New text comparison between CO 2 and other supercritical working fluids (ethane, Xe, CH 4 and N 2 ) in line- focusing solar power plants coupled to supercritical Brayton power cycles

Coco-Enríquez, Luis; Muñoz-Antón, Javier; Martínez-Val, José M.

doi:10.1016/j.ijhydene.2017.02.071

Cited by 58 publications

(25 citation statements)

References 24 publications

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“…Such applications where heat transfer fluids (HTF) have an important role are heat exchanging systems in power stations [1], cooling and heating systems in buildings [2], vehicles air conditioning (AC) system in transportations [3], and cooling systems of most of the processing plants [4]. In all of the aforementioned applications, the HTF's thermal conductivity has a strong influence on the efficiency of the heat transfer process and with it the overall efficiency of the system.…”

Section: Introductionmentioning

confidence: 99%

A Review on Nanofluids: Fabrication, Stability, and Thermophysical Properties

Ali

Teixeira

Addali

2018

Journal of Nanomaterials

308

178

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Nanofluids have been receiving great attention in recent years due to their potential usage, not only as an enhanced thermophysical heat transfer fluid but also because of their great importance in applications such as drug delivery and oil recovery. Nevertheless, there are some challenges that need to be solved before nanofluids can become commercially acceptable. The main challenges of nanofluids are their stability and operational performance. Nanofluids stability is significantly important in order to maintain their thermophysical properties after fabrication for a long period of time. Therefore, enhancing nanofluids stability and understanding nanofluid behaviour are part of the chain needed to commercialise such type of advanced fluids. In this context, the aim of this article is to summarise the current progress on the study of nanofluids, such as the fabrication procedures, stability evaluation mechanism, stability enhancement procedures, nanofluids thermophysical properties, and current commercialisation challenges. Finally, the article identifies some possible opportunities for future research that can bridge the gap between in-lab research and commercialisation of nanofluids.

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Section: Introductionmentioning

confidence: 99%

A Review on Nanofluids: Fabrication, Stability, and Thermophysical Properties

Ali

Teixeira

Addali

2018

Journal of Nanomaterials

308

178

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“…This work presents air-cooled s-CO2 cycle configurations specifically selected for a CSP application. The estimated cost calculation of the PTC (parabolic trough collector) and LF (linear Fresnel) systems were developed with the following equation [42]: The adoption of s-CO 2 cycles is particularly promising for large-scale, high-temperature CSP plants [2]. Four factors are important for incorporating s-CO 2 into CSP plants: superior performance vs. steam Rankine cycles, the ability to integrate thermal energy storage, ultimate heat sink thermal energy storage [36][37][38], and dry cooling [41].…”

Section: Results Of 'Group A' Mixtures (Substances For Reducing the Cmentioning

confidence: 99%

Supercritical CO2 Mixtures for Advanced Brayton Power Cycles in Line-Focusing Solar Power Plants

2019

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This work quantifies the impact of using sCO2-mixtures (s-CO2/He, s-CO2/Kr, s-CO2/H2S, s-CO2/CH4, s-CO2/C2H6, s-CO2/C3H8, s-CO2/C4H8, s-CO2/C4H10, s-CO2/C5H10, s-CO2/C5H12 and s-CO2/C6H6) as the working fluid in the supercritical CO2 recompression Brayton cycle coupled with line-focusing solar power plants (with parabolic trough collectors (PTC) or linear Fresnel (LF)). Design parameters assessed are the solar plant performance at the design point, heat exchange dimensions, solar field aperture area, and cost variations in relation with admixtures mole fraction. The adopted methodology for the plant performance calculation is setting a constant heat recuperator total conductance (UAtotal). The main conclusion of this work is that the power cycle thermodynamic efficiency improves by about 3–4%, on a scale comparable to increasing the turbine inlet temperature when the cycle utilizes the mentioned sCO2-mixtures as the working fluid. On one hand, the substances He, Kr, CH4, and C2H6 reduce the critical temperature to approximately 273.15 K; in this scenario, the thermal efficiency is improved from 49% to 53% with pure s-CO2. This solution is very suitable for concentrated solar power plants coupled to s-CO2 Brayton power cycles (CSP-sCO2) with night sky cooling. On the other hand, when adopting an air-cooled heat exchanger (dry-cooling) as the ultimate heat sink, the critical temperatures studied at compressor inlet are from 318.15 K to 333.15 K, for this scenario other substances (C3H8, C4H8, C4H10, C5H10, C5H12 and C6H6) were analyzed. Thermodynamic results confirmed that the Brayton cycle efficiency also increased by about 3–4%. Since the ambient temperature variation plays an important role in solar power plants with dry-cooling systems, a CIT sensitivity analysis was also conducted, which constitutes the first approach to defining the optimum working fluid mixture for a given operating condition.

