complete paper acreconf india 2013 on refrigerant types, issues, trends and future options

Paper submitted for ACRECONFINDIA 8th – 9th Feb’2013

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Refrigerant types, issues, trends and future options Track Code : C2 (Effective use of Unitary HVAC Systems in today’s Buildings)

Selvaraji Muthu DGM-NTD, Subros Limited, C-51, Phase-2, Noida, U.P. [email protected] +91- 9910307727

Aseem Kumar Jaiswal AVP –R&D, NTD, Subros Limited, C-51, Phase-2, Noida, U.P. [email protected] +91- 9810435765

Abstract: Seminar is focused on the fundamentals of Vapor Compression refrigeration system which is principally applicable for all Automotive, Domestic and Industrial Air-Conditioning and Refrigeration Applications. Briefly, introduction to be given to the heart of the system, which is Compressor and types and functions. The flood of the Air-conditioner, that is, the refrigerants, their properties, merits and demerits are summarized to map the various types and their classifications. Detailed comparison is made on first generation, second generation and third generation refrigerants, including the option of using HCs and CO2. Main focus is given to the Montreal Protocol and Kyoto Protocols. Possibilities of changeover from CFC/HCFC based refrigerants to HFC or HFO based third and fourth generation refrigerants are also covered. At the end of the session, all attendees would able get the absolute clarity on the function, selection and their merits and demerits of various Refrigerants in terms of design of the system and their components, ODP, GWP & TEWI indexes. Duration : 60 Minutes (2 Consecutive Sessions) Keywords: CFC, HCHC, HFC, HFO, HC-Hydro Carbons, Co2 Refrigerants, Vapor Compression Refrigeration system, ODP -Ozone Deletion Potential, GWP-Global warming Potential, TEWI-Total Equivalent Warming Index, Montreal Protocol, Kyoto Protocol CFC ; Chloro Fluro Carbons HCFC : Hydro Chloro Fluro Carbons HFC : Hydro Fluro Carbons HC : Hydro Carbons HFO : Hydro Fluro Olefins Table of Contents:

1. Abstract 1 2. Introduction 2 3. Refrigerant Properties 3 4. Types of Refrigerants 3 5. Generation of Refrigerants 5 6. What is ODP? 6 7. Montreal Protocol 7 8. What is GWP? 9 9. What is TEWI? 11 10. Kyoto Protocol 11 11. Fourth generation Refrigerants 12 12. Future options 13 13. Conclusion 15 14. References 16


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2. Introduction: Simple Vapor Compression Refrigeration System: A simple vapour compression refrigeration system consists of the following equipments in the sequence as shown in Fig-1: i) Compressor ii) Condenser iii) Expansion valve iv) Evaporator.

Fig-1 Vapour Compression refrigeration Circuit The change of state and their processes are listed as below. C1 to D : Compression (Polytrophic) Compressor D to E : De-super heating (Isobaric) E to A : Condensation (Isobaric, Isothermal) Condenser A to A1 : Sub-cooling (Isobaric) A1 to B : Expansion (throttling, Isenthalpic) TXV Valve B to C : Evaporation (Isobaric, Isothermal) Evaporator C to C1 : Super heating (Isobaric) Function of Compressor:

• To suck the Low Pressure refrigerant in vapour form from Evaporator • To compress the refrigerant to higher pressure with super heated vapour • To pump this high pressure high temperature super heated vapour to Condenser


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Fig-2, Classification of compressor Technologies 3. Refrigerant Properties Irrespective of the size and efficiency of the individual parts in the vapour compression circuit, the good refrigerant is the one, ensuring the highest overall effectiveness of the system. Required Properties of Ideal Refrigerant: 1) Low boiling point and Low freezing point. 2) Low specific heat and High latent heat. 3) High critical pressure and temperature 4) Low specific volume to reduce the size of the compressor. 5) High thermal conductivity to compact evaporator and condenser. 6) Non-flammable, non-explosive, non-toxic and non-corrosive. 7) High miscibility with lubricating oil 8) High COP in the working temperature range. 9) Compatible with legal requirement 10) Availability and cost 4. Types of Refrigerants The different types of refrigerants can be grouped as given below (ASHRAE 2008).

