GROUND SOURCE COOLING SYSTEM

MINOR PROJECT GROUND SOURCE COOLING SYSTEM SUBMITTED BY-SAHIL KAPOOR

SECTION-F-12(MAE) ROLL NO.11096203610 Table of Contents ACKNOLEDGEMENT ......................................................................................... 4 Abstract ............................................................................................................... 7 INTRODUCTION ................................................................................................. 8 Module I ............................................................................................................... 9 CONCEPT ........................................................................................................... 9 TYPES OF GROUND SOURCE HEAT PUMP 91. Closed Geothermal Ground Loops 92. Open Geothermal Ground Loops ................................................................. 11 MODULE II .......................................................................................................... 12 Components ........................................................................................................ 12 Module III ............................................................................................................. 15 WORKING ........................................................................................................... 15 Module III ............................................................................................................. 16 DRAWING PLAN ..................................................................................................16 Module IV ............................................................................................................. 18 Test observations: ................................................................................................ 18 Calculations .......................................................................................................... 18 MODULE V ........................................................................................................... 20 Advantage of ground source cooling system ........................................................ 20 PROJECT RELATED PHOTOGRAPHS………………………………………………22

BIBLIOGRAPHY .................................................................................................... 26

ACKNOWLEDGEMENT I would like to express my deepest appreciation to all those who provided me the possibility to complete this report. A special gratitude I give to our final year project manager, Mr.KUMAR ANKUR, whose contribution in stimulating suggestions and encouragement, helped me to coordinate my project especially in writing this report. Furthermore I would also like to acknowledge with much appreciation the crucial role of the staff of MECHANICAL & AUTOMATION department, who gave the permission to use all required equipment and the necessary materiasl to complete the task “GROUND SOURCE COOLING SYSTEM”. I have to appreciate the guidance given by other supervisor as well as the panels especially in our project presentation that has improved our presentation skills thanks to their comment and advices

INTRODUCTION Ground Source Cooling Systems use the relative constant temperature of the ground water to regulate the temperature of a home or building efficiently. The system does not create heat through combustion of fuel or passing electricity through resistors, it moves heat from the house or building to the ground for cooling.This system does not use any fluid or gas refrigerant. One of the main reasons that so many people dismiss the idea of using geothermal energy intheir homes is because they think it is simply too expensive. This is actually a common misconception, and many people can actually save a lot of money by switching to geothermal home heating and cooling.The truth is that a geothermal heat pump system is quite in expensive to operate, but it will cost a considerable amount to have it installed.The earth absorbs almost 50% of all solar energy and remains anearly constant temperature of 10°C to 22°Cdepending on geographic

location. Working with an underground loop system, geothermal heating or cooling systems utilize this constant temperature to exchange energy between the house and the earth as needed for cooling and heating. G r o u n d s o u r c e cooling system is cost effective because it uses energy efficiently. This project report deals in depth this project we have designed andhave a future alternative to traditional and air conditioning systems.Ground Source Cooling System relatively constant temperature of to regulate the temperature of building at very high effective eff system does not create hecombustion of fuel or passing through resistors; it moves heaground to the home/building for the opposite direction for cooling.the heat in the ground that theseis supplied by the sun, they renewable energy.As an additional benefit, grocooling/heating system can inexpensive hot water, either todomestic water heater. Ground efficiently.At the initial stage the project work1)Digging 5 X 5 X 10

Figure 1: Layout of AGround source cooling system

Module I CONCEPT Ground Source cooling uses the earth or ground water or both as the sources of heat in thewinter, and as the "sink" for heat removed from the home in the summer. For this reason,Ground Source cooling systems have come to be known as earth-energy systems (EESs).Heat is removed from the earth through a liquid, such as ground water or an antifreezesolution, upgraded by the heat pump, and transferred to indoor air. During summer months,the process is reversed: heat is extracted from indoor air and transferred to the earth throughthe ground water or antifreeze solution.

