Geothermal-driven ejector refrigeration system

Mark Anthony B. Redo, Menandro S. Berana

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

A mathematical model of a heat-driven ejector refrigeration system that uses geothermal energy as the heat source was established. Philippine low-enthalpy geothermal resources were investigated and became the bases in computing for the heat at the generator part of the ejector refrigeration system. Analysis and comparison of the performance of the cycle considering working fluids like ammonia (R717) and R134a as the refrigerants were conducted. The properties of those fluids were based on an available thermodynamic database of various refrigerants. The governing principles and conservation equations for energy, mass and momentum were successively applied to control volume of ejector components. The properties for both fluid and flow were solved iteratively for isentropic and irreversible processes wherein entropy generation and frictional losses were accounted for. This included simulation of flows in two-phase region. Input parameters were set like the generating temperature and condensing temperature. The range of 60 to 100 °C available geothermal fluid temperature could produce 50 to 90°C of generating temperature for the fluid refrigerant. This range of generating temperature yielded an evaporating temperature of 8 to 25 °C at a fixed condensing temperature of 40 °C. After numerical analyses, the determined coefficient of performance was at the range of 0.21 to 0.39, while nozzle and ejector efficiencies were from 94% to 99%. The geometric profiles of the ejector were also projected along with the varying generating temperature for both fluids. From the calculation, ammonia offers higher performance and efficiencies and lower evaporating temperatures suitable for larger cooling needs.

Original languageEnglish
Title of host publicationEnergy
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Print)9780791856284
DOIs
Publication statusPublished - 2013 Jan 1
Externally publishedYes
EventASME 2013 International Mechanical Engineering Congress and Exposition, IMECE 2013 - San Diego, CA, United States
Duration: 2013 Nov 152013 Nov 21

Publication series

NameASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
Volume6 A

Other

OtherASME 2013 International Mechanical Engineering Congress and Exposition, IMECE 2013
CountryUnited States
CitySan Diego, CA
Period13/11/1513/11/21

ASJC Scopus subject areas

  • Mechanical Engineering

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