Vicente Dolz Ruiz [email protected] 1
ASME ORC 2017 4th International Seminar on ORC Power Systems
13-15 September 2017, Milano, Italy
Vicente Dolz Ruiz [email protected]
DYNAMIC MODELING OF AN ORGANIC RANKINE CYCLE TO RECOVER WASTE
HEAT FOR TRANSPORTATION VEHICLES
LMS Imagine.Lab Amesim
Vicente Dolz Ruiz [email protected]
ORC facility. Mock up
expander
brake
expander vessel
boiler
pump
2
IC engine
FS
T T
FS
T P
T P
Evaporator
Brake
Electric motor & freq. var.
Exhaust gas
P
T P
T P
Condenser
T P
T
P
Expander T
T
Tank
Expander vessel
T
T
FS
Cooling water
Pump
Ethanol
T
FS
Temp. sensor
Pres. sensor
Flow sensor
• ORC facility • Model description • NEDC modeling • Conclusions
Vicente Dolz Ruiz [email protected] 3
Swash-plate characteristics
Working fluid ethanol
Pistons working 3
Bore 40 mm
Stroke 31 mm
Maximum expander speed 4500 rpm
ORC facility. Expander
• ORC facility • Model description • NEDC modeling • Conclusions
Vicente Dolz Ruiz [email protected] 4
ORC facility. Working points
Ford Explorer 2 liter turbocharged gasoline engine
Point 84km/h
Point 114km/h
Vehicle speed (km/h) 84 114
Engine speed (rpm) 2000 2700
Fuel power (kW) 69.6 119.1
Engine power output (kW) 22.2 38.5
Inlet temperature of the exhaust gas (°C) 526 646
Mass flow exhaust gas (g/s) 24 41
• ORC facility • Model description • NEDC modeling • Conclusions
Vicente Dolz Ruiz [email protected] 6
2000 rpm 3000 rpm
Point 114km/h (25 kW heat power)
Model description. ORC validation
• ORC facility • Model description • NEDC modeling • Conclusions
Vicente Dolz Ruiz [email protected] 7
Point 114km/h (25 kW heat power)
Model description. ORC validation
• ORC facility • Model description • NEDC modeling • Conclusions
Vicente Dolz Ruiz [email protected] 8
LMS Imagine.Lab Amesim
Model description. Vehicle model + ORC
• ORC facility • Model description • NEDC modeling • Conclusions
Vicente Dolz Ruiz [email protected] 9
0
25
50
75
100
125
150
-30
0
30
60
90
120
150
0 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375
velo
city
[km
/h]
torq
ue [N
m]
time [s]
engine torque total torque (engine +ORC) vehicle velocity
0
25
50
75
100
125
150
-30
0
30
60
90
120
150
300 305 310 315 320 325 330 335 340 345 350 355 360
velo
city
[km
/h]
torq
ue [N
m]
time [s]
Extra-urban part of NEDC
NEDC modeling. Vehicle model + ORC
• ORC facility • Model description • NEDC modeling • Conclusions
Gear changes
Vicente Dolz Ruiz [email protected] 10
NEDC modeling. Vehicle model + ORC
0
25
50
75
100
125
150
180
200
220
240
260
280
300
300 305 310 315 320 325 330 335 340 345 350 355 360
velo
city
[km
/h]
bsfc
[g/k
Wh]
bsfc without ORC
bsfc with ORC
vehicle velocity
-15
-10
-5
0
5
300 305 310 315 320 325 330 335 340 345 350 355 360
bsfc
diff
eren
ce [%
]
time [s]
• ORC facility • Model description • NEDC modeling • Conclusions
Vicente Dolz Ruiz [email protected] 11
Conclusions
• A vehicle model to reproduce the vehicle behavior has been coupled to an ORC system model with ethanol as working fluid. In this model, the engine shaft is directly coupled to the expander shaft to estimate the fuel consumption reduction during the extra-urban part of the NEDC.
• The ORC system is more efficient on extra-urban conditions (vehicle speeds higher than 50 km/h). At 120 km/h bsfc can be reduced a 10% by using an ORC. On the other hand, on urban driving conditions (speeds below 50km/h), these systems have not enough power to start the cycle (to evaporate the ethanol).
• This model can be used in complex engine layouts to optimize different strategies. In case of hybrid vehicles the ORC mechanical power can be used to increase the engine shaft torque or to recharge the batteries. The strategy to answer this question could be optimized by using similar models.
• ORC facility • Model description • NEDC modeling • Conclusions