heat pump water heater modelling iea ... - hpt annex 46€¦ · buildsyspro | 03/02/2016 | 22...

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HEAT PUMP WATER HEATER MODELLING

IEA PRESENTATION

M. RADULESCU, K.R. DEUTZ

10/02/2016

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AGENDA

1. INTRODUCTION TO THE STUDY

2. MODELLING A HEAT PUMP WATER HEATER

3. OUR TOOLS AT EDF

MODELICA/DYMOLA

BUILTSYSPRO

TIL-TLK

EXPERIMENTAL FACILITIES

4. RESULTS

Titre de la présentation | mm/aaaa

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HPWH STUDY INTRODUCTION


Market study

• Analyse market trends • Bibliography research, patents

Modelling

• Detailed modelling of the basic cycle – SPLIT • Using TIL Library (Dymola/Modelica)

Experimental validation

• Validation based on experimental tests • Temperature levels, energy consumption and efficiency

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HPWH STUDY INTRODUCTION


Market study

• Analyse market trends • Bibliography research, patents

Modelling

• Detailed modelling of the basic cycle – SPLIT • Using TIL Library (Dymola/Modelica)

Experimental validation

• Validation based on experimental tests • Temperature levels, energy consumption and efficiency

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MODEL EXPECTATIONS


• Precision Possibility to test different heat pump cycle layouts

• Simulation speed Easily perform daily simulations with draw-off profiles

• Extensiveness A base model to be extended to all possible configurations

Model specifications

Objective: simulate one of the most occuring technology on the French market (30%)

Split type HPWH with mantle HX

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MODELLING METHODOLOGY

Split type Mantle heat exchanger air_to-water HPWH

Vapor compression

cycle

Performance sensible

to climatic conditions

Cycle configuration

Refrigerant type

Control strategy

Defrosting

Stratification

Convection when

charging

Draw-off jets

Heat losses

The Heat Pump Water Heater: « thermo-hydraulic » system

Thermo Hydraulic

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BIBLIOGRAPHY– TANK MODEL – « HYDRAULIC » PART

Precision

Speed

Fully mixed 1D nodal Pseudo 1D Zonal Pseudo CFD CFD 2D

D. Blandin

(2010), Inard et

Kenjo (2007),

Nizami,

Lightstone,

Harrison, &

Cruickshank

(2013)

Bonvini et Leva

(2012)

K. Johannes

(2005), Druck

(2006), (Zurigat,

Ghajar, & Moretti

(1988)

Nelson,

Balakrishnan &

Murthy (1997),

Steinert,

Goppert, &

Platzer, 2013,

K. Osman

(2008), Oliveski,

Krenzinger, &

Vielmo (2003),

Shah & Furbo

(2003), Arslan

(2005

K. O. Homan &

SOO (1997), K.

Osman (2008),

Oliveski,

Krenzinger, &

Vielmo (2003),

Shah & Furbo

(2003), Arslan

(2005

CFD 3D

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TANK MODELLING METHODOLOGY – « HYDRAULIC » PART


COOLING

zonal model

DRAW-OFFS

1D model

Heating

Zonal model

Mixed conditions

1D model

Temps

« Hybrid » modelling depending on conditions


• « Machine learning » techniques based on experimental or detailed models data

• Experimental study of COP versus operating conditions

• Well suited for fast long term simulations or control strategies with low level of detail required

Empirical – black box models

• Componental and equational based models

• Some components based on empirical formulations e.g. compressors

• Well suited for comparing cycles

Semi-empirical – gray box models

• Complicated parametrization, needs good know-how

• Long time to model and slow simulation

• Well fit for individual component studies

Physics based – white box models

HPWH MODELLING TECHNIQUES – « THERMO » PART

Black Box Heat

Pump

Fine Heat Pump

model

Ch

osen

in

pu

ts

Ch

ose

n i

np

uts

CO

P

Mu

ltip

le in

pu

ts

Mu

ltip

le o

utp

uts

M

ult

iple

ou

tpu

ts

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DYMOLA


Object Oriented

e.g. « A heat pump is composed

of a compressor and a

condensor »

