- expressionExpression to parse to create the function to evaluate
C++ Type:FunctionExpression
Unit:(no unit assumed)
Controllable:No
Description:Expression to parse to create the function to evaluate
ParsedChainControl
This ChainControl allows the user to specify a function expression to be parsed and evaluated to populate a new ChainControlData named <control>:value, where <control> is the user-given name of the ParsedChainControl.
See ChainControlParsedFunctionWrapper for a list of acceptable types of values for the entries in "symbol_values" and acceptable syntax for "expression".
Input Parameters
- depends_onThe Controls that this control relies upon (i.e. must execute before this one)
C++ Type:std::vector<std::string>
Controllable:No
Description:The Controls that this control relies upon (i.e. must execute before this one)
- execute_onINITIAL TIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
Default:INITIAL TIMESTEP_END
C++ Type:ExecFlagEnum
Options:XFEM_MARK, FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, LINEAR_CONVERGENCE, NONLINEAR, NONLINEAR_CONVERGENCE, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, MULTIAPP_FIXED_POINT_CONVERGENCE, MULTISYSTEM_FIXED_POINT_ITERATION_END, FINAL, FAILED, CUSTOM, PRE_MULTIAPP_SETUP
Controllable:No
Description:The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
- point0 0 0Spatial point at which to evaluate the function
Default:0 0 0
C++ Type:libMesh::Point
Controllable:No
Description:Spatial point at which to evaluate the function
- symbol_namesSymbols (excluding t,x,y,z) that are bound to the values provided by the corresponding items in the symbol_values vector.
C++ Type:std::vector<std::string>
Controllable:No
Description:Symbols (excluding t,x,y,z) that are bound to the values provided by the corresponding items in the symbol_values vector.
- symbol_valuesConstant numeric values, postprocessor names, function names, and scalar variables corresponding to the symbols in symbol_names.
C++ Type:std::vector<std::string>
Controllable:No
Description:Constant numeric values, postprocessor names, function names, and scalar variables corresponding to the symbols in symbol_names.
Optional Parameters
- control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
- enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.
- implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Controllable:No
Description:Determines whether this object is calculated using an implicit or explicit form
Advanced Parameters
Input Files
- (test/tests/chaincontrols/parsed_chain_control/parsed_chain_control.i)
- (test/tests/chaincontrols/activate_objects_once/activate_objects_then_deactivate_logic.i)
- (test/tests/chaincontrols/pid_chain_control/pid_chain_control.i)
- (modules/thermal_hydraulics/test/tests/problems/brayton_cycle/recuperated_brayton_cycle.i)
symbol_values
C++ Type:std::vector<std::string>
Controllable:No
Description:Constant numeric values, postprocessor names, function names, and scalar variables corresponding to the symbols in symbol_names.
expression
C++ Type:FunctionExpression
Unit:(no unit assumed)
Controllable:No
Description:Expression to parse to create the function to evaluate
(test/tests/chaincontrols/parsed_chain_control/parsed_chain_control.i)
# Tests ParsedChainControl
#
# The following test functions are used:
# myvar: u = 4
# myfn: f(x,y,z,t) = x * (t + 5)
# ctrl_fn: g(x,y,z,t) = y * (t + 2)
#
# real_ctrl: h(t) = g(x=0,y=1,z=0,t)
# parsed_ctrl: j(t) = f(x=1,y=2,z=3,t) + u + real_ctrl:value + 1 + 0 + x(=1) + y(=2) + z(=3) + t + 3
# = t + 5 + 4 + real_ctrl:value + 1 + 0 + 1 + 2 + 3 + t + 3
# = real_ctrl:value + 2*t + 19
#
# Note controls execute BEFORE post-processors, except for INITIAL, so here
# the initial PP value is incorrect, but the others are correct:
# INITIAL:
# test_pp <- parsed_ctrl:value = 0
# real_ctrl:value <- h(0) = 0
# parsed_ctrl:value <- j(0) = 19
# TIMESTEP_END (t = 1):
# real_ctrl:value <- h(1) = 3
# parsed_ctrl:value <- j(1) = 24
# test_pp <- parsed_ctrl:value = 24
# TIMESTEP_END (t = 2):
# real_ctrl:value <- h(1) = 4
# parsed_ctrl:value <- j(1) = 27
# test_pp <- parsed_ctrl:value = 27
# TIMESTEP_END (t = 3):
# real_ctrl:value <- h(1) = 5
# parsed_ctrl:value <- j(1) = 30
# test_pp <- parsed_ctrl:value = 30
[Mesh]
