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Jms-0112 Design and Analysis of an Absorption Refrigeration System

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Jms-0112 Design and Analysis of an Absorption Refrigeration System Project Number: JMS-0112 DESIGN AND ANALYSIS OF AN ABSORPTION REFRIGERATION SYSTEM A Major Qualifying Project Report Submitted to the Faculty Of the WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the Degree of Bachelor of Science in Mechanical Engineering by Kajano, Joseph Lucas, Doug Muyuka, Glorius Date: April 26, 2012 Approved: Professor John M Sullivan, Major Advisor 1 ABSTRACT This project focuses on the construction of a three fluid gas absorption refrigeration unit, intended to operate in a 20 environment, with a compartment temperature of 3 . Gas absorption systems, unlike vapor-compression systems, use a heat source to facilitate refrigeration. Three fluid gas absorption refrigerators use no electricity and no moving parts, such as pumps and compressors, and operate at a single system pressure. Unlike the vapor- compression cycle, which utilizes pressure gains and drops to produce refrigeration, the three fluid gas absorption cycle uses the principle of partial pressure between two fluids to create the cooling effect. Extensive analysis of the thermodynamics, heat transfer, and chemical properties of a three fluid gas absorption system was conducted to design and construct the structural model shown in the report. This model was pressure tested for structural integrity and leakage and a safety analysis of the fluids involved was undertaken to insure proper functionality when the gases are introduced. 2 TABLE OF CONTENTS ABSTRACT ............................................................................................................................................... 1 TABLE OF FIGURES ................................................................................................................................... 4 TABLE OF NOMENCLATURE ..................................................................................................................... 5 GOAL STATEMENT ................................................................................................................................... 7 INTRODUCTION ....................................................................................................................................... 8 BACKGROUND ......................................................................................................................................... 9 Refrigeration Cycles ........................................................................................................................... 10 Magnetocaloric Refrigeration System ............................................................................................ 10 Thermoelectric Refrigeration System ............................................................................................. 11 The Vapor-Compression Refrigeration System ............................................................................... 12 The Absorption Refrigeration System ............................................................................................. 15 Two Fluid Absorption Refrigeration System.................................................................................... 16 Three Fluid Absorption Refrigeration System ................................................................................. 23 System Selection............................................................................................................................ 25 SYSTEM ANALYSIS AND DESIGN ............................................................................................................. 25 Refrigerant and Third Fluid ................................................................................................................ 25 Material Selection ............................................................................................................................. 29 Refrigerator Cabinet .......................................................................................................................... 30 Evaporator ........................................................................................................................................ 41 ABSORBER ............................................................................................................................................. 54 Condenser Analysis............................................................................................................................ 55 Generator Analysis ............................................................................................................................ 58 System Theoretical Performance ................................................................................................... 70 DETERMINATION OF MASSES ................................................................................................................ 83 Hydrogen Mass .............................................................................................................................. 84 Ammonia: ...................................................................................................................................... 85 Liquid Ammonia Hydroxide: ........................................................................................................... 86 PART DESCRIPTION ................................................................................................................................ 87 Part Prices ......................................................................................................................................... 92 CONSTRUCTION..................................................................................................................................... 92 FILLING PROCEDURE .............................................................................................................................. 98 3 SYSTEM SAFETY ................................................................................................................................... 100 TESTING AND MEASURING PROCEDURES ............................................................................................ 106 Volume Measurement ..................................................................................................................... 106 Bubble Pump Testing ....................................................................................................................... 107 Pressure Testing .............................................................................................................................. 108 RESULTS .............................................................................................................................................. 108 Liquid solution and total system volume ...................................................................................... 108 Masses of all fluids ....................................................................................................................... 109 Bubble Pump Flow rate ................................................................................................................ 109 Pressure Test ............................................................................................................................... 109 CONCLUSION ....................................................................................................................................... 110 APPENDIX 1 ......................................................................................................................................... 111 APPENDIX 2 ......................................................................................................................................... 112 APPENDIX 3 ......................................................................................................................................... 113 WORKS CITED ...................................................................................................................................... 115 4 TABLE OF FIGURES Figure 1 Heat engine thermodynamic schematic. (Karonen) .................................................................... 9 Figure 2 Magnetocaloric effect on Gadolinium alloy. ............................................................................. 11 Figure 3 Thermoelectric plate diagram .................................................................................................. 12 Figure 4 Vapor-compression system diagram......................................................................................... 14 Figure 5 Vapor-compression P vs. v diagram .......................................................................................... 14 Figure 6 Vapor-compression T vs. s diagram .......................................................................................... 15 Figure 7 Ammonia-water single stage absorption refrigeration system flow diagram ............................. 18 Figure 8 T vs. s graph of pure ammonia made from data in table 10. ..................................................... 21 Figure 9 P vs. v of pure ammonia constructed from data in table 10. ..................................................... 21 Figure 10 Diagram with state points of a basic three fluid absorption system. ....................................... 24 Figure 11 simplified model of absorber. ................................................................................................. 27 Figure 12 T vs. s diagram
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