Massive Water Chiller

[Stewie007]

I lined the top of the shroud with insulation tape and the table top as well. Once I clamp down the fans it will provide a nice air seal. I'll have to test to see if insulation will be required on the shroud. It may not be.

I initially tested the system for pressure differential. It didn't work out so well at first. The compressor check valve wasn't allowing for pressure differential to hold. However, after vacuuming, I applied pressure between cycles and two clicks. One was the solenoid valve, and the other must have been the internal compressor valve. The inline check valve clicked separately. I heard it. At that point, I was able to pressurize to 300 PSI on the high side and the low side held at lower pressure. No bleed over!

I protected myself (probably not well) behind a double thick sheet of MDF LOL. I wouldn't recommend it. I had my face shield on though. The nitrogen regulator started leaking at 300, so I couldn't go further.

[Stewie007]

That's it so far.

[Buckeye]

Looks good Stew !!

[Stewie007]

Thanks. Its getting close to being done, too! The chiller at least.... the chest is another story.. hehe.

All I have yet to do with the chiller is the water piping, insulation, and then the attachment of the controls and wiring. Hopefully my valve comes in this week and I can finally finish the refrigerant side.

The chest will be built after I finish testing the unit. I have to make certain determinations before I build it based on the type of internal conditions that the unit will exhibit given circulating air temperature and exhaust from the chest. Fun stuff.

[runmc]

Great project Stew!!
Please correct me if I'm wrong and not seeing things correctly, but I don't think your receiver will work laying down.

[Stewie007]

Great project Stew!!
Please correct me if I'm wrong and not seeing things correctly, but I don't think your receiver will work laying down.

Not to worry MC.. Refrigeration Research Model 1947

I bought it specifically for its use as a horizontal receiver. You are seeing correctly.

[Buckeye]

Good to hear Stew.

I had one of those ... oh crap moments after seeing Ron's post

[Stewie007]

The all to familiar record scratching sound echoing in your head? hehehehe

Yeah, while I was designing this thing, I was having difficulty figuring out how to fit certain things in with the way I was designing the system. The vertical receivers weren't going to fit the way I wanted, and I found that gem largely by chance while browsing URI's catalog.

This week while I have time between now and the weekend, I'm going to be designing the chest. I'll post some updates later on that progress and the overall mechanics of the design.

[runmc]

Not to worry MC.. Refrigeration Research Model 1947

I bought it specifically for its use as a horizontal receiver. You are seeing correctly.

hehehe - very good
Live and learn. I didn't know there was such an animal.

[Stewie007]

Tomorrow I'm playing golf, so I did only a little bit today. I ran out of gas, and it figures.... I wanted to at least close up the refrigeration system. Oh well.

Got my coils, although the 10W coil just won't do for the smaller solenoid; need 22W. The 10W coil is the one pictured below. It just fits in there nicely.

I placed the pressure controls to the side of the compressor, and it fits well. The problem is, I can't find a good place to put the rest of the controls. I wanted to contain them in electrical boxes, but I'm not sure they'll fit. I don't really have a proper enclosure, unfortunately. Maybe I'll find one. The pressure controls fit into place, but barely. Its pretty dang close to the filter drier, but far enough away that they won't touch. In the photo, it looks like they're touching, but its just the angle. They aren't.

[Stewie007]

I may wind up redesigning that oil line. I am thinking that I will have to install a riser before the pressure sensor. Looking that over and I may wind up blowing oil into the sensor line.

What I will do is use a tee with the center connection aligned vertically. Flow will be directed through the horizontal axis and the vertical line will be reduced to quarter inch tubing to further minimize migration.

I'm kind of glad that I ran out of gas...

[limpkorn]

Wow,

This is massive! Can't wait to see the final results!

[Stewie007]

Thanks. Before I utilize it, I will be extensively testing the system. I am considering converting the suction line to a flare system in case I have to change out components. I will want to test it extensively to make sure that's necessary.