Methane Group

Ethane Group

Propane group

Zeotrope mixtures

Azeotrope mixtures

organic compounds

inorganic compounds

Series with isolated carbon

10 Series 100 Series

200 Series

400 Series 500 Series 600 Series 700 +mw Series

> 1100 Series

as per Numbering Logic

Numbering Convention does not work

as per Numbering Logic

R11 R123 R404a •600 Hydrocarbons

R717- ammonia NH3

R1100s R1200s

R12 R134a R407c R507c •610 Oxygen compounds

R718- water

R1234ze

R22 R410a •620 Sulfur compounds

R744- CO2 R1234yf

etc.. etc.. etc.. etc.. etc.. •630 Nitrogen compounds

R729 - Air R1270 etc…

Table-1 : Grouping of refrigerants


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The numbering logic is explained as below. R()13 4 a

isomer# of fluorine atoms per molecule# of hydrogen atoms + 1 per molecule# of carbon atoms -1 per molecule (left off when 0)# of unsaturated carbon bonds (left off when 0)

Fig-3 Numbering Logic for refrigerants There is a simple methodology followed to decode the above numbering, which is shown as below.

# of Fluorine atoms per molecule# of Hydrogen atoms per molecule# of Carbon atoms per molecule

R134+90 =( ) 2 2 4R1234+90=(1)3 2 4R134+90 =( ) 2 2 4R1234+90=(1)3 2 4

# of unsaturated carbon bonds (left off when 0)

# of Chlorine atoms per molecule(calculated from balance carbon bonding

Fig-4 Decoding of Refrigerants Since, each refrigerants are having superiority in terms of different properties, there are mixtures developed to arrive a required level of multiple properties to make the overall system performance (COP) better. The following classification is made to show the non-mixtures and mixtures.

Fig-5 Types of Refrigerants


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Table-2 Mapping of Refrigerants on Toxicity & Flammability

5. Generation of Refrigerants Either or all of the 4 listed requirements are demanding the invention of new generation refrigerants one after another (Calm 2008).

Zero ozone depletion potential (ODP) low global warming potential (GWP) short atmospheric lifetime (tatm) high efficiency.

1st Generation Refrigerants First generation refrigerants, used for almost one hundred years (1830 ~ 1930 ), were a variety of volatile compounds ( ethers,CO2,NH3, SO2,HCs,H2O etc. ), that worked. Ammonia (NH3), methyl chloride (CH3Cl), and sulfur dioxide (SO2) are toxic gases. Several fatal accidents occurred in the 1920s because of methyl chloride leakage from refrigerators, which pushed the entire world to look for next generation refrigerants. 2nd Generation Refrigerants

CFCs (1930s) and later HCFCs (1940s) were invented by Thomas Midgley Jr. (aided by Charles Franklin Kettering).

As per the patent no. 2104882 (1931) of Thomas Midgley Jr., these halogen derivatives of aliphatic mono-fluorides may be represented by the formula CnHmFpXr in which C represents carbon and n is the number of carbon atoms in the molecule which is always equal to one or more. H represents hydrogen and m is the number of atoms thereof, which may equal zero and still fulfill the requirements of invention. F represents fluorine and p is the number of atoms thereof which is always equal to one or more. X represents chlorine, bromine or iodine or combinations thereof and r is the total number of such atoms. r may be zero when p is greater than one


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3rd Generation Refrigerants The third generation of refrigerants includes chemical groups, such as hydro-fluoro-carbons (HFCs), that do not damage the ozone layer as that was the perceived environmental danger at the time. However, as the effects of refrigerant leakages on global warming and climate change has become evident, next generation refrigerants are required. 4th Generation Refrigerants It is interesting that chemicals used in the first generation are being reconsidered as possible fourth generation refrigerants. The `synthetic refrigerants' such as HFCs are being replaced with HFOs (R1234ze, R12234yf) or `natural refrigerants'. The concerns for safety, endurance and efficiency that encouraged evolution away from these `natural refrigerants' in the past are still relevant now. For modern refrigerants there are even more essential characteristics to be considered. These include: Propane (R-290) and CO2 (R-744) are being proposed as new generation refrigerants, CO2 is non-flammable, non-ozone depleting, non-toxic and has a GWP of 1. The four generations included slightly overlapping periods as given below, (Calm JM, 2010).

1st Gen

1830 -1930s

CO2NH3SO2HCsH2O…..

2nd Gen

1931 -1990s

CFCsHCFCsHFCsNH3H2O…..

3rd Gen

1990 -2010s

HFCsHCsCO2NH3H2O…..

4th Gen

2012 onwards

HFOsHCFOs

HCsCO2NH3

H2O …

Global Warming

Ozone Layer Protection

Safety and Durability

Whatever worked

5th Gen

2020s ?

CO2NH3

H2O …

Efficiency & Trade-offs

Fig-6 Generations of Refrigerants 6. What is ODP? ODP is Ozone Depletion Potential of with reference to CFC R11 as 1.

