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New refrigerants for vapour compression refrigeration and heat pump systems: evaluation in a context of the requirements set by the F-gas Regulation and the Paris Agreement goals.
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.ORCID iD: 0000-0003-2378-711X
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Given the global commitment to reduce the impact of fluorinated gases on climate and the regulations controlling their use in the European Union (EU), this thesis investigates new refrigerants that have been recently proposed to meet the demands of the refrigeration industry in the EU, which must satisfy the legislative requirements of the F-gas Regulation and facilitate meeting the goals of the Paris Agreement.

The legislative requirements of the EU have intensified refrigerant development with reduced GWP. New refrigerants have been identified in the form of six new substances and 40 new refrigerant mixtures that have been added to the ANSI/ASHRAE 34 standard during a period following the proposal for the F-gas Regulation.

New refrigerants have been theoretically analysed in comparison with the commonly used fluorinated refrigerants R134a, R404A and R410A. While new refrigerants provide a variation in operating parameters when used in a refrigeration, air conditioning or heat pump (RACHP) system, none of the new refrigerants can be considered being fully design compatible with R134a, R404A or R410A.

Several commercially available refrigerants have been further evaluated in experimental studies to analyse their suitability for replacing R134a and R404A in existing systems with regards to their thermal properties, requirements for component safety and energy efficiency. R450A and R513A have been analysed as alternatives to R134a in a small capacity refrigeration system, and an R449A was studied in a retrofit of an R404A supermarket indirect system. It was shown that the analysed refrigerants can replace baseline HFCs in the analysed systems, but the variation in energetic performance and main operation parameters should be taken into account when considering such replacement.

LCCP metric has been used to analyse the overall climate impact of a heat pump system using refrigerants with various GWP values. It was shown that most climate impact from an RACHP system is due to indirect emissions relating to energy use. Thus, addressing the overall climate impact of RACHP systems is necessary to facilitate meeting the goals of the Paris Agreement. It is possible to facilitate a comparative LCCP analysis by addressing the uncertainties of the input data.

Abstract [sv]

Med tanke på det globala åtagandet att minska effekterna av fluorerade gaser på klimatet och regler som styr deras användning i Europeiska unionen (EU), undersöker denna avhandling nya köldmedier som nyligen har föreslagits för att möta kraven från kylindustrin i EU, och som måste uppfylla lagstiftningskraven i F-gas förordningen och underlätta att Parisavtalets mål uppfylls.

Lagkraven i EU har intensifierat utvecklingen av köldmedier med reducerad GWP. Nya köldmedier har identifierats i form av sex nya ämnen och 40 nya köldmedieblandningar som har lagts till ANSI/ASHRAE 34-standarden efter det att förslaget till F-gasförordningen publicerats.

Nya köldmedier har analyserats i teoretisk jämförelse med de ofta använda fluorerade köldmedierna R134a, R404A och R410A. Medan nya köldmedier ger en variation i driftsparametrar när de används i ett kyl-, luftkonditionerings- eller värmepumpssystem, kan inget av de nya köldmedierna anses vara helt designkompatibelt med R134a, R404A eller R410A.

Flera kommersiellt tillgängliga köldmedier har utvärderats vidare i experimentella studier för att analysera deras lämplighet för att ersätta R134a och R404A i befintliga system med avseende på deras termiska egenskaper, krav på komponenternas säkerhet och energieffektivitet. R450A och R513A har analyserats som alternativ till R134a i ett kylsystem med liten kapacitet, och R449A studerades i en retrofit av ett indirekt R404A system i en livsmedelsbutik. Det visades att de analyserade köldmedierna kan ersätta befintliga HFC:er i de analyserade systemen, men variationen i energiprestanda och huvuddriftparametrar bör beaktas när man överväger en sådan ersättning.