Complementary interfaces

Modelling first, then simulation

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MODELICA


Equation based

Acausal style of modelling

Inheritance

e.g. a rotary compressor is a

type of compressor

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DYMOLA/TIL


Modelica/Dymola based library

Thermo-component library based on

objected oriented architecture

Thermal property calculation

Extensiveness

compressor or valve mass and

energy equations

Modularity

Possible to easily modify geometry

Heat exchange correlations

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EDF BUILDSYSPRO OPEN SOURCE LIBRARY**

The BuildSysPro open source library

Dymola modelling and simulation environment (compliant with OpenModelica)

Modelica language • Modelling complex multi-physic systems

Non causal equation based language

Multi-physic modelling

• Standardised programming language

Object-oriented

Non-proprietary language

equation

G*dT = Q_flow;

end ThermalConductor;

EDF’s internal

Energy and

Building’s

simulation library

Building

Geometries

HVAC systems

Climates

Scenarios

**Available in February 2016, see annex

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EXPERIMENTAL FACILITIES

Possibility to vary seasons: external temperature and

humidity

Interactive control using automated test rigs,

models/Real time simulation and online acquisition

Measuring the performance of heat pumps for heating

and hot water production

Normative experiments

Pure investigation, e.g analyzing the stratification in a

water tank according to different draw-off profiles


Ambiant environment

External environment

Labview

Dymola

P T

0

5

10

15

20

25

30

35

40

45

50

55

60

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

5500

6000

03

:30

:00

05

:30

:00

07

:30

:00

09

:30

:00

11

:30

:00

13

:30

:00

15

:30

:00

17

:30

:00

19

:30

:00

21

:30

:00

Température ( C)P pac (W) et Débit

(L/h)

Temps

P pac

Débit

T ballon

Tc 6(haut)Tc 7

Tc 8

Tc 9

Tc 1

Tc 2

Tc 3

Tc 4

Tc 5 (bas)

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EXPERIMENTAL INVESTIGATION

Measuring:

Temperatures along the heat pump cycle

Energy consummed and produced

Analysing performances according to

regulatory frameworks

Non standardised protocoles for investigation

and optimisation



Extended TIL models

connected together

Specific HX models

Expansion valve models

Variable speed

compressors

Valves

Hybrid modelling

Fluid convective

movements when

heating, cooling

and defrosting

Plug flow draw-

offs

Control scenarios

Compressor & fan speed, defrosting strategies

Water draw-off profiles

Climate

External temperature and humidity

MODELLING METHODOLOGY

Split type Mantle heat exchanger HPWH


Satisfying correlation between

experimental and modeled

temperatures in the tank

Stil some deviations

Heat loss models

Numerical precision

EXPERIMENTAL VALIDATION – TANK TEMPERATURE PROFILES

Thermal bridges with the

ambiant not taken into account

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EXPERIMENTAL VALIDATION – HEAT PUMP CYCLE 7°C(EXT.)


Condenser Evaporator

Surface temperature vs fluid

temperature

Thermostatic Expansion Valve

hunting not taken into account


EXPERIMENTAL VALIDATION – PERFORMANCES (TEXT)

7°C external air temperature 15°C external air temperature

Data Model Error

Qth (kWh) 3.87 3.96 2.33%

Qelec (kWh) 1.24 1.27 2.78%

COP 3.13 3.12 -0.44%

Data Model Error

Qth (kWh) 3.73 3.84 2.87%

Qelec (kWh) 1.41 1.36 -3.16%

COP 2.65 2.81 6.23%

Compressor

model error

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CONCLUDING REMARKS

Several methodologies exist for modelling Heat Pump Water Heaters

Need to take into account both system part (Energy engineering) and thermal storage (Fluid

mechanics)

Actual model still partly incomplete but interesting results

Temperature profiles when charging the tank

Temperature profiles along the HP cycle

Power consumption

Deviation in compressor model efficiencies, need for more laboratory data

This type of modelling a bit complex and too specific for one type of machine (Mantle HX)

Might not fit with the modelling objectives of the annex


| 22 BuildSysPro | 03/02/2016

ANNEX-USING BUILDSYSPRO

BuildSysPro is going open source, and now compatible with OpenModelica!

Available February 2016! E-mail [email protected] to get the newsletter!

Open source models

Private models

Industry and measured

data

mailto:[email protected]

heat pump water heater modelling iea ... - hpt annex 46€¦ · buildsyspro | 03/02/2016 | 22...

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