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“…A solar water heater is integrated with a fuel cell system for simultaneous generation of heat and hydrogen is simulated by TRNSYS . In literature, many researchers have used carbon dioxide as mediating fluid for solar water heating and space and industrial heating process . An energy‐efficient and environment‐friendly CO 2 based heat pump was developed by Nekså et al The prototype developed at NTNU revealed the importance of CO 2 as the working fluid for the tap water heater.…”

Section: Solar Thermal Heating and Coolingmentioning

confidence: 99%

“…83 In literature, many researchers have used carbon dioxide as mediating fluid for solar water heating 84,[139][140][141] and space and industrial heating process. 142,143 An energy-efficient and environmentfriendly CO 2 based heat pump was developed by Nekså et al 144 The prototype developed at NTNU revealed the importance of CO 2 as the working fluid for the tap water heater. The energy consumption for electricity or gas fuel systems is reduced by 75% when hot tap water system using CO 2 as working fluid was used.…”

Section: Pressure Relief Protectionmentioning

confidence: 99%

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Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

2019

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Summary Refrigerants bearing high global warming potential (GWP) and ozone depletion potential (ODP) were outlawed or facing time‐beared permission under the Montreal (1987), Kyoto (1997) protocols, F‐Gas law (2015), Paris Accord (2016), and recent Kigali Amendment to Montreal Protocol (2019). In order to modify followed by the paradigm shift of existing heating and cooling systems, American Society of Heating, Refrigeration, and Air‐Conditioning Engineers (ASHRAE) envisaged natural and synthetic refrigerants (Synrefs) are under investigation globally. Carbon dioxide (CO2) is a popular natural refrigerant (Natref) replacing Synrefs used in commercial heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems globally. A rampant rise is observed in markets of Asia (Japan and China), North America (the United States and Canada), the Australian continent, and Africa (South Africa) by reaching 20 000 CO2‐stores around the globe. The European markets are leading the utilization of CO2 in the heat pump, and refrigeration, CO2 based markets estimate 14% of the total food retail stores (400 m2). Japan is the second leading market of CO2 heat pump and refrigeration with more than 10 200 CO2 condensing units. CO2 transcritical systems have a share of more than 10% in only European market (large stores); however, their share is less than 10% of total stores in other major markets of the world. New pump and compressor‐driven transcritical CO2 systems integrate ejectors, condensers, and booster systems to reduce energy consumptions, enhance efficiency, efficacy, and coefficient of performance. This article reports a critical review of the CO2 based heating, cooling, and refrigeration system and presents updated literature along with barriers and challenges on commercial use of Natref‐based heating and cooling applications worldwide.

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New text comparison between CO 2 and other supercritical working fluids (ethane, Xe, CH 4 and N 2 ) in line- focusing solar power plants coupled to supercritical Brayton power cycles

Cited by 58 publications

References 24 publications

A Review on Nanofluids: Fabrication, Stability, and Thermophysical Properties

A Review on Nanofluids: Fabrication, Stability, and Thermophysical Properties

Supercritical CO2 Mixtures for Advanced Brayton Power Cycles in Line-Focusing Solar Power Plants

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

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New text comparison between CO 2 and other supercritical working fluids (ethane, Xe, CH 4 and N 2 ) in line- focusing solar power plants coupled to supercritical Brayton power cycles

Cited by 58 publications

References 24 publications

A Review on Nanofluids: Fabrication, Stability, and Thermophysical Properties

A Review on Nanofluids: Fabrication, Stability, and Thermophysical Properties

Supercritical CO2 Mixtures for Advanced Brayton Power Cycles in Line-Focusing Solar Power Plants

Review of carbon dioxide (CO 2 ) based heating and cooling technologies: Past, present, and future outlook

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Product

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Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook