WP3 – Space heating

WP 3.1 – Compact Chemical Heat Storage

Initial characterisation and understanding of MgSO4

Tests include = TGA(+RGA), DSC, SEM, Vapour Sorption – Completed cycle and heating rate tests

Development and characterisation of composite materials

Created and tested on a small (~10mg) scale Zeolite+MgSO4(Xwt%) composite materials – same test

methods as above.

Identify suitable method to develop pellet TCES materials.

Tested different methods (agglomeration, rolled, pellet press)- pellet press = best.

Develop (~200g) experimental setup to test the de/hydration characteristics of TCES material’s.

Optimise the pellet development method – tested 4 different possible pellet development methods

(Mix 1,5 & Impreg 1,5).

Tested on a large scale (200g) within custom built experiment setup.

Tested on a small scale – see above experimental methods.

Assess the feasibility of a TCES+VFPC system.

Enhance the TCESM pellets – Increase the energy density and power output – Currently ~here

• Trial and test different wt% composite materials with different absorbents.

• Test on a 200g and small (~10mg) scale using above test methods

• Design and Develop a larger scale reactor system – prototype design.

• Select and test a TCESM (possibly several) within newly developed system.

Approach/Near Future Plan

•13x adsorbent cheaper, with promising properties

•Tested in different forms and mixtures

•Surprisingly 13x+MgSO4(12.9wt%) has the lowest energy and mass loss – Pore Blocking?

•Below shows TGA mass loss with time

Characterisation of alternative materials

•Results from 200g Tests to date.

•Minimum Scaling losses from 13x+MgSO4 sample.

•13x pellets expected to perform well considering DSC results (~600J/g) and should not experience pore blocking

200g Tests vs. DSC Tests Summary

1. Added Vacuum Tube Collector(VTC) and Flat Plate Collector (FPC).

• Below shows comparison of energy savings from each system. Location

Loughborough – VFPC systems clearly most beneficial.

• Change in TCES material has limited impact on the overall energy savings

Feasibility Study Changes

WP3.1: Compact Chemical Heat Store

Potential as per proposal: Inter seasonal or long term heat storage

Original timescale: Year 2 - Year 4

Achievements / outputs to date:

Conference presentation at the UKES conference, Birmingham, 2 Journal papers drafted, 2

prototype lab scale systems developed, materials characterised and methods of matrix

impregnation developed.

Revised or restated potential:

The potential to store heat for long duration in a compact volume with minimum loss

enables increased utilisation of renewables for example solar thermal or excess electricity

generated by wind turbines. If large scale cost effective systems can be realised this

technology will be disruptive.

This technology is still at a low TRL.

Synergies with other WPs: 1.2, 1.3, 1.4, 3.3

Recommendations:

Continued

Targets / deliverables for 3rd annual report or elsewhere:

2 papers accepted for publication, route/options for scale up identified

WP 3.2 – Compact Latent Heat Storage

Research Aim • Design, develop and test a 10kWh prototype latent heat storage container to meet domestic daily space

heating demand backed up by a heat pump;

• Design and develop a latent heat storage system to meet 2-4 hours of peak district heating demand using near industrial waste heat demand;

• Design and develop a latent heat storage system to meet daily district heating demand backed up by a solar thermal collector array;

Approach Screening and material characterization of candidate PCMs:

• 30 – 60 °C – Space heating; 70 – 90 °C – District heating;

120 – 250 °C – medium temperature thermal applications;

Calibration of the numerical models with experimental work;

• Design and numerical modelling latent heat storage containers for:

• Domestic space heating;

• Backed up by a heat pump;

• District heating

• Constant heat supply (industrial waste heat); Varying heat supply (solar thermal);

in progress

Material Review

• Organic compounds are less interesting than Salt Hydrates below 100 °C;

• Below 200 °C Urea mixtures seem promising;