[Stewie007]

I could post other pictures, but I figured one was enough. I've redesigned the chest to accommodate a different type of intake and exhaust. Instead of the previous design I have a slot on either side of the top. Some of the air inside will be recycled, but these will provide enough for intake and exhaust.

[Stewie007]

Well, I got the refrigerant loop mostly finished. The last touches will be the installation of the gauges, however its pretty much done with respect to piping. (Water lines in progress).

I am unfortunately not able to test the operation of the solenoid valve that controls the oil outlet. The rotor inside the compressor is obviously in a neutral position that doesn't cut off the bleed, because I can't pressurize the high side or low side without getting bleed through. The valve functions properly, and I did not overheat it. So I don't think its the valve that is malfunctioning. I also ensured that I installed it properly; which I did.

The first image is that of the newly designed oil line. It discharges the oil into a "U" return line that follows an elbow toward the suction line instead of previously. This way the oil will follow a more natural path. The tee branch faces up and has a 3/8 to 1/4" bushing that connects the system to the pressure sensor. This will better prevent oil from blowing into the sensor capillary line. The next images show the newly designed return line and pressure sensor connection.

I did some work on the chill reservoir; however I am a bit unhappy with the results given the difficulty of aligning the pump inlet line. I'm a bit mad that it went all eyed and now the reservoir doesn't fit into place as well as I wanted. It fits, but barely. No biggie I guess, I can work around it, but I didn't get any real pics of that. I did find a good location to install the relay box. Its pretty close to the reservoir, but I can water proof that pretty easily. The capacitors are going to be the issue. I don't have a good spot for them as of yet. Pretty soon I'll be wiring the system up.

The last pictures show how its shaping up. So far its looking pretty good. Its heavy though, hehe.... Its going to be a tough one getting it into place. I bet it'll weight 300 lbs all together with the chest. There just isn't a way given the design of the chest to avoid that. That said, I'm going to build the chest out of white pine; a rather light weight and warp resistant wood (unlike yellow pine). It will probably weight about 120-130lbs itself. I know, that's pretty heavy, but most of that weight comes from the base boards and the top. When you start talking about a 60" x ~30" chest, it adds up. The base also adds a big portion of that. Its nothing compared to what it would be if it was oak.. Weight is also estimated based on known density and mass.

[Buckeye]

HAHAHA Stew, 300 lbs !!!!

That is a beast for sure !

[Stewie007]

I bet I'm over-estimating.... but those heat exchangers are heavy for sure... hehe. The water alone will probably be about 60 pounds all together, so it makes up a big chunk of it.

[Xeon th MG Pony]

Rotory vane compressors are not possitive sealing, you will never stop bleed over from them, they use oil film as the final seal mechanism.

I am sure when you fire the system up it will all run exactly as you had designed it to.

[Stewie007]

Well, the problem that presents is that pump down will be unsuccessful.

Do you think that will be a problem?

[Stewie007]

I've done a bit of research. As it turns out, a check valve must be installed on the suction line for pump down cycles...

Should have looked at Tecumseh's library hehehe

[Xeon th MG Pony]

this does indeed tend to help with designing a complex system! any rotory piston compressor will rely on oil for the main seal and only make an effective pump while running and quickly equalize on shut down, hence their prevalence as an air con compressor.

[Stewie007]

Thing is I did a lot of research and discussed it quite a lot. Much of the system tweaking will be left to the testing phase, but some things are just easily missed I guess.

That's pretty much the main reason I try to put everything out there so that others might have an idea of what the problem is. I hadn't even considered a check valve for pump down on the suction side. I'll stop by united and get the second one this week when I get a chance.

[bigmac11]

Great job so far

[n00b 0f l337]

Wait, why do you need a check valve?

[Stewie007]

To stop the bleed through the compressor from causing excessive short cycling. It would trip the low pressure sensor that controls the compressor.