type = GeneratedMesh
dim = 1
nx = 1
[]
[Functions]
[myfn]
type = ParsedFunction
expression = 'x * (t + 5)'
[]
[ctrl_fn]
type = ParsedFunction
expression = 'y * (t + 2)'
[]
[]
[AuxVariables]
[myvar]
family = SCALAR
order = FIRST
initial_condition = 4
[]
[]
[Postprocessors]
[test_pp]
type = ChainControlDataPostprocessor
chain_control_data_name = parsed_ctrl:value
execute_on = 'INITIAL TIMESTEP_END'
[]
[]
[ChainControls]
[real_ctrl]
type = GetFunctionValueChainControl
function = ctrl_fn
point = '0 1 0'
[]
[true_ctrl]
type = ConstantBoolChainControl
value = true
[]
[false_ctrl]
type = ConstantBoolChainControl
value = false
[]
[parsed_ctrl]
type = ParsedChainControl
expression = 'fn + u + realval + trueval + falseval + x + y + z + t + num'
symbol_names = 'fn u realval trueval falseval num'
symbol_values = 'myfn myvar real_ctrl:value true_ctrl:value false_ctrl:value 3.0'
point = '1 2 3'
[]
[]
[Problem]
solve = false
[]
[Executioner]
type = Transient
dt = 1
num_steps = 3
[]
[Outputs]
csv = true
[]
(test/tests/chaincontrols/activate_objects_once/activate_objects_then_deactivate_logic.i)
# Tests tripping a boolean then disabling it on the next time step
!include base.i
[Functions]
[heaviside]
type = ParsedFunction
expression = 'if(t>1.1, 1, 0)'
[]
[]
[ChainControls]
[false_then_true]
type = GetFunctionValueChainControl
function = 'heaviside'
execute_on = 'INITIAL TIMESTEP_END'
[]
[convert_to_bool]
type = RealToBoolChainControl
input = 'false_then_true:value'
[]
[has_activated]
type = UnitTripChainControl
input = convert_to_bool:value
trip_on_true = true
[]
[has_activated_old]
type = UnitTripChainControl
input = convert_to_bool:value
trip_on_true = true
use_old_input = true
[]
# This chain control lets us perform the flip so the control activates objects for a single time step
[should_activate]
type = ParsedChainControl
expression = 'if(has_activated,if(was_activated, 0, 1), 0)'
symbol_names = 'has_activated was_activated'
symbol_values = 'has_activated:tripped has_activated_old:tripped'
[]
[convert_should_activate_to_bool]
type = RealToBoolChainControl
input = 'should_activate:value'
[]
[set_value_ctrl]
type = SetBoolValueChainControl
parameter = Postprocessors/test_pp/enable
value = convert_should_activate_to_bool:value
execute_on = 'INITIAL TIMESTEP_END'
[]
[]
[Postprocessors]
[test_pp]
type = FunctionValuePostprocessor
function = test_fn
execute_on = 'INITIAL TIMESTEP_END'
[]
[]
(test/tests/chaincontrols/pid_chain_control/pid_chain_control.i)
# Tests PIDChainControl
#
# The PID controller is used to solve the equation y(alpha) = alpha^2 = 25 for alpha.
# Each time step takes one iteration, and these iterations should be converging to alpha = 5.
[Mesh]
type = GeneratedMesh
dim = 1
nx = 1
[]
[ChainControls]
[get_alpha_ctrl]
type = GetPostprocessorChainControl
postprocessor = pid
[]
[y_ctrl]
type = ParsedChainControl
expression = 'alpha^2'
symbol_names = 'alpha'
symbol_values = 'get_alpha_ctrl:value'
[]
[y_set_ctrl]
type = ParsedChainControl
expression = '25'
[]
[pid_ctrl]
type = PIDChainControl
input = y_ctrl:value
set_point = y_set_ctrl:value
K_p = 0.1
K_i = 0.01
K_d = 0.001
[]
[]
[Postprocessors]
[pid]
type = ChainControlDataPostprocessor
chain_control_data_name = pid_ctrl:value
execute_on = 'INITIAL TIMESTEP_END'
[]
[]
[Problem]
solve = false
[]
[Executioner]
type = Transient
dt = 1
num_steps = 50
[]
[Outputs]
csv = true
[]
(modules/thermal_hydraulics/test/tests/problems/brayton_cycle/recuperated_brayton_cycle.i)
