Questions about OilHeatExchanger/HydronicHeatExchanger about qsdsan HOT 20 CLOSED

Are power_delivery_orc and pipe_heat_loss used anywhere?

Similarly, heat_output_water and heat_loss_water_pipe?

from qsdsan.

How come there's 4/200 of an HX and 2.834/2.7 of a pump?

Similarly for Pump here:

If adjusting cost based on flow rate, the cost decorator should be used

from qsdsan.

The _run method of HydronicHeatExchanger does not include simulation of streams (and OilHeatExchanger does not set the phase of hot_gas_in), if effluents and influents are the same (or have the same mass flow), then something like hot_gas_out.copy_like(hot_gas_in) should be included

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For DryerFromHHX (as well as OilHeatExchanger and HydronicHeaExchanger)

• I don't see how energy balance is calculated
• And heat_in (assuming it's referring to the energy?) should not be a stream, a stream should be created to carry the energy information
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 46 in e9fdbf1

  Dewatered solids, heat.

• What if this happens?
• This calculation is not correct
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 97 in e9fdbf1

  # set necessary moisture content of effluent as 35%

  
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 105 in e9fdbf1

  # if heat_needed_to_dry_35 > heat_supplied:

• Do we want to add this or not?
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 119 in e9fdbf1

  # add conversion factor for COD to TC?

• The following is not correct, there should be a conversion from CO2/CH4 to C, and it didn't adjust the volume correctly
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 129 in e9fdbf1

  waste_out._COD = (waste_in.COD * (waste_in.F_vol/waste_out.F_vol)) - ((drying_CO2_to_air + drying_CH4_to_air) / self.carbon_COD_ratio)

• Why C calculation is commented out?
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 132 in e9fdbf1

  # waste_out.imass['C'] -= ((drying_CO2_to_air + drying_CH4_to_air))

• The following is not correct, there should be a conversion from NH3 to N
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 134 in e9fdbf1

  waste_out.imass['N'] -= drying_NH3_to_air

• Are these really being used?

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 137 in e9fdbf1

  # jacket loss data and calculate losses due to convection and radiation

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Based on the description, the OilHeatExchanger should something to burn to generate the heat, the stream is currently not included in the unit.

The OHX leverages heat produced in the carbonizer base. It does not generate the heat.

from qsdsan.

Are power_delivery_orc and pipe_heat_loss used anywhere?

QSDsan/qsdsan/sanunits/_oil_heat_exchanger.py

Line 94 in e9fdbf1

self.power_delivery_orc = self.oil_flowrate * ((273.15 + self.oil_temp_out) - (273.15 + self.oil_temp_in)) * self.oil_density * self.oil_specific_heat * (60/1000) # MJ/hr

Similarly, heat_output_water and heat_loss_water_pipe?

QSDsan/qsdsan/sanunits/_hydronic_heat_exchanger.py

Line 100 in e9fdbf1

self.heat_output_water = self.water_flowrate * ((273.15 + self.water_out_temp) - (273.15 + self.water_in_temp)) * self.water_density_kg_m_3 * self.water_heat_capacity_k_j_kg_k * (60/1000) # MJ/hr

You are correct that these values are not used. These calculations are intended to be used for future research on the heat balance of the system and are not used in the current analysis.

from qsdsan.

The _run method of HydronicHeatExchanger does not include simulation of streams (and OilHeatExchanger does not set the phase of hot_gas_in), if effluents and influents are the same (or have the same mass flow), then something like hot_gas_out.copy_like(hot_gas_in) should be included

You are correct. Added on my end. Thanks!

from qsdsan.

How come there's 4/200 of an HX and 2.834/2.7 of a pump?

QSDsan/qsdsan/sanunits/_oil_heat_exchanger.py

Line 103 in e9fdbf1

design['OilHeatExchanger'] = OHX_quant = (4/200)

QSDsan/qsdsan/sanunits/_oil_heat_exchanger.py

Line 104 in e9fdbf1

design['Pump'] = Pump_quant = (2.834/2.27)

Similarly for Pump here:

QSDsan/qsdsan/sanunits/_hydronic_heat_exchanger.py

Line 114 in e9fdbf1

design['Pump'] = Pump_quant = (17.2/2.72)

If adjusting cost based on flow rate, the cost decorator should be used

These assumptions were made to scale the size equipment based on availability of data for the LCA. Should a comment be added to example these assumptions?

from qsdsan.

Calculations pertaining to the heat balance were added to be leveraged for future research.

breakpoint() for moisture content was added as a check when code was under development and can be removed.

CO2/CH4 to C and NH4 to N were updated on my end. Thanks!

Carbon balance was done based on COD to be consistent between units. C calculations that are commented out can be removed here.

For DryerFromHHX (as well as OilHeatExchanger and HydronicHeaExchanger)

• I don't see how energy balance is calculated

• And heat_in (assuming it's referring to the energy?) should not be a stream, a stream should be created to carry the energy information
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 46 in e9fdbf1

  Dewatered solids, heat.

• What if this happens?

