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Made necessary changes to centrifuge
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Changed pump settings and using exponent scaling for equipments in dewatering unit.
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@RaiSaumitra
RaiSaumitra committed Aug 10, 2023
1 parent 3558014 commit c980302
Showing 1 changed file with 41 additions and 41 deletions.
82 changes: 41 additions & 41 deletions qsdsan/sanunits/_sludge_treatment.py
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Original file line number Diff line number Diff line change
Expand Up @@ -672,24 +672,26 @@ def __init__(self, ID='', ins=None, outs=(), thermo=None, isdynamic=False,
'Volume of bowl': 'm3',

'Stainless steel for bowl': 'kg',
'Stainless steel for conveyor': 'kg',

'Polymer feed rate': 'kg/hr',
'Pump pipe stainless steel' : 'kg',
'Pump stainless steel': 'kg'
'Pump stainless steel': 'kg',
'Number of pumps': '?'
}


def _design_pump(self):
ID, pumps = self.ID, self.pumps
self._inf.copy_like(self._mixed)

self._sludge.copy_like(self.outs[0])
sludge = self._sludge
ins_dct = {
'inf': self._inf,
'sludge': sludge,
}

type_dct = dict.fromkeys(pumps, '')
type_dct = dict.fromkeys(pumps, 'sludge')
inputs_dct = dict.fromkeys(pumps, (1,))

D = self.design_results
influent_Q = sludge.get_total_flow('m3/hr')/D['Number of centrifuges']
influent_Q_mgd = influent_Q*0.00634 # m3/hr to MGD

for i in pumps:
if hasattr(self, f'{i}_pump'):
Expand All @@ -700,11 +702,11 @@ def _design_pump(self):
capacity_factor=1
# No. of pumps = No. of influents
pump = WWTpump(
ID=ID, ins=ins_dct[i], pump_type=type_dct[i],
Q_mgd=None, add_inputs=inputs_dct[i],
ID=ID, ins= ins_dct[i], pump_type=type_dct[i],
Q_mgd=influent_Q_mgd, add_inputs=inputs_dct[i],
capacity_factor=capacity_factor,
include_pump_cost=True,
include_building_cost=True,
include_building_cost=False,
include_OM_cost=True,
)
setattr(self, f'{i}_pump', pump)
Expand All @@ -713,30 +715,28 @@ def _design_pump(self):
for i in pumps:
p = getattr(self, f'{i}_pump')
p.simulate()
# try: p.simulate()
# except: breakpoint()
p_design = p.design_results
pipe_ss += p_design['Pump pipe stainless steel']
pump_ss += p_design['Pump stainless steel']
return pipe_ss, pump_ss


def _design(self):

self._mixed.mix_from(self.ins)
mixed = self._mixed

D = self.design_results
TSS_rmv = self._TSS_rmv
solids_feed_rate = 44.66*self.solids_feed_rate # 44.66 is factor to convert tonne/day to kg/hr
# Cake's total solids and TSS are essentially the same (pg. 24-6 [3])
# If TSS_rmv = 98, then total_mass_dry_solids_removed = (0.98)*(influent TSS mass)
total_mass_dry_solids_removed = (TSS_rmv/100)*((self._mixed.get_TSS()*self.ins[0].F_vol)/1000) # in kg/hr
total_mass_dry_solids_removed = (TSS_rmv/100)*((mixed.get_TSS()*self.ins[0].F_vol)/1000) # in kg/hr
D['Number of centrifuges'] = np.ceil(total_mass_dry_solids_removed/solids_feed_rate)
k = 0.00000056 # Based on emprical formula (pg. 24-23 of [3])
g = 9.81 # m/s2
# The inner diameterof the bowl is calculated based on an empirical formula. 1000 is used to convert mm to m.
D['Diameter of bowl'] = (self.g_factor*g)/(k*np.square(self.rotational_speed)*1000) # in m
D['Total length of bowl'] = self.LtoD*D['Diameter']
D['Total length of bowl'] = self.LtoD*D['Diameter of bowl']
# Sanity check: L should be between 1-7 m, diameter should be around 0.25-0.8 m (Source: [4])

fraction_cylindrical_portion = 0.8
Expand All @@ -753,40 +753,38 @@ def _design(self):
density_ss = 7930 # kg/m3, 18/8 Chromium
D['Stainless steel for bowl'] = D['Volume of bowl']*density_ss # in kg

