Dynamic simulation of an air cooled lithium bromide-water absorption cooling system operating with solar energy

The objective of this paper is to investigate theoretically a solar driven 60 kW absorption cooling system. The system is constituted of a combined ejector single-effect absorption cycle coupled with a linear Fresnel solar concentrator and using water/lithium bromide as working fluid. The combined ejector single-effect absorption cycle exhibits high performances, almost equal to that of double-effect absorption device. However, higher driving heat temperatures are required than in the case of conventional single-effect machines. A mathematical model is set up to analyze the optical performance of the linear Fresnel concentrator. Simulations are carried out to study the overall system performance COPsystem and the performances of the combined absorption machine COPcycle for generator driving temperatures and pressures in the ranges 180°C – 210°C and 198 kPa – 270 kPa, respectively. Further, the effect of operating parameters such as the cooling medium and chilled water temperatures is investigated. A maximum cycle performance of 1.03 is found for a generator pressure of 272 kPa and chilled and cooling water temperatures of 7°C and 25°C, respectively. A case study is investigated for a typical summer Tunisian day, from 8:00 to 18:00. The effect of ambient temperature and solar radiation on cycle and system performances is simulated. The optical performances of the concentrator are also analyzed. Simulation results show that between 11:00 and 14:00 the collector efficiency is 0.61 and that the COPcycle reaches values always higher than 0.9 and the COPsystem is larger than 0.55. Globally the performances of the investigated cycle are similar to those of double-effect conventional absorption system.

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Economic feasibility analysis with the parametric dynamic simulation of a single effect solar absorption cooling system for various climatic regions in Turkey

Renewable Energy ◽

10.1016/j.renene.2020.01.055 ◽

2020 ◽

Vol 152 ◽

pp. 75-93 ◽

Cited By ~ 5

Author(s):

A.F. Altun ◽

M. Kilic

Keyword(s):

Dynamic Simulation ◽

Cooling System ◽

Economic Feasibility ◽

Feasibility Analysis ◽

Solar Absorption ◽

Climatic Regions ◽

Absorption Cooling ◽

Single Effect ◽

Solar Absorption Cooling ◽

Absorption Cooling System

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Thermodynamic Analysis of a Half-Effect Absorption Cooling System Powered by a Low-Enthalpy Geothermal Source

Applied Sciences ◽

10.3390/app9061220 ◽

2019 ◽

Vol 9 (6) ◽

pp. 1220 ◽

Cited By ~ 1

Author(s):

Javier Alejandro Hernández-Magallanes ◽

Jonathan Ibarra-Bahena ◽

Wilfrido Rivera ◽

Rosenberg J. Romero ◽

Efraín Gómez-Arias ◽

...

Keyword(s):

Thermodynamic Analysis ◽

Cooling System ◽

Real Data ◽

Exergy Efficiency ◽

Volcanic Complex ◽

Lithium Nitrate ◽

Absorption Cooling ◽

Geothermal Wells ◽

Absorption Cooling System ◽

System Operating

A thermodynamic analysis of a half-effect absorption cooling system powered by a low-enthalpy geothermal source was carried out. This paper presents modeling of the half-effect absorption cooling system operating with an ammonia/lithium nitrate mixture and based on the first and second laws of thermodynamics, using as energy inputs real data from two geothermal wells located at Las Tres Vírgenes volcanic complex, Baja California Sur, México. Plots of coefficients of performance and exergy efficiency against condenser, evaporator, and generator temperatures are presented for the half-effect cooling system. The results showed that the system was able to operate at generation temperatures between 56 and 70 °C, which were supplied by the geothermal wells in order to produce cooling at temperatures as low as −16 °C, achieving coefficients of performance between 0.10 and 0.36, while the exergy efficiency varied from 0.15 to 0.40 depending on the system operating temperatures.

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