I need to simulate a sea water heat exchanger. How can I simulate the properties of the sea water? I tried to include in a new compound but I need to introduce an additional parameter that is the salinity.
Thank you in advance.
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Hi Daniel,
the model that I would like to apply is derived from IAPWS for the thermodinamic properties and some empirical relation from the normal practice in the salt water desalination. In any case, the salinity is considered as total value and is measured in ppm. For the model point of view, is considered a parameter.
I'm entering progressively in your simulator and really compliments because the software is really usefull and user friendly.
Thank you for your availability.
Regards.
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I can implement it in DWSIM as a property package. I would have to add a new generic compound called "Salt", which you would use to indirectly define the salinity, and it would precipitate or not depending on the process... what equipment would you like to simulate to process seawater?
Regards
Daniel
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Hi Daniel,
I suggest to include for the sea water the model proposed by IAPWS becasue the data are regressed on a large amount of sea water types and therefore more general. http://www.iapws.org/relguide/Advise5.html.
I am agreed with your suggestion to include the salinity as "Salt".
Thank you and regards.
Cristian
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Maximum salinity for correlations is 0.12 kg/kg, but DWSIM will calculate equilibrium up to saturation (0.36) and then precipitate the excess as a solid phase.
Regards
Daniel
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Hi Daniel,
I used the sea water model and works very well. I have only a note about the definition of the salinity. Is better that you indicate the salinity not only NaCl but with the terms TDS (total dissolved solid) because the seawater that we are treating contains not only NaCl but also other compounds that could be affected during several treatments.
Thank you.
Regards.
Cristian
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Thanks, I'm glad it works for you. Regarding my definition, where exactly should I change it? The "salt" compound is based on NaCl but that doesn't actually mean anything other than showing compound properties from it. All water properties are calculated by the library, I mean, it doesn't care if the salt is NaCl or not...
Daniel
Last edit: Daniel Medeiros 2015-11-26
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Hi Daniel,
I tried to adapt with proper custom unit operations (that I will send to you for your use) DWSIM for the water treatment world. I mean reverse osmosis, ultrafiltration, biological oxidation, etc... and I tried to work with the salinity compunds of the water with equilibrium and conversion reactions for having the different electrolyte composition in the water during the different dosing/pH corrections, etc.... The salinity expressed in the IAPWS that you have correctly introduced is based on the total amount of the ions dissolved in the water (Na+, Cl-, K+, etc....) that is defined as TDS. The other compounds that I have introduced into the water is the TSS (total suspended solids), BOD, COD, etc.... Is the reason because I suggest to use the term TDS instead of NaCl.
In addition, in the composition of the water that characterize the material stream, I suggest to include also the term ppm in the concentration field.
I think that DWSIM, with the custom, flowsheet and spreadsheet unit operation is very usefull for the application in the water treatment world.
Thank you for your help.
Regards.
Cristian
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The reason for choosing NaCl as the base for the "Salt" compound is just for simulation purposes. Since the model must be able to handle precipitation of this "salt" compound as a solid, I chose to start with NaCl, which is the salt present in the highest amount in seawater.
With the base properties inherited from NaCl, you'll have a better solid phase description than if I had chosen another "random" salt. The other option is to rigorously simulate all salts and ions with water, describe the dissociation reactions and use the Electrolyte Property Package, but it is almost certain not to work yet because of convergence issues that I'm still trying to figure out...
I don't know much about desalination processes, it would be really nice to get some info about it. If you agree, we can include your simulations as samples to be distributed together with DWSIM.
Regards
Daniel
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Hi Daniel,
I need to simulate a sea water heat exchanger. How can I simulate the properties of the sea water? I tried to include in a new compound but I need to introduce an additional parameter that is the salinity.
Thank you in advance.
What properties do you need? Is your salinity expressed in mg/L? Which salt species do you want to include?