Inner_diameter_conveyor = 0.108 # in m (based on Alibaba's product)
Length_screw_conveyor = D['Total length of bowl'] # in m
thickness_conveyor_wall = 0.01 # in m (!!! NEED A RELIABLE SOURCE !!!)
Outer_diameter_conveyor = Inner_diameter_conveyor + 2*thickness_conveyor_wall
Cylinder_conveyor_volume = np.pi*(np.square(Outer_diameter_conveyor/2) - np.square(Inner_diameter_conveyor/2))*Length_screw_conveyor # in m2

outer_projection_screw = 0.05 # in m (!!! NEED A RELIABLE SOURCE !!!)
Outer_diameter_screw = Outer_diameter_conveyor + 2*outer_projection_screw
thickness_screw = 0.01 # in m (!!! NEED A RELIABLE SOURCE !!!)
number_of_screws_per_unit_length = 10 # in m-1 (!!! NEED A RELIABLE SOURCE !!!)
Number_of_circles_in_screw = D['Total length of bowl']*number_of_screws_per_unit_length # !!! NEED A RELIABLE SOURCE !!!
Screw_volume = np.pi*(np.square(Outer_diameter_screw/2) - np.square(Outer_diameter_conveyor/2))*thickness_screw*Number_of_circles_in_screw # in m3
D['Stainless steel for conveyor'] = (Cylinder_conveyor_volume + Screw_volume)*density_ss # in kg

polymer_dosage_rate = 0.000453592*self.polymer_dosage # convert from (lbs, polymer/tonne, solids) to (kg, polymer/kg, solids)
D['Polymer feed rate'] = (polymer_dosage_rate*solids_feed_rate) # in kg, polymer/hr

# Pumps
pipe, pumps = self._design_pump()
D['Pump pipe stainless steel'] = pipe
D['Pump stainless steel'] = pumps

# design['Projected Area at Inlet'] = np.pi*np.square(design['Diameter']/2) #in m2
# design['Hydraulic_Loading'] = (self.ins[0].F_vol*24)/design['Projected Area at Inlet'] #in m3/(m2*day)
# For centrifuges
D['Number of pumps'] = D['Number of centrifuges']

def _cost(self):

D = self.design_results
C = self.baseline_purchase_costs

self._mixed.mix_from(self.ins)
mixed = self._mixed

# Construction of concrete and stainless steel walls
C['Bowl stainless steel'] = D['Number of centrifuges']*D['Stainless steel for bowl']*self.stainless_steel_unit_cost
C['Conveyor stainless steel'] = D['Number of centrifuges']*D['Stainless steel for conveyor']*self.screw_conveyor_unit_cost_by_weight
# C['Conveyor stainless steel'] = D['Number of centrifuges']*D['Stainless steel for conveyor']*self.screw_conveyor_unit_cost_by_weight
C['Polymer'] = D['Number of centrifuges']*D['Polymer feed rate']*self.polymer_cost_by_weight

# Conveyor
# Source: https://www.alibaba.com/product-detail/Engineers-Available-Service-Stainless-Steel-U_60541536633.html?spm=a2700.galleryofferlist.normal_offer.d_title.1fea1f65v6R3OQ&s=p
base_cost_conveyor = 1800
base_flow_conveyor = 10 # in m3/hr
thickener_flow = mixed.get_total_flow('m3/hr')/D['Number of centrifuges']
C['Conveyor'] = D['Number of centrifuges']*base_cost_conveyor*(thickener_flow/base_flow_conveyor)**0.6
base_power_conveyor = 2.2 # in kW
conveyor_power = D['Number of centrifuges']*base_power_conveyor*(thickener_flow/base_flow_conveyor)**0.6

# Pump (construction and maintainance)
pumps = self.pumps
add_OPEX = self.add_OPEX
Expand All @@ -804,10 +802,10 @@ def _cost(self):
opex_o += p_add_opex['Pump operating']
opex_m += p_add_opex['Pump maintenance']

C['Pumps'] = pump_cost
C['Pump building'] = building_cost
add_OPEX['Pump operating'] = opex_o
add_OPEX['Pump maintenance'] = opex_m
C['Pumps'] = pump_cost*D['Number of pumps']
C['Pump building'] = building_cost*D['Number of pumps']
add_OPEX['Pump operating'] = opex_o*D['Number of pumps']
add_OPEX['Pump maintenance'] = opex_m*D['Number of pumps']

# Power
pumping = 0.
Expand All @@ -816,8 +814,10 @@ def _cost(self):
if p is None:
continue
pumping += p.power_utility.rate
self.power_utility.rate = pumping


pumping = pumping*D['Number of pumps']
self.power_utility.rate += pumping
self.power_utility.rate += conveyor_power
# %%

class Incinerator(SanUnit):
Expand All @@ -840,7 +840,7 @@ class Incinerator(SanUnit):
The calorific value of influent sludge in KJ/kg. The default value used is 12000 KJ/kg.
calorific_value_fuel : float
The calorific value of fuel employed for combustion in KJ/kg.
The default fuel is natural gas with calofific value of 50000 KJ/kg.
The default fuel is natural gas with calorific value of 50000 KJ/kg.
Examples
--------
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