The Technology Of A Geothermal Heat Pump Engineering Essay

Energy forms a cardinal portion of adult male ‘s mundane activity and energy ingestion has been on the addition for the last three decennaries, likely due to the many proficient and electronic progresss witnessed in recent old ages ( Dickson & A ; Fanelli, 2003 ) . The statistics of united land energy ingestion by Department of Trade and Industries ( 2003 ) showed that from the period of 1970 to 2001, the overall energy ingestion in United Kingdom increased by 13 per cent since 1970 and by 11 per cent since 1990 ( DTI, 2003 ) . Harmonizing to DTI statistics from 1970-2001, crude oil provided 32 per cent of energy consumed, natural gas provided 40 per cent of energy consumed, coal provided 17 per cent while renewable provided merely 1 per cent.

Due to the environmental concerns associated with the usage of dodo fuel, the demand to happen alternate beginning of energy that is clean and sustainable has grown over the old ages ( Carraro, 2000 ) . It lead to the UK authorities subscribing on to the 1997 Kyoto protocol to cut down green house gas emanation by 5.2 per cent below 1990 degrees by 2012 ( Carraro, 2000 ) . In 2003, the UK authorities announced its aspiration for a 60 % decrease in CO2 emanations by 2050 relation to 1990 degrees ( Martinot et al, 2007 ) . In add-on, the EU set a mark of 20 per cent renewable energy by 2020 for its Member provinces ( Cockrofta & A ; Kelly, 2006 ) . This has lead to greater attending been paid to the harnessing of energy from air current, solar, H2O, wave, geothermic and biofuels in order to cut down green house gases emanation ( Cockrofta & A ; Kelly, 2006 ) . Renewable energy is going popular in United Kingdom, and groundss shows that the sale of geothermic heat pumps has increased yearly by 10 per cent ( Curtis et al, 2005 ) .

This work is a critical reappraisal of geothermic heat pumps as a possible energy beginning in United Kingdom.

A geothermic heat pump or land beginning heat pump ( GSHP ) is a cardinal warming and/or chilling system that pumps heat to or from the land, it uses the Earth as a heat beginning in the winter or a heat sink in the summer ( WGC, 2005 ) . It was developed by Peter Ritter von Rittinger in 1855 ( Bridgewater & A ; Bridgewater, 2007 ) . In the late fortiess Robert C. Webber built the first direct exchange ground-source heat pump. The first successful commercial undertaking was installed in the Commonwealth Building in Portland, Oregon in 1946 ( Bridgewater & A ; Bridgewater, 2007 ) .

2. Technology of geothermic heat pump

A geothermic heat pump system or land beginning heat pump system consists of indoor heat pump equipment, a land cringle, and a flow centre to link the indoor and out-of-door equipment, the heat pump equipment works like a reversible icebox by taking heat from one location and lodging it in another location ( Sanner et al, 1998 ) . The land cringle, which is unseeable after installing, allows the exchange of heat between the Earth and the heat pump. Geothermal heat pumps can be unfastened or closed-loop ( Sanner et al, 1998 ) . Open-loop systems draw good H2O for usage as the heat beginning or heat sink, and after usage, return the well H2O to a drainage field or another good, while closed-loop or earth-coupled systems use a H2O and antifreeze solution, circulated in a land cringle of pipe to pull out heat from the Earth. Ground loops can be installed in a perpendicular well or a horizontal cringle ( Sanner et al, 1998 ) . Vertical Wellss are normally more expensive and used where infinite is limited. The length of loop pipe required will change with dirt type, cringle constellation, and system capacity ( Sanner et al, 1998 ) . Loop length can run from 250 to 1,000 pess per ton of capacity. Particular heat pump characteristics can include variable velocity blowers and multiple-speed compressors, these characteristics can better comfort and efficiency in countries where warming and chilling tonss are rather different. Add-on characteristics include the capableness to bring forth hot H2O ( Sanner et al, 1998 ) . In add-on, ace warmers can be added to supplement the production of domestic hot H2O when there is a demand for infinite warming or chilling ( Sanner et al, 1998 ) . These devices make usage of extra heat during the cooling rhythm and utilize some of the heat during the warming rhythm to supplement hot H2O production. Dedicated H2O warmers can be added which operate whenever there is a demand for hot H2O ( Sanner et al, 1998 ) .

2.1. Basic description of the constituent parts of a geothermic heat pump or land beginning heating pump

A heat pump packaged unit: Water-Water ( or Brine-Water ) type, about the size of a little electric refrigerator incorporating a brace of cold-water ( ethanediol ) and a brace of heated-water connexions ( Curtis et al, 2005 ) .

The heat beginning: This is normally a closed cringle of plastic pipe incorporating a Glycol Antifreeze solution. This pipe is buried in the land in perpendicular boreholes or horizontal trenches. The trenches take either consecutive pipe or coiled pipe, buried about 1.5 to 2m below the surface. A big country is needed for this ( Curtis et al, 2005 ) .

The heat distribution system: This is either under floor warming pipes or conventional radiators of big country connected via normal H2O pipes ( Curtis et al, 2005 ) .

