Natural refrigerants, a complete solution Latest technological advancements for warm climates

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2 Natural refrigerants, a complete solution Latest technological advancements for warm climates Prof. Dr. Armin Hafner No 7491 Trondheim Norway E mail: armin.hafner@ntnu.no

3 Introduction The revival of natural refrigerants Marine applications Premium quality fish from R744 equipped vessels Fishing vessels with R744 RSW unit outside Africa Commercial refrigeration Market trends from Asia Ejector supported parallel compression SuperSmart Summary Content 1

4 Working fluids history 2 Until / now Use of natural working fluids Air, ethyl ether, SO 2, methyl chloride, ammonia, propane, isobutane, CO 2, etc. Introduction of synthetic working fluids, like CFC12 and HCFC22 Montreal protocol established, CFC and HCFC ozone depletion due to chloride/bromine. Phasing out CFC (1995) and HCFC (2010) Hydrogen-Fluor-Carbons (HFC) introduced Kyoto protocol established, HFC regulated due to high GWP factor EUs F-gas directive Phase down of high GWP fluids Increasing focus on use of natural working fluids, especially ammonia, hydrocarbons and CO 2

5 Ref-Production, CFC 12 More 2000 CFC 11 than half of all the HFC 1800 Production CFC refrigerant ever produced Released 1400 Europe, nor for 1200 the world is 1000 HCFC 22 in the atmosphere!!! 800 HFC 134a 600 MMTCO 2 e Global reported accumulated Production and Release of HFC 134a in Million Metric Tons of CO 2 equivalent Not a sustainable solution for year Source: AFEAS Alternative Fluorocarbons Acceptability Study 2006 Source:

6 What next after Paris COP Meeting? 4 Companies focusing on Natural Working Fluids will face no risk to invest into technologies being on the phase out agenda in the future <=> Safe & sustainable investment

7 5 Marine R744 applications Premium quality fish from R744 equipped vessels Fishing vessels with R744 RSW unit outside Africa

8 Industrial CO 2 /NH 3 cascade 6 System MS Kvannøy (N) Design system 11 plate freezers, 9 RSW-tanks and one ice machine Refrigeration load 1350 kw at -48 C System Ammonia in top stage 6 piston compressors for CO 2 2 screw compressors for ammonia Special built 50 bar CO 2 piston compressor for hot gas defrosting Liquid separator equipped with cold finger" and pressure release valve Challenges Demanding dynamic in the interaction between the CO 2 og NH 3 screw compressors Operating experience Freezing time are reduced with 40% and corresponding increase in freezing capacity Satisfactory safety in operation

9 Premium quality fish from R744 equipped vessels 7

10 Premium quality fish from R744 equipped vessels 8

11 Faster Freezing = Higher Food Quality QUALITY -FROM CATCH TO END USER 9 R744 FREEZING TRADITIONAL FREEZING HCFC 22 No delays on board after catch No reduction in fish quality No delay prior freezing No reduction in fish quality 25% faster freezing Lower freezer temp. = smaller crystals = better/ premium quality Faster de-icing No boiling of fish surface Preventing discoloration Excellent part load performance 50% reduction in energy use «Refreshed» No reduction in quality Low wastage Socio-Economically profitable. Ethically correct Better quality than fresh fish. Higher price accepted

12 10 Premium quality fish from R744 equipped vessels One Vessel equipped with CO 2 RSW unit was in operation around the Canarian Islands and is now outside Mauretania!

13 Commercial refrigeration Light commercial: a success story Market trends from Asia Ejector supported parallel compression SuperSmart 11

14 Light commercial ref. units / standalone units Important players are joining: 12 They have installed more than 3.5 million units using natural refrigerants both in developing and industrialised countries. This is real PHASE IN of natural refrigerants! CONGRATULATIONS

15 Commercial Refrigeration; Supermarkets In future: supermarket refrigeration system provides entire energy flow and demand in the building (and surrounding) Air Conditioning (direct or chilled water) Heat recovery: hot water production, space heating, ice protection Heat pump function & export of heat CO 2 (R744) is the preferred alternative of the end-users across Europe for new installations Predictable no restrictions CO 2 booster units are proven technology with potential to further improve COP (parallel compression + ejector technology) Training and support is key for success (SuperSmart) 13 Promising global perspectives for a successful Phase-in

16 Market trends from Asia 14 HFC R744 27% energy usage 1300 stores with R744 in 2016 Source:

17 Market trends from Asia stores with R744 in Indonesia! Source:

18 16 This is good news for Southern Europe!!! Energy efficient R744 systems for small shops are available! If they operate successfully in Indonesia (below the equator), why not in Europe?

19 Commercial Refrigeration; Supermarkets The average annual refrigerant leakage rates: in Europe: % of the total charge, mainly HFC 404A Worldwide about 30 % of the charge, mainly HCFC Evolution of R744 Commercial Refrigeration since 2003: R744 simple Booster SEER + 10% SEER: Seasonal Energy Efficiency Rating Parallel Compression (PC) SEER % Ejector System (Supporting PC)

20 Booster Evolution 18 Standard CO 2 booster First unit in 2004 in CH (Linde) > 6000 units globally Higher SEER than HFK units in the North No efficient integration of AC (only MT temperature) CO 2 with parallel compression First unit 2008 in CH (enex) ~ 100 units globally Higher SEER than HFK units in most European regions good integration of AC CO 2 with parallel compression and ejector support First unit 2014 in CH (enex) < 10 units globally Higher SEER than HFC everywhere Optimum integration of AC Flooded evaporators all year

