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View Full Version : Replacement R22 for NH3/CO2 or NH3







mjcornelissen
17-10-2012, 10:02 AM
Becouse of the new rules of the EU R22 is forbidden to use after 1-1-2015

We have here 5 blast freezers (each one can hold 50 pallets double stack so 100 total) which uses R22.
We have 2 mycoms running in our engine room to get a evaporate temperature around -27 degrees celcius at the 5 blast freezers.

Now we have asked 2 contractor for a complete new installation.

contractor 1 says go for NH3 with 2 Grasso V1100T total amount of 280KW
2 pumps for circulation of the NH3 (makes it 300KW according the contractor)
evaporate temperature -34 degrees celcius
Condensation temperature 25 degrees celcius

Contractor 2 says go for a NH3/CO2 system.
Based on the same evaporate en condensation temperature as above.
2 NH3 compressor OSKA7471/2 eco on 1 frame. (OSKA is Bitzer right?)
3 CO2 compressor 4NHC -20/3 on 1 frame

Both contractors are speaking for there own project.
So we can't choose between both systeems.
Constructor 1 says NH3 is the best
Constructor 2 says NH3/CO2 is the best
So our question is which one is the best in your eyes?

1: Energy consumption
2: Maintance.
3: Difficulty to control the system
4: Environment problems
5: Building Difficulty for the constructor
6: COP
7: Safety for products and employers.
8: Durability
9: Suction or screw compressor
10: Which system has the best build to upgrade in a later stadium?

ALFONSOTHAWE
17-10-2012, 12:06 PM
Go for NH3, the best natural refrigerant for cold storage facilities. Worked on several CO2 plants in Africa on commercial level. You can't go wrong with NH3.

Cool Is Good

chemi-cool
17-10-2012, 03:34 PM
How about cleaning the the system from mineral oil, replace the compressor and TXV and use R-507 instead?

mjcornelissen
17-10-2012, 07:04 PM
How about cleaning the the system from mineral oil, replace the compressor and TXV and use R-507 instead?

Well we don't want to use any CFK's (HCFK) for our new installation.
And we are trying to get a lower energy consumption. And with R-507 or any other Refrigerants except NH3 or NH3/CO2 it wil increase our energy consumption by 10 til 25% in compare of R22
So that's a no go.
And the EU is ****ting around with there GWP list. R22 is now forbidden the next ones are already on the list.
So we want to stick with futureproof refrigerant.

Goober
18-10-2012, 02:45 AM
Not a Ammonia expert by any means, but your set up seems perfect for Ammonia.

Don't know why the other contactor is trying to sell a hybrid NH3/Co2 system, more expensive to install, loss of efficiancy through the stage from NH3 to CO2.

mad fridgie
18-10-2012, 02:57 AM
Is your location industrial or commercial/residential.

NH3 is great refrigerant, but is not so much human friendly! The NH3 system will have a large charge, so if there is a big leak, who and what will it effect. The combo system has a much reduced NH3 charge, so a lot less of an issue.

Magoo
18-10-2012, 05:40 AM
I have a preference for ammonia, being the efficiency of ammonia etc..and that the powers to be, cannot at this stage tax natural refrigerants. But dependent on site location local authourities take a dim veiw of ammonia in certain areas.

mjcornelissen
18-10-2012, 06:56 AM
Is your location industrial or commercial/residential.

NH3 is great refrigerant, but is not so much human friendly! The NH3 system will have a large charge, so if there is a big leak, who and what will it effect. The combo system has a much reduced NH3 charge, so a lot less of an issue.

It's a industrial location.
we use nh3 for almost 30 years in our normale warehouse.
2000 kg of nh3 is used for that.
And those compressors are still running smoothly and low maintance.. (Grasso's)

mjcornelissen
18-10-2012, 06:58 AM
Is your location industrial or commercial/residential.

NH3 is great refrigerant, but is not so much human friendly! The NH3 system will have a large charge, so if there is a big leak, who and what will it effect. The combo system has a much reduced NH3 charge, so a lot less of an issue.

Constructor said it's only using around 600 kg of NH3 if you go for complete NH3 installation. (and somehow i'm not sure about that 600 kg if the other old installation (30years) takes 2000 kg)
Compare with i said here down below.. (other engine room has 2000kg of NH3) it's piece of cake then.

mad fridgie
18-10-2012, 08:25 AM
Charge does seem a bit low for a pump system.
So your familiar NH3 and location is not an issue, So it must come down to capital cost and if they are close then a piece of cake it is!!

Volvo245GLT
18-10-2012, 10:36 PM
Reclaim R22 and charge it up with R290 instead.
No need to replace the oil or anything else, and energy efficiency will actually increase some.

Goober
18-10-2012, 10:48 PM
Reclaim R22 and charge it up with R290 instead.
No need to replace the oil or anything else, and energy efficiency will actually increase some.

