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An introductory presentation on ENER-G ground source and gas absorption heta pumps
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Ground Source Heat Pumps
Jason Cox – National Sales Manager
CPD
ENER-G Group Overview
CPD
Products & Solutions
ENER-G Sustainable Technologies
Heat pumps
Heat Pumps
Design Supply Install Commission Maintenance
Technology Principles
Standard Rating Conditions
GSHP – Brine 0C & Water @ 35/30C
ASHP – Air @ 7C & Water @ 35/30C
EN14511
ASHP Performance Curves
Heat Output kW
Entering Water Temperature 35°C
50 °C
ASHP Performance Curves
C.O.P.
Entering Water Temperature 35 °C
50 °C
Standard Rating Conditions
GSHP – Brine 0C & Water @ 35/30C
ASHP – Air @ 7C & Water @ 35/30C
EN14511
GSHP Performance Curves
Heat Output kW
Entering Water Temperature 35 °C
50 °C
GSHP Performance Curves
C.O.P.
Entering Water Temperature 35 °C
50 °C
Ground Source Applications
Collector Options
•Borehole Installation
•Slinky / Horizontal Installation
•Lake / Pond Loops
•Energy Pile Installations
Vertical & Horizontal Loops
Collectors & Chambers
Design Data
•Peak loads•Load profile•Geology•Available space
Ground Loop Design
Assumptions Output 99kW
Natural gas 3.1pkWh
Electricity 11.46p kWh
Running hours 1250
Electricity *0.524g/kWh
Natural gas *0.183g/kWh
Full load hours x Output (kW) = kWh divided by efficiency = InputInput x Cost of energy = Annual running cost
*http://www.bre.co.uk/filelibrary/SAP/2009/SAP-2009_9-90.pdf
Ground Source Heat Pumps
System Capital Cost (£) Annual Running Cost (£) Carbon Output
GSHP 98,000 3,545(RHI £5,375)
16,211
1250 kWh x 99kW = 123,750kWh per annum divided by 4 C.O.P = 30,938kWh
30,938kWh x 11.46ppkWh = £3,545 Annual Running Cost
RHI @ 4.3pkWh for installation less than 99kW
Comparison Table (99kW)
System Efficiency (COP)
Capital Cost (£) Annual Running Cost (£)
Carbon Output
Boiler 0.9 15,000 4,262 25,162
ASHP *2.2 60,000 6,446 29,475
GSHP 4.0 98,000 3,545(RHI £5,375)
16,211
*http://www.energysavingtrust.org.uk/Media/node_1422/Getting-warmer-a-field-trial-of-heat-pumps-PDF
Longfield Academy case study
New-build high school combines ground source heat pumps and solar thermal technology for renewable heating and cooling
The project The construction of a new academy building for 1,150 students combines ground source heat pumps, with solar thermal technology to maximise renewable energy efficiency.
The solutionENER-G has installed 35 boreholes and completed work on the plant room, to accommodate four ground source heat pumps with a combined capacity of 200kW. A total of 22 solar thermal panels have been installed, covering 44 square metres of the Academy’s flat roof.
The benefits •It is expected to achieve a minimum ‘Very Good’ rating under BREEAM for schools, as a result of using renewable power sources, and extensive use of insulation to secure a thermal performance 15% beyond current standards. •The installed renewable technologies will supply heating and hot water to the academy, together with passive under-floor cooling in the summer months. This is projected to reduce the Academy’s carbon dioxide emissions from its heating system by up to 40%.
Malvern Community Hospital case study
New hospital combines ground source heat pumps and a combined heat and power system to generate its own green power.
The project The new-build Malvern Community Hospital opened in autumn 2010 and provides both in-patient and out-patient services. ENER-G delivered a solution that was considered the most efficient means of meeting the building’s heating demands combining two low carbon technologies – a ground source heat pump system and a combined heat and power (CHP) unit. This is the first time that these technologies have been used in combination in the UK’s healthcare sector.
The solution The ground source system comprises 25 boreholes and two heat pumps with combined capacities of 125kW for both heating and cooling. The ENER-G CHP system is a reciprocating gas engine rated at 33kW of electrical output generating 55kW of useful thermal output for the building and the ground loop for the heat pump.