# This input file models an open, recuperated Brayton cycle with a PID
# controlled start up using a coupled motor.
#
# Heat is supplied to the system by a volumetric heat source, and a second heat
# source is used to model a recuperator. The recuperator transfers heat from the
# turbine exhaust gas to the compressor outlet gas.
#
# Initially the fluid and heat structures are at rest at ambient conditions,
# and the shaft speed is zero.
# The transient is controlled as follows:
# * 0 - 2000 s: Motor increases shaft speed to approx. 85,000 RPM by PID control
# * 1000 - 8600 s: Power in main heat source increases from 0 - 104 kW
# * 2000 - 200000 s: Torque supplied by turbine increases to steady state level
# as working fluid temperature increases. Torque supplied by
# the motor is ramped down to 0 N-m transitioning shaft control
# to the turbine at its rated speed of 96,000 RPM.
I_motor = 1.0
I_generator = 1.0
generator_torque_per_shaft_speed = -0.00025
motor_ramp_up_duration = 3605
motor_ramp_down_duration = 1800
post_motor_time = 2160000
t1 = ${motor_ramp_up_duration}
t2 = ${fparse t1 + motor_ramp_down_duration}
t3 = ${fparse t2 + post_motor_time}
D1 = 0.15
D2 = ${D1}
D3 = ${D1}
D4 = ${D1}
D5 = ${D1}
D6 = ${D1}
D7 = ${D1}
D8 = ${D1}
A1 = ${fparse 0.25 * pi * D1^2}
A2 = ${fparse 0.25 * pi * D2^2}
A3 = ${fparse 0.25 * pi * D3^2}
A4 = ${fparse 0.25 * pi * D4^2}
A5 = ${fparse 0.25 * pi * D5^2}
A6 = ${fparse 0.25 * pi * D6^2}
A7 = ${fparse 0.25 * pi * D7^2}
A8 = ${fparse 0.25 * pi * D8^2}
recuperator_width = 0.15
L1 = 5.0
L2 = ${L1}
L3 = ${fparse 2 * L1}
L4 = ${fparse 2 * L1}
L5 = ${L1}
L6 = ${L1}
L7 = ${fparse L1 + recuperator_width}
L8 = ${L1}
x1 = 0.0
x2 = ${fparse x1 + L1}
x3 = ${fparse x2 + L2}
x4 = ${x3}
x5 = ${fparse x4 - L4}
x6 = ${x5}
x7 = ${fparse x6 + L6}
x8 = ${fparse x7 + L7}
y1 = 0
y2 = ${y1}
y3 = ${y2}
y4 = ${fparse y3 - L3}
y5 = ${y4}
y6 = ${fparse y5 + L5}
y7 = ${y6}
y8 = ${y7}
x1_out = ${fparse x1 + L1 - 0.001}
x2_in = ${fparse x2 + 0.001}
y5_in = ${fparse y5 + 0.001}
x6_out = ${fparse x6 + L6 - 0.001}
x7_in = ${fparse x7 + 0.001}
y8_in = ${fparse y8 + 0.001}
y8_out = ${fparse y8 + L8 - 0.001}
hot_leg_in = ${y8_in}
hot_leg_out = ${y8_out}
cold_leg_in = ${fparse y3 - 0.001}
cold_leg_out = ${fparse y3 - (L3/2) - 0.001}
n_elems1 = 5
n_elems2 = ${n_elems1}
n_elems3 = ${fparse 2 * n_elems1}
n_elems4 = ${fparse 2 * n_elems1}
n_elems5 = ${n_elems1}
n_elems6 = ${n_elems1}
n_elems7 = ${n_elems1}
n_elems8 = ${n_elems1}
A_ref_comp = ${fparse 0.5 * (A1 + A2)}
V_comp = ${fparse A_ref_comp * 1.0}
I_comp = 1.0
A_ref_turb = ${fparse 0.5 * (A4 + A5)}
V_turb = ${fparse A_ref_turb * 1.0}
I_turb = 1.0
c0_rated_comp = 351.6925137
rho0_rated_comp = 1.146881112
rated_mfr = 0.25
speed_rated_rpm = 96000
speed_rated = ${fparse speed_rated_rpm * 2 * pi / 60.0}
speed_initial = 0
eff_comp = 0.79
eff_turb = 0.843
T_ambient = 300
p_ambient = 1e5
hs_power = 105750
[GlobalParams]
gravity_vector = '0 0 0'
initial_p = ${p_ambient}
initial_T = ${T_ambient}
initial_vel = 0
initial_vel_x = 0
initial_vel_y = 0
initial_vel_z = 0
fp = fp_air
closures = closures
f = 0
scaling_factor_1phase = '1 1 1e-5'
scaling_factor_rhoV = 1
scaling_factor_rhouV = 1e-2
scaling_factor_rhovV = 1e-2
scaling_factor_rhowV = 1e-2
scaling_factor_rhoEV = 1e-5
scaling_factor_temperature = 1e-2
rdg_slope_reconstruction = none
[]
[FluidProperties]
[fp_air]
type = IdealGasFluidProperties
emit_on_nan = none
[]
[]
[SolidProperties]
[steel]
type = ThermalFunctionSolidProperties
rho = 8050
k = 45
cp = 466
[]
[]
[Closures]
[closures]
type = Closures1PhaseSimple
[]
[]
[Functions]
##########################
# Motor
##########################
# Functions for control logic that determines when to shut off the PID system
[is_tripped_fn]
type = ParsedFunction
symbol_names = 'motor_torque turbine_torque'
symbol_values = 'motor_torque turbine_torque'