TYPES OF GROUND SOURCE HEAT PUMP1. Closed Geothermal Ground Loops The most typical geothermal installation utilizes a closed loop system. In a closed loop system, aloop of piping is buried underground and filled with water or antifreeze that continuously circulatesthrough the system. There are four major types of closed loop geothermal systems: horizontalloops, vertical loops, slinky coils and pond loops. a. Horizontal Geothermal Ground Loops If adequate soil or clay based land is available,horizontal geothermal ground loops are typicallyone of the more economical choices. In horizontalgeothermal ground loops , several hundred feet of five to six feet deep trenches are dug with abackhoe or chain trencher. Piping is then laid inthe trench and backfilled. A typical horizontalground loop will be 400 to 600 feet long for eachton of heating and cooling. Because of theamount of trenching involved, horizontal groundloops are most commonly used for newconstruction. Finally, because horizontalgeothermal ground loops are relatively shallow,they are often not appropriate for areas withextreme climates such as the north or DeepSouth. b. Vertical Geothermal Ground Loops When extreme climates, limited space or rockyterrain is a concern, vertical geothermal groundloops are often the only viable option. This makesthem popular for use on small lots and in retrofits.In vertical geothermal ground loops , a drilling rigis used to drill 150 to 300 foot deep holes in whichhairpin shaped loops of pipe are dropped and thengrouted. A typical vertical ground loop requires300 to 600 feet of piping per ton of heating andcooling. Vertical loops are typically moreexpensive than horizontal loops, but areconsiderably less complicated than drilling forwater. Less piping is also required for verticalgeothermal ground loops as opposed to horizontalloops as the earth temperature is more stable atdepth. c. Slinky Coil Geothermal Ground Loops Slinky coil geothermal ground loops are gaining popularity, particularly in residential geothermalsystem installations. Slinky coil ground loops are essentially a more economic and space efficientversion of a horizontal ground loop. Rather than using straight pipe, slinky coils, as you mightexpect, use overlapped loops of piping laid out horizontally along the bottom of a wide trench.Depending on soil, climate and your heat pumps run fraction, slinky coil trenches

can be anywherefrom one third to two thirds shorter than traditional horizontal loop trenches. d. Geothermal Pond Loops If at least a ½ acre by 8 ft deep pond orlake is available on your property, a closedloop geothermal system can be installed bylaying coils of pipe in the bottom of a bodyof water. However, a horizontal trench willstill be needed to bring the loop up to thehome and close the loop. Due to theinherent advantages of water to water heattransfer, this type of geothermal system isboth highly economical and efficient.

Open Geothermal Ground Loops With open geothermal ground loops , rather than continuously running the same supply of water orantifreeze through the system, fresh water froma well or pond is pumped into and back out of the geothermal unit. Both an abundant source of clean water and an adequate runoff area arerequired for a successful open loop system.While double well designs can be economical,use of open geothermal ground loops is generallydiscouraged and even prohibited in some jurisdictions. Water quality is key to an openloop design as mineral content and acidity canquickly damage geothermal units. Also,improper installation or runoff management of an open loop geothermal system can result inground water contamination or depletedaquifers

1.2.1.1Horizontal GeothermalGround LoopSystem If adequate soil or clay based land is available, horizontal geothermal ground loops are typically one of the more economical choices. In horizontal geothermal ground loops,several hundred feet of five to six feet deep trenches are dug witha backhoe or chain trencher. Piping is then laid in the trench and backfilled. A typical horizontal ground loop will be 400to 600 feet long for each ton of heating and cooling. Because of the amount of trenching involved, horizontal ground loops are most commonl y used for new construction. Finally, because horizontal geothermal ground loops are relativelyshallow,they are often not appropriate for areas with extreme climates such as the North or DeepSouth.Figure 5:Horizontal Geothermal Ground Loop System

