WP3 – Space heating
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
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kWh
Average heat demand per household
y = 0.0004x2 + 0.046x + 2.6782 R² = 0.9929
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P @
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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
WP3.3 Advanced electric heat pumps (Ulster)
WP3.3 Advanced electric heat pumps (Ulster)
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
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
Case COP
Previous design – 10 kg steel
1.29
New design – 2 kg steel 1.35
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
Case COP
Previous design – 10 kg steel
1.29
New design – 2 kg steel 1.35
• New domed end flange design reduces the mass of steel from 10kg to 2kg
• Now manufactured and installed on the machine
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
Case COP
Previous design – 10 kg steel
1.29
New design – 2 kg steel 1.35
• New domed end flange design reduces the mass of steel from 10kg to 2kg
• Now manufactured and installed on the machine
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
Case COP
Previous design – 10 kg steel
1.29
New design – 2 kg steel 1.35
• New domed end flange design reduces the mass of steel from 10kg to 2kg
• Now manufactured and installed on the machine
Two strand strategy:
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
1. Prove existing prototype system / compare against predictions to demonstrate ability and feasibility.
2. Evaluate alternative materials and generator designs to further reduce size and capital cost
Top valve assembly
Bottom valve assembly
Generators Gas heat exchanger
Burner
Evaporators Original version, ‘Pre i-STUTE’ Tested May 2011
Case COP
Previous design – 10 kg steel
1.29
New design – 2 kg steel 1.35
• 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
WP3.4 Next generation gas powered heat pump (Bob Critoph)
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
WP3.4 Next generation gas powered heat pump (Bob Critoph)
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.
WP3.4 Next generation gas powered heat pump (Bob Critoph)
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