• This calculation is not correct
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 97 in e9fdbf1

  # set necessary moisture content of effluent as 35%

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 105 in e9fdbf1

  # if heat_needed_to_dry_35 > heat_supplied:

• Do we want to add this or not?
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 119 in e9fdbf1

  # add conversion factor for COD to TC?

• The following is not correct, there should be a conversion from CO2/CH4 to C, and it didn't adjust the volume correctly
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 129 in e9fdbf1

  waste_out._COD = (waste_in.COD * (waste_in.F_vol/waste_out.F_vol)) - ((drying_CO2_to_air + drying_CH4_to_air) / self.carbon_COD_ratio)

• Why C calculation is commented out?
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 132 in e9fdbf1

  # waste_out.imass['C'] -= ((drying_CO2_to_air + drying_CH4_to_air))

• The following is not correct, there should be a conversion from NH3 to N
  

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 134 in e9fdbf1

  waste_out.imass['N'] -= drying_NH3_to_air

• Are these really being used?

  QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

  Line 137 in e9fdbf1

  # jacket loss data and calculate losses due to convection and radiation

Calculations pertaining to the heat balance were added to be leveraged for future research.

breakpoint() for moisture content was added as a check when code was under development and can be removed.

CO2/CH4 to C and NH4 to N were updated on my end. Thanks!

Carbon balance was done based on COD to be consistent between units. C calculations that are commented out can be removed here.

from qsdsan.

A note has been added in the documentation of this class to reflect this

The OHX leverages heat produced in the carbonizer base. It does not generate the heat.

from qsdsan.

Left notes at these places (they are currently commented out to avoid unnecessary calculations)

You are correct that these values are not used. These calculations are intended to be used for future research on the heat balance of the system and are not used in the current analysis.

from qsdsan.

Also updated in the units used in the gates branch

You are correct. Added on my end. Thanks!

from qsdsan.

I've left notes on the documentation of these classes on this, on the gates branch

These assumptions were made to scale the size equipment based on availability of data for the LCA. Should a comment be added to example these assumptions?

from qsdsan.

I added a Warnings section in the documentation of these classes to note people that energy balance is not performed (since this is typically expected for a heat exchanger).

For HHXdryer, I also let it issue a warning (during simulation) when the calculated heat_needed_to_dry_35 exceeds heat_supplied (and turns out it exceeds a lot of times), @lsrowles just want to make sure you are aware of this

Calculations pertaining to the heat balance were added to be leveraged for future research.

from qsdsan.

I've removed this in the gates branch

breakpoint() for moisture content was added as a check when code was under development and can be removed.

from qsdsan.

I changed the following line

to (note the inclusion of methane)
waste_out._COD = (waste_in.COD*waste_in.F_vol - (drying_CO2_to_air/44*12+drying_CH4_to_air/16*12) / self.carbon_COD_ratio)

And

to
waste_out.imass['N'] -= drying_NH3_to_air / 17 * 14

With notes that 44/12/16/17/14 are molecular weights of CO2/C/CH4/NH3/N

@lsrowles let me know if this doesn't look correct to you, especially concerning the methane thing

CO2/CH4 to C and NH4 to N were updated on my end. Thanks!

from qsdsan.

Sounds great, I think this also explains the question you had when we were discussing about this issue, I've removed these legacy comments in the gates branch

Carbon balance was done based on COD to be consistent between units. C calculations that are commented out can be removed here.

from qsdsan.

I added a Warnings section in the documentation of these classes to note people that energy balance is not performed (since this is typically expected for a heat exchanger).

For HHXdryer, I also let it issue a warning (during simulation) when the calculated heat_needed_to_dry_35 exceeds heat_supplied (and turns out it exceeds a lot of times), @lsrowles just want to make sure you are aware of this

Calculations pertaining to the heat balance were added to be leveraged for future research.

The calculations for heat_supplied are not accurate because the area_surface here is just an assumed valued. It is a hypothetical surface area. I added these calculations for future research on the system to leverage. Would you fix the reference in _dryer_from_hhx.tsv for area_surface to be assumed, please? Thanks!

from qsdsan.

OK I've fixed it in de0ac1a!

Would you fix the reference in _dryer_from_hhx.tsv for area_surface to be assumed, please?

from qsdsan.

There's a minor bug in the fixes below and it's been fixed in 39e4479, all problems in this issue have been fixed

I changed the following line

QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

Line 129 in e9fdbf1

waste_out._COD = (waste_in.COD * (waste_in.F_vol/waste_out.F_vol)) - ((drying_CO2_to_air + drying_CH4_to_air) / self.carbon_COD_ratio)

to (note the inclusion of methane) waste_out._COD = (waste_in.COD*waste_in.F_vol - (drying_CO2_to_air/44*12+drying_CH4_to_air/16*12) / self.carbon_COD_ratio)

And

QSDsan/qsdsan/sanunits/_dryer_from_hhx.py

Line 134 in e9fdbf1

waste_out.imass['N'] -= drying_NH3_to_air

to waste_out.imass['N'] -= drying_NH3_to_air / 17 * 14

With notes that 44/12/16/17/14 are molecular weights of CO2/C/CH4/NH3/N

@lsrowles let me know if this doesn't look correct to you, especially concerning the methane thing

CO2/CH4 to C and NH4 to N were updated on my end. Thanks!

from qsdsan.