Hi Daniel,
the model that I would like to apply is derived from IAPWS for the thermodinamic properties and some empirical relation from the normal practice in the salt water desalination. In any case, the salinity is considered as total value and is measured in ppm. For the model point of view, is considered a parameter.
I'm entering progressively in your simulator and really compliments because the software is really usefull and user friendly.
Thank you for your availability.
Regards.
Hi Cristian,
I found this library => http://www.teos-10.org/software.htm
I can implement it in DWSIM as a property package. I would have to add a new generic compound called "Salt", which you would use to indirectly define the salinity, and it would precipitate or not depending on the process... what equipment would you like to simulate to process seawater?
Regards
Daniel
Hi Daniel,
I suggest to include for the sea water the model proposed by IAPWS becasue the data are regressed on a large amount of sea water types and therefore more general. http://www.iapws.org/relguide/Advise5.html.
I am agreed with your suggestion to include the salinity as "Salt".
Thank you and regards.
Cristian
Hi Daniel,
for the viscosity, please refer to "Fundamental of salt water desalination". In the appendix A there are several relations on the sea water.
Regards.
Cristian
Hi Cristian,
My implementation uses the SIA library which is based on IAPWS-08: http://www.teos-10.org/software.htm#2
Some missing property calculations were taken from here: http://web.mit.edu/seawater/
Maximum salinity for correlations is 0.12 kg/kg, but DWSIM will calculate equilibrium up to saturation (0.36) and then precipitate the excess as a solid phase.
Regards
Daniel
Hi Daniel,
the relations are the same. For me is perfect because I work in the O&G water treatments and the desalination is one of the most important processes.
Regards.
Cristian
Hi Daniel,
I used the sea water model and works very well. I have only a note about the definition of the salinity. Is better that you indicate the salinity not only NaCl but with the terms TDS (total dissolved solid) because the seawater that we are treating contains not only NaCl but also other compounds that could be affected during several treatments.
Thank you.
Regards.
Cristian
Hi Cristian,
Thanks, I'm glad it works for you. Regarding my definition, where exactly should I change it? The "salt" compound is based on NaCl but that doesn't actually mean anything other than showing compound properties from it. All water properties are calculated by the library, I mean, it doesn't care if the salt is NaCl or not...
Daniel
Last edit: Daniel Medeiros 2015-11-26
Hi Daniel,
I tried to adapt with proper custom unit operations (that I will send to you for your use) DWSIM for the water treatment world. I mean reverse osmosis, ultrafiltration, biological oxidation, etc... and I tried to work with the salinity compunds of the water with equilibrium and conversion reactions for having the different electrolyte composition in the water during the different dosing/pH corrections, etc.... The salinity expressed in the IAPWS that you have correctly introduced is based on the total amount of the ions dissolved in the water (Na+, Cl-, K+, etc....) that is defined as TDS. The other compounds that I have introduced into the water is the TSS (total suspended solids), BOD, COD, etc.... Is the reason because I suggest to use the term TDS instead of NaCl.
In addition, in the composition of the water that characterize the material stream, I suggest to include also the term ppm in the concentration field.
I think that DWSIM, with the custom, flowsheet and spreadsheet unit operation is very usefull for the application in the water treatment world.
Thank you for your help.
Regards.
Cristian
Hi Cristian,
Thanks for the explanation.
The reason for choosing NaCl as the base for the "Salt" compound is just for simulation purposes. Since the model must be able to handle precipitation of this "salt" compound as a solid, I chose to start with NaCl, which is the salt present in the highest amount in seawater.
With the base properties inherited from NaCl, you'll have a better solid phase description than if I had chosen another "random" salt. The other option is to rigorously simulate all salts and ions with water, describe the dissociation reactions and use the Electrolyte Property Package, but it is almost certain not to work yet because of convergence issues that I'm still trying to figure out...
I don't know much about desalination processes, it would be really nice to get some info about it. If you agree, we can include your simulations as samples to be distributed together with DWSIM.
Regards
Daniel