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  1. #51
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    Re: Propylene System



    Aha
    This project has been done now, it running well.
    Not a DX control, it uses 8 flooded evaporators.
    This system is consist of 4 compressors, 2 evaporative condensors, 2 liquid receivers, and 8 evaporators.
    Results as following:
    O ring is Viton.
    Don't use drier-filter.
    ......
    Thanks all.
    This forum is great to me!



  2. #52
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    Re: Propylene System

    Hi, sagittarius

    Quote Originally Posted by sagittarius View Post
    Aha
    This project has been done now, it running well.
    Not a DX control, it uses 8 flooded evaporators.
    This system is consist of 4 compressors, 2 evaporative condensors, 2 liquid receivers, and 8 evaporators.
    Results as following:
    O ring is Viton.
    Don't use drier-filter.
    ......
    Thanks all.
    This forum is great to me!
    Nice to hear that.

    Can you tell us something more about....type of compressors/control, evaporators, condensers, etc.....some scheme, photo...

    Best regards, Josip

    It's impossible to make anything foolproof because fools are so ingenious...

    Don't ever underestimate the power of stupid people when they are in large groups.

    Please, don't teach me how to be stupid....
    No job is as important as to jeopardize the safety of you or those that you work with.

  3. #53
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    Re: Propylene System

    Ok. I learned a lots from this forum,it helps me to design the system.
    comp.:V35,(equivalet to WRV510132 HOWDEN) V32,(equivalet to WRV321165 HOWDEN),each 2sets,with economizers,local manufacture
    evaporative condensors:CXV-T1584,BAC
    liquid tank: volumn 20m^3, 2sets
    evaporators: 8sets,flooded type, float valve control

  4. #54
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    Re: Propylene System

    Quote Originally Posted by Peter_1 View Post
    I have a friend who's a teacher HVAC/R and he once converted a set-up to R-290.

    He said that the properties were similar to those of the old R12, so very similar to R134a.

    .
    I have designed several propane and propylene refrigeration systems using twin rotor screws by Howden and Mycom as well as Mycom and Vilter recip compressors. Even did a couple with carrier 5H compressors. The properties are no where near like R-12. Look at the pressures, temperatures and specific volumes. They are more like R-22.

    I hope your old instructor was teaching something other than refrigeration.

    You can use mineral oils, but synthetics work much better due to solubility with the refrigerant.

    Both R-290 and R-1270 are considered high pressure refrigerants and R-12 and R-134a are considered medium pressure refrigerants.

    I even have one iso-butane (R-600a) system with three 700HP GEA compressors. R-600a is more like R-11 in its characteristics. With R-600a you have to be very careful with the suction and have a minimum of 40 dF suction superheat as the constant entropy lines go back into the saturation dome on the PH chart.

    Hydrocarbons are excellent refrigerants in certain applications. You have to watch the oil return issues, liquid carry over is very critical and all of the safety issues as it is an explosive. As a minimum, most agencies will require it to be what the US calls Class 1 Division 2 area classification. Class 1 Division 1 is fully explosion proof.

    I have used Sporlan driers in hydrocarbon systems to make sure you capture any moisture. They make a core thast is compatible with HC's. If you are operating above freezing, water will not bother the control valves, but will effect the oil system on the screw compressors. The oil filters are typically a paper element and a 15 micron filter will swell the paper elements and give you a high filter pressure drop and eventually cause an oil pressure related shut down.

  5. #55
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    Re: Propylene System

    The system I have designed is running well.
    I wanna know other way to charging refrigerants.I charged propelene by this way.
    First filling 5bar Nitrogen gas in receiver,then charging propelene, to enough quantities,running the system,purging the N2 by the air separation parts.
    This way is to provide the propelene flash in the normal pressure receiver.

  6. #56
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    Re: Propylene System

    Hi, sagittarius

    Quote Originally Posted by ;96334
    The system I have designed is running well.
    I wanna know other way to charging refrigerants.I charged propelene by this way.
    First filling 5bar Nitrogen gas in receiver,then charging propelene, to enough quantities,running the system,purging the N2 by the air separation parts.
    This way is to provide the propelene flash in the normal pressure receiver.
    why nitrogen, it was possible to charge gaseous propylene maybe .... what will happen if you fill propylene in empty receiver..... at 5 bar Te is -5*C at 0 bar -60*C what is dangerous for receiver material...but charging slowly you will soon rise pressure.... or maybe there are some other reasons.... please, explain

    Best regards, Josip

    It's impossible to make anything foolproof because fools are so ingenious...