expression = 'turbine_torque > motor_torque'
[]
[PID_tripped_constant_value]
type = ConstantFunction
value = 1
[]
[PID_tripped_status_fn]
type = ParsedFunction
symbol_values = 'PID_trip_status'
symbol_names = 'PID_trip_status'
expression = 'PID_trip_status'
[]
[time_fn]
type = ParsedFunction
expression = t
[]
# Shutdown function which ramps down the motor once told by the control logic
[motor_torque_fn_shutdown]
type = ParsedFunction
symbol_values = 'PID_trip_status time_trip'
symbol_names = 'PID_trip_status time_trip'
expression = 'if(PID_trip_status = 1, max(2.4 - (2.4 * ((t - time_trip) / 35000)),0.0), 1)'
[]
[motor_torque_fn]
type = ConstantFunction
value = 0 # controlled
[]
# Generates motor power curve
[motor_power_fn]
type = ParsedFunction
expression = 'torque * speed'
symbol_names = 'torque speed'
symbol_values = 'motor_torque shaft:omega'
[]
##########################
# Generator
##########################
# Generates generator torque curve
[generator_torque_fn]
type = ParsedFunction
expression = 'slope * t'
symbol_names = 'slope'
symbol_values = '${generator_torque_per_shaft_speed}'
[]
# Generates generator power curve
[generator_power_fn]
type = ParsedFunction
expression = 'torque * speed'
symbol_names = 'torque speed'
symbol_values = 'generator_torque shaft:omega'
[]
##########################
# Reactor
##########################
# Ramps up reactor power when activated by control logic
[power_fn]
type = PiecewiseLinear
x = '0 1000 8600'
y = '0 0 ${hs_power}'
[]
##########################
# Compressor
##########################
# compressor pressure ratios
[rp_comp1]
type = PiecewiseLinear
data_file = 'rp_comp1.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_comp2]
type = PiecewiseLinear
data_file = 'rp_comp2.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_comp3]
type = PiecewiseLinear
data_file = 'rp_comp3.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_comp4]
type = PiecewiseLinear
data_file = 'rp_comp4.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_comp5]
type = PiecewiseLinear
data_file = 'rp_comp5.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
# compressor efficiencies
[eff_comp1]
type = ConstantFunction
value = ${eff_comp}
[]
[eff_comp2]
type = ConstantFunction
value = ${eff_comp}
[]
[eff_comp3]
type = ConstantFunction
value = ${eff_comp}
[]
[eff_comp4]
type = ConstantFunction
value = ${eff_comp}
[]
[eff_comp5]
type = ConstantFunction
value = ${eff_comp}
[]
##########################
# Turbine
##########################
# turbine pressure ratios
[rp_turb0]
type = ConstantFunction
value = 1
[]
[rp_turb1]
type = PiecewiseLinear
data_file = 'rp_turb1.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_turb2]
type = PiecewiseLinear
data_file = 'rp_turb2.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_turb3]
type = PiecewiseLinear
data_file = 'rp_turb3.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_turb4]
type = PiecewiseLinear
data_file = 'rp_turb4.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
[rp_turb5]
type = PiecewiseLinear
data_file = 'rp_turb5.csv'
x_index_in_file = 0
y_index_in_file = 1
format = columns
extrap = true
[]
# turbine efficiency
[eff_turb1]
type = ConstantFunction
value = ${eff_turb}
[]
[eff_turb2]
type = ConstantFunction
value = ${eff_turb}
[]
[eff_turb3]
type = ConstantFunction
value = ${eff_turb}
[]
[eff_turb4]
type = ConstantFunction
value = ${eff_turb}
[]
[eff_turb5]
type = ConstantFunction
value = ${eff_turb}
[]
[]
[Components]
# system inlet pulling air from the open atmosphere
[inlet]
type = InletStagnationPressureTemperature1Phase
input = 'pipe1:in'
p0 = ${p_ambient}
T0 = ${T_ambient}
[]
# Inlet pipe
[pipe1]
type = FlowChannel1Phase
position = '${x1} ${y1} 0'
orientation = '1 0 0'
length = ${L1}
n_elems = ${n_elems1}
A = ${A1}
[]
# Compressor as defined in MAGNET PCU document (Guillen 2020)
[compressor]
