def adjust_speed(self, new_speed):
"""Defines pump characteristics that are based on pump speed.
Only applies to variable displacement (centrifugal) pumps. Variable names match pump law equations.
:param new_speed: Requested (new) speed of the pump
:return: Pump speed, flow rate, outlet pressure, and power
:rtype: tuple
"""
n2 = new_speed # Validate input
if self.speed == 0: # Pump initially stopped
n1 = 1
else:
n1 = self.speed
v1 = self.flow
hp1 = self.outlet_pressure
self.flow = v1 * (n2 / n1) # New flow rate
self.outlet_pressure = hp1 * math.pow((n2 / n1), 2) # New outlet pressure
self.speed = n2 # Replace old speed with new value
delta_p = self.diff_press_psi(self.head_in, utility_formulas.press_to_head(self.outlet_pressure))
self.power = self.pump_power(self.flow, delta_p)
def gate7_open():
ffc.gate7.open()
ffc.pump3.head_in = utility_formulas.press_to_head(ffc.gate7.press_out)
def gate6_open():
ffc.gate6.open()
ffc.pump2.head_in = utility_formulas.press_to_head(ffc.gate6.press_out)
def gate5_open():
ffc.gate5.open()
ffc.pump1.head_in = utility_formulas.press_to_head(ffc.gate5.press_out)
gate5 = valve.Gate("Gate valve 5")
gate5.calc_coeff(4)
gate6 = valve.Gate("Gate valve 6",
sys_flow_in=gate3.flow_out + gate4.flow_out,
press_in=gate3.press_out + gate4.press_out)
gate6.calc_coeff(4)
gate7 = valve.Gate("Gate valve 7")
gate7.calc_coeff(4)
# Fuel pumps
# 1480 rpm
pump1 = pump.PositiveDisplacement("Pump 1",
flow_rate_out=0.0,
pump_head_in=utility_formulas.press_to_head(
gate5.press_out),
displacement=0.24)
pump2 = pump.PositiveDisplacement("Pump 2",
flow_rate_out=0.0,
pump_head_in=utility_formulas.press_to_head(
gate6.press_out),
displacement=0.24)
pump3 = pump.PositiveDisplacement("Pump 3",
flow_rate_out=0.0,
pump_head_in=utility_formulas.press_to_head(
gate7.press_out),
displacement=0.24)
# Pump outlet manifold
Water level is 4 feet above tank bottom; total water head = 14 feet.
"""
import utility_formulas
from PipingSystems.pump.pump import CentrifPump, PositiveDisplacement
from PipingSystems.valve.valve import Gate, Globe, Relief
# Gate Valve 1
valve1 = Gate("Valve 1", position=100, flow_coeff=200, sys_flow_in=utility_formulas.gravity_flow_rate(2, 1.67),
press_in=utility_formulas.static_press(14))
valve1.flow_out = valve1.flow_in
valve1.press_drop(valve1.flow_out)
valve1.get_press_out(valve1.press_in)
# Centrif Pump
pump1 = CentrifPump("Pump 1", pump_head_in=utility_formulas.press_to_head(valve1.press_out))
pump1.start_pump(1750, 50, 16)
# Globe valve 1
throttle1 = Globe("Throttle 1", position=100, flow_coeff=21, press_in=pump1.outlet_pressure,
sys_flow_in=pump1.flow)
throttle1.flow_out = throttle1.flow_in
throttle1.press_drop(throttle1.flow_out)
throttle1.valve_flow_out(throttle1.Cv, throttle1.deltaP)
throttle1.get_press_out(throttle1.press_in)
# Gate Valve 2
valve2 = Gate("Valve 2", position=100, flow_coeff=200, press_in=throttle1.press_out, sys_flow_in=throttle1.flow_out)
valve2.flow_out = valve2.flow_in
valve2.press_drop(valve2.flow_out)
valve2.valve_flow_out(valve2.Cv, valve2.deltaP)
def test_pump1_input_press(self):
pump1.head_in = utility_formulas.press_to_head(valve1.press_out)
assert pump1.head_in == 8.119222584669064
def test_pump2_input_press(self):
pump2.head_in = utility_formulas.press_to_head(valve3.press_out)
assert pump2.head_in == 23.542088964737797