LCCP-analys har använts för att analysera den totala klimatpåverkan av ett värmepumpsystem med köldmedier med olika GWP-värden. Det visades att den största klimatpåverkan från ett RACHP-system beror på indirekta utsläpp relaterade till energianvändning. Således är det nödvändigt att redovisa och ta hänsyn till den totala klimatpåverkan av RACHP-system för att uppfylla målen i Parisavtalet. Det är möjligt att underlätta en jämförande LCCP-analys genom att ta itu med osäkerheterna i inmatningsdata.

Place, publisher, year, edition, pages
Universitetsservice US-AB , 2019. , p. 111
Series
TRITA-ITM-AVL ; 2019:25
Keywords [en]
refrigerant, retrofit, drop-in, HFC, HFO, F-gas Regulation, Kigali Amendment, Montreal protocol, Life cycle climate performance, LCCP, climate change
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
URN: urn:nbn:se:kth:diva-257530ISBN: 978-91-7873-296-8 (print)OAI: oai:DiVA.org:kth-257530DiVA, id: diva2:1347734
Public defence
2019-09-24, F3, Lindstedtsvägen 26, Stockholm, 13:00 (English)
Opponent
Supervisors
Available from: 2019-09-02 Created: 2019-09-02 Last updated: 2019-09-02Bibliographically approved
List of papers
1. Recent investigations in HFCs substitution with lower GWP synthetic alternatives: Focus on energetic performance and environmental impact
Open this publication in new window or tab >>Recent investigations in HFCs substitution with lower GWP synthetic alternatives: Focus on energetic performance and environmental impact
2017 (English)In: International journal of refrigeration, ISSN 0140-7007, E-ISSN 1879-2081, Vol. 82, p. 288-301Article in journal (Refereed) Published
Abstract [en]

Kigali's amendment on Montreal Protocol has recognized the great impact of hydrofluorocarbons (HFCs) on climate change. In the European Union, the Regulation (EU) No. 517/2014 (F-gas Regulation) controls the use of HFCs in several applications. This paper reviews the recent investigations performed because of F-gas Regulation, with focus on lower global warming potential (GWP) synthetic alternatives. The GWP limit and the date of prohibition have an influence on the studies found for each application. The major relevance of the studies has been observed on mobile air conditioners for pure hydrofluoroolefins (HFOs), possibly caused by the earlier control. Additionally, a great number of studies have been found for stationary refrigeration systems using several mixtures and residential air conditioners using R32. An important number of articles investigate synthetic alternatives for domestic refrigerators given the flammability barriers for hydrocarbons in some countries. Despite higher GWP allowance on cascade supermarket systems, few articles are available on this topic. Given the extent of the current studies and the rate of new refrigerant developments, an increase in studies using the new synthetic mixture is expected in the coming years.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Global warming potential, HFO/HFC mixtures, Refrigeration, Air conditioning, F-gas regulation
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-214840 (URN)10.1016/j.ijrefrig.2017.06.026 (DOI)000423259600001 ()2-s2.0-85026881157 (Scopus ID)
Projects
Effsys Expand 08
Funder
Swedish Energy Agency
Note

QC 20170925

Available from: 2017-09-22 Created: 2017-09-22 Last updated: 2019-09-02Bibliographically approved
2. Retrofit of lower GWP alternative R449A into an existing R404A indirect supermarket refrigeration system
Open this publication in new window or tab >>Retrofit of lower GWP alternative R449A into an existing R404A indirect supermarket refrigeration system
2017 (English)In: International journal of refrigeration, ISSN 0140-7007, E-ISSN 1879-2081, Vol. 76, p. 184-192Article in journal (Refereed) Published
Abstract [en]

