#include <CoolSystem_HVAC.hpp>

Inheritance diagram for slide::CoolSystem_HVAC:

Collaboration diagram for slide::CoolSystem_HVAC:

Public Member Functions
	CoolSystem_HVAC ()

	CoolSystem_HVAC (size_t Ncells, int control, double Q0)

double	getQcoolAC_tot ()

double	dstate (double Etot, double Echildren, double t) override
	calculate the new coolant temperature from a heat exchange of Etot More...

void	control (double Thot_local, double Thot_global) override

virtual void	storeData (size_t Ncells) override

virtual void	writeData (const std::string &prefix) override

CoolSystem_HVAC *	copy () override

Public Member Functions inherited from slide::CoolSystem
	CoolSystem ()

	CoolSystem (size_t Ncells, int control)

virtual	~CoolSystem ()=default

double	T ()

void	setT (double Tnew)

virtual double	dstate (double Etot, double Echildren, double t)
	calculate the new coolant temperature from a heat exchange of Etot More...

virtual double	getH ()

auto	getFlr ()

auto	getControl ()

auto	getEoperation ()

void	reset_Eoperation ()

void	setControl (int control)

virtual void	control (double Thot_local, double Thot_global)

virtual void	storeData (size_t Ncells)

virtual void	writeData (const std::string &prefix)

auto	getHeatEvac ()
	for unit testing, total heat evacuated from children over entire lifetime More...

auto	getHeatabsorbed ()
	for unit testing, total heat evacuated from children over entire lifetime (heat capacity not constant -> cannot convert Tend-T1 to energy) More...

auto	getTotalTime ()
	total time this coolsystem has existed for [s] More...

virtual CoolSystem *	copy ()

Public Attributes
CoolSystem_HVACData	HVACdata
	#TODO -> needs to be protected. More...

Public Attributes inherited from slide::CoolSystem
CoolSystemData	coolData

Protected Member Functions
double	getACoperatingPower (double Qac, double t)
	calculate the operating power of the AC unit More...

Protected Attributes
double	Q_ac
	cooling power from the AC system [W]. This value will be controlled similarly to the flowrate inside the container More...

double	COP
	coefficient of performance of the AC system [-] More...

double	controlAC_onoff_Ton
	T when the AC unit switches on. More...

double	controlAC_onoff_Toff
	T when the AC unit switches off, ie minimum temperature. More...

double	controlAC_onoff_Q
	cooling power when on More...

double	controlAC_prop_T
	T to which the proportional control cools the container. More...

double	controlAC_prop_gain
	gain of the proportional controller for the AC unit More...

Protected Attributes inherited from slide::CoolSystem
double	Tcoolant { settings::T_ENV }
	< state More...

double	flowrate {}
	flow rate of cooling fluid [m3/s] More...

double	fluid_rho
	density of cooling fluid kg / m3 More...

double	fluid_cp
	heat capcity of cooling fluid J / kG / K More...

double	fluid_V
	total volume of coolant available for this coolsystem m3 More...

size_t	Ncells { 0 }
	cooling system properties More...

int	control_strategy
	integer indicating how the cooling is done More...

double	control_onoff_Ton
	T when the system switches on. More...

double	control_onoff_Toff
	T when the system switches off. More...

double	control_onoff_flr
	flow rate when on More...

double	control_prop_T
	T to which the proportional control cools the children. More...

double	control_prop_gain
	gain of the proportional controller More...

double	Across
	cross section of the fluid [m2], used to convert flow rate to flow speed More...

double	eta { 0.5 }
	efficiency More...