The benefits • The hospital has achieved BREEAM rating ‘Excellent’ and is projected to save on its energy bills and reduce its carbon emissions by 15 tonnes per annum.• A low maintenance option, with the ground source system having a lifetime in excess of 50 years, and the heat pumps lasting up to 25 years. • With the presence of a CHP system at the same site the electricity generated by the CHP unit can be utilised to power the heat pump
Summary
Feasibility
Project Management
In-house drilling rigs & teams
In-house heat pump install team
Single point responsibility
Thank You
www.energ.co.uk
Gas Absorption Heat Pumps
Mark Wilson – National Product Manager
CPD
Contents
Gas Absorption Heat Pumps - Absorption Technology - Different types of GAHP - Benefits - Integration
Absorption TechnologyDifferent types of GAHPBenefitsIntegration
Gas Absorption Heat Pumps
Development of Gas Absorption Heat Pumps
Principle of Compression Heat PumpPrinciple of compression heat pump
USEFUL EFFECT
Principle of gas absorption heat pump
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
How does a GAHP work? 1. Gas burner heats ammonia and water
solution.
2. Ammonia gas enters condenser, condenses and releases heat.
3. High pressure ammonia liquid converted into low pressure ammonia liquid.
4. Ammonia liquid evaporates and draws in heat.
5. Ammonia gas absorbs into ammonia water solution.
6. Solution pump powers process.
How does a GAHP work?
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
1
2
3
4
5
6
7
1. Generator Within the generator, the low Nox gas-fired burner heats the ammonia/water solution via a heat exchanger, increasing the temperature and pressure. The strong ammonia vapour travels to the condenser (2) whilst the weak ammonia solution is circulated to the Absorber (5)
How does a GAHP work?
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
1
2
3
4
5
6
7
2. Condenser The high temperature, high pressure ammonia vapour releases its heat into the heating system in the condenser. The vapour becomes a liquid and travels to the expansion valve (3) on its way to the evaporator (4)
How does a GAHP work?
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
1
2
3
4
5
6
7
3. Expansion valve The high pressure ammonia passes through the expansion valve where the pressure falls. The ammonia now has a reduced boiling point and the liquid changes back to a vapour. This vapour passes on to the Evaporator (4)
How does a GAHP work?
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
1
2
3
4
5
6
7
4. Evaporator A fan draws ambient air through the evaporator. The ambient air captured by the ammonia vapour, contains a high amount of free, renewable energy. The now heated, low pressure vapour passes on to the Absorber (5)
How does a GAHP work?
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
1
2
3
4
5
6
7
5. Absorber In the absorber the weak ammonia solution recombines with the heated vapour, changing its state into a liquid. This releases further heat to the heating system. The now recombined ammonia solution is pumped (7) back to the generator.
How does a GAHP work?
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
1
2
3
4
5
6
7
6. Second expansion valve This second valve controls the flow of weak ammonia between the Generator (1) and the Absorber (5)
How does a GAHP work?
Expansion valve
Heat pump
Cold liquidVery cold liquid
Low temperature gas
Hot gas
Heating return
Expansion valve
1
2
3
4
5
6
7
7. Heat pumpThe pump moves the ammonia solution from the Absorber (5) back to the Generator (1) where the process starts again.
The Technology• Water-ammonia sealed circuit : no top-up, no drain, extremely simple maintenance; • Natural refrigerant : no CFC, HCFC, HFC;• One single moving component (solution pump) : very high reliability;• Exhaust flue gas water vapour condensation: reduced energy losses in the exhaust gas;• Very low electrical consumption1/10 of an equivalent electrical heat pump.
Absorption TechnologyDifferent types of GAHPBenefitsIntegration
Gas Absorption Heat Pumps
• Nominal efficiency 170% by means of heat recovery from renewable source (ground)
• LT or HT versions (55 °C / 65 °C)
• Domestic Hot Water production up to 70°C
• Indoor installation
• Reduction in borehole quantity by up to 60%
• Cheaper civils costs against electric ground source
GAHP GS: Ground source applications
Ground Source applications
Collector Options
•Borehole Installation
•Slinky / Horizontal Installation
•Lake / Pond Loops
•Energy Pile Installations
The Open University
The UK’s largest closed-loop ground source, gas absorption heat pump project, providing low carbon heat and reducing energy consumption by up to 50%The project Building 12 is a 2,000m2 new-build development that forms part of the Walton Hall Campus. The new building is targeting a BREEAM ‘Outstanding’ rating. It incorporates natural ventilation, night time cooling, solar chimneys, automatic lighting controls, a green roof, solar water heating and photovoltaic panels.
