||A Computational Steady State Thermodynamic Analysis of Ammonia-Water and Lithium Bromide-Water Absorption Cooling System
||International Master Degree Program on Energy Engineering
||Jamir Aldair Cal
Coefficient of Performance (COP)
Steady state simulation
Lithium bromide water solution
Ammonia water solution
In this study, various simulations were conducted to analyze, optimize, and compare two types of absorption cooling: lithium bromide (LiBr) and ammonia water solution systems. Simulations to calculate the optimum Coefficient of Performance (COP) were performed for each system. The study was divided into three parts.
In the first part of this research, a steady state simulation model was created in the Excel software. The simulation was created in the form of a datasheet calculator by selecting an appropriate thermodynamic model. The calculator was able to calculate the COP and energy flow for different components in the ammonia water absorption cycle like the generator, absorber, condenser, and evaporator. The COP obtained was validated with previous studies and the COP obtained was 0.59. In the second part of this research for the LiBr system, a steady state simulation model was developed, optimized, and validated using a software called Simulink in the program, MATLAB®. The simulation was able to calculate the COP and essential values at any component at any given set temperatures of the condenser, evaporator, absorber, and generator. The COP obtained was validated with previous studies and the COP obtained was 0.94.
In the third part, a comparison was made between them whereby the lithium bromide proved to have a higher COP than the ammonia water solution. Hence, the lithium bromide has better efficiency at higher cooling temperatures, but the ammonia-water system can work better at lower temperatures. Finally, the absorber temperature proved to be the most influential factor in determining the COP of each system while comparing.
Table of Contents iii
List of Tables v
List of Figures vi
Chapter 1 Introduction 1
1.1. Background 1
1.2. Motivation and objectives 4
1.3. A schematic of experimental procedure 4
Chapter 2 Literature Review 6
2.1. Operating conditions for ammonia-water absorption cooler. 6
2.2. Operating conditions for LiBr-water absorption cooler. 7
Chapter 3 Theory and Methodology 9
3.1. Computer modeling of a single-stage ammonia–water absorption cooler system in Excel. 9
3.1.1. Thermodynamic properties mathematical model 9
3.1.2. Input data for ammonia-water thermodynamic model 11
3.2. Computer modeling of a single-stage LiBr–water absorption cooler system in Simulink, MATLAB 12
Chapter 4 Results and Discussion 19
4.1. Thermodynamic model of a single stage ammonia-water absorption cooler in Excel. 19
4.2. Simulation and optimization of a thermodynamic model of a single stage LiBr-water absorption cooler in Simulink. 20
4.3. Ammonia-water and LiBr-water absorption system simulation comparison analysis 27
Chapter 5 Conclusions and Future Works 29
5.1. Conclusions 29
5.2. Future works 30
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