Review of innovative approaches of thermo‐mechanical refrigeration systems using low grade heat

Sleiti, Ahmad K.; Al‐Ammari, Wahib A.; Al‐Khawaja, Mohammed

doi:10.1002/er.5556

Cited by 33 publications

(14 citation statements)

References 143 publications

(156 reference statements)

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“… In hot climate regions, cooling demand has the highest part of the consumed energy and the most contributor to the peak load of the grid [1,3,5].  Besides, these regions usually suffer from the shortage of freshwater resources [6].…”

Section: Resultsmentioning

confidence: 99%

Novel Solar driven Cooling System Integrated with Solar Still System

Sleiti¹,

Al‐Ammari²,

Al‐Khawaja³

2020

University of the Future: Re-Imagining Research and Higher Education

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Novel integrated solar cooling and solar distillation system is introduced to meet the high cooling and fresh water demands in hot and arid regions such as Qatar. The system is composed of a solardriven ejector cooling system coupled with a single-slope solar still. The introduced novel system is the first study that integrates two solar systems for cooling and water production with outputs significantly higher than any existing system. The results show that the productivity of the solar still is improved by enhancing the evaporation rate (using heating coil) and by increasing the condensation rate (using cooling coil). Simultaneously, this improved the COP of the ejector system by increasing its entrainment ratio with a slight increase in the required solar collector area. The performance of four different scenarios of integration between the proposed cooling and distillation systems is investigated. The results showed that the productivity of the still is five times higher than that of the conventional solar still. The annual produced water considering the hourly variation of the radiant flux was 5067 kg/year, which is 5.7 times more than the conventional systems. The estimated cost of one-liter distilled water per 1 m2 area of the present solar still is $0.04, which is only 18% of the water cost of other still technologies.

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Section: Resultsmentioning

confidence: 99%

Novel Solar driven Cooling System Integrated with Solar Still System

Sleiti¹,

Al‐Ammari²,

Al‐Khawaja³

2020

University of the Future: Re-Imagining Research and Higher Education

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“…• Introduction  Refrigeration and air-conditioning systems consume about 30 % of the generated electrical energy in Qatar [1,7].  Exiting thermal refrigeration systems usually require heat source temperature much higher than 100°C [2].  It is necessary to develop cooling system that has: very low effects on the environment, simple design, low cost, flexible performance, and could be powered by various sources of renewable energy and waste heat.…”

Section: Main Advantagesmentioning

confidence: 99%

Subcritical and Supercritical Operation of Innovative Thermal Mechanical Refrigeration System

Sleiti¹,

Al‐Ammari²,

Al‐Khawaja³

et al. 2020

University of the Future: Re-Imagining Research and Higher Education

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Around 17% of the globally generated energy is consumed for residential, commercial, and transportation refrigeration. The current cooling technologies utilize refrigerants with high Ozone Depletion and Global Warming Potentials. Furthermore, the current technologies are expensive alongside with toxicity and flammability hazards. On the other side, energy produced by combustion of fossil fuels results in substantial amounts of waste heat. Therefore, it is necessary to develop new refrigeration technologies that utilize waste heat as a source of energy with ecofriendly refrigerants with zero ozone depletion potential and zero global warming potential. In addition, this thermal mechanical refrigeration (TMR) technology improves the energy efficiency of the source of waste heat system and minimizes the emissions of the carbon dioxide (CO2). In this study, a novel thermo-mechanical refrigeration system is proposed. It operates with low-grade energy sources (such as waste heat) at temperature range of 60 oC to 100 oC. Furthermore, it has the advantage of working with low-frequency driver-compressor unit, which eliminates noise and increases its lifetime. Moreover, the TMR system is adaptable to commercial, transportation, and residential refrigeration applications.

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“…Various thermal refrigeration systems, reviewed in Sleiti et al, [8] can be powered with low-temperature heat sources such as absorption/adsorption systems, [9][10][11] ejector systems, [12,13] organic Rankine cycle (ORC) systems, [12,[14][15][16] and Stirling engine systems. [17,18] Nevertheless, these systems have their own technical problems that limit their applications.…”

Section: Introductionmentioning

confidence: 99%

“…The ORC is a proven technology, but ORC systems are not economical at heat source temperatures less than 100 C. [8] Also, the expanders used in the ORC are modified compressors with low efficiency and high cost (around 69% of the capital cost). [8] Sleiti et al [8] have presented a detailed review of the innovation approaches of thermomechanical refrigeration systems, including ejector systems, ORC systems, and isothermal and isobaric heat engines. They highlighted the major advantages of these systems over the other thermal refrigeration systems.…”

Section: Introductionmentioning

confidence: 99%

Isobaric Expansion Engines Powered by Low‐Grade Heat—Working Fluid Performance and Selection Database for Power and Thermomechanical Refrigeration

Sleiti

2020

Energy Tech

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A database is developed for the most suitable working fluids for Worthington‐type and Bush‐type isobaric engines based on their performances for a wide range of heat source temperature, from 40 to 300 °C, and operating pressures from 1 to 100 bar. Thermodynamics models are developed and simulated to study the effects of different operating temperatures and pressures on the efficiency and back work ratio of both engines. Results show that in temperature range from 40 to 60 °C, the achieved efficiency is less than 4% for most cases, suggesting that practical applications in this range are very limited. Ammonia and R32 show the highest efficiencies (≈11%) at high pressure of 50 bar for the temperature range of 100–300 °C. The refrigerant R161 has high performance for pressures between 10 and 50 bar for the full range of temperatures from 80 to 300 °C, which makes R161 the choice fluid for a wide range of applications. Novel applications are introduced, which integrate these isobaric engines with vapor compression refrigeration systems. The thermodynamic cycles of the heat driven compressor with the selected working fluids as in the current study and the simplified technological solutions are crucial components of the study novelty.

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Review of innovative approaches of thermo‐mechanical refrigeration systems using low grade heat

Cited by 33 publications

References 143 publications

Novel Solar driven Cooling System Integrated with Solar Still System

Novel Solar driven Cooling System Integrated with Solar Still System

Subcritical and Supercritical Operation of Innovative Thermal Mechanical Refrigeration System

Isobaric Expansion Engines Powered by Low‐Grade Heat—Working Fluid Performance and Selection Database for Power and Thermomechanical Refrigeration

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