R404A is going to be phased out from most of the commercial refrigeration systems due to its high GWP value of 3943. R449A (GWP of 1282) has been proposed to replace R404A with only minor system modifications in supermarkets. This paper presents the measurements of a light retrofit replacement of R404A using R449A in a medium temperature indirect refrigeration system (secondary fluid temperature at the evaporator outlet between −9 and −4 °C). It has been demonstrated that with a slight expansion device adjustment and 4% increase of refrigerant charge, R449A can be used in this refrigeration system designed for R404A because of its suitable thermodynamic properties and acceptable maximum discharge temperature. At a secondary fluid temperature at condenser inlet of 30 °C, the COP of R449A nearly matches that of R404A (both were between 1.9 and 2.2), despite having approximately 13% lower cooling capacity. As a conclusion, attending to the GWP reduction and similar energy performance, it was demonstrated using the TEWI methodology that the use of the recently developed refrigerant R449A in these applications can reduce the total CO2equivalent emissions of an indirect supermarket refrigeration system designed for R404A refrigerant.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Supermarket refrigeration, R404A, R449A, HFC HFO mixture, Low GWP, Alternative refrigerant
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-203869 (URN)10.1016/j.ijrefrig.2017.02.009 (DOI)000401106300019 ()2-s2.0-85014859450 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 20170330

[Remplacement du R404A par du R449A comme alternative à plus faible GWP dans un système de froid indirect de supermarché]

Available from: 2017-03-18 Created: 2017-03-18 Last updated: 2019-09-02Bibliographically approved
3. Experimental study of R450A drop-in performance in an R134a small capacity refrigeration unit
Open this publication in new window or tab >>Experimental study of R450A drop-in performance in an R134a small capacity refrigeration unit
2017 (English)In: International journal of refrigeration, ISSN 0140-7007, E-ISSN 1879-2081Article in journal (Refereed) In press
Abstract [en]

The Kigali's amendment to the Montreal Protocol has highlighted the hydrofluorocarbons (HFCs) phase out as a priority to reduce the future global Earth's mean temperature increase. R134a is the most abundant HFC in the atmosphere and therefore it must be substituted using environmentally benign alternatives. In the short term, blends of HFCs and hydrofluoroolefins can replace R134a. This paper experimentally evaluates R450A (GWP of 547), a non-flammable mixture of R1234ze(E) and R134a, in an R134a small capacity refrigeration system. The controlled experimental conditions cover evaporating temperatures from -15 to 12.5 °C and condensing temperature of 25, 30 and 35 °C (36 tests in total for each refrigerant). The experimental results showed that with only a thermostatic expansion valve adjustment the average R450A cooling capacity and COP are 9.9 and 2.9% lower than those measured using R134a. Besides, the observed compressor discharge temperature values of R450A are not greater than that of R134a.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
vapor compression system, GWP, drop-in replacement, zeotropic refrigerant, HFC/HFO mixture, energy assessment
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-214839 (URN)10.1016/j.ijrefrig.2017.08.010 (DOI)000414654000004 ()2-s2.0-85030323293 (Scopus ID)
Projects
Effsys Expand 08
Funder
Swedish Energy Agency
Note

QC 20170925

Available from: 2017-09-22 Created: 2017-09-22 Last updated: 2019-09-02Bibliographically approved
4. R450A and R513A as lower GWP mixtures for high ambient temperature countries: Experimental comparison with R134a
Open this publication in new window or tab >>R450A and R513A as lower GWP mixtures for high ambient temperature countries: Experimental comparison with R134a
2019 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 166, p. 223-235Article in journal (Refereed) Published
Abstract [en]

In recognition of the impact of the refrigeration sector on climate change, global commitments are achieved to replace hydrofluorocarbon substances with more planet-friendly alternatives. In this regard, countries with high ambient temperatures (HAT) face additional problems in identifying suitable alternatives due to the impact of such temperatures on energy performance in vapor compression systems. This paper presents an experimental analysis using R134a and two lower global warming potential (GWP) mixtures in a small capacity vapor compression refrigeration system for HAT environments. The range of evaporating and condensing conditions was selected to simulate a refrigeration system working at HAT conditions. The experimental operating results show that although R450A values are acceptable, R513A shows better adaptation to the refrigeration system in terms of pressure ratio, discharge temperature, and mass flow rate. Then, attending to experimental energetic results, R450A energy performance (quantified by COP) and cooling capacity are lower than R513A and R134a. TEWI analysis of a small refrigeration unit shows CO2 equivalent emission saving when using R450A in the different condensation conditions. However, taking into account the variation of cooling capacity, R513A system results in the lowest TEWI when normalizing per unit of delivered cooling capacity.