MODULE II Components The ground source cooling system requires three primary components; loop of G.I. pipes, a liquidpumps pack, Coolant and a radiator (heat transfer device). A loop field can be installed horizontallyor vertically as convenient. 1) Loop of G.I. pipes A closed loop system, the most common, circulates the fluid through the loop fields’ G.I. pipes. In aclosed loop systemthere is no directinteraction betweenthe fluid and theearth; only heattransfer across theG.I. pipe. The amountof vertical orhorizontal looprequired is a functionof the groundformation thermalconductivity, deepearth temperature,and heating andcooling powerneeded, and alsodepends on thebalance between the amount of heat rejected to and absorbed from the ground during the course of the year. A rough approximation of the soil temperature is the average daily temperature for the region. 2) Heat exchanger (Radiator) The radiator is designed to dissipate theheat that the coolant has absorbed fromthe system. Radiators are filled with tubesthat the coolant passes through. The fancarries heat off of the radiator. Thecoolant enters the receiving tank at thetop of the radiator, passes through thetubes inside, losing the heat it hascollected, and then collects in thedispensing tank at the bottom for the water pump to circulate it back 3) Monoblock pump: These are single phase capacitor smud, grit etc. for domestic applicaas a booster pump to fill the overhfor multi storaged buildings. Pumpwith a non return valve, which dallow water to return in the suctthereby delivering theinstantaneorsly when the pump is son Ball Bearing sealed on both sithe entire load with ample factorand additional lubrication in not rCopper alloy die-cast forged imphigh strength to with stand wear augh the cooling system.art and run, 2 pole design pump used for clear wion andad tankis fittedoes notion line,waterwitchedes takef safetyequired.ller hasnd tear.13ater free from The pump is available in three different bodies namely: Aluminium die-cast body, Cast iron body andSteel body. 4) Coolant (Water) The most common coolant is water. Its high heat capacity and low cost makes it a suitableheat-transfer medium. It is usually used with additives, like corrosion inhibitors andantifreezes. Antifreeze, a solution of a suitable organic chemical (most often ethylene glycol,diethylene glycol, or propylene glycol) in water, is used when the waterbased coolant has towithstand temperatures below 0 °C, or when its boiling point has to be raised.Very pure demonized water, due to its relatively low electrical conductivity, is used to coolsome electrical equipment, often high-power transmitters.Heavy water is used in some nuclear reactors; it also serves as a neutron moderator.

Some common used thermal properties for water: 5) Maximum density at 4 o C - 1,000 kg/m 3 , 62.43 Lbs./Cu.Ft, 8.33 Lbs./Gal., 0.1337 Cu.Ft./Gal.6) Freezing temperature - 0 o C (Official Ice at 0 o C)7) Boiling temperature - 100 o C8) Latent heat of melting - 334 kJ/kg9) Latent heat of evaporation - 2,270 kJ/kg10)

Critical temperature - 380 - 386 o C11) Critical pressure - 221.2 bar, 22.1 MPa (MN/m 2 )12) Specific heat capacity water - 4.187 kJ/kgK13) Specific heat capacity ice - 2.108 kJ/kgK14) Specific heat capacity water vapor - 1.996 kJ/kgK15) Thermal expansion from 4 o C to 100 o C - 4.2x10 -2 16)

Bulk modulus elasticity - 2.15 x 10 9 (Pa, N/m 2 )

Module III WORKING Ground Source cooling systems work on a different principle than an ordinary furnace/airconditioning system, and they require little maintenance or attention. Furnaces must create heat byburning a fuel, typically natural gas, propane, or fuel oil. With Ground Source cooling systems,there's no need to create heat, hence no need for chemical combustion at the building (though, of course, the electricity used is usually made viacombustion). Instead, the Earth's natural heat iscollected in winter through a series of pipes,called a loop, installed below the surface of theground or submersed in a pond or lake. Fluidcirculating in the loop carries this heat to thehome. An indoor Ground Source cooling systemthen uses electrically-driven compressors andheat exchangers in a vapor compression cycle -the same principle employed in a refrigerator toconcentrate the Earth's energy and release itinside the home at a higher temperature. Intypical systems, duct fans distribute the heat tovarious rooms; other applications include water-to-water transfer, as seen in a radiant floorsystem.In summer, the process is reversed in order to cool the home. Excess heat is drawn from the home,expelled to the loop, and absorbed by the Earth. Ground Source cooling systems provide cooling inthe same way that a refrigerator keeps its contents cool, by drawing heat from the interior, not by injecting cold air.

