Consultation about HXN

[zasddsgg]

Hello, may I ask you some questions about HXN? Thanks for your help. Wish you a good day.

a) If there is already heat exchange in the process, such as where ethanol is recovered in cellulosic model, do I need to cancel the heat exchange and then proceed to HXN?

b) Is it necessary to re-build the process according to the heat exchange scheme after the execution of HXN? For example, the original heat exchange is cancelled, and with the new heat exchange scheme, the position and number of heat exchangers may change, resulting in the need to re-build the process?

c) In the already reported article on BioSTEAM, has the process been reconfigured according to the HXN recommended heat transfer scheme? Or is the process before HXN still used (just add HXN unit in the process before HXN, so the process is still the process before HXN), but the reported TEA and LCA results are after HXN has been performed?

d) Is there any other bio-refining process in BioSTEAM that first does the heat transfer of ethanol recovery and then executes HXN?

e) When executing HXN, why is heat transfer sometimes performed by all units (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/cane/systems/sugarcane/sugar_ethanol.py#L60) and sometimes between several units (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/cane/systems/sugarcane/ethanol.py#L87-L88)?

f) If there are already heat exchange units in the process, do these units need to be deducted when executing HXN? or BioSTEAM will automatically re-exchange heat for all units, including above already heat exchange units? Or does BioSTEAM not take into account units that have already performed heat transfer when performing HXN, only perform HXN on units that have not performed heat transfer?

g) After BioSTEAM executes HXN, how can we see that the infrastructure cost will be increased (https://biosteam.readthedocs.io/en/latest/API/facilities/HeatExchangerNetwork.html#:~:text=The%20heat%20exchanger%20network%20reduces%20the%20heating%20and%20cooling%20utility%20requirements%20of%20the%20system%20and%20may%20add%20additional%20capital%20cost.)? Will additional heat exchangers be added after BioSTEAM executes HXN？

h) If some units have already exchanged heat through bilateral heat exchangers (HXprocess unit), will they re-participate in the heat exchange network optimization after BioSTEAM executes HXN?

i) After BioSTEAM executes HXN, could I consult you how to check the steam consumption and power consumption of the process after HXN?

j) Could I trouble you take some time to look at the question #115 about HXN.

[zasddsgg]

Hello, could I trouble you take some time to look at this problem. Thanks for your help. Wish you a good day.

[sarangbhagwat]

Hi @zasddsgg,

The HXN facility automatically designs a full heat exchanger network based on your system's heating and cooling demand units. Then, from system results, it removes the installed equipment costs associated with the original heat exchangers, adds the installed equipment costs associated with the newly designed heat exchangers, and adds negative duties and flows for heating and cooling utility agents based on the saved amounts. Your system diagram will still show all original heat exchangers, but no further changes to the system will be needed.

Hope this helps! Sarang

[zasddsgg]

Thank you for your answer.

a) Is the Itemized costs, Cash flow and Utilities data table in excel exported after HXN execution still the cost before HXN execution? Where is the installed equipment costs associated with the newly designed heat exchangers in excel after HXN execution? Is the installed equipment costs associated with the newly designed heat exchangers taken into account when TEA is executed after HXN execution (HXN = bst.HeatExchangerNetwork('HXN', T_min_app = 10), tea = create_tea(sys))?

b) So after HXN execution, do the results of TEA and LCA reported in the article, as well as the results of uncertainty analysis, refer to the results after HXN execution? The process flow diagram in the article (sys.diagram ('thorough')) still use the process flow diagram before HXN execution, right?

c) Is the cost of the areas obtained by code bst.process_tools.UnitGroup.df_from_groups(area_groups) also the cost of the areas prior to executing HXN?

d) Could I trouble you look at the other questions in this issue? Thanks for your help. Wish you a good day.