Frank Sherwood Rowland, Professor of Chemistry at the University of California, Irvine and Mario Molina, who had got PhD in Chemistry at the University of California had together discovered that CFCs decompose in sunlight, to release chlorine atoms. Chlorine atoms convert ozone to oxygen, and can then attack other ozone molecules. A single atom can destroy millions of ozone molecules before it is neutralized. Cl + O3 -> ClO + O2 ClO + O3 -> Cl + 2O2

Molina and Rowland’s findings were published in 1974 and shocked the entire world. Their findings were later confirmed by scientists around the world, especially the British Antarctic Survey in 1986. This led to the Montreal Protocol of 1987 that banned CFCs around the world. They received the Nobel Prize for Chemistry in 1995.


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CFCs Refrigerants:

HCFCs Refrigerants

Table -3 ODP of refrigerants (Montreal Protocol) 7. Montreal Protocol The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion. The treaty was opened for signature on September 16, 1987. Article A 5 (1) : Special situation of developing countries Any Party that is a developing country and whose annual calculated level of consumption of the controlled substances in Annex A is less than 0.3 kilograms per capita on the date of the entry into force of the Protocol for it.

Fig-7 Phase-out of CFCs


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Fig-8 Phase-out of HCFCs

Fig-10 Ozone Chlorine Concentration (NASA report)


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Fig-11 Effective Stratospheric Chlorine Projection 8. What is GWP? Global warming potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale that compares a gas to that of the same mass of CO2 (GWP of CO2 is by definition 1).

Species Chemical formula

Lifetime (years)

Global Warming Potential (100 Years)

CO2 CO2 variable 1 Methane CH4 12 21 Nitrous oxide N2O 120 310

HFC-23 CHF3 264 11700 HFC-32 CH2F2 5.6 650 HFC-41 CH3F 3.7 150 HFC-125 C2HF5 32.6 2800 HFC-134 C2H2F4 10.6 1000 HFC-134a CH2FCF3 14.6 1300

Table-4 GWP of refrigerants

Velders et al., PNAS, 2007


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Ref: The U.S. Response to the Kyoto Protocol, Kevin Klein, Professor of Economics, Illinois College March 2, 2007 Fig-12 CO2 Concentrations

Fig-13 Emissions of CO2

World avoided by the Montreal Protocol

Reduction Montreal Protocol of ~11 GtCO2-eq/yr

5-6 times Kyoto target

(incl. offsets: HFCs, ozone depl.)

CO2 emissions

Velders et al., PNAS, 2007

Effects on climate


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9. What is TEWI?

Total equivalent warming impact (TEWI) is a measure used to express contributions of GHG to global warming.

It is defined as sum of the direct (chemical emissions) and indirect (energy use) emissions of greenhouse gases (GHG).

The method of calculating TEWI is provided below (AIRAH guide – methods of calculating TEWI): TEWI = GWP (direct; refrigerant leaks incl. EOL) + GWP (indirect; operation) = (GWP x m x L annual x n) + (GWP x m x (1- α recovery)) + (E annual x β x n) Where: GWP = Global Warming Potential of refrigerant, relative to CO2 (GWP CO2 = 1) L annual = Leakage rate p.a. (Units: kg) n = System operating life (Units: years) m = Refrigerant charge (Units: kg) α recovery = Recovery/recycling factor from 0 to 1 E annual = Energy consumption per year (Units: kWh p.a.) β = Indirect emission factor (Units: kg CO2 per kWh) 10. Kyoto Protocol The Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto, Japan, on 11 December 1997 that set binding obligations on the industrialized countries to reduce their emissions of greenhouse gases.

Regional Shares of World Carbon Emissions, 1997 & 2020

Ref: The U.S. Response to the Kyoto Protocol, Kevin Klein, Professor of Economics, Illinois College March 2, 2007 Fig-14 Regional Shares of World Carbon Emissions, 1997 & 2020


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11. Fourth Generation Refrigerants

HFO Refrigerants HFO (hydro-fluoro-olefin) refrigerants are the fourth generation of fluorine-based refrigerants. HFC refrigerants are composed of hydrogen, fluorine and carbon atoms connected by single bonds between the atoms. HFO refrigerants are composed of hydrogen, fluorine and carbon atoms, but contain at least one double bond between the carbon atoms. The HFOs, currently being developed by DuPont and Honeywell, are HFO 1234ze and HFO 1234yf, which are having GWP of 6 & 3 respectively, replacement for R134a.

