Architectural Engineering

 

First Advisor

Yuebin Yu

Date of this Version

7-2016

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Architectural Engineering, Under the Supervision of Professor Yuebin Yu, Lincoln, Nebraska: July, 2016

Copyright 2016 Ziqi Shen

Abstract

This project was funded by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE RP-1462). It is a three years’ research, including the literature review, labs construction, experiments and data analysis.

In this thesis, first of all, we conducted literature review of mechanism motion influence on heat and mass transfer and additive effect in absorption chiller. This part helps us understand the basic idea of how mechanism motion affects the heat and mass transfer of sorption fluids and gives us reference on how to select the experiment instrument and the experiment operation range.

In the second part, the instrument selection and lab construction are introduced. A commercial absorption chiller, a vertical vibration table and a statistic water loop system are used in our lab. This test facility has the capability of realizing mechanism motion in real systems with adjustable wide range vibration and long term stabilized auxiliary water supply. A commercial absorption chiller with a capacity of 10kW is utilized in this project. A water loop system was constructed to maintain a repetitive experimental condition when the outdoor conditions change. We also installed a data acquisition system for in-line measurement of the solution concentration and temperature and flow rate of the solution and water loops. We can use these measurements to calculate the heat and mass transfer capacity in the absorber in steady-state. The enhancement is obtained by comparing the temperature differences, before a vibration and during a vibration.

In the third section, we illustrate the methodology of how to analyze the heat and mass transfer in the absorber and the data under different conditions. We separate the experiment into three big groups, including the conditions without additive, with n-octanol additive and with 2-ethylhexanol(2EH) additive. Different film thickness (spray amount), vibration frequency, and vibration amplitude comparisons were considered under each condition. And we also cross-compared all these three groups. The results of this project revealed the optimal frequency and amplitude combinations (at 25 Hz & 0.2mm) for the absorption chiller tested in this study. The results of this project provided information filling the knowledge gap about the influence of mechanical motion in absorption chiller technology.

Advisor: Yuebin Yu

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