type = ShaftConnectedCompressor1Phase
position = '${x2} ${y2} 0'
inlet = 'pipe1:out'
outlet = 'pipe2:in'
A_ref = ${A_ref_comp}
volume = ${V_comp}
omega_rated = ${speed_rated}
mdot_rated = ${rated_mfr}
c0_rated = ${c0_rated_comp}
rho0_rated = ${rho0_rated_comp}
# Determines which compression ratio curve and efficiency curve to use depending on ratio of speed/rated_speed
speeds = '0.5208 0.6250 0.7292 0.8333 0.9375'
Rp_functions = 'rp_comp1 rp_comp2 rp_comp3 rp_comp4 rp_comp5'
eff_functions = 'eff_comp1 eff_comp2 eff_comp3 eff_comp4 eff_comp5'
min_pressure_ratio = 1.0
speed_cr_I = 0
inertia_const = ${I_comp}
inertia_coeff = '${I_comp} 0 0 0'
# assume no shaft friction
speed_cr_fr = 0
tau_fr_const = 0
tau_fr_coeff = '0 0 0 0'
[]
# Outlet pipe from the compressor
[pipe2]
type = FlowChannel1Phase
position = '${x2} ${y2} 0'
orientation = '1 0 0'
length = ${L2}
n_elems = ${n_elems2}
A = ${A2}
[]
# 90 degree connection between pipe 2 and 3
[junction2_cold_leg]
type = VolumeJunction1Phase
connections = 'pipe2:out cold_leg:in'
position = '${x3} ${y3} 0'
volume = ${fparse A2*0.1}
[]
# Cold leg of the recuperator
[cold_leg]
type = FlowChannel1Phase
position = '${x3} ${y3} 0'
orientation = '0 -1 0'
length = ${fparse L3/2}
n_elems = ${fparse n_elems3/2}
A = ${A3}
[]
# Recuperator which transfers heat from exhaust gas to reactor inlet gas to improve thermal efficency
[recuperator]
type = HeatStructureCylindrical
orientation = '0 -1 0'
position = '${x3} ${y3} 0'
length = ${fparse L3/2}
widths = ${recuperator_width}
n_elems = ${fparse n_elems3/2}
n_part_elems = 2
names = recuperator
solid_properties = steel
solid_properties_T_ref = '300'
inner_radius = ${D1}
[]
# heat transfer from recuperator to cold leg
[heat_transfer_cold_leg]
type = HeatTransferFromHeatStructure1Phase
flow_channel = cold_leg
hs = recuperator
hs_side = OUTER
Hw = 10000
[]
# heat transfer from hot leg to recuperator
[heat_transfer_hot_leg]
type = HeatTransferFromHeatStructure1Phase
flow_channel = hot_leg
hs = recuperator
hs_side = INNER
Hw = 10000
[]
[junction_cold_leg_3]
type = JunctionOneToOne1Phase
connections = 'cold_leg:out pipe3:in'
[]
[pipe3]
type = FlowChannel1Phase
position = '${x3} ${fparse y3 - (L3/2)} 0'
orientation = '0 -1 0'
length = ${fparse L3/2}
n_elems = ${fparse n_elems3/2}
A = ${A3}
[]
# 90 degree connection between pipe 3 and 4
[junction3_4]
type = VolumeJunction1Phase
connections = 'pipe3:out pipe4:in'
position = '${x4} ${y4} 0'
volume = ${fparse A3*0.1}
[]
# Pipe through the "reactor core"
[pipe4]
type = FlowChannel1Phase
position = '${x4} ${y4} 0'
orientation = '-1 0 0'
length = ${L4}
n_elems = ${n_elems4}
A = ${A4}
[]
# "Reactor Core" and it's associated heat transfer to pipe 4
[reactor]
type = HeatStructureCylindrical
orientation = '-1 0 0'
position = '${x4} ${y4} 0'
length = ${L4}
widths = 0.15
n_elems = ${n_elems4}
n_part_elems = 2
names = core
solid_properties = steel
solid_properties_T_ref = '300'
[]
[total_power]
type = TotalPower
power = 0
[]
[heat_generation]
type = HeatSourceFromTotalPower
power = total_power
hs = reactor
regions = core
[]
[heat_transfer]
type = HeatTransferFromHeatStructure1Phase
flow_channel = pipe4
hs = reactor
hs_side = OUTER
Hw = 10000
[]
# 90 degree connection between pipe 4 and 5
[junction4_5]
type = VolumeJunction1Phase
connections = 'pipe4:out pipe5:in'
position = '${x5} ${y5} 0'
volume = ${fparse A4*0.1}
[]
# Pipe carrying hot gas back to the PCU
[pipe5]
type = FlowChannel1Phase
position = '${x5} ${y5} 0'
orientation = '0 1 0'
length = ${L5}
n_elems = ${n_elems5}
A = ${A5}
[]
# 90 degree connection between pipe 5 and 6
[junction5_6]
type = VolumeJunction1Phase
connections = 'pipe5:out pipe6:in'
position = '${x6} ${y6} 0'
volume = ${fparse A5*0.1}
[]
# Inlet pipe to the turbine
[pipe6]
type = FlowChannel1Phase
position = '${x6} ${y6} 0'
orientation = '1 0 0'
length = ${L6}