    Don't ever underestimate the power of stupid people when they are in large groups.

    Please, don't teach me how to be stupid....
    No job is as important as to jeopardize the safety of you or those that you work with.

  7. #57
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    Re: Propylene System

    If you first charge with nitrogen as a pressure test, I next blow the low points using the N2 pressure to sweep them clear of trash. N2 is an inert and has to be cleared from the system. Next problem is the moisture in the system. You need to pull a good vacuum to clear the moisture or it will freeze in the first expansion device you have.

    As for the materials of the receiver, it should be very small as the system is generally critically charged on the low temp system of a cascade.

    When you break the vacuum on a system, you should not break it with liquid into a high pressure receiver. Break it with vapor until you have a positive pressure then feed some liquid in a small amount or equalize it with the charging tank and pump the liquid at ambient temperature to the receiver.

    But charging the low side of a cascade is a bit tricky fro the uneducated.

    Ken

  8. #58
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    Re: Propylene System

    To avoid propylene instantaneous flash in the vacuum receiver,I can charge liquid propylene to the receiver.The pressure of being charged propylene into receiver is about 8bar.Another reason is that I am afraid of instant flash causing exploding.
    After charged the propylene, purging N2 by air seperator in the system.
    Txiceman said is for the cascade system?thanks a lot. I've desigened my first cascade system recently,it will be first started up. I need some help about the cascade system.

  9. #59
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    Re: Propylene System

    with any HC, no air = explosion impossible, after all even the oil we use will burn if there is air! So why worry about the HC?!?!?!

    Treat hydrocarbons just like any other refrigerant, but keeping in mind they are slightly more flammible then standerd refrigerants (Which are infact quite capable of burning and exploding).

    Pull the standerd 500 micron vacuum (If you are like me lower, much lower, for an HC systems I let it go to 200micron) then charge liquid directly to the receiver, then finnish off via low side adjusting. There is no need to mess around with N2 and such, far more important things to be worried about!


    After seeing propylens curves compared to R-290 & R-22 I think I'll be procuring some! looks verry nice.

  10. #60
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    Re: Propylene System

    Quote Originally Posted by NoNickName View Post
    Propane you shall use is refrigeration grade. Not LPG from the fuel station.
    Odd you say this as for majourity of my "for fun" builds use just that, interestingly enough I find no performance differances, other then the scenting agent needs to be scrubed out first. Once scrubed it works fine.

  11. #61
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    Re: Propylene System

    I taught that LPG is mixture of propane and butane?
    Now, when I am officialy citizen off EU, I am looking for decent job! For any job offer please check my profile!

  12. #62
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    Re: Propylene System

    Not here, propane is suposed to be propane, and Butane butan, given there is some of each mixed in as impurities how ever purity is as such if I use bbq grade R-290 it will match the PT for R-290 flawlesly, so not enough to degrade performance in any serious matter, in other places I don't know.

  13. #63
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    Re: Propylene System

    There are several grades of propane and the refrigerant grade is not the purest. HD-5 is a grade you often see in the refineries and chemical plants. It has some heavy end and light end products as well as some free water.

    The heavy products will settle in the evaporator and the light ends will tend to concentrate in the condenser and raise the partial pressure which causes an increased discharge pressure for the compressor. You can vent the light end concentrations and bring the condensing properties back pretty close to pure propane.

    BBQ or bottled propane has some butane as well as some other HC products. I don't remember the mixture.

    Ken

  14. #64
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    Re: Propylene System

    There is a new question about this system.
    Looking back recently,I think how to handle the emergency for the r1270 (hc etc.)system. I have set the emergency port on the bottom of liquid receiver tank.But the R1270 liquid where to go?
    To ammonia we can purge it with water to the drainage.To R1270 directly to the torch? It maybe not a good idea.R1270 liquid may expand and become gas,ice forming on the port of emergency pipe.what to do?

  15. #65
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    Re: Propylene System

    Relieving liquids to flare is a different ball game than vapor. You can't put the liquid directly to flare. Normally you have to put the liquids to a vaporizer or to a flare knock out drum.

