11 replies to this topic

[tonywen]

Hello my friends,

I am a freshman of the FLARENET. Recently I found that even though I set up a long list of components at the beginning of a new model, in each source(like control valvve or relieve valve) Flarenet chooses only two kinds of substance to calcule, whose Mol. Weights are near the number of Mol.weight you set. Is it a approximate method?

Thanks a lot.

[joerd]

If you define the source flow with a mol. weight, Flarenet will mix the available components to give the specified mol. weight. Alternatively, you may specify the composition directly, and leave the mol. weight blank (this will be calculated from the composition.)

[JoeWong]

If you define the source flow with a mol. weight, Flarenet will mix the available components to give the specified mol. weight. Alternatively, you may specify the composition directly, and leave the mol. weight blank (this will be calculated from the composition.)

tonywen,

If you choose to input MW and let the FLARENET to mix the available components, please make sure you enter "good & correct" component.

I have carried out similar excersive as mentioned above, the "predicted" mixture is quite different than the provided mixture (after it is available in later stage). Relief device outlet temperature was far out and seriously affect the backperssure and MACH no. This main due to JT cooefficent are different for each component.

Please take note.

JoeWong

[tonywen]

If you define the source flow with a mol. weight, Flarenet will mix the available components to give the specified mol. weight. Alternatively, you may specify the composition directly, and leave the mol. weight blank (this will be calculated from the composition.)

tonywen,

If you choose to input MW and let the FLARENET to mix the available components, please make sure you enter "good & correct" component.

I have carried out similar excersive as mentioned above, the "predicted" mixture is quite different than the provided mixture (after it is available in later stage). Relief device outlet temperature was far out and seriously affect the backperssure and MACH no. This main due to JT cooefficent are different for each component.

Please take note.

JoeWong

Thank you Joewong,

It seems that we'd better define precisely the component. But in reality we only know the average Mol Weight and approximate substances’ types in the process. We don’t know the exact Mol Fraction of each component. So in these cases we need defining a Mol Weight. The problem as I said before is that FLARENET will choose available components( 2 types, one is bigger and the other is smaller. E.g. if I set my components as methane (16), ethane (30) and propane (46), then I define the Mol Weight as 31, FLARENET choose only ethane and propane ( 30<31<46). The result is different then, as you told me. How to solve this Problem?

I also have two questions for you about the drawing of the pipe network:
1, how to draw a 90-degree pipe? You know in plants there are some turning in the pipe net but FLARENET has only a TEE to describe this kind of pipe. Can I use TEE branch and then add only a in one side (upstream or downstream).
2, how to define the height of a pipe network? The elevation change is relative and through this option we can draw vertical, horizontal or inclined pipes. To draw a big plant network, I think we should define a referential point. Do you agree? Anyhow Flarenet is a 2D software and we can’t realize the 3D changing.

thanks in advance.

Tony

[tonywen]

If you define the source flow with a mol. weight, Flarenet will mix the available components to give the specified mol. weight. Alternatively, you may specify the composition directly, and leave the mol. weight blank (this will be calculated from the composition.)

tonywen,

If you choose to input MW and let the FLARENET to mix the available components, please make sure you enter "good & correct" component.

I have carried out similar excersive as mentioned above, the "predicted" mixture is quite different than the provided mixture (after it is available in later stage). Relief device outlet temperature was far out and seriously affect the backperssure and MACH no. This main due to JT cooefficent are different for each component.

Please take note.

JoeWong

Thank you Joewong,

It seems that we'd better define precisely the component. But in reality we only know the average Mol Weight and approximate substances’ types in the process. We don’t know the exact Mol Fraction of each component. So in these cases we need defining a Mol Weight. The problem as I said before is that FLARENET will choose available components( 2 types, one is bigger and the other is smaller. E.g. if I set my components as methane (16), ethane (30) and propane (46), then I define the Mol Weight as 31, FLARENET choose only ethane and propane ( 30<31<46). The result is different then, as you told me. How to solve this Problem?