n_elems = ${n_elems6}
A = ${A6}
[]
# Turbine as defined in MAGNET PCU document (Guillen 2020) and (Wright 2006)
[turbine]
type = ShaftConnectedCompressor1Phase
position = '${x7} ${y7} 0'
inlet = 'pipe6:out'
outlet = 'pipe7:in'
A_ref = ${A_ref_turb}
volume = ${V_turb}
# A turbine is treated as an "inverse" compressor, this value determines if component is to be treated as turbine or compressor
# If treat_as_turbine is omitted, code automatically assumes it is a compressor
treat_as_turbine = true
omega_rated = ${speed_rated}
mdot_rated = ${rated_mfr}
c0_rated = ${c0_rated_comp}
rho0_rated = ${rho0_rated_comp}
# Determines which compression ratio curve and efficiency curve to use depending on ratio of speed/rated_speed
speeds = '0 0.5208 0.6250 0.7292 0.8333 0.9375'
Rp_functions = 'rp_turb0 rp_turb1 rp_turb2 rp_turb3 rp_turb4 rp_turb5'
eff_functions = 'eff_turb1 eff_turb1 eff_turb2 eff_turb3 eff_turb4 eff_turb5'
min_pressure_ratio = 1.0
speed_cr_I = 0
inertia_const = ${I_turb}
inertia_coeff = '${I_turb} 0 0 0'
# assume no shaft friction
speed_cr_fr = 0
tau_fr_const = 0
tau_fr_coeff = '0 0 0 0'
[]
# Outlet pipe from turbine
[pipe7]
type = FlowChannel1Phase
position = '${x7} ${y7} 0'
orientation = '1 0 0'
length = ${L7}
n_elems = ${n_elems7}
A = ${A7}
[]
# 90 degree connection between pipe 7 and 8
[junction7_hot_leg]
type = VolumeJunction1Phase
connections = 'pipe7:out hot_leg:in'
position = '${x8} ${y8} 0'
volume = ${fparse A7*0.1}
[]
# Hot leg of the recuperator
[hot_leg]
type = FlowChannel1Phase
position = '${x8} ${y8} 0'
orientation = '0 1 0'
length = ${L8}
n_elems = ${n_elems8}
A = ${A8}
[]
# System outlet dumping exhaust gas to the atmosphere
[outlet]
type = Outlet1Phase
input = 'hot_leg:out'
p = ${p_ambient}
[]
# Roatating shaft connecting motor, compressor, turbine, and generator
[shaft]
type = Shaft
connected_components = 'motor compressor turbine generator'
initial_speed = ${speed_initial}
[]
# 3-Phase electircal motor used for system start-up, controlled by PID
[motor]
type = ShaftConnectedMotor
inertia = ${I_motor}
torque = 0 # controlled
[]
# Electric generator supplying power to the grid
[generator]
type = ShaftConnectedMotor
inertia = ${I_generator}
torque = generator_torque_fn
[]
[]
# Control logics which govern startup of the motor, startup of the "reactor core", and shutdown of the motor
[ChainControls]
# Bring the postprocessors used by the controls into the control data system
[get_shaft_RPM]
type = GetPostprocessorChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
postprocessor = shaft_RPM
name_data_same_as_postprocessor = true
[]
[get_motor_torque]
type = GetPostprocessorChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
postprocessor = motor_torque
name_data_same_as_postprocessor = true
[]
[get_turbine_torque]
type = GetPostprocessorChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
postprocessor = turbine_torque
name_data_same_as_postprocessor = true
[]
# Sets desired shaft speed to be reached by motor NOTE: SHOULD BE SET LOWER THAN RATED TURBINE RPM
[set_point]
type = GetFunctionValueChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
function = ${fparse speed_rated_rpm - 9000}
[]
# PID with gains determined by iterative process NOTE: Gain values are system specific
[initial_motor_PID]
type = PIDChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
set_point = set_point:value
input = shaft_RPM
initial_integral = 0
K_p = 0.0011
K_i = 0.00000004
K_d = 0
[]
# Determines when the PID system should be running and when it should begin the shutdown cycle. If needed: PID output, else: shutdown function
[logic]
type = ParsedChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
expression = 'if(motor+0.5 > turb, PID, shutdown_fn)'
symbol_names = 'motor turb PID shutdown_fn'
symbol_values = 'motor_torque turbine_torque initial_motor_PID:value motor_torque_fn_shutdown'
