Propane Propylene blend, glide ?

buffalobillpatrick · 05-15-14, 02:00 PM

Has anyone tried a blend of Propane R290 with Propylene R1270 ? Or Isobutane R600a ?

Would the zeotropic glide work well ?

AC_Hacker · 05-15-14, 02:33 PM

Quote:

Originally Posted by buffalobillpatrick

Has anyone tried a blend of Propane R290 with Propylene R1270 ? Or Isobutane R600a ? Would the zeotropic glide work well ?

Sounds like a very interesting and useful project!

-AC

NiHaoMike · 05-15-14, 03:28 PM

I'm using R433b (sold as ES22a) in my homemade unit, which is 95% R290 and 5% R1270. From my understanding, the R1270 was added to slightly raise pressures so that a R22 TXV would work with no adjustments.

buffalobillpatrick · 05-15-14, 03:57 PM

How much difference does the 5% R1270 seem to make vs. 100% R290?

Is the .2*C glide (Wikipedia) noticeable ?

Also if normal azeotropic boiling points are: R290 = -42.1C & R1270 = -47.6C
It seems like the glide s/b around 5.5C

I read somewhere that a blend of 60% R290 & 40% R600a isobutane gave 2.3 to 4% gain in eff. Vs. R22

NiHaoMike · 05-15-14, 04:11 PM

Hard to tell without pure R290 to compare it to, but the sight glass appears to bubble a little when properly charged. Go by subcooling to determine proper charge. I couldn't find a R433b PT chart, so I just did a weighted average of the R290 and R1270 PT charts in LibreOffice Calc, which was more than accurate enough. (And I even used that to generate the lookup tables so that the DSP can calculate the high and low side pressures from temperature measurements!)

buffalobillpatrick · 05-17-14, 03:49 PM

From Wikipedia:

"Commercially available "propane" fuel, or LPG, is not pure. Typically in the United States and Canada, it is primarily propane (at least 90%), with the rest mostly ethane, propylene, butane, and odorants including ethyl mercaptan.[12][13] This is the HD-5 standard, (Heavy Duty-5% maximum allowable propylene content, and no more than 5% butanes and ethane) defined by the American Society for Testing and Materials by its Standard 1835 for internal combustion engines."

sounds like glide is guaranteed but uncontrolled mixture.

jeff5may · 05-19-14, 07:16 PM

If you need pure propane for a research project, procure a bottle of R290 at high expense. The quality and purity will ensure the soundness of your results. You don't need a license, just lots of cash. It isn't too hard to find and acquire.

If you are doing "practical science", on a limited budget, common "worthington" propane bottles work fine. In typical production at the refinery, LP gas is very pure. The ethane, methane, and butane are refined out at high efficiency and sold as separate products. The two main contaminants are propylene and "stink oil". Propylene is OK, it helps the propane act more like r22. Stink oil is basically mineral oil and mercaptan. If you have a filter dryer in your system, the mercaptan will be trapped in it, and the oil will pass through.

buffalobillpatrick · 05-19-14, 11:00 PM

Propane Butane Mix - Evaporation Pressure

05-15-14, 02:00 PM	#1
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Propane Propylene blend, glide ? Has anyone tried a blend of Propane R290 with Propylene R1270 ? Or Isobutane R600a ? Would the zeotropic glide work well ? Last edited by buffalobillpatrick; 05-15-14 at 02:10 PM..

05-15-14, 03:28 PM	#3
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	I'm using R433b (sold as ES22a) in my homemade unit, which is 95% R290 and 5% R1270. From my understanding, the R1270 was added to slightly raise pressures so that a R22 TXV would work with no adjustments. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

05-15-14, 03:57 PM	#4
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	How much difference does the 5% R1270 seem to make vs. 100% R290? Is the .2C glide (Wikipedia) noticeable ? Also if normal azeotropic boiling points are: R290 = -42.1C & R1270 = -47.6C It seems like the glide s/b around 5.5C I read somewhere that a blend of 60% R290 & 40% R600a isobutane gave 2.3 to 4% gain in eff. Vs. R22 Last edited by buffalobillpatrick; 05-15-14 at 04:20 PM..*

05-15-14, 04:11 PM	#5
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Hard to tell without pure R290 to compare it to, but the sight glass appears to bubble a little when properly charged. Go by subcooling to determine proper charge. I couldn't find a R433b PT chart, so I just did a weighted average of the R290 and R1270 PT charts in LibreOffice Calc, which was more than accurate enough. (And I even used that to generate the lookup tables so that the DSP can calculate the high and low side pressures from temperature measurements!) __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

05-17-14, 03:49 PM	#6
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	From Wikipedia: "Commercially available "propane" fuel, or LPG, is not pure. Typically in the United States and Canada, it is primarily propane (at least 90%), with the rest mostly ethane, propylene, butane, and odorants including ethyl mercaptan.[12][13] This is the HD-5 standard, (Heavy Duty-5% maximum allowable propylene content, and no more than 5% butanes and ethane) defined by the American Society for Testing and Materials by its Standard 1835 for internal combustion engines." sounds like glide is guaranteed but uncontrolled mixture.

05-19-14, 07:16 PM	#7
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	If you need pure propane for a research project, procure a bottle of R290 at high expense. The quality and purity will ensure the soundness of your results. You don't need a license, just lots of cash. It isn't too hard to find and acquire. If you are doing "practical science", on a limited budget, common "worthington" propane bottles work fine. In typical production at the refinery, LP gas is very pure. The ethane, methane, and butane are refined out at high efficiency and sold as separate products. The two main contaminants are propylene and "stink oil". Propylene is OK, it helps the propane act more like r22. Stink oil is basically mineral oil and mercaptan. If you have a filter dryer in your system, the mercaptan will be trapped in it, and the oil will pass through.

05-19-14, 11:00 PM	#8
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Propane Butane Mix - Evaporation Pressure