Friends
struct	CoolSystem_HVACData

Constructor & Destructor Documentation

◆ CoolSystem_HVAC() [1/2]

slide::CoolSystem_HVAC::CoolSystem_HVAC ( )

< Nominal power of the AC system (active cooling of the container) For a battery of 2700 cells (continous 1C cycling) we need to evacuate about 4 kW continuously (at the begin of life) or about 1.5 W per cell (this is the heat evacuated by the top level module from its children, during equilibrium equal to total heat generation of all cells) which is 2.5% of total cell energy (cell power ~ 4V * 15A = 60 W) During degradation, R can easily double so we expect to have to cool about 3 W per cell continuous So the maximum power should be about double so we can cool down (3 W heating + 7.5 W cooling = cool down at 4.5 W or 50% faster than the cells heated up)

< cool 7.5 W per cell (5 times the heating load at begin of life)

< value from Schimpe's paper of thermal model of battery but double check

< if this value is < settings::T_ENV, then coolsystems can cool cells below their initial temperature (which is settings::T_ENV) resulting in negative total heat energy absorbed in cells. See unit tests for module_s and then some unit tests might fail because they demand positive heating energy (cells must heat up due to cycling) therefore, it is not recommended to set this T below settings::T_ENV (20 degrees at the moment)

< 1 at the T where the on/off control would go on, 0 at the target T

< Data storage

Here is the call graph for this function:

Here is the caller graph for this function:

◆ CoolSystem_HVAC() [2/2]

slide::CoolSystem_HVAC::CoolSystem_HVAC	(	size_t	Ncells,
		int	control,
		double	Q0
	)

< cool 20 W per cell (cell power ~ 4V * 15A = 60 W so worst case 30% losses)

< value from Schimpe's paper of thermal model of battery but double check

< Increase the inertia of the coolsystem if Q0 >>>> Qac_per_cell * Ncells since the inertia in CoolSystem is based on Ncells only, and designed for 7.5W per cell

< increase proportional to the fraction of Q0 of the total heating

< todo control hotspot -> 20 to 30

< todo control the local T to 20 degrees

< todo control the hotspot to 25 degrees

< todo do something similar to cool3

< todo

< 1 at the T where the on/off control would go on, 0 at the target T

< Data storage

Here is the call graph for this function:

Member Function Documentation

◆ control()

void slide::CoolSystem_HVAC::control	(	double	Thot_local,
		double	Thot_global
	)

overridevirtual

< Call the base class function to control the fan inside the container to cool the racks

< variables

< control the cooling power of the AC system note that the off criterium is always the same, never cool below the minimum temperature this is because we are controlling an active system, so in theory it would keep cooling to freezing, -100 and even -Inf degrees if you wouldn't stop it

< always on unless T of the container < minimum temperature

< on/off depending on child T -> on and off based on T of container

< on/off depending on global hot spot temperature -> on based on T of hottest cell, off based on T of container

< proportional to T of hottest child SU -> proportional to T of container

< error on the local temperature

< ensure we never go negative

< avoid very small cooling powers

< can't do more than the design-power

< proportional to global hot spot temperature -> on based on T of hottest cell, off based on T of container

< error on the global temperature

< ensure we never go negative

< avoid very small cooling powers

< can't do more than the design-power

< always on

Reimplemented from slide::CoolSystem.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ copy()

CoolSystem_HVAC * slide::CoolSystem_HVAC::copy ( )

inlineoverridevirtual

Reimplemented from slide::CoolSystem.

Here is the call graph for this function:

◆ dstate()

double slide::CoolSystem_HVAC::dstate	(	double	Etot,
		double	Echildren,
		double	t
	)

overridevirtual

calculate the new coolant temperature from a heat exchange of Etot

< Ensure Qtot == Qchildren for consistency

< - since it is cooling down

< calculate the new temperature

< increase the power required to run the cooling system power scales like speed ^ 3 and rho ^1 (kinetic energy/mass * flow rate = rho * A * v * v^2 / 2) see also https://fluidflowinfo.com/fan-performance-and-fan-laws/, and my undergrad course on wind energy [fan = opposite wind turbine]

< speed of the fluid

< this is the energy to speed up air from stationary to the required speed to cool the child SUs [W]

< this is the energy to operate the AC unit

< update the mean cooling power

< heat extracted from children, only until next data collection interval (reset to 0 in storeData)

< only until next data collection interval (reset to 0 in storeData)

< time since start of simulations

< increase the total operating energy for the fan

< increase the total lifetime operating poer

< increase the total operating energy for the AC unit

< heat extracted from the entire coolsystem by the AC system

< cout<<"\t HVAC system: Total heat energy "<<Qtotal<<", HVAC cooling "<<Q_ac*t<<" giving net energy "<<Q<<" and new T "<<Tnew<<" after "<<t<<" seconds"<<endl;

Reimplemented from slide::CoolSystem.

