System capacity

[skyboy6142]

Dear Friends,

As you know system with sub-cooler or economizer increase system and compressor capacity, I understand this matter.
While we take some portion of liquid line to sub-cooler or economizer we also decrease our expansion valve feed but why totally twice we have capacity increase ?

Thanks.

[mbc]

Hi
Subcooling could made from different way
Heat exchange - Evaporat Water cold Condenser -
4 pipe suction aculamator- and...
Also One of them is a ECO.
In Eco. We have subcooling the liquid But main thing is cooling discharge gas in first Stage.
When we cool in first Stage we have low temperature and more mass of refrigeration for second stage.

[RANGER1]

Dear Friends,

As you know system with sub-cooler or economizer increase system and compressor capacity, I understand this matter.
While we take some portion of liquid line to sub-cooler or economizer we also decrease our expansion valve feed but why totally twice we have capacity increase ?

Thanks.

Can you explain a bit more on what you would like to know.
Not sure what you are asking.
Thanks

[Josip]

Dear Friends,

As you know system with sub-cooler or economizer increase system and compressor capacity, I understand this matter.
While we take some portion of liquid line to sub-cooler or economizer we also decrease our expansion valve feed but why totally twice we have capacity increase ?

Thanks.

This is not simple to explain ...

but each sub-cooler is not an economizer too ...
only economizers reduce power consumption and increase efficiency of refrigeration system ...
i.e. economizers are connected to screw compressor ECO port and usually increase compressor
capacity up to 20% but increase in used electric power is much less and from this
we get the name economizer ...

but, please .... read carefully this and then return to clarify if something is not clear

https://www.swep.net/refrigerant-handbook/10.-systems/asdf4/

https://www.mashav-ind.co.il/sites/default/files/publications/mollier_diagram_can_be_improved_0.pdf

https://en.wikipedia.org/wiki/Economizer

https://www.theseus.fi/bitstream/handle/10024/54142/Vinogradova_Ekaterina.pdf?sequence=1&isAllowed=y

Hope this will be of some help.

Best regards, Josip

[skyboy6142]

Can you explain a bit more on what you would like to know.
Not sure what you are asking.
Thanks

Dear My friend,
I know exactly what is subcooler and economizer.
Installing compressor with economizer (in screw compressors) and subcooler (in two stage compressors) increase compressor capacity, It is fact and very clear.

I say my mean in very simple way, At economizer and subcooler we cool liquid line and definitely it helps us to increase compressor capacity, OK.
But question is here, Beside of cooling liquid line and increasing compressor capacity also we decrease expansion valve feed, Isn't it ?!
As you know for installing economizer/Subcooler we branch main liquid line in two ways.
One way our main liquid line that goes to evp. expansion valve and the other way goes to subcooler/economizer.
When we branch liquid line in two way, It means we decrease feeding of evaporator, Is it true ?
Now I want to know we have a positive effect means cooling liquid line and cooling compressor and negative effect we decrease expansion valve feeding.
Resultant is increasing system capacity ? Or I think in a wrong way ?

Thanks.

[RANGER1]

Dear My friend,
I know exactly what is subcooler and economizer.
Installing compressor with economizer (in screw compressors) and subcooler (in two stage compressors) increase compressor capacity, It is fact and very clear.

I say my mean in very simple way, At economizer and subcooler we cool liquid line and definitely it helps us to increase compressor capacity, OK.
But question is here, Beside of cooling liquid line and increasing compressor capacity also we decrease expansion valve feed, Isn't it ?!
As you know for installing economizer/Subcooler we branch main liquid line in two ways.
One way our main liquid line that goes to evp. expansion valve and the other way goes to subcooler/economizer.
When we branch liquid line in two way, It means we decrease feeding of evaporator, Is it true ?
Now I want to know we have a positive effect means cooling liquid line and cooling compressor and negative effect we decrease expansion valve feeding.
Resultant is increasing system capacity ? Or I think in a wrong way ?

Thanks.

The expansion valve feeds liquid into evaporator with sub cooled high quality liquid.
So less flash gas, but also still controls required superheat.
Less liquid could enter evaporator because less flash gas, but at same time increased refrigeration effect occurs, evaporator has more capacity

[Josip]

Dear My friend,
I know exactly what is subcooler and economizer.
Installing compressor with economizer (in screw compressors) and subcooler (in two stage compressors) increase compressor capacity, It is fact and very clear.


NO! Wrong .... only economizer increase actual compressor capacity due to ECO port connectiton ... the same compressor gives around 20% more capacity but we need to imput 12% more electric power ... end economizer we can utilize only with screws
it is not necessary to be a two stage plant to utilize economizer as subcooler and again get a more capacity with SINGLE compressor ... nominal capacity for cooling and additional capacity through ECO port


If not connected to ECO port then we have subcooler helping also to reduce flash gas, but actual compressor capacity for cooling is reduced due to part load for subcooler and here we can use other than screw compressors to do the work ... compressor must be with bigger capacity calculated both for cooling and for subcooling and we have to pay full price

I say my mean in very simple way, At economizer and subcooler we cool liquid line and definitely it helps us to increase compressor capacity, OK. YES and NO!
But question is here, Beside of cooling liquid line and increasing compressor capacity also we decrease expansion valve feed, Isn't it ?!
NO! We need to calculate feeding line to be big enough for expansion valve and for economizer otherwise plant will not work.

As you know for installing economizer/Subcooler we branch main liquid line in two ways.
One way our main liquid line that goes to evp. expansion valve and the other way goes to subcooler/economizer.
When we branch liquid line in two way, It means we decrease feeding of evaporator, Is it true ? NO! We do not decrease feeding line ... system will not work.
Now I want to know we have a positive effect means cooling liquid line and cooling compressor and negative effect we decrease expansion valve feeding.
Resultant is increasing system capacity ? Or I think in a wrong way ?
Yes, a little bit wrong;)

Thanks.

Best regards, Josip

[Aik]

Dear Friends,

As you know system with sub-cooler or economizer increase system and compressor capacity, I understand this matter.
While we take some portion of liquid line to sub-cooler or economizer we also decrease our expansion valve feed but why totally twice we have capacity increase ?

Thanks.

For understanding you may analyze simple formula:
Q=(H2-H1)*G,
Q - cooling capacity
H - entalpy of refrigerant (1 -for start evaporating process 2- for end evaporating process)
G - mass flow or refrigerant
When you have a subcooled refrigerant than you have greater entalpy difference (H2-H1). In general with subcooling entalpies defference (H2-H1) more big than decrease mass flow (G), and you can see that expension valve needs less size (becourse it regulated mass flow) and cooling capacity increase.