Sorry, I have to jump in here, ignore this fool. Retrofit to R290 (propane) with no other changes to the system? Here is the result from doing this stupidity!

http://www.fire.org.nz/Media/News/2008/Pages/Tamahere-Icepak-Coolstore-report-released.aspx

mjcornelissen
19-10-2012, 06:52 AM
Retrofitting isn't a option.
They will all consume more power then the R22

And indeed how stupid are people of getting propane?

cricri
19-10-2012, 06:53 PM
Hi mjcornelissen,
NH3 is the best choice for you. -34 is the uper limit for CO2 pumped and good COP/ammonia. the main difference is hot gaz defrost, easy with ammonia, much more difficult with Bitzer NHC (Tc max is +5C). GRASSO V compressors have a very good efficiency and very low oil carry over.

josei
24-10-2012, 07:28 PM
Both contractors are speaking for there own project.
So we can't choose between both systeems.


[*=1]OP1>Constructor 1 says NH3 is the best
[*=1]OP2>Constructor 2 says NH3/CO2 is the best




So our question is which one is the best in your eyes?
1: Energy consumption >OP1
2: Maintance.>OP1
3: Difficulty to control the system> Unknow
4: Environment problems > None
5: Building Difficulty for the constructor >OP2
6: COP : OP1
7: Safety for products and employers. > OP2
8: Durability >OP1
9: Suction or screw compressor : What do you mean?
10: Which system has the best build to upgrade in a later stadium? OP1




Since contractors emit unsubstantiated opinions, I guess my opinions for or against either require no sustain (although facts exist).
I think that the best choices favor the Contractor 1 in 5/2.

Peter_1
24-10-2012, 09:44 PM
MJ, zonder enige twijfel, NH3 en zeker niet CO2/NH3

mjcornelissen
25-10-2012, 08:01 AM
constructor 2 says he can get a 10% less energy consumption system then the old R22.
constructor 1 is still counting how many % energy saving he will get in compare of the old R22

There are several articles of dutch organisations which says you can get 15% till 30% less energy consumption in compare of a HFK system.
Anyone has reached such numbers with new installations/plants?

@ Peter can you give me some reasons/facts why to choose for NH3 and not CO2/NH3.
Do you have experience with both systems?

josei
25-10-2012, 04:24 PM
Mr.Cornelissen:
In regard to comparison between CO2 / NH3 system and pure NH3 two stages system, I may refer to an study by J.W. Pillis(1), presented in 2009 IIAR Conference , where conclusion are among other the following:


CO2 cascade systems compared with two stage ammonia systems


CO2 cascade system demand more energy; the penalty for using CO2 cascade is about 13% at –20F (–28.9 C) evaporating temperature;energy savings is not the reason to choose CO2 cascade over direct two-stage ammonia as it will almost always require additional power consumption.




CO2 Cascade’s low cycle efficiency, and the need for the cascade condenser with its unavoidable approach temperature, cause increased power consumption and a reduction in overall COP.

Any more info I'll supply you by PM at your request,
Josei

=============================================================
(1)Energy Consumption with CO2/Cascade Systems by J.W. Pillis .Director Global Engineering – Refrigeration, Johnson Controls, Waynesboro, Pensylvania
2009 Industrial Refrigeration Conference & Exhibition, International Institute of Ammonia Refrigeration

Peter_1
25-10-2012, 06:51 PM
MJ, I tjink Josei's post explains it' perfect. If you compare NH3 and R22, then you should also compare both refrigerants at the same working conditions. They mostly take in account low condenesing pressurs for NH3 due toe the evaporative condensors. But you then have to take teh same pressure also for R22. 15% is possible but 30% is exagerated.
Anyhow, NH3 wil lrun at better COP's at the same conditions. NH32 is by far the best refrigerant thermodynamically seen.
CO2/NH3 makes it much more prone to failures and the power needed will be higher. More difficult to service afterwards and you're stuck then also with you original contractor.
Take proven technology since decades (!!)and choose for the setup with the lmeast chance for failures and the lowest power consumption: NH3.

Magoo
26-10-2012, 05:03 AM
Intergrate the existing two mycoms into site system. Load shedding at part load etc.,with cross over pipe work, swing compressors applications all on ammonia. Have a low side surge vessel and a high side chiller surge existing

mad fridgie
26-10-2012, 09:58 PM
A point I should have picked up earlier.
The present system is on R22 Te is -27C, the NH3 system has a Te of -34C, are you changing the temp of your storage and processes.
Does you present system do roughly what you require, if so and no other temp changes are required, why have the NH3 so low, is this purely to reduce the capital cost of the evaporators, I would ask at new figures where the Te on NH3 is -27C (capital will be higher, but long term efficiency will also be higher)
On a very basic look at the design, by increasing you Te, your COP may go up by approx 0.5 . That is a big saving over 20 years.

mjcornelissen
28-10-2012, 01:27 PM
Well it takes several days (5) to freeze the products.. And we want to make it going faster. (4days)
so quality is better and faster ready for shipment.

Josip
28-10-2012, 05:27 PM
Hi, mjcornelissen :)



Well it takes several days (5) to freeze the products.. And we want to make it going faster. (4days) so quality is better and faster ready for shipment.


My suggestion is to go with NH3 .... and you cannot miss

... above you have all need answers .... just find someone to do the right job .... to choose good components and make a good installation...