Eutectics Z1 Z2 Tmelt Hmelt Edensity Price

% °C kJ/kg kWh/m3 £/kWh £/m3

Water 0 333 97 0.00 0

Formic Acid 8 276 92 4.18 245

Dipotassium Phosphate Trihydrate 19 231 118 9.76 737

Sodium Sulfate Decahydrate 32 254 111 0.70 50

Disodium Phosphate Dodecahydrate 36 270 118 3.20 242

Magnesium Sulphate Heptahydrate 48 202 97 0.83 52

Mg(NO3)2.6H2O - MgCl2.6H2O 59 41 59 146 71 1.41 100

Trisodium Phosphate Dodecahydrate 70 190 88 2.99 168

Urea - NaNO3 71 29 83 200 89 2.53 225

Magnesium Nitrate Hexahydrate 89 163 80 2.57 131

Urea - NH4Cl 85 15 102 206 78 2.10 163

Oxalic Acid Dihydrate 105 350 160 4.43 474

Urea – NaCl 90 10 112 236 91 1.82 165

Magnesium Chloride Hexahydrate 117 169 79 1.10 56

NaNO3-Ca(NO3)2 55 45 147 150 100 3.32 331

FeCl3-LiCl 81 19 150 326 243 7.48 1818

HCOONa – HCOOK 45 55 168 217 118 3.74 443

Material Review

• Below 500 °C Chloride , Carbonate and Sulphate mixtures seem promising;

Eutectics Z1 Z2 Z3 Z4 Tmelt Hmelt Edensity Price

% °C kJ/kg kWh/m3 £/kWh £/m3

FeCl3 - KCl – LiCl 66 33 1 239 281 196 3.49 841

Sodium Formate 253 260 145 2.17 201

K2CO3 - Li2CO3 – LiOH 62 15 23 350 628 354 6.01 2127

KCl - NaCl - MgCl2 19 22 59 385 421 230 0.47 107

Ba(NO3)2 – NaCl 88 12 408 293 253 1.87 472

KCl - MgCl2 65 35 435 357 187 1.13 212

NaCl - MgCl2 48 52 450 450 247 0.24 60

CaCl2 - NaCl - SrCl2 32 22 46 456 280 192 0.79 152

CaCl2 - KCl - MgCl2 – NaCl 53 6 39 2 460 332 194 0.60 117

K2CO3 - MgCO3 65 35 460 415 284 3.48 989

Fe2(SO4)3 - NaCl - Na2SO4 21 32 48 465 300 209 0.45 93

KCl - MgCl2 36 64 470 392 213 0.71 151

CaCl2 - CaSO4 – NaCl 65 4 30 485 338 198 0.65 129

CaCl2 – NaCl 68 32 495 342 200 0.53 105

Na2CO3 - Li2CO3 58 42 498 550 336 7.04 2366

KCl - NaCl - SrCl2 25 18 57 500 283 192 1.06 204

Container analysis + Model calibration • Tube in tube • Packed bed • Staggered cylinder

Heating Demand modelling • The UK’s Detached and semi

detached dwellings represent the vast majority (around 70% according to Summerfield et al. [4]) of the British household market;

• The study considered improved dwellings (better insolation, air tigh, etc.)

• For space heating purposes, the typical UK radiator has 600mm height;

Figure 5 - Typical UK semi-detached house topographic view (A) and photo of its south façade (B), retrieved from [4].

[4] -A. J. Summerfield, T. Oreszczyn, I. G. Hamilton, D. Shipworth, G. M. Huebner, R. J. Lowe, and P. Ruyssevelt, “Empirical variation in 24-h profiles of delivered power for a sample of UK dwellings: Implications for evaluating energy savings,” Energy Build., vol. 88, pp. 193–202, Feb. 2015. Figure 6 - Typical UK detached house topographic view (A) isometric view (B).

Daily heat demand

On the 15th January for Leicester coordinates weather, the amount of energy spent daily: • For detached dwellings:

• 30.02 kWh • 70.45 W/K; • 0.70 W/(mdweling area

2 . K)

• For semi –detached dwellings: • 20.14 kWh

• 51.61 W/K • 0.645 W/(mdweling area

2 . K)

Figure 8 - Daily variation of the total electrical demand in the winter months

Figure 9 - Adjusted heat demand profile accounting 19°C of internal temperature for detached (A) and semi-detached (B) dwellings.

• Profiles were calculated using the outside temperature and the global daily energy consumption for space heating;

WP3.2: Compact Latent Heat Store

Potential as per proposal: Short term compact heat storage

Original timescale: Year 1 - Year 2

Achievements / outputs to date: Extensive range of materials characterised. Lab systems

fabricated and experiments performed. Simulation models developed. Conference paper

presented at Eurosun, 1 journal paper in review, 2 journal papers drafted.

Revised or restated potential:

‘Design, develop and test a prototype system scalable to meet 2-4 hours of maximum winter space heating load. Such a storage system would enable significant peak electrical load management if heat pumps are deployed in large numbers.’

