An overview
LIQUID COOLING LIBRARY
Modelon © 2016
• What is Liquid Cooling Library?
Key features & capabilities
• Example use case
Vehicle thermal management
• Library contents
Fluid components
Medium property models
AGENDA
• Modelica library by Modelon
• High performance modeling of incompressible flow, including closedcircuits. Real-time applications.
• Suitable for a wide range of applications, ranging from automotive and aerospace to industrial equipment and process industry
• Highly customizable; Realize non-standard circuits and add in-house IP
WHAT IS LIQUID COOLING LIBRARY?
• Large set of fluid component models
Generic, customizable components
Geometry based components
• Medium property models
Water
Aqueous solutions of glycol, alcohols, glycerol, ammonia, chlorides and salts
Jet fuels and motor oil
• Plug-and-play compatible with other Modelon libraries for thermal management
KEY FEATURES
• Cooling systems for automotive and process industry
• Engine cooling
• Battery thermal management
• Component selection
• Pump dimensioning
• System performance studies
• Transient response studies
• Easy realization of non-standard circuits
• Support control system development and evaluation
KEY CAPABILITIES
Power [W]
Position [0-1]
1.53 336.1 0.4
p(bar) h(kJ/kg)
T(degC) m_flow
80.1
engineVolume
radiator
1.50 214.5 0.2
p(bar) h(kJ/kg)
T(degC) m_flow
51.0
resistance2
expansionVolume
V=0.008
Gas
p T
gasPressureBoundary
T . m
gasFlowBoundary
heatSource
Q
pump
35088
Main
Bypass
1.50 377.7 0.2
p(bar) h(kJ/kg)
T(degC) m_flow
90.0
ramp2
duration=5
0.568 90.0
25.0
73.7
57.5
41.2
Temperature [degC]
EXAMPLE USE CASES
• Vehicle Thermal Management (VTM)
• Problem: Balancing system level requirements for cooling and energy usage
• Solution: Model-based system design/optimization and control design
• Tools: Dymola + Liquid Cooling Library + Heat Exchanger library
• Easy integration with: Engine Dynamics Library, Vapor Cycle Library, Vehicle Dynamics Library. Also Air Conditioning Library via special adapter.
• Partner: OEM | Work flow: Calibrate & validate component / subsystem models, then build system and exercise over critical drive cycles
VEHICLE THERMAL MANAGEMENT
Coolant loop
Power [W]
Position [0-1]
1.53 336.1 0.4
p(bar) h(kJ/kg)
T(degC) m_flow
80.1
engineVolume
radiator
1.50 214.5 0.2
p(bar) h(kJ/kg)
T(degC) m_flow
51.0
resistance2
expansionVolume
V=0.008
Gas
p T
gasPressureBoundary
T . m
gasFlowBoundary
heatSource
Q
pump
35088
Main
Bypass
1.50 377.7 0.2
p(bar) h(kJ/kg)
T(degC) m_flow
90.0
ramp2
duration=5
0.568 90.0
25.0
73.7
57.5
41.2
Temperature [degC]
• Integrated model for fuel economy and vehicle thermal management
Vehicle model with loads and losses
Vehicle heat loads (engine, friction, transmission)
Lumped engine thermal model
Coolant and oil circuits with possible additions of other thermal fluid circuits
Drive cycles (speed, grade, wind, etc.)
Airflow effects
Key vehicle and thermal controls (fan)
INTEGRATED VTM MODEL
VTM SYSTEM MODEL• Thermal
• Mechanical
• Electrical
• Coolant
• Air
• Controls
SAMPLE RESULTS – DRIVE CYCLE
Boundary – vehicle speed
Boundary – engine torque
Actuator - fan
Controlled temperature
Actuator - thermostat
• Pipes and bends
• Flow resistances
• Volumes and tanks
• Junctions
• Pump and fan
• Heat exchangers and stacks
• Flow modifiers and sources
• Solid heat transfer
• Single-phase coolants and refrigerants
LIBRARY CONTENTS
• Generic pipes with different fidelity and replaceable correlations Lumped or discretized
Pressure drop
Heat transfer
Transport delay
• Components with geometric loss coefficient data: Straight pipes
Circular bend
Mitre bend
PIPES
The library includes loss coefficient data for all geometric components.