Electrical input and controls: The system will necessitate an electrical input, three-phase being preferred, but individual stage is absolutely equal for most systems. A specialized accountant will be incorporated to supply temperature and clocking maps of the system ( Curtis et al, 2005 ) .

2.2. Application of geothermic heat pump instance point ( Eco house, University of Nottingham ) sourced from ( Doherty et al, 2004 )

An 8 kilowatt reversible land beginning heat pumps system/geothermal heat pump system was successfully installed and tested at the Eco-House, University of Nottingham. The Eco-House is a four sleeping room detached brooding constructed of brick, block, glass and steel. The geothermic heat pump was installed to supply warming and chilling for the Eco house. The geothermic beginning heat pump installed contained a land heat money changer which was made from high denseness polythene ( HDPE ) tubing stuff, a heat pump unit ( Climate Master WE036 ) with heating capacity of 8 kilowatts, and a control system and package installed to automatize the recording of ambient temperatures, land heat money changer temperatures, heating/cooling circuit temperatures and room temperatures. Below in slug points are the benefits of the geothermic heat pump installed in Eco house in University of Nottingham

The installed land beginning heat pump system was able to fulfill the warming and chilling demands of the Eco-House

The sum of CO2 saved for Eco house was 3.8 metric tons per annum compared to heating with domestic gas and 11.3 metric tons per annum compared to electrical warming.

Analysis showed that a payback period for the system installed is 0.25 old ages compared with electrical warming, or 5.71 old ages compared to heating with domestic gas.

2.3. Advantages of geothermic heat pump

The biggest advantages of geothermic heat pump is the low warming costs, it saves every bit much as 80 % money over the cost of fossil fuels.

It uses significantly less electricity than standard heating systems

Its is a renewable energy beginning

Geothermal energy is 48 % more efficient than gas furnaces and 75 % more efficient than oil furnaces

It heats the house and besides cools the house

It does non necessitate furnace or chimneys

Care of geothermic warming system is really inexpensive since it requires merely altering of the heat pump unit ‘s air filter.

2.4 Disadvantages of geothermic heat pump

It is really expensive to put in since it requires a really large pace for horizontal installing and a bedrock free land for perpendicular installing

It take about 2-10 old ages for installing cost to be recouped

Its is non 100 percent clean energy since it emits small measure of green house gases and causes air pollution

2.5 Environmental Concerns of geothermic heat pump

Making a warming system that has zero impact on the environment is likely non possible, while geothermic heat pump has low impact, it still can hold some impact. If the geothermic heat pump is an unfastened cringle, it requires a supply of fresh H2O, which in some topographic points is non ever available. In add-on, this H2O needs to be disposed of decently. While it is non toxic, it can still make a job due to the big volume. If the geothermic heat pump is closed-loop, it contains a refrigerant, or antifreeze, that is toxic. Equally long as the system remains sealed, this is non a job, but if there is a leak, so there could be a serious environmental impact. CO2 is emitted from geothermic heat pump systems, but are really low in measure compared to Gas, LPG, Oil and Electrical warming systems

2.6 Constrains of geothermic heat pump

Not all countries are acceptable to geothermal, in order words if a land is non warm enough it would non be able to bring forth the necessary heat and hence geothermic heat pump would non be practically efficient in that country. ( Phetteplace, 2007 ) .

It is hard to happen a reputable company to put in it, this is because the figure of companies that install the systems is rather little compared to the figure that can put in a conventional system ( Phetteplace, 2007 ) .

Installing a geothermic heat pump is really expensive, typically it can be up to two times every bit much as a traditional warming system ( Phetteplace, 2007 ) .

3. Potential part of geothermic heat pump to the UK energy supply

The potency for utilizing geothermic heat pumps as an alternate beginning of energy in the United Kingdom on commercial rudimentss was foremost examined by the Department of Energy during the oil crisis in 1973, but the thought was dropped due to the autumn of crude oil monetary values during that period ( Downing & A ; Gray, 1986 ) . In the United Kingdom, Southampton was the first to make energy from geothermic power in 1987 and presently the geothermic heat pump heats a figure of edifices in the metropolis and provides 16 GWh of heat per twelvemonth. Investigation was carried out from 1977-1984 by the British geological study to determine the potency of geothermic energy in the UK, and consequences from the study indicated that the country in the north sea on the Continental shelf was suited for the usage of geothermic heat pumps as an alternate beginning of energy ( Downing & A ; Gray, 1986 ) . In add-on, grounds has shown that there is an addition in the figure of domestic geothermic heat pump installing in UK and the demand for UK to achieve the EU mark of 20 per cent of renewable energy by 2020 has propelled the addition in the usage of geothermic heat pumps.

4. Decision

Advocacy for the usage of renewable energy beginning has grown quickly in Uk since the acceptance of white paper by Uk authorities for the decrease of C emanation by 60 per cent by 2050. Records shows that the sale of geothermic heat pumps has increased in the UK as a beginning of renewable energy, though there are still some constrains impacting the usage of geothermic heat pump, constrains such as high cost of installing, deficiency of lands that can back up geothermic heat pumps and besides the fact that it is non 100 per cent clean energy beginning. In decision, geothermic heat pump has a great potency to lend to UK renewable energy demands if authorities can put massively in it.

July 25, 2017