Best regards, Josip :)

mad fridgie
29-10-2012, 01:47 AM
Well it takes several days (5) to freeze the products.. And we want to make it going faster. (4days)
so quality is better and faster ready for shipment.
And that makes perfect sense!

mjcornelissen
31-10-2012, 10:20 PM
Charge does seem a bit low for a pump system.
So your familiar NH3 and location is not an issue, So it must come down to capital cost and if they are close then a piece of cake it is!!

1600 kg is the correct charge.

The CO2/NH3 constructor 2 is going to make a offer for a NH3 installation instead of NH3/CO2.
we have 2 appointment in the next weeks.

constructor 1 had some cool news for us in regarding of the power consumption.. He will visit us to tell it.

I will keep updating about this matter.

BTW: Anyone wanna buy 2 mycoms R22 ;)
Or anyone know a company's which will terminate the old installation? and probally ship to china or Africa for further freezing with R22 without EU rules

josei
01-11-2012, 04:27 PM
BTW: Anyone wanna buy 2 mycoms R22 ;)
Or anyone know a company's which will terminate the old installation? and probally ship to china or Africa for further freezing with R22 without EU rules

Some types of compressors Mycom R22 are convertible to NH3.
Ask your distributor in Netherlands, could you use them in your project. ;)

mad fridgie
02-11-2012, 01:26 AM
1600 kg is the correct charge.

The CO2/NH3 constructor 2 is going to make a offer for a NH3 installation instead of NH3/CO2.
we have 2 appointment in the next weeks.

constructor 1 had some cool news for us in regarding of the power consumption.. He will visit us to tell it.

I will keep updating about this matter.

BTW: Anyone wanna buy 2 mycoms R22 ;)
Or anyone know a company's which will terminate the old installation? and probally ship to china or Africa for further freezing with R22 without EU rules

Glad to see the charge issue is sorted.

It will be interesting to see what they say about energy use.

Do you use hot water? If so ask for a heat recovery option. Also ask about about floating suction control?
For example, you are in storage mode only (not freezing), you are able to drive your suction pressure up, saving even more energy.

Is does come down to understanding your sites processes, electrical pricing structures.

Peter_1
02-11-2012, 08:16 PM
constructor 1 had some cool news for us in regarding of the power consumption.. He will visit us to tell it.



Let us know this 'cool' news

RANGER1
02-11-2012, 11:10 PM
Well it takes several days (5) to freeze the products.. And we want to make it going faster. (4days)
so quality is better and faster ready for shipment.

Sounds like a long time to blast freeze something!

What are you freezing 7 how is it packed, most blast freezers of good design would be 24 hours. A carton tunnel in abbatoir on NH3 is 40 hours.
Maybe a serious review of blast freezers could save a lot of time & power.

Do you then have to store product for awhile or is it shipped straight away?

If you have a good design then suction pressure can run higher which makes a massive difference to size & capacity of equipment as well as power consumed.



Do you have description of the design etc?

Magoo
03-11-2012, 01:12 AM
Good point Ranger,
the longer the freeze cycle the product quality reduces, perhaps blast freezing pre packaging, time to re-think the whole process. Also the mycom compresssor recip or screw can be adapted to ammonia from R22.

mjcornelissen
15-11-2012, 10:10 PM
constructor 1 had some cool news for us in regarding of the power consumption.. He will visit us to tell it.

I will keep updating about this matter.



constructor 1 made the visit.
And it wil be around 10% till 15% less energy consumption compare to the old R22 installation.
He even made a calculation about the NH3/CO2 installation and surprise: it will increase with 10% energy consumption compare the old R22 installation
With the R22 on max capacity
and the NH3 on 80% capacity so we have another 20% for expanding in the future.

With this said.. Constructor 2 needs to explain his earlier 10% less energy consumption.

We just received today his offer for a complete NH3 installation which we asked for.
Didn't had time yet to review it.

@josei.
This was very helpfull. They even didn't know about this paper.

In regard to comparison between CO2 / NH3 system and pure NH3 two stages system, I may refer to an study by J.W. Pillis(1), presented in 2009 IIAR Conference , where conclusion are among other the following:

More news coming soon.!

josei
16-11-2012, 02:17 PM
@josei.
This was very helpfull. They even didn't know about this paper.

In regard to comparison between CO2 / NH3 system and pure NH3 two stages system, I may refer to an study by J.W. Pillis(1), presented in 2009 IIAR Conference...


@mjcornelissen
You are welcome , please spread kindly the knowledge about nh3 refrigeration, its energy savings and environment protection. A lot of engineer's analisys I have available to decision makers. You can see into my profile, colaborations that I worked before.

Segei
16-11-2012, 04:56 PM
As far as I remember Mr. Pillis compared only low sides of the plants. What about high sides?

josei
16-11-2012, 05:11 PM
As far as I remember Mr. Pillis compared only low sides of the plants. What about high sides?

@Segei What about high sides??

Segei
16-11-2012, 06:29 PM
When we talk about energy savings, we should compare energy efficiency of the whole(low sides and high sides) refrigeration plants. Mentioned technical paper was focused on energy efficiency of low sides of the refrigeration plants.