The solutionENER-G drilled 13 boreholes to a depth of more than 100 metres to install a ground loop system that feeds four gas absorption heat pumps, with a combined capacity of 140kW heat output. This system supplies the building’s heating requirements and will achieve carbon dioxide savings of approximately 45%, in comparison to a system heater via a condensing boiler
The benefits •Energy consumption reductions of up to 50%•Exemption from the climate change levy•Cost savings relating to the Carbon Reduction Commitment (CRC) energy efficiency scheme and improved Building Energy Certificate ratings (EPC and DEC)•Reduced regulatory costs as a result of low emissions, enabling points for BREEAM assessment and compliance with Part L2A and Part L2B of the building regulations
GAHP A: Air source applications•Nominal efficiency 165% by means of heat recovery from renewable source (air)
• LT or HT versions (55 °C / 65 °C)
• Domestic Hot Water production up to 70°C
• Outdoor installation to free up plant room space
• Minimal drop off of output and efficiency in low ambient temperatures against electric heat pumps
GAHP A: Air source
GAHP AR: Alternate heating and cooling
• Heating or cooling from the same unit
• 2-1 ratio of heating to cooling
• Efficiency in excess of 144%
• Outdoor installation to free up plant room space
GAHP ACF & WS: Simultaneous production of hot/cold water
• Heating to cooling ratio 2.5 to 1
• Efficiency in excess of 227%
• Indoor installation
• Very low electrical consumption
Absorption TechnologyDifferent types of GAHPBenefitsIntegration
Gas Absorption Heat Pumps
Direct use of energy CO₂ savings
http://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdf
Direct use of energy CO₂ savings • Gas produces 0.1836 kgCO₂ / kWh
• Electricity from the grid produces 0.5246 kgCO₂ /kWh
http://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdf*
Direct use of energy CO₂ savings • Utilized electricity from the grid produces 3* times the CO₂ of
natural gas• Electric HP Seasonal COP 2.25**• GAHP Seasonal GUE 1.4
Therefore a gas absorption heat pump produces 46 % less CO₂/kWh than a air source heat pump.
• If we use an example of 60 hours per week 6 months of the year…..
http://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdf*
**http://www.energysavingtrust.org.uk/Media/node_1422/Getting-warmer-a-field-trial-of-heat-pumps-PDF
Example: GAHP-A Air Source Heat Pump (36.2kW)(Running 60 hours per week / 6 months per year)
Robur Gas Heat Pump= 1560 (hrs) x 25.7 (kW gas) x 0.1836 (kgCO2/kWh gas)= 7.3 Tonnes of CO2 per year
Electric Air Source Heat Pump (seasonal COP of 2.25)= 1560 (hrs) x 16 (kW electricity) x 0.5246 (kgCO2/kWh elec)= 13 Tonnes of CO2 per year
To put that into perspective……..
Direct use of energy CO₂ savings
1 year’s CO₂ difference would fill the Olympic swimming pool at the 2012 games 12 times!
Also take into account…
No use/leakage of F-Gases
A typical 37kW air to air electric heat pump contains about 14kg of R410a gas.
If the leakage from the system is for example 10% of the charge per year *(estimates put the Global Annual leakage rates of refrigerants at 27.8% !!)
This is equivalent to 2.5 Tonnes of CO2 per year
Another 5 swimming pools worth!
* Institute of refrigeration report 2008 (New high pressure Low GWP refrigerant blends)
Example : GAHP-A Air Source Heat Pump (36.2kW)(Running 60 hours per week / 6 months per year)
Annual running costs
Saving £500 over a condensing boiler or £1200 over an Electric Heat Pump
Note: gas and electricity prices from SAP 2009 http://www.bre.co.uk/filelibrary/SAP/2009/SAP-2009_9-90.pdf
Robur Gas Heat Pump (seasonal efficiency of
140%)= [1560(hrs) x 0.75(LF) x
36.2(kW) x 3.1(p/kWh)] / 1.40
= £ 938 per year
Condensing Boiler (seasonal efficiency of
90%)= [1560(hrs) x 0.75(LF) x
36.2(kW) x 3.1(p/kWh)] / 0.90
= £ 1,459 per year
Electric Air Source Heat Pump (seasonal
COP of 2.25)= [1560(hrs) x 0.75(LF) x
36.2(kW) x 11.46(p/kWh)] / 2.25
= £ 2,157 per year
Annual running costs
There are significant running cost savings to be achieved by using a Gas Absorption Heat Pump.
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30
40
5060
70
80
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October November December January Febtuary March AprilMonth
Hea
ting
Load
[kW
]
GAHP
Boiler
Boiler
GSHP GAHP Covering Base LoadCovering Base Load
Absorption TechnologyDifferent types of GAHPBenefitsIntegration
Gas Absorption Heat Pumps
Integration of other heat sources
Thank You
www.energ.co.uk
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