Main reference: Internal Flow Systems, D S Miller
GEOMETRIC FRICTION MODELS
Straight pipe loss coefficient Circular bend loss coefficient
The liquid pipe uses transport delay instead of internal control volumes. This is often more accurate for liquid flow at low discretization numbers.
PIPE SEGMENTATION
Temperature profile for 4 volumes
Temperature profile for 4 transport delays
0 4 8 12 16 20
20
40
60
80
100
pipe.T[1] pipe.T[2] pipe.T[3] pipe.T[4]
0 4 8 12 16 20
20
40
60
80
100
pipe.T[1] pipe.T[2] pipe.T[3] pipe.T[4]
• Generic flow resistances Replaceable friction model
• Geometric flow resistances with tabulated loss coefficient data Orifice plate and long orifice
Abrupt contraction and expansions
Flush mounted intakes
FLOW RESISTANCES
• Closed volumes Energy storage
Different port configurations
Heat transfer and solid thermal mass
• Expansion volume
• Open tank
VOLUMES AND TANKS
• Combining and dividing junctions
• Geometric loss coefficient data for many geometries
JUNCTIONS
• Control valves
• Thermostatic valves Two and three-legged
Replaceable friction and opening characteristics
Possible to include hysteresis effects
VALVES
Example thermostatic valvecharacteristics with hysteresis
Pump and fan• Flexible parameterization
Multiple options for pump and fan curves
Heat exchangers• Simplified heat exchanger
models Based on tabulated efficiency
e-NTU approach
• Possible configurations Gas – Gas
Gas – Liquid
Liquid – Liquid
• Stacks Containing 2 to 8 heat exchangers
PUMP, FAN, HEAT EXCHANGERS
BASIC COMPONENTS
The AggregateVolume object calculates the total liquid volume in the system – useful for dimensioning
LCL includes models for single phase coolants and refrigerants. For each mixture, the concentration can be set anywhere between zero and the eutectic composition. List of available media (aqueous solutions):
MEDIUM PROPERTIES
Reference: International Institute of Refrigeration, 2010
• Calcium chloride• Ethylene glycol• Propylene glycol• Ethyl alcohol• Methyl alcohol• Glycerol• Ammonia• Potassium carbonate• Magnesium chloride
• Sodium chloride• Potassium acetate• Potassium formate• Lithium chloride
Media models of motor oil and jet fuel are also available
Templates are predefined test benches for quick set up of own experiments. They include parameters for:• Visulization
• Steady State Initialization
• Aggregated Liquid Properties
Experiments are available to illustrate;• Flow branching and merging
• Individual component tests
• Open fluid networks
• Closed cooling circuits
• Heat exchanger stack test
EXPERIMENTS
Water circuit model with trace component
TRACE VARIABLE
In this example the trace componentintroduced in pipe1 can be followed in the system (in pipe 8 with time delay, and in pipe 10 controlled via valve). step
startTime=40
pipe5
2
pipe3
2
pipe8
2
pipe9
2
pipe10
2
step1
startTime=15
step2
startTime=25
ramp
duration=10
75.0
25.0
62.5
50.0
37.5
Temperature [degC]
• It is possible to visualize the temperature and pressure of the components, the opening of valves and more.
See bath tub example below.
VISULIZATION
• MATLAB
• Python
• Excel
BATCHED SIMULATION
Experiment settings
Parameter modifiers
An example of batched simulation in Modelonproduct FMI Add-in for Excel (FMI-E)
VTM EXAMPLE WITH STACKED HEX
Constant road grade sweep (-0.5 to +2.0 %) at constant vehicle speed
More grade increases engine cooling temperature (top left).Transmission oil cooler thermostat opening (bottom right) affects radiator air inlet temperature (top right)