[]
# Takes the output generated in [logic] and applies it to the motor torque
[motor_PID]
type = SetRealValueChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
parameter = Functions/motor_torque_fn/value
value = logic:value
[]
# Determines when to turn on heat source
[power_logic]
type = ParsedChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
expression = 'power_fn'
symbol_names = 'power_fn'
symbol_values = 'power_fn'
[]
# Applies heat source to the total_power block
[power_applied]
type = SetRealValueChainControl
execute_on = 'INITIAL TIMESTEP_BEGIN'
parameter = component::total_power/power
value = power_logic:value
[]
[]
[Controls]
# Enables set_PID_tripped
[PID_trip_status]
type = ConditionalFunctionEnableControl
conditional_function = is_tripped_fn
enable_objects = 'AuxScalarKernels::PID_trip_status_aux'
execute_on = 'TIMESTEP_END'
[]
# Enables set_time_PID
[time_PID]
type = ConditionalFunctionEnableControl
conditional_function = PID_tripped_status_fn
disable_objects = 'AuxScalarKernels::time_trip_aux'
execute_on = 'TIMESTEP_END'
[]
[]
[AuxVariables]
# Creates a variable that will later be set to the time when tau_turbine > tau_motor
[time_trip]
order = FIRST
family = SCALAR
[]
# Creates variable which indicates if tau_turbine > tau_motor....... If tau_motor > tau_turbine, 0, else 1
[PID_trip_status]
order = FIRST
family = SCALAR
initial_condition = 0
[]
[]
[AuxScalarKernels]
# Creates variable from time_fn which indicates when tau_turbine > tau_motor
[time_trip_aux]
type = FunctionScalarAux
function = time_fn
variable = time_trip
execute_on = 'TIMESTEP_END'
[]
# Overwrites variable PID_trip_status to the value from PID_tripped_constant_value (changes 0 to 1)
[PID_trip_status_aux]
type = FunctionScalarAux
function = PID_tripped_constant_value
variable = PID_trip_status
execute_on = 'TIMESTEP_END'
enable = false
[]
[]
[Postprocessors]
# Indicates when tau_turbine > tau_motor
[trip_time]
type = ScalarVariable
variable = time_trip
execute_on = 'TIMESTEP_END'
[]
##########################
# Motor
##########################
[motor_torque]
type = ShaftConnectedComponentPostprocessor
quantity = torque
shaft_connected_component_uo = motor:shaftconnected_uo
execute_on = 'INITIAL TIMESTEP_END'
[]
[motor_power]
type = FunctionValuePostprocessor
function = motor_power_fn
execute_on = 'INITIAL TIMESTEP_END'
[]
##########################
# generator
##########################
[generator_torque]
type = ShaftConnectedComponentPostprocessor
quantity = torque
shaft_connected_component_uo = generator:shaftconnected_uo
execute_on = 'INITIAL TIMESTEP_END'
[]
[generator_power]
type = FunctionValuePostprocessor
function = generator_power_fn
execute_on = 'INITIAL TIMESTEP_END'
[]
##########################
# Shaft
##########################
# Speed in rad/s
[shaft_speed]
type = ScalarVariable
variable = 'shaft:omega'
execute_on = 'INITIAL TIMESTEP_END'
[]
# speed in RPM
[shaft_RPM]
type = ParsedPostprocessor
pp_names = 'shaft_speed'
expression = '(shaft_speed * 60) /( 2 * ${fparse pi})'
execute_on = 'INITIAL TIMESTEP_END'
[]
##########################
# Compressor
##########################
[comp_dissipation_torque]
type = ElementAverageValue
variable = dissipation_torque
block = 'compressor'
execute_on = 'INITIAL TIMESTEP_END'
[]
[comp_isentropic_torque]
type = ElementAverageValue
variable = isentropic_torque
block = 'compressor'
execute_on = 'INITIAL TIMESTEP_END'
[]
[comp_friction_torque]
type = ElementAverageValue
variable = friction_torque
block = 'compressor'
execute_on = 'INITIAL TIMESTEP_END'
[]
[compressor_torque]
type = ParsedPostprocessor
pp_names = 'comp_dissipation_torque comp_isentropic_torque comp_friction_torque'
expression = 'comp_dissipation_torque + comp_isentropic_torque + comp_friction_torque'
[]
[p_in_comp]
type = PointValue
variable = p
