictly for subcooling the refrigerant as it leaves the condenser. The combination should be very productive. The Rechis will allow me to subcool the York compressor stream without reducing the performance of the tandem group. Typically, you have to split a portion of the main stream to provide for subcooling. I won't have to do this. The four Rechis will have that task all to themselves.

Shingoshi

EDIT: I guess you can't write Matsu****a, without this forum automatically thinking you've cursed!

[Shingoshi]

And they're twins!
The Towers of York have arrived, Behold!

[IMG=http://img27.imageshack.us/img27/5177/compressortwins.th.jpg] [IMG=http://img27.imageshack.us/img27/9008/compressorlabel.th.jpg] [IMG=http://img11.imageshack.us/img11/5134/compressortwinsvertical.th.jpg]
I finally found the documentation for these units.
[IMG=http://img15.imageshack.us/img15/8163/matsushiacompressortabl.th.jpg]

They are a pair of K-Series Matsushi+a rotary compressors. These units appear to have a lower capacity than what was advertised. I'm not sure if I should file a complaint with Ebay or not? This was only my second time doing business on Ebay, and I don't know how strict they are about advertising correctly about specifications. These compressors have only a 19.6cc/rev displacement. I'm glad I didn't pay anywhere near full price!

Shingoshi

[teyber]

holy those are huge

[Shingoshi]

holy those are huge

I am a bit disappointed though about how much smaller they are than what they were said to be. These aren't two ton units, and that's what I paid for. So if anyone has any input about what I should or could do about this, let me know. Because I think the price should have been lower, or I would have offered less had I know their true size.

They do fit inside the case with it laying flat. But they're less than the 15" height of the case. I was thinking I might have to stand the case on it's side (which would have given me 22" of height) to accommodate them. But the base is too wide (9.5" square) to do that without making some sort of platform to stand them on. I may still do that though. Because having the case mounted on it's side presents opportunities that I won't otherwise have.

Shingoshi

EDIT: Here are some more pics to show the relative size between the larger and smaller compressors.
[IMG=http://img132.imageshack.us/img132/7775/compressortwinsplacemen.th.jpg] [IMG=http://img132.imageshack.us/img132/8569/rechicompressorcapacito.th.jpg]
Funny thing is, I just realized I have the start capacitors for the Rechi compressors. I hadn't opened the rest of their packaging until now!

[Shingoshi]

It may be more relevant here.

As always, click on my images to see the links they point to!

The system you are talking about is a two-stage system. You should know what you are doing if you atempt this. If the "condenser" (really a gas cooler) is to efficiant you wil have liquid out of it. But the good thing about this if you do it right is that you will have a lower spesific volume, and lower gastemperature. That means lower displacement on the sencond stage, and lower power consumption overall. It's a good idea to have a liquid seperator after the gass cooler (middle pressure cooler) to avoid a broken compressor. In industrial cooling this is actually a normal way to do things (mainly because you will have lower gas temp into the condenser, pluss a lower power consumption)

I'm guessing you'd want to use something like this:

So then the question now becomes,
1.) Which refrigerants are pretty much guaranteed not to condense at room temperature? R-744?
2.) Specifically, which refrigerants need very low temperatures to condense? I know that R-14 is a candidate.
3.) Should both compressors be a different size? The first one larger than the second?
4.) Could such a system function with only a single refrigerant? Or would you still need another seeding refrigerant (like R-600a) to work for the subcooler downstream from the second compressor?
5.) Could you have a combination of refrigerants all incapable of condensing at room temperature? (That seems to make sense)
6.) So which refrigerants require an even lower condensing temperature than R-744/CO2?

Shingoshi
EDIT: Sorry for repeating myself. I keep re-editing my text, and I wind up with redundant questions.

EDIT: I always learn so much from these guys!


EDIT: I think this applies to this subject as well:


A very interesting link from YouTube on the phases of R-744.
Triple-Point Analysis of Carbon-Dioxide

[EvoCarlos]

i think you shold post this project on RE i think they will all say wtf for

and i linked you the co2 clip in another thread

oh and is it build yet i just wonderd as its getting cold over here in the uk and thought you may have swiched it on

[Shingoshi]

This was an answer to the questions listed below. But my response will show the direction I'm taking in the planning of this project. So it really needs to be here as well.