Here is the call graph for this function:

◆ getACoperatingPower()

double slide::CoolSystem_HVAC::getACoperatingPower	(	double	Qac,
		double	t
	)

protected

calculate the operating power of the AC unit

Data storage

< if the environment is too hot, use active cooling with the AC system

< else we can suck in cold air

< flow rate of environment air we need (cooling energy = flow rate * rho * cp * dT)

< assume the surface area of the fan to suck in air is twice the surface area of the fan to cool the cells

< speed of the air

< energy to operate the fan

Here is the call graph for this function:

Here is the caller graph for this function:

◆ getQcoolAC_tot()

double slide::CoolSystem_HVAC::getQcoolAC_tot ( )

inline

◆ storeData()

void slide::CoolSystem_HVAC::storeData ( size_t Ncells )

overridevirtual

< Call parent function to store conventional data

< sets ttot to 0 so do this after wards

Reimplemented from slide::CoolSystem.

Here is the call graph for this function:

◆ writeData()

void slide::CoolSystem_HVAC::writeData ( const std::string & prefix )

overridevirtual

< store histograms and degradation state of cell utilisation

< #TODO -> since we are doing append we cannot write like this IMPORTANT!!!!!

Reimplemented from slide::CoolSystem.

Here is the call graph for this function:

Friends And Related Function Documentation

◆ CoolSystem_HVACData

friend struct CoolSystem_HVACData

friend

Member Data Documentation

◆ controlAC_onoff_Q

double slide::CoolSystem_HVAC::controlAC_onoff_Q

protected

cooling power when on

◆ controlAC_onoff_Toff

double slide::CoolSystem_HVAC::controlAC_onoff_Toff

protected

T when the AC unit switches off, ie minimum temperature.

◆ controlAC_onoff_Ton

double slide::CoolSystem_HVAC::controlAC_onoff_Ton

protected

T when the AC unit switches on.

◆ controlAC_prop_gain

double slide::CoolSystem_HVAC::controlAC_prop_gain

protected

gain of the proportional controller for the AC unit

◆ controlAC_prop_T

double slide::CoolSystem_HVAC::controlAC_prop_T

protected

T to which the proportional control cools the container.

◆ COP

double slide::CoolSystem_HVAC::COP

protected

coefficient of performance of the AC system [-]

◆ HVACdata

CoolSystem_HVACData slide::CoolSystem_HVAC::HVACdata

#TODO -> needs to be protected.

◆ Q_ac

double slide::CoolSystem_HVAC::Q_ac

protected

cooling power from the AC system [W]. This value will be controlled similarly to the flowrate inside the container

The documentation for this class was generated from the following files:

src/cooling/CoolSystem_HVAC.hpp
src/cooling/CoolSystem_HVAC.cpp

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Friends

Constructor & Destructor Documentation

◆ CoolSystem_HVAC() [1/2]

◆ CoolSystem_HVAC() [2/2]

Member Function Documentation

◆ control()

◆ copy()

◆ dstate()

◆ getACoperatingPower()

◆ getQcoolAC_tot()

◆ storeData()

◆ writeData()

Friends And Related Function Documentation

◆ CoolSystem_HVACData

Member Data Documentation

◆ controlAC_onoff_Q

◆ controlAC_onoff_Toff

◆ controlAC_onoff_Ton

◆ controlAC_prop_gain

◆ controlAC_prop_T

◆ COP

◆ HVACdata

◆ Q_ac