point = '${x1_out} ${y1} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[p_out_comp]
type = PointValue
variable = p
point = '${x2_in} ${y2} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[p_ratio_comp]
type = ParsedPostprocessor
pp_names = 'p_in_comp p_out_comp'
expression = 'p_out_comp / p_in_comp'
execute_on = 'INITIAL TIMESTEP_END'
[]
[T_in_comp]
type = PointValue
variable = T
point = '${x1_out} ${y1} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[T_out_comp]
type = PointValue
variable = T
point = '${x2_in} ${y2} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[T_ratio_comp]
type = ParsedPostprocessor
pp_names = 'T_in_comp T_out_comp'
expression = '(T_out_comp - T_in_comp) / T_out_comp'
execute_on = 'INITIAL TIMESTEP_END'
[]
[mfr_comp]
type = ADFlowJunctionFlux1Phase
boundary = pipe1:out
connection_index = 0
equation = mass
junction = compressor
[]
##########################
# turbine
##########################
[turb_dissipation_torque]
type = ElementAverageValue
variable = dissipation_torque
block = 'turbine'
execute_on = 'INITIAL TIMESTEP_END'
[]
[turb_isentropic_torque]
type = ElementAverageValue
variable = isentropic_torque
block = 'turbine'
execute_on = 'INITIAL TIMESTEP_END'
[]
[turb_friction_torque]
type = ElementAverageValue
variable = friction_torque
block = 'turbine'
execute_on = 'INITIAL TIMESTEP_END'
[]
[turbine_torque]
type = ParsedPostprocessor
pp_names = 'turb_dissipation_torque turb_isentropic_torque turb_friction_torque'
expression = 'turb_dissipation_torque + turb_isentropic_torque + turb_friction_torque'
[]
[p_in_turb]
type = PointValue
variable = p
point = '${x6_out} ${y6} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[p_out_turb]
type = PointValue
variable = p
point = '${x7_in} ${y7} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[p_ratio_turb]
type = ParsedPostprocessor
pp_names = 'p_in_turb p_out_turb'
expression = 'p_in_turb / p_out_turb'
execute_on = 'INITIAL TIMESTEP_END'
[]
[T_in_turb]
type = PointValue
variable = T
point = '${x6_out} ${y6} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[T_out_turb]
type = PointValue
variable = T
point = '${x7_in} ${y7} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[mfr_turb]
type = ADFlowJunctionFlux1Phase
boundary = pipe6:out
connection_index = 0
equation = mass
junction = turbine
[]
##########################
# Recuperator
##########################
[cold_leg_in]
type = PointValue
variable = T
point = '${x3} ${cold_leg_in} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[cold_leg_out]
type = PointValue
variable = T
point = '${x3} ${cold_leg_out} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[hot_leg_in]
type = PointValue
variable = T
point = '${x8} ${hot_leg_in} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[hot_leg_out]
type = PointValue
variable = T
point = '${x8} ${hot_leg_out} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
##########################
# Reactor
##########################
[reactor_inlet]
type = PointValue
variable = T
point = '${x4} ${y4} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[reactor_outlet]
type = PointValue
variable = T
point = '${x5} ${y5_in} 0'
execute_on = 'INITIAL TIMESTEP_END'
[]
[]
[Executioner]
type = Transient
scheme = 'bdf2'
end_time = ${t3}
[TimeStepper]
type = IterationAdaptiveDT
dt = 0.01
growth_factor = 1.1
cutback_factor = 0.9
[]
dtmin = 1e-5
dtmax = 1000
steady_state_detection = true
steady_state_start_time = 200000
solve_type = NEWTON
nl_rel_tol = 1e-8
nl_abs_tol = 1e-8
nl_max_its = 15
l_tol = 1e-4
l_max_its = 10
petsc_options_iname = '-pc_type'
petsc_options_value = ' lu '
[]
[Outputs]
[e]
type = Exodus
file_base = 'recuperated_brayton_cycle_out'
[]
[csv]
type = CSV
file_base = 'recuperated_brayton_cycle'
execute_vector_postprocessors_on = 'INITIAL'
[]
[console]
type = Console
show = 'shaft_speed p_ratio_comp p_ratio_turb'
[]
[]