1,2)This is kind of andvanced stuff but anyway. You don't look for a refridgerant that does not condense in room temperature. You can do this with every rifridgerant. You just "get rid of" the gas superheating (cooling the gas, so it gets closer to condensing temperature at the spesific pressure).

3) Usually the first compressor (that sucks superheated gas from the evaporator) is close to 3 times larger than the sencond compressor. This is due to the lower spesific volume on the gass after the intercooler.

4) The difference between cascade and traditional two-stage system is that you just have one refridgerant in a two stage system. (The same refridgerant runs through the entire system). In a cascade you can have the same refridgerant, but they run in a independent loop that heat exchange (The 1st. stage is condensing against the 2. stage evaporator).

5) You chose refridgerant based on the pressure and temperature you want the system to have. Things like oil blend capability, and oil types is also a factor. The critical pressure/temp (the maximum pressure that a refridgerant can have in order to condens/evaporate) is a major factor.

6) Nitrogen has an extremely low critical point. (34bar/-147c) But this is not what you want to consentrate on.

Hope this helps!

1+2.) Let's concentrate on R-744 as my baseline for this discussion. I need to look at how much pressure I need to get the condensation point low enough to work with. I need to take the time to convert bar to psi to see what I'm working with here. My main concern is that I don't want too much pressure inside my gas coolers. Specifically because they weren't designed for this (They're actually very large 32"x12"x3" Turbocharger Intercoolers). So I don't want the pressure inside of them to be higher than say 200psi. I want to use my smaller compressors to bump the pressure up from there.

3.) My two compressor sizes are 19.6cc and 7.75cc respectively for the Matsushi+a (York) and Rechi. That's about a 2.5x difference between them.

4.) I have a total of six compressors. Two York and four Rechi. See my link I posted above to see them together. I want to use the two York (Panasonic/Matsu) compressors in tandem/parallel for my first stage. I simply want to use them to provide for the system's volume/load capacity. I then want to divide the four Rechi compressors into two separate tandem/parallel groups. The first tandem group will be used to bump the pressure of the refrigerant up coming from the gas coolers. The second tandem group will be used to subcool the refrigerant leaving the first group, passing the heat back to the outbound refrigerant.

So there will be two completely separate refrigerant loops in the system. The first loop will have the combination of both the York and Rechi compressors. This loop will likely have R-744 as the main refrigerant. The Yorks will be (first-stage) before the gas cooler, and the Rechis will be (second-stage) after the gas cooler. The second independent loop will have only the last two Rechi compressors to provide the subcooling. The subcooling loop will likely have R-600a as the refrigerant. The two loops (main flow and subcooling) will run in counterflow. The inside subcooling Rechi loop is moving refrigerant in the opposite direction against the main incoming refrigerant loop. Instead of the subcooling loop having it's own condenser, it will use a heat-exchanger to cool the subcooling refrigerant with the refrigerant coming from the evaporator of the main loop. This will also be done with the two Rechi compressors in the second stage.

I'll leave 4+5 alone for now.

Thanks for your time!
Shingoshi

[sdumper]

You know whats funny...your going to pull this thing off and were all going to be sitting here eating crow

Good luck and glad your compressors came in. Is 220v going to be a problem for you?

[MeltedDuron]

Check out Nasa. I watched something on Discovery the other day about Hubble and they fitted a cryo cooling unit for one of the cameras. Nitrogen cooler. Admitly it is -270c up there defore any extra cooling on items

[Shingoshi]

You know whats funny...your going to pull this thing off and were all going to be sitting here eating crow

Good luck and glad your compressors came in. Is 220v going to be a problem for you?

I found that out from the maintenance worker here. The electric heaters all use a separate 240V line to operate them. So I shouldn't have a problem with the current.

And I'll try not to gloat too much while everyone here is eating crow. Because the fact is, I'll have to eat some myself. I'll still be making mistakes along the way. So maybe we can just have a big BBQ and eat crow together!