Module III DRAWING PLAN

Module IV Test observations: S no. Source Observed temperature in ◦ C 1 Inlet temp of heat exchanger 272 outlet temp of heat exchanger 303 Room temp 324 Temp outside room 355 Outlet air temp from heat exchanger 28 Calculations 1) Heat transfer rate between radiator and room air As per forced convection fluid passing through the tube of a heat exchanger follows the Newton’slaw of cooling   {  .   = 13.1 X (0.3625 X 0.425)X(303 – 300)=13.1 X (0.3625 X 0.425)X 3=6.0546 WattsWhere, Q is the convective heat flow rate (watt)A is area exposed to heat transfer (m 2 ),t out = temp at outlet of heat exchanger (K)t in = temp at inlet of heat exchanger (K)h = heat transfer coefficient (W/m 2 K) 2) Heat transfer rate between pipe and earth Since conduction s essentially due to random molecular motion, the concept is termed as microformof heat transfer is usually referred to as diffusion of energy. Conduction is prescribed by Fourier law,   .      .  I  $ I = 50 X (0.0125) 2 X 0.785 X 0.5=0.003067 WattWhere, Q is the conduction heat flow rate (watt)

A is area exposed to heat transfer (m 2 ),t out = temp at outlet of pipe (K)t in = temp at inlet of pipe (K)k = thermal conductivity (W/mK

MODULE V Advantage of ground source cooling system Geothermal systems are able to transfer heat to and from the ground with minimal use of electricity.When comparing a geothermal system to an ordinary system a homeowner can saveanywhere from 30% to 70% annually on utilities. Even with the high initial costs of purchasing a geothermal system the payback period isrelatively short, typically between three and five years. Geothermal systems are environmentally friendly; they are a renewable energy source, non- polluting, and recognized as one of the most efficient heating and cooling systems on themarket. The U.S. Environmental Protection Agency (EPA) has called geothermal the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available.The life span of the system is longer than conventional heating and cooling systems. Mostloop fields are warranted for 25 to 50 years and are expected to last at least 50 to 200 years. Geothermal systems do not use fossil fuels for heating the house and eliminate threats caused by combustion, like carbon monoxide poisoning. The fluids used in loop fields are designedto be biodegradable, non-toxic, non-corrosive and have properties that will minimize pumping power needed.Geothermal heat pumps are especially well matched to underfloor heating systems which donot require extremely high temperatures (as compared with wall-mounted radiators). Thusthey are ideal for open plan offices. Using large surfaces such as floors, as opposed toradiators, distributes the heat more uniformly and allows for a lower temperature heat transfer fluid.The Earth below the frost line remains at a relatively constant temperature year round. Thistemperature equates roughly to the average annual air-temperature of the chosen location, sois usually 7-21 degrees Celsius (45-70 degrees Fahrenheit) depending on location. Becausethis temperature remains constant, geothermal heat pumps perform with far greater efficiencyand in a far larger range of extreme temperatures than conventional air conditioners andfurnaces, and even air-source heat pumps.A particular advantage is that they can use electricity produced from renewable sources, likesolar and wind power, to heat spaces and water much more efficiently than an electric heater.This allows buildings to be heated with renewable energy without transporting and burning biomass on site, producing biogas for use in gas furnaces or relying solely upon solar heating.Geothermal heat pump technology is a Natural Building technique. It is also a practicalheating and cooling solution that can pay for itself within a few years of installation