21 Pioneer R744 Ejector Installations 19 Ref: Eric Wiedenmann, ATMOsphereEurope 2015

22 Pioneer R744 Ejector Installations 20 R744 PC with and without Ejector Field test results from Ibach / CH 2 identical R744 Racks Ref: Eric Wiedenmann, ATMOsphereEurope 2015

23 Evolution of R744 Commercial Refrigeration 21 SEER + 10% SEER % R744 simple Booster simple (Baseline) many units in the market flash gas bypass low cost (below HFC in Scandinavia) COP / SEER baseline for moderate cold ambient temp. Parallel Compression advanced system higher investment cost flash gas (auxiliary) compression Ejector System advanced system flooded evaporators: possible simple (no pump) pre-compression higher load on auxiliary compressors

24 Classic Ejector Ejector system Ejector system High pressure control with needle in motive nozzle High eff. at design point Part load operation challenges Low motive flow rate and Large mixing chamber Requires oil return strategy Ejector off (low pumping ability) superheat operation of evaporators Discontinues operations Venturi type Part load challenges Liquid Ejector only Enables flooded evaporators all year Applicable for booster and parallel compression system Simple on/off control Requires low pressure accumulator Ejector supported parallel Compression Fixed nozzle ejectors: designed for pumping liquid and precompressing vapour (ex: Multi- Ejector block) Enables flooded evaporators all year, requires small low pressure accumulator Higher load on auxiliary compressors. 22 Pressure lift can be adapted to provide efficient AC

25 Next generation R744 com-ref unit 23 High pressure: up to 120 bar AC Ejector GC HR AC_Evap t o = +5 C p= 48 bar Parallel Compressor MT Comp MT Comp MT Compressor vapour Multi- Ejector p= 33 bar Separator p= 17 bar LT Compressor GC liquid MT- Receiver ref_ ref_ evapsref_ evaps MT_Evap t evaps o = 2 C LT_Evap t o = 25 C AC = Air Conditioning MT = Medium temp cooling LT = Low-temp freezing GC = Gascooler HR = Heat Recovery

26 R744 ejector versus HFC404A 24

27 Performance of commercial refrigeration systems 25 Ref: Finckh 2011 ICR 2011

28 Annual temperature bins for selected cities 26 North America South America South Europe Africa India China Australia Source Meteonorm

29 Relative annual energy usage (exclusive AC part) 27

30 How to make real systems? 28 Ejectors are widely used in refrigeration systems to pump lubricant inside compressors Since a few years many European OEM s are developing R744 ejectors for units with a cooling capacity above 5 kw: Supermarkets require high efficient systems with natural working fluids all across Europe and abroad Laboratory and real pilot units are required for development More advanced system configuration requires good understanding during the design and implementation phase Training and technology transfer is important

31 Example: Multi-ejector module 29 Modular design (ejector cartridges placed into a monoblock casing) developed by Danfoss in cooperation with SINTEF/NTNU Six fixed geometry ejectors kw cooling capacity

32 Multi-ejector lab tests 30

33 Multi-ejector performance mapping 31 Performed for a typical configuration of operating conditions motive nozzle inlet conditions defined by (i) 5K subcooling for subcritical operation and (ii) discharge pressure optimized according to the maximum system COP for transcritical operation suction nozzle inlet conditions determined by two levels of evaporation pressure, i.e., 28 bar and 32 bar; saturated liquid conditions for the LEJ group and superheated (by ca. 10 K) vapour conditions were maintained for the VEJ group, pressure lift between 4 bar and 7 bar. Two separate flow variables recorded: motive nozzle mass flow rate, suction nozzle mass flow rate. Derivative performance parameters (entrainment ratio, ejector efficiency by Elbeland Hrnjak, 2008) calculated based on the imposed boundary conditions and recorded flow rates

34 Multi-ejector performance mapping 32 Motive nozzle mass flow rate for VEJ1

35 Multi-ejector performance mapping 33 Ejector efficiency for VEJ1

36 Multi-ejector ejector efficiency 34 t evap = -8 C, t SH = 10 K, constant load, automated ejectors controlling

37 Summary / conclusions / outlook (CO 2 R744) 35» Tremendous development of CO 2 technology since 1988» Energy efficient CO 2 systems have been introduced in the market» CO 2 systems enable flooded evaporators and offer to integrate: Ref. + HVAC + Eco Cute» Adapted ejector technology offer high system performances and COP's, even at high ambient» CO 2 is a viable natural refrigerant PHASE IN candidate for many applications, globally 37

38 36 Summary / conclusions / outlook» Natural Refrigerants are already PHASED IN in many applications > there is more potential» OEM s with a clear strategy towards a fast introduction of NRs will gain market shares, not wasting investments towards intermediate solutions» Authorities have to support the introduction of NRs despite the lobby attempts of chemical companies» Knowledge transfer + Training is key + SuperSmart will support this 38

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43 A wise man said 20 years ago We have heard a great deal lately of the harmful effects to the environment when Prof. Gustav Lorentzen ( ) halocarbon refrigerants are lost to the atmosphere. This should not really have come as a surprise since similar problems have happened over and over again. Numerous cases are on record where new chemicals, believed to be a benefit to man, have turned out to be environmentally unacceptable, sometimes even in quite small quantities (DDT, PCB, Pb etc.). In the present situation, when the CFCs and in a little longer perspective the HCFCs are being banned by international agreement, it does not seem very logical to try to replace them by another family of related halocarbons, the HFCs, equally foreign to nature. 41 Int. Journal of Refrigeration 9. Vol. 18, No. 3, pp , 1995

44 Thank you very much!.