Shingoshi

EDIT: One thing about the gas coolers mentioned above. I think I will be using four of them, all mounted vertically to the bottom of the case, so that their inlets/outlets are at the top. That will effectively prevent any chance of fluid coming back into the second-stage compressors. Here are the pics of these units again, so you can see what I'm talking about.
[IMG=http://img38.imageshack.us/img38/6015/fmic3210031.th.jpg] [IMG=http://img38.imageshack.us/img38/3728/fmic3210036.th.jpg] [IMG=http://img38.imageshack.us/img38/519/fmic3210033.th.jpg] [IMG=http://img38.imageshack.us/img38/9519/fmic32100345.th.jpg] [IMG=http://img38.imageshack.us/img38/226/fmic3210032.th.jpg]
As should be obvious to everyone, I'll have to put endcaps on each of these with concentrically-located nipples mounted for my gas lines. That shouldn't be difficult to do. So I'll either be brazing or heliarc welding them, depending on which metal the endcaps are.

[wdrzal]

That doesn't look like a capacitor but a thermal overload for those rechie's. Capacitors will have a uf or mfd rating.

[runmc]

That doesn't look like a capacitor but a thermal overload for those rechie's. Capacitors will have a uf or mfd rating.

yepp

[Shingoshi]

That doesn't look like a capacitor but a thermal overload for those rechie's. Capacitors will have a uf or mfd rating.

I don't know anything! I just saw something and thought maybe I got the capacitors after all. I know someone else who brought these same compressors had complained about not being able to find the right ones. So when I saw these things, I thought maybe I got lucky. But then, I'm rarely ever lucky!

When the time comes, I'll be asking you guys how or where to install them. They seem like they go on the top of the unit. So the capacitors must mount remotely from the compressors themselves, huh?

Hi guys! I was wondering where you all have been.
Shingoshi

[sdumper]

I don't know anything! I just saw something and thought maybe I got the capacitors after all. I know someone else who brought these same compressors had complained about not being able to find the right ones. So when I saw these things, I thought maybe I got lucky. But then, I'm rarely ever lucky!

When the time comes, I'll be asking you guys how or where to install them. They seem like they go on the top of the unit. So the capacitors must mount remotely from the compressors themselves, huh?

Hi guys! I was wondering where you all have been.
Shingoshi

Run caps are dirt cheap so dont sweat it but yes the one pictured is an overload protector which is more expensive than a start or run cap

Pictures do wonders for getting us to post Honestly, I am fairly busy and dont always have the time to read all of the detail but when I see a picture with a short question then that i can handle

[Shingoshi]

I really want to say Thank You, sdupmer. I actually felt a sense of, they may begin to take me seriously after all. And that felt good. So Thank You!

About the camera issue. When I first started this project, I didn't own a digital camera. I brought one just for this project. The first one I brought about two months ago, died. It simply won't power up no matter what I do. The lens locked in the open position, and gave up the ghost. So I brought another digital camera. Ironically, I got it earlier the same day I got my compressors. And given my experience with the last one, I wasn't sure what to expect with this one. But as can clearly be seen, for the time being anyway, it's working. So I hope I will be able to maintain my earlier promise to have pictures of every stage of this project. And I'll try not to be too excessive, which can be a problem for me (As some may have noticed!).

I guess you can all thank naja002 for kicking me in the pants to get a camera. So I guess I should thank him too!

So I'll need to get two caps for the York compressors, and four for the Rechis. Good to know they're not expensive. So another question I have is whether anyone has ever seen any other major device combined with an oil-trap?

I read in one of the other threads (in this forum) that some one thought the image of the combination accumulator/sub-cooler (I've posted again) would have worked for oil trapping as well. It was just a suggestion. So I'm wondering if such a thing really exists? I'm the kind of guy who likes things that can perform more than one function.

