add convinient set_design_result method

biosteam/_unit.py

@@ -935,6 +935,34 @@ def get_design_result(self, key: str, units: str):
  """
  return convert(self.design_results[key], self._units[key], units)
 
+
+ def set_design_result(self, key: str, units: str, value: float):
+ """
+ Set design result in given the units of measure.
+ 
+ Parameters
+ ----------
+ key :
+ Name of design result.
+ units :
+ Units of measure.
+ value:
+ Value of the design result.
+ 
+ Examples
+ --------
+ >>> import biosteam as bst
+ >>> bst.settings.set_thermo(['Water'], cache=True)
+ >>> feed = bst.Stream(None, Water=100)
+ >>> tank = bst.StorageTank(None, feed)
+ >>> tank.simulate()
+ >>> tank.set_design_result('Total volume', 'm3', 1000)
+ >>> tank.get_design_result('Total volume', 'm3')
+ 1000.0
+ 
+ """
+ self.design_results[key] = convert(value, units, self._units[key])
+
  def reset_cache(self, isdynamic=None):
  pass
 

biosteam/facilities/_boiler_turbogenerator.py

@@ -228,7 +228,7 @@ def __init__(self, ID='', ins=None,
  if satisfy_system_electricity_demand is None: satisfy_system_electricity_demand = True
  if fuel_source is None: fuel_source = 'CH4'
  if oxygen_rich_gas_composition is None: oxygen_rich_gas_composition = dict(O2=21, N2=79, phase='g', units='kg/hr')
- if CO2_emissions_concentration is None: CO2_emissions_concentration = 0.055 # Usually between 4 - 7 for biomass and natural gas
+ if CO2_emissions_concentration is None: CO2_emissions_concentration = 0.055 # Usually between 4 - 7 for biomass and natural gas (https://www.sciencedirect.com/science/article/pii/S0957582021005127)
  bst.Facility.__init__(self, ID, ins, outs, thermo)
  settings = bst.settings
  self.boiler_efficiency_basis = boiler_efficiency_basis