HFO-R1234yf HFO-R1234ze CH2=CF-CF3 CHF=CH-CF3

Environmental• ODP = 0• GWP100 = 4• Atmospheric Life: 11 days

Environmental• ODP = 0• GWP100 = 6• Atmospheric Life: 18 days

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

-20 0 20 40 60 80 100

1234ze(E)

134a

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

-20 0 20 40 60 80 100

134a

1234yf

Vapor Pressure Vs. Temperature Vapor Pressure Vs. Temperature

Temperature, oC

Pres

sure

, MPa

Pres

sure

, MPa

Temperature, oC

Fig-15 HFO refrigerants Properties Natural Refrigerants

Table-6 Natural refrigerants properties


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12. Future options The transitions between successive generations required very large research, development, plant construction, evaluation, product redesign, testing, training, and additional investments, but they also created significant business opportunities. While actual transition to the fourth generation has just begun, a number of challenges are emerging that may dictate later transition to a fifth generation predicated in the absence of ideal refrigerants. Among the potential driving factors are efficiency, momentum, prices, litigation and liability, unforeseen suitability issues, local impacts, and political aspects. HFOs (R1234ze & R1234yf) & Natural refrigerants (NH3, CO2 etc..)

Fig-16 Comparison of R134a and R12234yf


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Ref: NIST Chemistry WebBook

Fig-17 PH Diagram of CO2

Important (ex.230g) Special jointSealing etc.NecessaryNecessary

Necessary ----

NecessarySpecial joint---


Cost for safety Charge reductionJointElectronic partsLeak detectorVentilation

Modified facilityQualificationQualified personQualified person

Two-stage comp.High-pressure etc.

Cheap

CO2(R744)

Larger comp. Larger pipe etc.

Near as R410A Same as R410A

Modification required Same as R22

Cost for performance Compressor, EX, etc.

Modified facilityModificationModificationModificationModification

Expensive

HFO1234yf

Cheap Cheap Refrigerant price


Special facilityQualificationQualified personQualified personQualification

Cost for handlingManufacture Supply chainInstallationServiceDisposal

R32 Propane (R290)

Important (ex.230g) Special jointSealing etc.NecessaryNecessary

Necessary ----



Cost for safety Charge reductionJointElectronic partsLeak detectorVentilation

Modified facilityQualificationQualified personQualified person

Two-stage comp.High-pressure etc.

Cheap

CO2(R744)

Larger comp. Larger pipe etc.

Near as R410A Same as R410A

Modification required Same as R22

Cost for performance Compressor, EX, etc.


Expensive

HFO1234yf

Cheap Cheap Refrigerant price


Special facilityQualificationQualified personQualified personQualification

Cost for handlingManufacture Supply chainInstallationServiceDisposal

R32 Propane (R290)

The Example of Room A/C Component which increases cost

Fig-18 : mapping of various refrigerants and their challenge points


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13. Conclusion Thomas Midgley (1928) had invented the CFCs & HCFCs, but the large use of these refrigerants had created severe threat to the earth in terms of ozone layer depletion and global warming. McNeill has stated that Midgley "had more impact on the atmosphere than any other single organism in Earth's history. Not only the inventors but all end users are more responsible for the consequences of usage of refrigerants. 14. References: 1. ASHRAE, 2007, https://osr.ashrae.org/Public%20Review%20Draft%20Standards%20Lib/34z-

2007%201st%20PPR%20Draft.pdf 2. ASHRAE, 2008,

http://www.ashrae.org/File%20Library/docLib/Public/20080807_34m_thru_34v_final.pdf 3. Anant et al. Investigation of Cubic EOS models for HFO-1234yf Refrigerant Used in Automotive

Application, International Refrigeration and Air Conditioning Conference at Purdue, July 16-19, 2012

4. Björn Palm, REFRIGERANTS OF THE FUTURE, 10thIEA Heat Pump Conference 2011, 16 - 19 May 2011, Tokyo, Japan http://kth.diva-portal.org/smash/get/diva2:483181/FULLTEXT01

5. Calm JM, Composition Designations for Refrigerants, ASHRAE Journal, November 1989 6. Calm JM, Global Warming Impacts of Chillers, Heating Piping Air Conditioning, February 1993 7. Calm JM, Refrigerant Safety, ASHRAE Journal, 1994 8. Calm JM, The next generation of refrigerants - Historical review, considerations, and outlook,

Int. J. Refrig. 31 (7), 1123-1133 (2008). http://dx.doi.org/10.1016/j.ijrefrig.2008.01.013 9. Calm JM, Refrigerant Transitions ... Again. ASHRAE-NIST Refrigerants Conference 2012 10. Carmen J. Giunta THOMAS MIDGLEY, JR., AND THE INVENTION OF

CHLOROFLUOROCARBON REFRIGERANTS: IT AIN’T NECESSARILY SO , Bull. Hist. Chem., VOLUME 31, Number 2 (2006)