Place, publisher, year, edition, pages
Institutt for energiteknikk, 2019
Keywords
HFC HFO mixtures, Energy performance, High ambient temperature (HAT), Vapor compression system, Refrigerants, Drop-in replacement
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-242992 (URN)10.1016/j.energy.2018.09.001 (DOI)000455694300018 ()2-s2.0-85056153669 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 20190204

Available from: 2019-02-04 Created: 2019-02-04 Last updated: 2019-09-02Bibliographically approved
5. The influence of climate conditions on Life Cycle Climate Performance of low GWP refrigerant based heat pumps
Open this publication in new window or tab >>The influence of climate conditions on Life Cycle Climate Performance of low GWP refrigerant based heat pumps
2014 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The paper studies the effect of different climate conditions (average, cold and warm European climate) on total lifetime global warming gas emissions of 30 kW capacity air/water heat pump systems designed for retrofitting of heating systems in European building sector applications. The analysis is performed for low GWP refrigerant selection with GWP values not greater than 150 (including R152a, R1234yf, R290, R1270 and others). The results are compared with R410A which is used as a reference refrigerant. Indirect emissions are shown to dominate the total lifetime emissions of the heat pump system. The amount of indirect emissions is dependent on a number of parameters, including the heat pump system performance under various climate conditions. That affects the total lifetime emission of air/water heat pump systems at different locations.

Series
ASHRAE Transactions, ISSN 0001-2505
Keywords
refrigerant, GWP, LCCP
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-152342 (URN)000346573500019 ()
Conference
ASHRAE 2014 Annual Conference,Seattle, WA, USA, APR 16, 2014
Note

QC 20150122

Available from: 2014-09-24 Created: 2014-09-24 Last updated: 2019-09-02Bibliographically approved
6. Uncertainty of life cycle climate performance (LCCP) analysis
Open this publication in new window or tab >>Uncertainty of life cycle climate performance (LCCP) analysis
2016 (English)In: Refrigeration Science and Technology, International Institute of Refrigeration , 2016, p. 162-169Conference paper, Published paper (Refereed)
Abstract [en]

Life cycle climate performance (LCCP) is environmental metrics that aim to indicate total environmental impact caused by a refrigeration or heat pump system. It often used to justify the choice of some refrigerant in favor of another when considering its effect on entire environmental impact from a system. Calculation of LCCP relies on a number of inputs that are often uncertain. This work introduces the cumulative uncertainty of LCCP metrics and analyses effect of the uncertainty on the comparative LCCP analyses. The results suggest that the uncertainties of LCCP analysis inputs should not be neglected. Moreover, when the uncertainties are taken into account, it can be speed up the analysis by focusing on refining the uncertainties of the inputs that have the greatest contribution to the uncertainty of the entire LCCP analysis. 

Place, publisher, year, edition, pages
International Institute of Refrigeration, 2016
Keywords
LCCP, Life cycle analysis, Refrigerant, TEWI, Uncertainty analysis
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-207548 (URN)10.18462/iir.gl.2016.1023 (DOI)000402544400019 ()2-s2.0-85017651513 (Scopus ID)9782362150180 (ISBN)
Conference
12th IIR Gustav Lorentzen Natural Working Fluids Conference, GL 2016, 21 August 2016 through 24 August 2016
Note

Conference code: 126956; Export Date: 22 May 2017; Conference Paper. QC 20170531

Available from: 2017-05-31 Created: 2017-05-31 Last updated: 2019-09-02Bibliographically approved

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