    You need to be sure that you design the liquid piping to meet the temperature requirements for the local code requirements fro temperature. If you design per ASME VII section UCS.66, you can derate the pipe for coincident pressure at the lower temperatures. Some allow this some do not. In any case if you drop the liquid to atmospheric pressure, R-1270 will be about -54 dF. The K.O. drum has to be designed fro the lower temperature and pressure as well.

    Usually the drum will have a heating source, electric or steam to vaporize the propylene as it is vaporized.

    It would be better to send only the vapors to the flare.

    Ken

  16. #66
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    Re: Propylene System

    Thanks!
    It's a good idea.The knock out drum with heating source at the outlet of liquid emergency port.But this drum maybe a bigger one.Need some mist eliminating device?

  17. #67
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    Re: Propylene System

    You need to have a drum large enough to catch the largest liquid slug you would expect. Some have a mist eliminator and most do not.

    The project I am currently working on has a flare to flare off waste on an FPSO. The drum is about 14' in diameter and 30' long and has a large electric heater in the boot.

    ken

  18. #68
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    Re: Propylene System

    dear all,
    we have problem of my system after upgrading refrigerant from R22 to propylene and change the chiller, economizer,condenser, we use screw compressor, refrigerant propylene and oil cpi-1507, but of the system if the temperature discharge low and temperature chiller very low and the system always oil carry over.why oil carry over?

  19. #69
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    Re: Propylene System

    Yadi, what temperature are you running at the evaporator. Tyep compressor and oil separator.

    If you are carrying excessive oil, you need to look at several issues:
    excessive liquid refrigerant carry over into the suction.
    Low condensing pressure,
    poorly designed oil separator
    Oil separator elements are "blown" and need replacing.
    Wrong oil, incorrect vapor (too low) pressure with refrigerant used.

    Any one of these can contribute to excessive oil carry over.

    Ken

  20. #70
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    Re: Propylene System

    The original question was about system with r290 ( PROPANE ) and the whole conversation has tried the Propylene systems ( r 1270) . What is the reason ?

  21. #71
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    Re: Propylene System

    Hi Saggitarius,

    Did you managed to find a supplier for Propylene Thermal Expansion Valve?

    Our local Sporlan and Danfoss supplier said they cannot supply any that is compatible for propylene.

  22. #72
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    Re: Propylene System

    Hi, Reach1e:

    I didn't find the exact propylene TX valves finally. I used an air-operated valve.
    For HC refrigerant it's not easy to find the TXV.
    I used Sporland TXV for R290 ever.

    Sagittarius

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    Re: Propylene System

    Hi Sagittarius, may I know if you've oil filter in your system?

    If so, who is the supplier? and anything special I need to look out for?

    This is because I'm looking for a new oil filter for our propylene compressor .
    Thanks

  24. #74
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    Re: Propylene System

    Quote Originally Posted by reach1e View Post
    Hi Sagittarius, may I know if you've oil filter in your system?

    If so, who is the supplier? and anything special I need to look out for?
    Yes. There are two parallel oil filters in the oil system. The oil filte is similar with ***** application. But there are a bit difference that the rubber material ( O ring or sealing ) is HNBR suitable with PAG. The cartridge is fabric about 20um filter efficiency.

    The filter body is carbon steel.
    Last edited by sagittarius; 11-12-2010 at 03:55 PM.

  25. #75
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    Re: Propylene System

    I have used Sporlan TXV's in propane and propylene systems. DO NOT depend on the local Sporlan distributor. Put in a call to the Sporlan factory and talk to the older rating engineers.

    Ken

  26. #76
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    Post Re: Propylene System

    Hi All,

    I am new to this forum and look forward to valuable inputs from all the members.

    I am looking for the replacement of TXV operating with Propylene as refrigerant. Unfortuantely, the local supplier (Sporlan) has shown inability to provide TXV for this service.

    Is there any other supplier who deals in the prylene system components. Will appreaciate if I can get some directions on this.

    Thank You!

  27. #77
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    Re: Propylene System

    You need to go back to the Sporlan factory for better suport. I am beginning to think that the local distributors must be hiring Wal Mart rejects.

    Ken

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