Synergies with other WPs: 1.2, 1.3, 1.4, 3.3

Recommendations:

Prototype systems indicate that required energy storage capacities and charge/discharge rates are achievable. Additional research to develop new heat exchangers and stores that provide the required output which are suitable for manufacture is required. Estimated time to a product that can be commercialised 3-5 years.

Continued

Targets / deliverables for 3rd annual report or elsewhere:

2 papers accepted for publication. New heat exchanger designs, other application

temperatures

WP3.3 Advanced electric heat pump (Ulster)

• Concept

• Strategy

• Targets for 3rd Annual Report

• Summary

• Electric heat pump and energy storage displacing natural gas boiler

• Phase 1.1: Heating a home with heat pump and energy storage (Y1)

• Phase 1.2: Demand Side Response/Pricing Cycles (Y2.5)

• Phase 2.0: Advanced Heat Pump & Advanced Thermal Store (Y2.5-Y5)

Heat Pump Concept

• Controllable heating modes via 2 3-PV:

1. Direct heating of house via electrical heat pump (DIRECT)

2. Heat pump stores heat in 600 litre tank (STORING)

3. Heating of house from storage tank (INDIRECT)

1. DIRECT 3. INDIRECT 2. STORING

Model of Operation

Mode of Operation

HP Storing HP Using

Actual System electricity demand for NI

Modified DSM control • Typical week of DSM control Mon 14th- Sun 20th March 2015

DSM of storing only - stored heat used at first call for heat until exhausted

HP Storing – RPi Controlled

1st Heat demand supplied from storage

until exhausted Actual System electricity demand

for NI

Overall Performance

HP electricity consumption (storing morning using evening)

Household electricity consumption

HP Storing Using stored heat: HP low impact on evening electric peak demand

HP Direct Heating: High HP electric

consumption to get house up to heat

An measurement in homes?

• Electricity – Low cost

• Temperature - Low cost

• Flow – Low cost?

• Detecting vibrations as flow rate changes

Energy Market Model PLEXOS common model workflow

9 June, 2014 Energy Exemplar 4

0

1

2

3

4

5

6

7

01

/01

/19

00

12

/01

/19

01

24

/01

/19

02

05

/02

/19

03

17

/02

/19

04

28

/02

/19

05

12

/03

/19

06

24

/03

/19

07

04

/04

/19

08

16

/04

/19

09

28

/04

/19

10

10

/05

/19

11

21

/05

/19

12

02

/06

/19

13

14

/06

/19

14

26

/06

/19

15

07

/07

/19

16

19

/07

/19

17

31

/07

/19

18

12

/08

/19

19

23

/08

/19

20

04

/09

/19

21

16

/09

/19

22

28

/09

/19

23

09

/10

/19

24

21

/10

/19

25

02

/11

/19

26

14

/11

/19

27

25

/11

/19

28

07

/12

/19

29

19

/12

/19

30

31

/12

/19

31

11

/01

/19

33

23

/01

/19

34

04

/02

/19

35

16

/02

/19

36

27

/02

/19

37

11

/03

/19

38

23

/03

/19

39

03

/04

/19

40

15

/04

/19

41

27

/04

/19

42

09

/05

/19

43

20

/05

/19

44

01

/06

/19

45

13

/06

/19

46

25

/06

/19

47

kWh

Average heat demand per household

y = 0.0004x2 + 0.046x + 2.6782 R² = 0.9929

0

0.5

1

1.5

2

2.5

3

3.5

4

-25 -20 -15 -10 -5 0 5 10 15 20

CO

P @

65

C

Temperature

Energy Market Model

Extrapolating to 20% of 2.5M Homes?

Original intentions and timescale:

• Heat pump displacement of gas boiler in space heating

• Thermal Storage has been integrated and managed by • Current Night Time Tariffs • Demand Side Response

Achievements to date:

• Heat pump and thermal storage installed • End-user satisfaction • Different run-charge/discharge strategies operated in Terrace Street • Energy Market Model developed • Data acquisition system developed for characterisation of home energy use

WP3.3 Advanced electric heat pumps (Ulster)

Outputs to date:

• 5 papers in a mixture of in press and published • Market simulations for wind curtailment & DSR with Heat Pumps and Storage

Has the effort been justified?

• Ulster has a test facility to demonstrate • New Heat Pumps • New Energy Storage • Business models for DSR

Yes!