I also have two questions for you about the drawing of the pipe network:
1, how to draw a 90-degree pipe? You know in plants there are some turning in the pipe net but FLARENET has only a TEE to describe this kind of pipe. Can I use TEE branch and then add only a in one side (upstream or downstream).
2, how to define the height of a pipe network? The elevation change is relative and through this option we can draw vertical, horizontal or inclined pipes. To draw a big plant network, I think we should define a referential point. Do you agree? Anyhow Flarenet is a 2D software and we can’t realize the 3D changing.

thanks in advance.

Tony

Hello my friend,

I found that in the Pipe Editor I can set up the fitting loss which means there is a bend instead of a pipe even though it's shown as a pipe in the PFD. Would you please explain in detail or give me some informations about this "fitting tap"? thanks a lot.

Tony

[JoeWong]

tonywen,

It seems that we'd better define precisely the component. But in reality we only know the average Mol Weight and approximate substances’ types in the process. We don’t know the exact Mol Fraction of each component. So in these cases we need defining a Mol Weight. The problem as I said before is that FLARENET will choose available components( 2 types, one is bigger and the other is smaller. E.g. if I set my components as methane (16), ethane (30) and propane (46), then I define the Mol Weight as 31, FLARENET choose only ethane and propane ( 30<31<46). The result is different then, as you told me. How to solve this Problem?

Let take an example, you have a composition 45% C1, 35% C2 & 20% H2. This give MW of 18.147. If you specify the initial component as C1, C2, C3, H2 & H2O and MW of 18.147, you will get 85% C1 + 15% C2. This not too bad. The worst is it give you 99% H2O + 1% C3. You can imagine your results....!

You may check with previous project or process engineer who handle the unit to provide you some indicative composition. Other than this, no sure what you can do.
Wish other Che Jedi can provide some advice on this.

1, how to draw a 90-degree pipe? You know in plants there are some turning in the pipe net but FLARENET has only a TEE to describe this kind of pipe. Can I use TEE branch and then add only a in one side (upstream or downstream).

2, how to define the height of a pipe network? The elevation change is relative and through this option we can draw vertical, horizontal or inclined pipes. To draw a big plant network, I think we should define a referential point. Do you agree? Anyhow Flarenet is a 2D software and we can’t realize the 3D changing.

1. if your pipe consist of 1 gate valve and 3 bends, model all these with a PIPE. Specify the pipe straight length and add the gate valve and bends in "Fitting" tab. FLARENET will calculate the pressure drop base the fitting loss. Please do some reading on the FLARENET manual. You definitely will find information as requested.

2. Within the DIMENSION tab in PIPE editor, you will find the elevation change. Agian, Please do some reading on the FLARENET manual. You definitely will find information as requested.


Hope this help.

regards,

JoeWong

[tonywen]

tonywen,

It seems that we'd better define precisely the component. But in reality we only know the average Mol Weight and approximate substances’ types in the process. We don’t know the exact Mol Fraction of each component. So in these cases we need defining a Mol Weight. The problem as I said before is that FLARENET will choose available components( 2 types, one is bigger and the other is smaller. E.g. if I set my components as methane (16), ethane (30) and propane (46), then I define the Mol Weight as 31, FLARENET choose only ethane and propane ( 30<31<46). The result is different then, as you told me. How to solve this Problem?

Let take an example, you have a composition 45% C1, 35% C2 & 20% H2. This give MW of 18.147. If you specify the initial component as C1, C2, C3, H2 & H2O and MW of 18.147, you will get 85% C1 + 15% C2. This not too bad. The worst is it give you 99% H2O + 1% C3. You can imagine your results....!

You may check with previous project or process engineer who handle the unit to provide you some indicative composition. Other than this, no sure what you can do.
Wish other Che Jedi can provide some advice on this.

1, how to draw a 90-degree pipe? You know in plants there are some turning in the pipe net but FLARENET has only a TEE to describe this kind of pipe. Can I use TEE branch and then add only a in one side (upstream or downstream).

2, how to define the height of a pipe network? The elevation change is relative and through this option we can draw vertical, horizontal or inclined pipes. To draw a big plant network, I think we should define a referential point. Do you agree? Anyhow Flarenet is a 2D software and we can’t realize the 3D changing.

