Final Year Project Report-ground Source Cooling System

Final year project report “GROUND SOURCE COOLING SYSTEM”

SUBMITTED BY AMANPREET SINGH MECHANICAL ENGINEERING 8TH SEMESTER ROLL NO. 40411010 CEC LANDRAN

A DISSERTATION REPORT ON

“GROUND SOURCE COOLING SYSTEM” In partial fulfillment of the requirement for the award of the degree of

BACHELOR OF TECHNOLOGY In

MECHANICAL ENGINEERING Submitted By

AMANPREET SINGH MECHANICAL ENGINEERING UNIVERSITY ROLL NO - 40411010 Under the Esteemed guidance of

MR. RADHY SHAAM (Lecturer, CEC LANDRAN)

CHANDIGARH ENGINEERING COLLEGE MOHALI (LANDRAN)

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CHANDIGARH ENGINEERING COLLEGE MOHALI (LANDRAN) Certificate This is to certify that this dissertation work entitled

“GROUND SOURCE COOLING SYSTEM” SYSTEM” is the bonafied work done

By Amanpreet Singh In partial fulfillment of the requirement for the award of the degree of Bachelor of technology In Mechanical engineering from Punjab Technical University During the academic year 2007-2008

Mr. Radhey Shaam (Lecturer, Department of Mechanical Engineering)

Dr. Rupinder Gupta (HOD Department of Mechanical Engineering)

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ACKNOLEDGEMENT

Every Orientation work has an imprint of many people and we hereby take this excellent opportunity to acknowledge all the help , guidance & support that we have received for the completion of this project. With supreme sincerity and deep sense of appreciation, we express our thanks to Dr. Rupinder Gupta, Head, Department of Mechanical Engineering, for his co-operation. I express my gratitude Mr. Radhey Shaam (lecturer CEC Landran) who has guided us regarding the project, for his kindness, courtesy, valuable suggestions and inspirations. Above all, I would like to thank my beloved parents for their direct and indirect help, moral support and blessings, without which, this would not have been possible. I would also like to express thanks to my colleagues and friends, for their help and moral support. Lastly I would like to thank all those who directly or indirectly helped me throughout my work.

AMANPREET SINGH

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CANDIDATE’S DECLARATION I hereby declare that the project work which is being presented in this report entitled GROUND SOURCE COOLING SYSTEM by Amanpreet Singh in partial fulfillment of requirement for the award of degree of B.Tech. in Mechanical Engineering submitted to the Department of Mechanical Engineering of Chandigarh Engineering College under Punjab Technical University, Jalandhar is authentic record of my own work carried out during Eighth Semester under the supervision of Mr. Radhey Shaam (Lecturer), Department of Mechanical Engineering, Chandigarh Engineering College Mohali (Landran). The matter presented in this report has not been submitted by me in any other university/ institute for the award of B.Tech. Degree.

(Signature of Student) This is to certify that the above statement made by the candidate is best of my knowledge.

(Signature of Supervisor) To B.Tech. Viva-Voce examination of Amanpreet Singh has been held on _______________and accepted.

Signature of the Supervisor ( Internal Coordinator)

(External Examiner)

(Signature of H.O.D)

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Table of Contents ACKNOLEDGEMENT.................................................................................................................................4 Abstract ...................................................................................................................................................7 INTRODUCTION .......................................................................................................................................8 Module I ..................................................................................................................................................9 CONCEPT .............................................................................................................................................9 TYPES OF GROUND SOURCE HEAT PUMP .......................................................................................9 1. 2.

Closed Geothermal Ground Loops ..........................................................................................9 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 .......................................................................................................................................24

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Abstract

This project work describes in detail, the project work undertaken by me during the final year of degree at Chandigarh Engineering College, Landran. The contents of this report includes a brief description of the Ground Source Cooling System, supplemented by a good number of necessary and descriptive drawings which makes this project report very easy to understand. In addition to these, the report also contains the details regarding the different type of other ground source cooling systems which are used these days. Above all, this report gives a detailed description of closed looped ground source cooling system. This description is empowered with the experimental analysis of the system and the heat transfer calculations. This report will be of help for those who wish to understand about the basic working of different ground source cooling systems especially those who wish to study close loop ground source cooling system.

