modeling & simulating

MODELING & SIMULATINGYOUR SYSTEM ON ALL ITS LIFECYCLE

M&S THERMAL SYSTEM

SYSTEM ENGINEERING DESIGN

Sherpa – Thermal System Design2

Multi-Physic modeling using PhiSim

HVAC Simulation Platform

PhiSim Simulation Platforms


HVAC Simulation platform – obtained by coupling of

▪ Control algorithms, including HMI logics

▪ Plant modelso Refrigerant loop model

o HVAC unit model

o Cabin Thermal and Air Quality models


HVAC System Simulation Platform Air Conditioning Plant

RefrigerantLoop

HVAC unit Cabin T°

& Air Quality


Applications – AC components design

▪ Air conditioning components design or evaluation

o Components sizing and requirement building

Settings : compressor cylindra, volumetric efficiency, isentropic efficiency

Refrigerant Loop

Settings : Heat Exchange Area (m2), Power (W)

-> link with geometrical characteristics of the evaporator (length/width/thickness, number of fins), and its power

Direct link with the thermal comfort


Possibility to link with experiment data :



RefrigerantLoop

HVAC unit Cabin T°

& Air Quality

Globally : vehicle speed, ambient T°, Hr, engine speed, EE states…

Locally : refrigerant flow, air flow, compressor speed, Pressures, T°…

Control SW analysis : bypass of commands algorithms, compare various calibration settings…


▪ Hierarchical control design in closed loop simulation platform

o Inputs signals treatment

- Filters, Range control, Failure modes

- HMI modes (Auto, manual…)

o Comfort Supervisor (Targets)

- Cabin T°, Air blown T°, Air Quality

- Stop&Start/Hybrid interaction

o Local loop control

- AC loop ctrl : Evaporator Temperature control, High Pressure control, Icing detection, Anti-mold strategy, Humidity control

- HVAC ctrl : Blower, Mixing, Distrib. mode, Recycling, Prevent/Postvent strategies

HVAC System Simulation Platform

Advantages :Control design in Closed Loop !Calibration in simulation, running a big range of conditionsAutocoding compliance of control algorithmsRapid Prototyping compliance (MIL, SIL, PIL)



▪ Adaptable synoptics to facilize real time analysis



▪ References

o Our simulation platforms are used by automotive OEMs

o The platforms have been customized for specific needs

▪ OEM’s component database,

▪ Plant adaptations (IHX, chiller, Heat Pump, HVACs, …)

▪ Specific OEM’s control design

o Examples of applications :

▪ Components requirements building (Refrigerant loop and HVAC)

▪ Control design and calibration / HMI software development

▪ Experiment preparation / experiment data analysis / rapid prototyping (bench tests, road test and missions)

▪ Durability studies (mission profile computation)

▪ Specific occurrence studies

- Front end blower optimization (2 speeds vs linear ; NVH / COP compromises)

- Stop&Start availability, under various climates




Sherpa’s offers

▪ Standard offer

− Simulation Platform

− Basic training to use the simulator

▪ Applicative adaptations with coaching

− Simulation Platform

− Adaptation of the simulator architecture to the customer’s own needs

• Option 1 : Training/Coaching to help the customer to adapt the standard simulator

• Option 2 : Turn-key adaptations of the standard simulator, with training

− Parametrization studies, based on customer’s data experiments

− Control strategies studies, hierarchical, in closed loop with the simulator

• Energy supervision/optimization of the E-Vehicle

• Thermal management, in all customer’s use cases

• Local control of sub-systems and components

▪ Know-How transfer (trainings) : make the customer able to

− use basic tools (Matlab/Simulink) and PhiSim technological Libraries

− use standard simulator

− become autonomous in modifying the simulator

MODELING & SIMULATINGYOUR SYSTEM ON ALL ITS LIFECYCLE


ANNEX


Examples : Design of Control Strategies

▪ HVAC Control Strategies▪ Air Quality Pre-conditioning study

− VOCs cleaning is more efficient in Fresh Air mode− But particles cleaning needs to be in Recycling mode (with HE Filter …)− MBD permits to test various pre-ventilation strategies and sequences to clean the

cabin− Additional functionalities of the Cabin Pollution Simulator:

• Ionization cleaning of the filter, after Recycling phase• End pre-ventilation phase with Fragrance diffusion!


▪ HVAC Control Strategies

Coupling AC loop model based on thermo-fluid libraries, and thermal comfort control model, to design Clean Air Control SW

o Example 1 : Dry evaporator control preventing bad smell

− Control the cooling level to avoid exceeding the dew point

of air and prevent water condensation on the evaporator


… to keep a dry evaporator…

Anti-mold strategy

… and prevent from mold and

bad smell

Air Conditioning Plant

Control of the AC loop…



▪ HVAC Control Strategies

Coupling AC loop model based on thermo-fluid libraries, and thermal comfort control model, to design Clean Air Control SW

o Example 2 : Recycling strategies

− Protections strategies from outside pollutants

− Clean cabin strategies to filter the inside particles

Control of the AC loop…

… to dry the air blown in the cabin…

Need a fogging control by drying the air blown

in the cabin

… and prevent windshield

fogging

Air Quality Recycling strategies Fogging

control




Example of HVAC Filter Design

▪ Components design

▪ Example : Filter Efficiency sizing and aging study

Reverse use of the simulator, to calculate the efficiency of a Filter that will

fit OEM’s vehicle Requirements


Air Quality Recycling strategies

Air Conditioning Plant

Dynamic Cleaning Efficiency Simulations

Filter exposition calculationsEfficiency RequirementsAging RequirementsPrediction of Maintenance Ionization cleaning strategies


Applications – Comfort Evaluation

▪ The platform can be linked to Comfort Evaluation Tools

Fanger’s PMV/PPD method (accessible in 0D model) :

- Controlled parameters : Air T°, Air Hr, MRT, Air Speed

- Additional inputs : Metabolic rate, Clothing

Global comfort indicesLocal comfort indices

Need for cabin and mannequin meshing

To calculate local comfort indices

CAD tools


RefrigerantLoop

HVAC unit

Cabin T°

& Air Quality

modeling & simulating

Documents