Natural refrigerants for refrigeration and air-conditioning systems

Riffat, Saffa; Afonso, Clito; Oliveira, Armando C.; Reay, David

doi:10.1016/1359-4311(96)00030-0

Cited by 106 publications

(32 citation statements)

References 3 publications

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“…Ammonia is an important industrial forming gas used in various fields including pharmaceuticals and chemical industries as well as national security [1][2][3][4][5][6][7][8]. However, it is flammable and poisonous that can cause seizures, collapse, lung damage, blindness, coma, and even death [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

NH3 sensing property and mechanisms of quartz surface acoustic wave sensors deposited with SiO2, TiO2, and SiO2-TiO2 composite films

Tang

et al. 2018

Sensors and Actuators B: Chemical

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Section: Introductionmentioning

confidence: 99%

NH3 sensing property and mechanisms of quartz surface acoustic wave sensors deposited with SiO2, TiO2, and SiO2-TiO2 composite films

Tang

et al. 2018

Sensors and Actuators B: Chemical

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“…It can work to temperatures up to 90 • C, such as at the Drammen heat pump plant (Norway), with a COP over 3. Its efficiency is comparable with the one of the synthetic refrigerants analysed in this survey, and it is moderately flammable and toxic, so it requires specific safety precautions [25]. Due to its corrosive properties and different working temperature and pressure, ammonia cannot be used to retrofit the heat pumps using synthetic refrigerants, such as R-22 and R-134a.…”

mentioning

confidence: 99%

“…Carbon dioxide (CO 2 )-Carbon dioxide is a non-toxic, non-flammable and non-corrosive refrigerant, which is generally obtained as a waste product, making it as one of the low-cost refrigerants [25]. It is also a transcritical fluid, meaning that temperature and pressure can be controlled individually, unlike other condensing (subcritical) refrigerants.…”

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confidence: 99%

Heat Roadmap Europe: Large-Scale Electric Heat Pumps in District Heating Systems

et al. 2017

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Abstract:The Heat Roadmap Europe (HRE) studies estimated a potential increase of the district heating (DH) share to 50% of the entire heat demand by 2050, with approximately 25-30% of it being supplied using large-scale electric heat pumps. This study builds on this potential and aims to document that such developments can begin now with technologies currently available. We present a database and the status of the technology and its ability of expansion to other European locations by reviewing experiences aimed at further research or application in the heating industry. This is based on a survey of the existing capacity of electric large-scale heat pumps with more than 1 MW thermal output, operating in European DH systems. The survey is the first database of its kind containing the technical characteristics of these heat pumps, and provides the basis for the analysis of this paper. By quantifying the heat sources, refrigerants, efficiency and types of operation of 149 units with 1580 MW of thermal output, the study further uses this data to analyze if the deployment of this technology on a large-scale is possible in other locations in Europe. It finally demonstrates that the technical level of the existing heat pumps is mature enough to make them suitable for replication in other locations in Europe.

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“…Other is the boiling point at atmospheric pressure (100ᵒC). Riffat et al (1997) say that there are few studies of water working with evaporating temperatures lower than 100ᵒC. Furthermore, since it has to work at low pressure (low volumetric cooling capacity of vapor), the volumetric flow rate is higher than other common refrigerants, leading to bigger equipment.…”

Section: Water (R718)mentioning

confidence: 99%

“…However, each one has different drawbacks, and the selection will depend on the application, in this case, for the SHW production: Ammonia (R717): Riffat et al (1997) showed that ammonia could have a better coefficient of performance (COP) than CFCs, HFCs, and other refrigerants. The main problem of Ammonia is the toxicity; it is considered highly toxic.…”

Section: Natural Refrigerants For the Shw Applicationmentioning

confidence: 99%

High capacity heat pump development for sanitary hot water production

Mocholi¹

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L'home viu d'emocions, no del seu currículum Kilian Journet i AcknowledgmentsEn primer lloc volia donar-li les gràcies als meus directors de tesis, José Gonzálvez i Emilio Navarro, perquè sense ells aquest treball no haguera sigut possible. Gràcies per donar-me l'oportunitat de treballar en el projecte Europeu NxtHPG, per tot el que m'heu ensenyat, pels bons consells i per les hores que hem passat analitzant els resultats o especulant sobre algun problema concret.Gràcies als meus companys del IIE, sobretot a tots aquells que en alguna mesura han participat en aquest projecte, en especial a José Miguel, Carla, i Alex, amb qui he passat moltes hores barallant-nos amb sensors, vàlvules d'expansió i altres aparells del dimoni. També volia nomenar a Estefania, qui continuarà amb el treball d'aquesta tesi, i amb qui, juntament amb Emilio, hem passat unes quantes hores donant-li voltes i repensant els cicles termodinàmics.Gràcies també als participants del projecte Europeu "Next Generation of Heat Pumps working with Natural fluids", de qui també he aprés moltes coses.Des d'una perspectiva més personal, volia començar nomenant a aquells que varen començar amb mi aquesta aventura universitària, en especial a Ausiàs, i com no a Guillermo, a qui vaig conéixer en la cua per a la matrícula d'industrials, i que 10 anys després hem viscut tantíssimes coses junts.To those guys who I met during my two years in Denmark and we became friends for life, the Xafaets: Andrea, Cristian and Niccolo.Als meus amics d'infància, d'adolescència, edat adulta, i segur que vellesa, Irak, Gabi (Pollo), i com no Jorge (Puxi) amb qui he compartit tantes hores de confidències, moments bons i roïns, però sobretot reconfortants.A Marinna, o meu sol do meio-dia, perquè el seu somriure ja m'alegra el dia, per tots els projectes que tenim i perquè amb ella sempre podré dir cueca.Per últim volia donar-li les gràcies a la meua família. Als meus germans Gabi i José, qui m'ha fet tio de les xiquetes més boniques del món, Olga i Núria. A ma Mare, perquè és una lluitadora, però sobretot una somiadora, en part li dec a ella la meua forma de ser. Però si he de dedicar aquesta tesi a algú, és a ell, a l'home del somriure permanent, a qui li dec l'altra part de la meua forma de ser, a mon Pare.iii AbstractHeat pumps have been identified as an efficient alternative to traditional boilers for the production of sanitary hot water (SHW). The high water temperature lift (usually from 10ᵒC to 60ᵒC) involved in this application has conditioned the type of used solutions. On the one hand, transcritical cycles have been considered as one of the most suitable solutions to overcome the high water temperature lift. Nevertheless, the performance of the transcritical CO2 heat pump is quite dependent on the water inlet temperature, which in many cases is above 10ᵒC. Furthermore, performance highly depends on the rejection pressure, which needs to be controlled to work at the optimum point in any condition. On the other hand, for the subcritical systems, subcooling seems to be c...

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Natural refrigerants for refrigeration and air-conditioning systems

Cited by 106 publications

References 3 publications

NH3 sensing property and mechanisms of quartz surface acoustic wave sensors deposited with SiO2, TiO2, and SiO2-TiO2 composite films

NH3 sensing property and mechanisms of quartz surface acoustic wave sensors deposited with SiO2, TiO2, and SiO2-TiO2 composite films

Heat Roadmap Europe: Large-Scale Electric Heat Pumps in District Heating Systems

High capacity heat pump development for sanitary hot water production

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