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INTRODUCTION

This project report deals in depth with our project “Closed Closed Loop Ground Source Cooling System” System”. In this project we have designed and established a closed loop ground source cooling system so as to have a future alternative to traditional heating, and air conditioning systems. Closed Loop Ground Source Cooling System use the relatively constant temperature of the ground to regulate the temperature of a home or building at very high effective efficiency. The system

does

not

create

heat

through

combustion of fuel or passing electricity through resistors; it moves heat from the ground to the home/building for heating and in the opposite direction for cooling. In so far as the heat in the ground that these systems sys use is supplied by the sun, they are using renewable energy. As an additional benefit, ground source cooling/heating

system

can

provide

inexpensive hot water, either to supplement or replace entirely the output of a conventional, domestic water heater.. Ground source heating and cooling is cost effective because it uses energy so efficiently. At the initial stage the project work was divided in to two parts: 1) Digging 5 X 5 X 10 feet deep pit 2) Preparing the rest of the apparatus as per the drawings For better etter description of the project work the project report has been divided in different modules as discussed further.

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Module I

CONCEPT Ground Source cooling uses the earth or ground water or both as the sources of heat in the winter, 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 antifreeze solution, 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 through the ground water or antifreeze solution. TYPES OF GROUND SOURCE HEAT PUMP 1. Closed Geothermal Ground Loops The most typical geothermal installation utilizes a closed loop system. In a closed loop system, a loop of piping is buried underground and filled with water or antifreeze that continuously circulates through the system. There are four major types of closed loop geothermal systems: horizontal loops, 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 typically one of the more economical choices. In horizontal geothermal ground loops, several hundred feet of five to six feet deep trenches are dug with a backhoe or chain trencher. Piping is then laid in the trench and backfilled. A typical horizontal ground loop will be 400 to 600 feet long for each ton of heating and cooling. Because of the amount of trenching involved, horizontal ground loops are most commonly used for new construction. Finally, because horizontal geothermal ground loops are relatively shallow, they are often not appropriate for areas with extreme climates such as the north or Deep South.

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b. Vertical Geothermal Ground Loops When extreme climates, limited space or rocky terrain is a concern, vertical geothermal ground loops are often the only viable option. This makes them popular for use on small lots and in retrofits. In vertical geothermal ground loops, a drilling rig is used to drill 150 to 300 foot deep holes in which hairpin shaped loops of pipe are dropped and then grouted. A typical vertical ground loop requires 300 to 600 feet of piping per ton of heating and cooling. Vertical loops are typically more expensive than horizontal loops, but are considerably less complicated than drilling for water. Less piping is also required for vertical geothermal ground loops as opposed to horizontal loops as the earth temperature is more stable at depth.

c. Slinky Coil Geothermal Ground Loops Slinky coil geothermal ground loops are gaining popularity, particularly in residential geothermal system installations. Slinky coil ground loops are essentially a more economic and space efficient version of a horizontal ground loop. Rather than using straight pipe, slinky coils, as you might expect, 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 anywhere from 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 or lake is available on your property, a closed loop geothermal system can be installed by laying coils of pipe in the bottom of a body of water. However, a horizontal trench will still be needed to bring the loop up to the home and close the loop. Due to the inherent advantages of water to water heat transfer, this type of geothermal system is both highly economical and efficient.

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2. Open Geothermal Ground Loops With open geothermal ground loops, rather than continuously running the same supply of water or antifreeze through the system, fresh water from a 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 are required for a successful open loop system. While double well designs can be economical, use of open geothermal ground loops is generally discouraged and even prohibited in some jurisdictions. Water quality is key to an open loop design as mineral content and acidity can quickly damage geothermal units. Also, improper installation or runoff management of an open loop geothermal system can result in ground water contamination or depleted aquifers.

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MODULE II

Components The ground source cooling system requires three primary components; loop of G.I. pipes, a liquid pumps pack, Coolant and a radiator (heat transfer device). A loop field can be installed horizontally or 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 a closed loop system there is no direct interaction between the fluid and the earth; only heat transfer across the G.I. pipe. The amount of vertical or horizontal loop required is a function of the ground formation thermal conductivity, deep earth temperature, and heating and cooling power needed, and also depends on the balance 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 the heat that the coolant has absorbed from the system. Radiators are filled with tubes that the coolant passes through. The fan carries heat off of the radiator. The coolant enters the receiving tank at the top of the radiator, passes through the tubes inside, losing the heat it has collected, and then collects in the dispensing tank at the bottom for the

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water pump to circulate it back through the cooling system.

3) Monoblock pump:

These are single phase capacitor start and run, 2 pole design pump used for clear water free from mud, grit etc. for domestic application and as a booster pump to fill the overhead tank for multi storaged buildings. Pump is fitted with a non return turn valve, which does not allow water to return in the suction line, thereby delivering the water instantaneorsly when the pump is switched on Ball Bearing sealed on both sides take the entire load with ample factor of safety and additional lubrication in not required. Copper alloy die-cast cast forged impeller has high strength to with stand wear and tear.

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The pump is available in three different bodies namely: Aluminium die-cast body, Cast iron body and Steel body.