1. if your pipe consist of 1 gate valve and 3 bends, model all these with a PIPE. Specify the pipe straight length and add the gate valve and bends in "Fitting" tab. FLARENET will calculate the pressure drop base the fitting loss. Please do some reading on the FLARENET manual. You definitely will find information as requested.

2. Within the DIMENSION tab in PIPE editor, you will find the elevation change. Agian, Please do some reading on the FLARENET manual. You definitely will find information as requested.


Hope this help.

regards,

JoeWong

Yes, I found in manuel that we take the bends, elbows or pipe entrance as losses in the "fitting tap" setting. Thanks. About the elevation change I knew it. And in reality Flarenet describes networks in 2D vertical plate, because for the massflow, the direction in the horizontal plate doesn't cause any difference. I want to show if the technology allows, we can construct the newwork in 3D, which is livelier and simpler.

best regards,

Tony

[JoeWong]

Yes, I found in manuel that we take the bends, elbows or pipe entrance as losses in the "fitting tap" setting. Thanks. About the elevation change I knew it. And in reality Flarenet describes networks in 2D vertical plate, because for the massflow, the direction in the horizontal plate doesn't cause any difference. I want to show if the technology allows, we can construct the newwork in 3D, which is livelier and simpler.

Tony,

Personally i would think...Process/safety engineer are interested in velocity, momentum, backpressure, flow regime, etc...where FLARENET is doing the job...As for 3D, other than visual satisfaction, there is not much incentive / interest to contruct the network in 3D. There are other piping software e.g. PDS, PDMS, etc doing this 3D job in a very satisfaction level. Don't you agree with me ?

regards,

JoeWong

[tonywen]

Yes, I found in manuel that we take the bends, elbows or pipe entrance as losses in the "fitting tap" setting. Thanks. About the elevation change I knew it. And in reality Flarenet describes networks in 2D vertical plate, because for the massflow, the direction in the horizontal plate doesn't cause any difference. I want to show if the technology allows, we can construct the newwork in 3D, which is livelier and simpler.

Tony,

Personally i would think...Process/safety engineer are interested in velocity, momentum, backpressure, flow regime, etc...where FLARENET is doing the job...As for 3D, other than visual satisfaction, there is not much incentive / interest to contruct the network in 3D. There are other piping software e.g. PDS, PDMS, etc doing this 3D job in a very satisfaction level. Don't you agree with me ?

regards,

JoeWong

Joewong,

I agree with you that Flarenet is a excellant software who can give us the interesting results. About 3D, I just wanted to express one of the developping tendance of the commercial softwares, even those of engineering, scientifique.

regards,

Tony

[Traileum]

I am having this same problem. I specified several compositions for each of my souces. However, when I go downstream inside the knock-out drum, it just shows just one component (100% Methane). Why is this? I had expected it would show several components similar to my individual sources. Am I doing something wrong.

Also, in the knock out drum, there is no temperature in the summary. I would like to know the temperature of all the mixtures. Is this possible?

Any explanation would be appreciated.

[JoeWong]

I am having this same problem. I specified several compositions for each of my souces. However, when I go downstream inside the knock-out drum, it just shows just one component (100% Methane). Why is this? I had expected it would show several components similar to my individual sources. Am I doing something wrong.

Also, in the knock out drum, there is no temperature in the summary. I would like to know the temperature of all the mixtures. Is this possible?

Any explanation would be appreciated.

You should open a new thread.

The observations that you mentioned are strange. I suggest you upload the source file (zipped it) and let forum member to check for the real problem.

[Traileum]

I am having this same problem. I specified several compositions for each of my souces. However, when I go downstream inside the knock-out drum, it just shows just one component (100% Methane). Why is this? I had expected it would show several components similar to my individual sources. Am I doing something wrong.

Also, in the knock out drum, there is no temperature in the summary. I would like to know the temperature of all the mixtures. Is this possible?

Any explanation would be appreciated.

You should open a new thread.

The observations that you mentioned are strange. I suggest you upload the source file (zipped it) and let forum member to check for the real problem.

I called Aspen and they helped figure what the problem was. The window I was looking at is user defined. That would be the pop-up that comes up when you click on a particular RV. However, to see the actual compositions, you need to click on results>composition.

Thanks.