The current use of geothermal heat pump technology has resulted in the following emissionsreductions • Elimination of more than 5.8 million metric tons of CO 2 annually • Elimination of more than 1.6 million metric tons of carbon equivalent annually 1.3BENEFITS OF GROUND SOURCE COOLING SYSTEM The mainbenefits of ground source cooling system is to provide a Year round comfort,Energy efficiency, Long lasting system, Noise reduction, Comfort and an Ecofriendlysystem. 1.3.1 Year Round Comfort One benefit of having a ground source coolingsystem installed is that it is the only homecomfort system you will need. While its name might suggest otherwise, a ground source coolingsystem can coolthehouse effectively, meaning that you will not need to invest in anytype of air conditioning system to compliment it. Once your ground source coolingsystem isin place, you will be assured a comfortable indoor environment all year long. 1.3.2 Energy Efficiency Ground source cooling system are also very energy efficient. Because they do not actuallyhave to generate heat, when compared to the outdoor unit of a split air conditioning system.Theyrun on very little electricity. While the actual amount that you will save annually by switching to ground source coolingsystem will vary depending on what you were paying before, you will be hard pressed to find any type of homecoolingsystemthat is ch eaper.When you use geothermal energy, you are depending on anenergy source that you, quiteliterally, do not have to pay for. 1.3.3 Long Lasting Compared to many of the more traditional home coolingsystems,ground source coolingsystems Are remarkably long lasting. While a typical air conditioning system may last somewhere between 15 and 20 years, the pipes installed with aground source cooling systemwill be good for 50 years or more. Basically, that means that you will probably never have to worry about replacing your home cooling system again when you switch toground source coolingsystem.And that makes your initial investment seem even more reasonable.Safe,secure & solid,ground source coolingsystemdo not use fossil fuels, they create no rust, rotor corrosion 1.3.4 Noise Reduction As they have no outside condensing units (such as those in air conditioners), there's no noise outside the home.Ground source coolingsystemare so quiet inside of a house that users may not be aware they are operating.

1.3.5Comfort Ground source coolingsystemdeliver consistent temperatures.Modern fans efficiently mixair from all corners ofthe housebut it maintains the same room temperature whereasgroundsource coolingsystemdraws fresh air from the atmosphere and cools the air.This creates amore even temperature throughout your home and requires less energy to balance previouslyhot and cold areas. 1.3.6 Eco-Friendly As ground source cooling system does not use any type of refrigerants there is no harm caused to the environment in the form of global warming and depletion of ozone layer.The coolant used here is water which is easily available in nature and is cheaper compared to other coolants.C o o l a n t s a r e u s u a l l y u s e d w i t h a d d i t i v e s , l i k e c o r r o s i o n i n h i b i t o r s andantifreeze.Antifreezei s a s o l u t i o n o f a s u i t a b l e o r g a n i c c h e m i c a l ( m o s t o f t e n e t h y l e n e g l y c o l , d i e t h y l e n e g l y c o l , o r propyleneglycol) but such additives are not necessary in ground source cooling system

PROJECT RELATED HOTOGRAPHS

BIBLIOGRAPHY Heat and Mass Transfer……………………….........by D. S. Kumar Heat and Mass Transfer………………….........by R. K Rajput Basic thermodynamics …………………………………………..by M.K.Muralidhara, 2001 Applied Thermodynamics………………………………………..by R.K.Hegde, 1999 Refrigeration and Air Conditioning………………………….......byAnanthanarayan, 1998 Web Sites Wikipedia.org Google.com About.com Kalsipumps.com http://en.wikipedia.org/wiki/Geothermal_heat_pumphttp http://www.yoakumdrilling.com/groundsource.html http://www.engineeringtoolbox.com/cooling-heating-efficiency RESEARCH PAPERS [1]. Spitler,J.D. and C. Underwood, “ Application of Direct Cooling Ground Source Heat Pump Systems ”,Proceedings of ASHRAE-CIBSE Conference, Edinburgh, Scotland,September 24-26, 2003. [2]. Mcquay International, American society of heating, Air-Conditioning andrefrigeration Engineers Inc. “ Design Of Geothermal Systems For Commercial and Institutional Buildings ”,Fort Wayne, IN, 2002. [3].Fridleifsson, I.B.,Geothermal energy for the benefit of the people, “Renewable and Sustainable Energy Reviews 5”, 299-312, 2001.[4]. International Geothermal Association,Report of the IGA tothe UN Commission onSustainable Development, Session 9 (CSD-9), New York, April, 2001.