Geothermal Heat Pump

Project вЂ" I

DESIGN OF GEOTHERMAL HEAT PUMP

A Project Report Submitted By

Peter Galimutti (2474762)

Neeraj Pastakia (2462895)

Balasubrahmanyam Vanum (2474858)

(MCE 622: Energy Conversion)

MASTER OF SCIENCE IN

MECHANICAL ENGINEERING

Fall 07

Under the esteemed guidance of

Dr.Earnest N.Poulous

(Associate Professor)

DEPARTMENT OF MECHANICAL ENGINEERING

FENN COLLEGE OF ENGINEERING

CLEVELAND STATE UNIVERSITY

ABSTRACT

To address energy problems in the very near future, especially in the area of heating and air-conditioning of building structures, it is proposed that a geothermal system be designed with emphasis on the residential application of heating and cooling. The proposed design will be using a single central reservoir cylindrical in shape which will be stored approximately 50 feet underground. The transfer of heat to or from the central reservoir will be achieved through a piping system connected to a special Freon evaporator installed above around in conjunction with glycol working fluid media. A directional valve will be provided to reverse the movement of the refrigerant to create the heating and cooling cycles.

The proposed geothermal energy system is basically a ground heat pump intended to replace currently used piping systems buried in extension ground trenches. The proposed underground central reservoir system will reduce the amount of excavation required by currently used systems, ground surface areas, and thereby the overall installation costs, and reduces the potential for an environmental mishap due to rupturing of the piping.

In this project software called SINDA/FLUINT has been used to design a geothermal system. SINDA is primarily intended for designing and analyzing thermal systems represented in electric analog, lumped parameter form. This software can solve both finite difference and finite element equations. The FLUINT is the most advanced one dimensional thermal/hydraulic code available for solving arbitrary fluid flow networks without presuming the application.

TABLE OF CONTENTS

ABSTRACT . . . . . . . . . . . . . . . . . 2

I. INTRODUCTION . . . . . . . . . . . . . . 4

II. Technical Report . . . . . . . . . . . . . 8

III. Calculations and SINDA/FLUINT Program . . . . . . 13

IV. Results and discussions . . . . . . . . . . 23

V. Conclusion . . . . . . . . . . . . . . 28

VI. References . . . . . . . . . . . . . . 31

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LIST OF FIGURES

Figure Page

1. Geothermal Reservoir . . . . . . . . . . . 5

2. Space/District heating. . . . . . . . . . . 6

3. Power Generation. . . . . . . . . . . . . 7

4. Heat Pump in winter . . . . . . . . . . . 10

5. Heat Pump in summer. . . . . . . . . . . . . 10

6. Schematic Diagram of proposed Geothermal system . . . . . 11

7. Thermodynamic Cycle . . . . . . . . . . . . 12

8. Top view of physical model of GHP . . . . . . . 14

9. R-C Network of the physical model . . . . . . . 15

INTRODUCTION

I. Introduction

Geothermal Energy

Geothermal power is energy generated by heat stored beneath the Earth's surface.The heat from the earth's core continuously flows outward. It transfers (conducts) to the surrounding layer of rock, the mantle. When temperatures and pressures become high enough, some mantle rock melts, becoming magma. Then, because it is lighter (less dense) than the surrounding rock, the magma rises (convects), moving slowly up toward the earth's crust, carrying the heat from below.

Sometimes the hot magma reaches all the way to the surface, where we know it as lava. But most often the magma remains below earth's crust, heating nearby rock and water (rainwater that has seeped deep into the earth) - sometimes as hot as 700 degrees F. Some of this hot geothermal water travels back up through faults and cracks and reaches the earth's surface as hot springs or geysers, but most of it stays deep underground, trapped in cracks and porous rock. This natural collection of hot water is called a geothermal reservoir. Fig 1 gives the idea about a geothermal reservoir.

Fig 1.Geothermal Reservoir