I'm going to need something to provide for the equalization of oil pressure between my compressors for the tandem arrangement to work properly. The Yorks already have quite substantial accumulators mounted on them. The Rechi's accumulators are much smaller. What do these images tell any of you about how I'd have to equalize the oil pressure between the York compressors? I've really not wanted to drill any holes in the compressors, (as has been suggested many times) without knowing what's on the other side. At least with the diagram now I can tell what's where.
[IMG=http://img25.imageshack.us/img25/695/compressordiagram.th.jpg] [IMG=http://img25.imageshack.us/img25/4508/compressoraccumilatorfu.th.jpg] [IMG=http://img25.imageshack.us/img25/9958/compressoraccumilatorbo.th.jpg] [IMG=http://img9.imageshack.us/img9/1166/compressorrechiaccumula.th.jpg]
One thing to keep in mind about all of this. I will need oil traps after each of the three tandem compressor groups. The separate subcooling loop won't be a problem, since it is isolated from the main refrigeration loop. But the main loop presents a bigger problem to deal with. That's because the larger York compressors will be in the same loop as the smaller Rechi compressors. Now it seems intuitive that I should be able to isolate the Yorks from the Rechis by simply having each tandem group return oil from their own trap, back to the same group. If that's correct, please let me know. But, I still need to equalize the pressure in each of the separate tandem groups.

Good thing I got the camera, huh?

Thanks guys!
Shingoshi

[ultralo1]

So another question I have is whether anyone has ever seen any other major device combined with an oil-trap?

Not sure if you are talking about an oil trap or an oil seperator. Oil traps are usually used in long suction piping runs that have a hieght difference between the condesing unit and evap. Oil seps are mounted near/in the condensing units and help prevent oil from leaving the condesing unit.

But yes I have seen these used with eithe. It is a suction accumulator with a subcooler. I think the last one I bought was a sporlan. Sorry I dont remember the mod numbers. The do not work as oil traps. It works the same as any other accumulator.

[Shingoshi]

I didn't realize the difference between the two types of oil handlers (traps and separators) in a system. What I really want to do is remove all the oil from my refrigerant stream BEFORE it enters the condensers. Because the way I will have the condensers mounted on the bottom of my case with their inlets/outlets on top, only gaseous refrigerant would ever be able to leave the condenser and any oil entering it would be trapped. So I have to keep oil from ever getting in the condenser to begin with. With that in mind, I will likely have to use a very good oil separator after the York compressors. And if I really don't feel absolutely confident about using only one separator, then I will use two in series, one behind the other.

But I really want to thank you for clarifying my previous confusion here.

Shingoshi

[ultralo1]

then I will use two in series, one behind the other.

Coalesing filters (temprite 901) work best in parallel

[Shingoshi]

But this was such a detail response, that I felt it deserved the attention of the few who would not know this, but are still following this thread.

I imagine you have made some autocaskade/cascade systems. When you build two-stage systems you have to think a bit different. And R744 (CO2) is really different from the usual refridgerants. I'm sorry but i'm not used to working with psi (i live in europe). R744 has a critical point of 73,6bar (31.1 °C). In other words to make a traditional system with condensing, and subcooling you must have a pressure below 57bar(20°C).

This is how a typical transkritical 2-stage R744 the system is buildt. As you can see the pressure in the middle pressure reciever is quite lower than the gas cooler pressure.




This system solution does not requier external cooling. and will give a good cooling capasity with low mass-flow. And therefor a low compressore displacement. Sub cooling before the evaporator vent is not neseserry in so small builds. You recomand having a suctiongass-heat exchanger on the low pressure compressor. Leting the middle pressure liquid heat exchange with the suction gass from the evaporator. This will superheat the gass before the compressor and subcool the liquid before the evaporator. And then secure your low pressure compressor from "liquid-hammering" (destry the compressor).

EDIT: Usually you have a 2 times larger dispacement on the low pressure compressor i R744 systems.

The valve between the gas cooler and the middle pressure reciever is important if you plan on running transcritical. If you don't have it you'll have a low evaporator performance.

I do not recomend building a sub-critcal system with R744 if you dont heat exchange the condensation with another refridgeration loop (cascade)

A solution for subcritical R744 is something like this:


This is a good way of doing things but requier a lot of automation + oil return systems.

Hope this helps.

This post just begged to be respected for the amount of information relayed.