4) Coolant (Water)

The most common coolant is water. Its high heat capacity and low cost makes it a suitable heat-transfer medium. It is usually used with additives, like corrosion inhibitors and antifreezes. Antifreeze, a solution of a suitable organic chemical (most often ethylene glycol, diethylene glycol, or propylene glycol) in water, is used when the water-based coolant has to withstand 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 cool some 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) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16)

Maximum density at 4 oC - 1,000 kg/m3, 62.43 Lbs./Cu.Ft, 8.33 Lbs./Gal., 0.1337 Cu.Ft./Gal. Freezing temperature - 0 oC (Official Ice at 0 oC) Boiling temperature - 100 oC Latent heat of melting - 334 kJ/kg Latent heat of evaporation - 2,270 kJ/kg Critical temperature - 380 - 386 oC Critical pressure - 221.2 bar, 22.1 MPa (MN/m2) Specific heat capacity water - 4.187 kJ/kgK Specific heat capacity ice - 2.108 kJ/kgK Specific heat capacity water vapor - 1.996 kJ/kgK Thermal expansion from 4 oC to 100 oC - 4.2x10-2 Bulk modulus elasticity - 2.15 x 109 (Pa, N/m2)

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Module III

WORKING Ground Source cooling systems work on a different principle than an ordinary furnace/air conditioning system, and they require little maintenance or attention. Furnaces must create heat by burning 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 via combustion). Instead, the Earth's natural heat is collected in winter through a series of pipes, called a loop, installed below the surface of the ground or submersed in a pond or lake. Fluid circulating in the loop carries this heat to the home. An indoor Ground Source cooling system then uses electrically-driven compressors and heat exchangers in a vapor compression cycle the same principle employed in a refrigerator - to concentrate the Earth's energy and release it inside the home at a higher temperature. In typical systems, duct fans distribute the heat to various rooms; other applications include waterto-water transfer, as seen in a radiant floor system. 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 in the same way that a refrigerator keeps its contents cool, by drawing heat from the interior, not by injecting cold air.

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Module III DRAWING PLAN

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Module IV

Test observations:

S no.

Source

Observed temperature in ◦C

1

Inlet temp of heat exchanger

27

2

outlet temp of heat exchanger

30

3

Room temp

32

4

Temp outside room

35

5

Outlet air temp from heat exchanger

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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’s law 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 Watts Where, Q is the convective heat flow rate (watt) A is area exposed to heat transfer (m2), tout = temp at outlet of heat exchanger (K) tin= temp at inlet of heat exchanger (K) h = heat transfer coefficient (W/m2K)

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2) Heat transfer rate between pipe and earth Since conduction s essentially due to random molecular motion, the concept is termed as microform of heat transfer is usually referred to as diffusion of energy. Conduction is prescribed by Fourier law,


 


  

 

      

= 50 X (0.0125)2 X 0.785 X 0.5 =0.003067 Watt

Where, Q is the conduction heat flow rate (watt) A is area exposed to heat transfer (m2), tout = temp at outlet of pipe (K) tin= temp at inlet of pipe (K) k = thermal conductivity (W/mK)

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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 save anywhere from 30% to 70% annually on utilities. Even with the high initial costs of purchasing a geothermal system the payback period is relatively short, typically between three and five years. Geothermal systems are environmentally friendly; they are a renewable energy source, nonpolluting, and recognized as one of the most efficient heating and cooling systems on the market. The U.S. Environmental Protection Agency (EPA) has called geothermal the most energyefficient, environmentally clean, and cost-effective space conditioning systems available. The life span of the system is longer than conventional heating and cooling systems. Most loop 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 designed to 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 do not require extremely high temperatures (as compared with wall-mounted radiators). Thus they are ideal for open plan offices. Using large surfaces such as floors, as opposed to radiators, 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. This temperature equates roughly to the average annual air-temperature of the chosen location, so is usually 7-21 degrees Celsius (45-70 degrees Fahrenheit) depending on location. Because this temperature remains constant, geothermal heat pumps perform with far greater efficiency and in a far larger range of extreme temperatures than conventional air conditioners and furnaces, and even air-source heat pumps. A particular advantage is that they can use electricity produced from renewable sources, like solar 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 practical heating and cooling solution that can pay for itself within a few years of installation.

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The current use of geothermal heat pump technology has resulted in the following emissions reductions • •

Elimination of more than 5.8 million metric tons of CO2 annually Elimination of more than 1.6 million metric tons of carbon equivalent annually

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PROJECT RELATED PHOTOGRAPHS P

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BIBLIOGRAPHY Heat and Mass Transfer……………………………………………………………………………………….........by D. S. Kumar Heat and Mass Transfer……………………………………………………………………………………….........by R. K Rajput

Web Sites Wikipedia.org Google.com About.com Kalsipumps.com

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