Synergies with other WPs :

Gas heat pumps, Storage, Radiators, New business models

Recommendations - is it worth continuing?

• Yes – New heat pumps to come

• Yes – New compact heat storage to come



Targets / deliverables for 3rd annual report or elsewhere

1. Tests on new working fluids with near zero GWP

2. New heat pump for home based on best fluids

3. New thermal storage integrated into homes

4. Revised market models

5. Feed into domestic heating vision

6. Ulster leading UK participation in IEA Heat Pump Annex 46:

Domestic Hot Water Heat Pumps

WP3.4 Next generation gas powered heat pump

(Bob Critoph)

• Concept

• Strategy

• Targets for 3rd Annual Report

• Summary

• Box-for-box exchange for conventional gas boiler – consumer

acceptance

• Air source – universally applicable

• 30-40% reduction in gas consumption – good payback (3 years)

Inside Outside (evaporator unit)

Heat Pump Concept

Two strand strategy:

1. Prove existing prototype system / compare against predictions to demonstrate ability and feasibility.

Top valve assembly

Bottom valve assembly

Generators Gas heat exchanger

Burner

Evaporators Original version, ‘Pre i-STUTE’ Tested May 2011



Top valve assembly



Burner


Case COP

Previous design – 10 kg steel

1.29

New design – 2 kg steel 1.35



Top valve assembly



Burner


Case COP


1.29


• New domed end flange design reduces the mass of steel from 10kg to 2kg

• Now manufactured and installed on the machine


ENG matrix Carbon

Monolithic Carbon

Silane bonded Carbon

Finned tube simulation

Optimised Finned tube Design

Design choice

Density Specific heat Conductivity Contact Resistance Porosity Stability

Shell and tube simulation

Optimised Shell and tube Design


2. Evaluate alternative materials and generator designs to further reduce size and capital cost

Top valve assembly



Burner


Case COP


1.29


• New domed end flange design reduces the mass of steel from 10kg to 2kg

• Now manufactured and installed on the machine

Targets for past six months:

ENG matrix Carbon

Monolithic Carbon

Silane bonded Carbon

Finned tube simulation

Optimised Finned tube Design

Design choice

Density Specific heat Conductivity Contact Resistance Porosity Stability

Shell and tube simulation

Optimised Shell and tube Design

WP3.4 Next generation gas powered heat pump (Bob Critoph)

Original intentions and timescale:

• The carbon reduction potential remains unchanged: at an average present consumption equivalent to 3tCO2 per year savings in the medium term (10 million units by 2035??) will be well into the Mt range.

• Commercial target is the 1.5 million p.a. replacement boiler market, and initially the 450,000 p.a. non-combi market.

• Products could be available 5 years from POC. • Hoped to have prototype fit to inspire industry by 2016!

Achievements to date:

• 2-bed machine with high thermal mass tested and validated computer model • 2-bed machine with domed (light) ends completed and under test • Extensive testing of alternative adsorbents completed • Simulation models of current design and finned tube design completed • Finned tubes ‘optimal’ design nearly complete • ThermExS test facility commissioned after much effort


Outputs to date:

• 5 papers presented to ‘Friends of Sorption’ one to be in Renewable Energy • Shell and tube, Finned tube simulations available as design tool for better

generator

Has the effort been justified?

• We still have a machine that is more compact than any other adsorption machine (Viessmann, Vaillant) and which could be smaller than Robur absorption

• The new design offers low capital cost with reliability. Yes!

Synergies with other WPs :

Electric heat pumps, Storage, Radiators, New business models

Recommendations - is it worth continuing?

• Yes – test out new generator design at LTJ level before building replacement

generators for testing in ThermExS lab


Technology: Reasonably optimistic for a 30-40% lower running

cost boiler replacement. Report on new design potential within

six months

Consumer: Aiming at box-for-box replacement so low risk of

adoption issues. Will need investment but payback will only be

1-2 years more than existing choice.

Policy: Would qualify for existing RHI and would meet existing

certification standards. Expected to survive without future

subsidy

Commercial: Industry structure & capabilities exists to

commercialise this. Other stages of value chain as per current.


Targets / deliverables for 3rd annual report or elsewhere

1. Tests on existing prototype completed

2. New design tested benchtop scale in LTJ

3. Energy rating predictions

4. Feed into domestic heating roadmap

WP3 – Space heating

Documents

Transcript of WP3 – Space heating