Exergy Analysis of a Solar Absorption Refrigeration System in Ngaoundere

Abstract

In this study, the first and second laws of thermodynamics are used to analyze the performance of a single-stage absorption refrigeration system powered by solar energy. The working pair used in this study is LiBr-H 2 O where water (H 2 O) is the refrigerant and the lithium bromide (LiBr) is the absorbent. A mathematical model based on exergy analysis is applied to analyse the system performance. Temperature, enthalpy, entropy, mass flow rate and exergy loss of each component including evacuated tube solar collector are evaluated. Furthermore, the overall coefficient of performance (COP cooling ) and the overall exergetic coefficient of performance (ECOP cooling ) of the solar absorption system (absorption system coupled to an evacuated tube solar collector) for cooling purpose are calculated from the thermodynamic properties of the working fluids under weather conditions of Ngaoundere city, Cameroon. The calculations were done on the basis of a half hourly analysis from 6:30 AM to 6:30 PM. The results were compared and they show that the exergy destruction highly occurs in the generator and the solar collector. The simulation results can be used for the thermodynamics optimization of solar absorption refrigeration systems.

Exergy Analysis of a Double-Effect Solar Absorption Refrigeration System in Ngaoundere

“…Ambient temperature and Solar insolation in Ngaoundere on the 15th of January 2014 [19]. Table 1 gives the solar insolation and the ambient temperature collected in the Meteological Station of Ngaoundere on the 15th of January 2014 by M. Tenkeng [19]. Table 2 presents the temperature of the components of the system at 12.30 PM.…”

“…Properties of the LiBr-H 2 O solution and typical overall heat transfer coefficient were adopted from Gur Mittelman [29]. For the heat transfer area or total conductance, we adopted the values from M. Tenkeng et al [19]: (UA)a = 1.800 kW/K, (UA)e = 2.250 kW/K, (UA)g = 1.000 kW/K, (UA)c = 1.200 kW/K. World Journal of Engineering and Technology…”

“…In this study, in order to analyse the system with a great accuracy, we decided to look more closely by the simulation of a half hour analysis, from 6:30 AM to 6:30 PM of a double effect series flow absorption refrigeration system, using water-lithium bromide solution as working fluid with an Evacuated tube solar collector type. The data, which are solar insolation and environmental temperature are taken from M. Tenkeng et al [19] and were collected on the 15th of January 2014, in Ngaoundere, Cameroon. The main focus of this study is concentrated on the exergy analysis of each component of the system, precisely the exergy loss [20].…”

A Review on Exergy Analysis of Solar Refrigeration Technologies

“…They observed that the evaporator and generator registered the great losses and were the components that needed to be optimized. Tenkeng et al [11] also presented a study on exergy analysis of a series double effect solar refrigeration in Ngaoundere, Cameroun on a half hourly basis, from 6.30AM to 6.30PM. A thermodynamic analysis was undertaken by simulation with a FORTRAN program and the results showed that the High Pressure Generator and the evaporator were the component needing a great attention in term of exergy efficiency and exergy loss.…”