EDIT: Now that I got my 2nd camera, I really need to get a good drawing program so I can sketch my concepts out for all to see. I realize it is a disadvantage for the rest of you not knowing exactly what I mean when I say something. And it doesn't help any of us for you who are knowledgeable to not be able to give precise answers to my questions. So I'm going to look again for an easy drafting program to learn and use. Suggestions for a good (and free) program to use would be very appreciated!

Shingoshi

[Shingoshi]

All of this criticism about me not taking pictures has led me back into my old first love. First I got one digital camera which failed and forced me to get another one. Now that I've gotten the second camera, I wanted something that could use to record video. So I tried bidding online for a Canon L1, thinking that I would have work done on it as required. I lost that bid and moved onto another. So I tried bidding on a Canon XL1 (which was absurdly foolish) and lost that too!

Ultimately in frustration, I decided to build my own video system. Having years of experience with interchangeable lenses, I didn't want a video system which didn't provide that functionality. So I thought, "what could give me what I want on the cheap without losing an quality in the process. The answer came as a CCTV camera which I purchased. It's a Samsung SSC-131A Digital CCTV camera. My next focus was on my lenses. For that, I chose to use the Leica M39 Thread Mount system. My second line of attack is the old Pentax M42 Universal lenses of old.

I'm telling you all of this for two reasons. One, to let you know why I haven't posted anything in a while. And two, to maybe give some of you the chance to consider alternative approaches to common problems. My goal here was to have a video system to document the progress of my build. Still pictures simply won't cut it here. I need to provide the means for some to actually see how things are put together in a way that provides greater clarity of the subject matter. So I'm posting pictures of what I've accomplished so far in my distraction, and probably won't post anything else here about the camera again. I just hope some of you find this fascinating. It has certainly brought a big smile to my face.

This is basic camera as it was acquired, and the Leica M39::C-mount adapter:
[IMG=http://img21.imageshack.us/img21/7971/samsungscc131adsc00054.th.jpg] [IMG=http://img195.imageshack.us/img195/1066/leitzoutdsc00070.th.jpg]
The camera with it's lens removed, and the new Leica M39 adapter waiting to be attached:
[IMG=http://img195.imageshack.us/img195/2315/leitzoutdsc00071.th.jpg]
The Leica M39 adapter now attached:
[IMG=http://img195.imageshack.us/img195/3656/leitzoutdsc00074.th.jpg]
The back of the camera (Note the BNC::RJ45 connector):
[IMG=http://img21.imageshack.us/img21/5761/samsungscc131adsc00056.th.jpg] [IMG=http://img43.imageshack.us/img43/893/scc131acamerabackdsc001.th.jpg] [IMG=http://img43.imageshack.us/img43/1395/scc131acamerabackdsc001r.th.jpg]
I also have a M42::C-mount adapter. It's shown here with the camera and the Lentar 28mm f/2.8 lens I just got today from Ebay for $26:
[IMG=http://img23.imageshack.us/img23/3914/tmountm39adapterlentard.th.jpg] [IMG=http://img23.imageshack.us/img23/5871/tmountm39adapterlentarde.th.jpg] [IMG=http://img23.imageshack.us/img23/4807/tmountm39adapterlentardc.th.jpg]
The lens I got today almost looks new, with the exception of some wear on the lens mount (like yours) which is never seen while in use. I'm going to post pictures of it for you to see. It's absolutely pretty!
http://img268.imageshack.us/img268/3...terlentard.jpg http://img195.imageshack.us/img195/4...eddsc00122.jpg http://img195.imageshack.us/img195/3...eddsc00123.jpg

I found this link when checking to see what quality I should expect from this lens. There may have been other links for others. But this page really convinced me this lens would be a good bet for my system. So as I have already done on Hin's Tech Corner, I really want to thank him for the affirmation to get this lens! Just look at his pictures to see why!

That's the end of my being off-topic!
At some point though, I will also install an observation camera inside the case as well. Something small with a very wide coverage angle.

Xavian-Anderson Macpherson
ShingoshiDao
[IMG=http://img24.imageshack.us/img24/4359/lentar28mmf28dsc00124.th.jpg]