11. CHARLES F. KETTERING , BIOGRAPHICAL MEMOIR of THOMAS MIDGLEY, JR. 1889-

1944, PRHSENTED TO THE ACADEMY AT THE ANNUAL MEETING, 1947. 12. Dylan S. Cousins and Arno Laesecke, Sealed Gravitational Capillary Viscometry of Dimethyl

Ether and Two Next-Generation Alternative Refrigerants Journal of Research of the National Institute of Standards and Technology, Volume 117 http://dx.doi.org/10.6028/jres.117.014 , 2012

13. G Venkatarathnam and S Srinivasa Murthy, Refrigerants for Vapour Compression Refrigeration

Systems, RESONANCE February 2012 14. GUIDE 2012: Natural Refrigerants Market Growth for Europe, shecco publications 15. Imke et al. Energy consumption of battery cooling in electric hybrid vehicles, International

Refrigeration and Air Conditioning Conference at Purdue, July 16-19, 2012 16. NASA, 2007, http://www.nasa.gov/vision/earth/environment/ozone_recovering.html Date:

March11, 2011 17. NIST Standard Reference Database 23, REFPROP - Thermo dynamic properties of refrigerants

and refrigerant mixtures, Version 3.04, NIST, USA, 1991. 18. M. Richter, M. O. McLinden, and E. W. Lemmon, Thermodynamic Properties of 2,3,3,3-

Tetrafluoroprop-1-ene (R1234yf): Vapor Pressure and p—ρ—T Measurements and an Equation of State, J. Chem. Eng. Data 56 (7), 3254-3264 (2011). http://dx.doi.org/10.1021/je200369m


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19. M. O. McLinden, M. Thol, and E. W. Lemmon, "Thermodynamic Properties of trans-1,3,3,3-tetrafluoropropene [R1234ze(E)]: Measurements of Density and Vapor Pressure and a Comprehensive Equation of State", Proceedings of the 2010 International Refrigeration and Air Conditioning Conference, Purdue, West Lafayette, IN, USA, Paper No. 2189. http://docs.lib.purdue.edu/iracc/1041/

20. Handbook for the Montreal Protocol on Substances that Deplete the Ozone Layer, Ninth edition

(2012), United Nations Environment Programme. 21. The Montreal Protocol and the Green Economy, 2012, UNEP. THE AUSTRALIAN INSTITUTE OF 22. METHODS OF CALCULATING TOTAL EQUIVALENT WARMING IMPACT (TEWI),

AIRAH, Best Practise Guidelines, 2012, 23. KYOTO PROTOCOL TO THE UNITED NATIONS FRAMEWORK CONVENTION ON CLIMATE

CHANGE, 1998, UN. 24. Reasor, Pamela; Aute, Vikrant; and Radermacher, Reinhard, "Refrigerant R1234yf

Performance Comparison Investigation" (2010). International Refrigeration and Air Conditioning Conference. Paper 1085 http://docs.lib.purdue.edu/iracc/1085/

25. R1234yf.fld - NIST, www.boulder.nist.gov/div838/theory/refprop/R1234YF.FLD 26. R1234ze.fld - NIST , www.boulder.nist.gov/div838/theory/refprop/R1234ZE.FLD 27. SAE, 2010a, http://www.sae.org/mags/aei/8702 , Date: April 22, 2011. 28. SAE, 2010b, http://www.sae.org/mags/AEI/8074 , Date: April 22, 2011. 29. SAE, 2011, http://www.sae.org/standardsdev/tsb/cooperative/altrefrig.htm , Date: April 22,

2011 30. http://www.reefercargocare.com/refrigerants.html 31. http://www.reefercargocare.com/ozone-depleting-substances.html 32. http://www.linde-

gas.com/en/products_and_supply/refrigerants/fluorine_refrigerants/hfo_refrigerants.html 33. http://humantouchofchemistry.com/frank-rowland-and-mario-molina.htm 34. http://www.beyonddiscovery.org/content/view.page.asp?I=89 35. Patents referred. Inventor : Thomas Midgley

No. US

Patent No.

dated patent Title filed as on

1 2013062 Sep.3, 1935 Preparation of aliphatic halofluoro compounds Feb. 26, 1931

2 2007208 July 9,1935 Manufacture of halo-fluoro derivative of aliphatic hydrocarbons

Feb. 24, 1931

3 2104882 Jan.11, 1938 Heat transfer and refrigeration Nov.19, 1931

4 2024008 Dec.10, 1935 Manufacture of antimony trifluoride June 30, 1934

5 2192143 Feb.27, 1940 Fluorination process May 7, 1938

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