Köldmedium? Mats Blomqvist Kylma AB 2014

Transkript

1 Köldmedium? Mats Blomqvist Kylma AB 2014

2 Agenda F-Gas HFC HFO HC CO 2 NH 3 2

3 Vilka köldmedium kan man använda?

4 Köldmedium kategori Evaluation is focused on Supermarket MT and LT applications (NH 3 and Hydrocarbons are not considered) 4

5 Design Pressure Levels, Safety Classification & Global Warming Potential Refrigerant Design Pressures [bar] Lower Flammability Limit [kg/m 3 ] Safety Group Practical Limit [kg/m 3 ] GWP [100 years] HFCs 28 (42) A HFC R A2(L) HCs A NH B2(L) CO 2 42 ( 150) A valid for non flammable refrigerants used in standard applications according to EN bar with R410A 42 (53) bar with subcritical, up to 150 bar with trans-critical systems Practical limit (EN378) represents highest concentration level in a humanly occupied space which will not result in any impairing (i.e. acute) effects. 5

6 Cooling Capacity 4000 HC Utveckling av HFC HFO HC Mildly Flammable 2L Refrigerants Non-Flammable Refrigerants 3500 L-41 R410A Unitary Air Conditioning N-40 L-40 Performax LT N-20 R22 L-20 Commercial Refrigeration R404A 1500 L-YF N-13 R134a Plug-ins & Large Chillers 1000 L-ZE GWP<150 Ultra Low GWP GWP<500 Low GWP Reduced GWP GWP

7 Finns det perfekta köldmediet? Ett köldmedium måste vara säkert, stabilt och kompatibelt Smörjningolja Kapacitet? Energieffektivitet Massflöde Överhettning GWP 7

8 HFC

9 Köldmedium kategorier Evaluation is focused on Supermarket MT and LT applications (NH 3 and Hydrocarbons are not considered) 9

10 Genetron Performax LT? ASHRAE R407F A1 ASHRAE klassning Reach registrerad Patenterad av Honeywell ODP = 0 GWP = 1824 (jfr R22) Framställd för att likna R22 vid såväl konvertering som nyinstallation Drop-in för R404A med smärre justeringar Klarar både låg- och mellantemperatur inom kommersiell kyla 10

11 Capacity % Kapacitet jämfört med R404A Refrigerating Capacity Evaporation Temperature o C Evaporation -35ºC to +5 o C Condensation +40 o C 11

12 COP COP jämfört med R404A Evaporation -35ºC to +5 o C Condensation +40 o C Evaporation Temperature o C 12

13 Discharge Temperature Hetgastemperatur jämfört med R404A Temperature limit Evaporation -35ºC to +5 o C Condensation +40 o C Evaporation Temperature o C 13

14 simplified sketch Hybrid Medium Temp R134a/ Low Temp R744 Cascade MT R134a DX Cascade Heat Exchanger LT CO 2 DX MT Compressors ETX HX MT Evaporators Alternative: Secondary System (also in combination with NH 3 or HC) LT Evaporators 14

15 Hybrid MT R134a / LT R744 Kaskad R134a Bäst för MT CO 2 Bäst för LT (kaskad) Styrka Hög termodynamisk effektivitet i MT, lägst GWP av HFCs låg energikostnad& TEWI Låga arbetstryck minskad läckpotential Kan ersättas med HFO/HFO blandning Högst volymetrisk köldalstring - liten slagvolym - små rördimensioner Hög COP LT (kaskad) Överlägsen värmeöverföring Låga tryckfall Försumbar GWP Svaghet Låg volymetrisk köldalstring - kräver större slagvolym - större rördimensioner - högre installationskostnad Begränsad till MT (ej frys) Utfasning i framtiden Låg kritisk temperatur (31 C) Utmanande installation och teknologi - framförallt transkritisk applikation (MT) Transkritisk drift: Reducerat COP med hög omgivande temperatur 15

16 Koncept Eco-Efficiency, exempel supermarket Lägre kostnader Eco-Efficiency och GWP 0,6 Kostnader investering drift kapital 0,8 1,0 R404A / R404A R134a / R404A R404A Brine / R404A R404A / R744 1,2 R134a / R744 R 717 Brine / R744 1,4 1,4 1,2 1,0 0,8 0,6 Minskande miljöpåverkan Source: IZW Hannover (Germany) Informationszentrum Wämepumpen und Kältetechnik e.v. 16

17 HFO = Hydro-Fluoro-Olefin

18 Köldmedium kategori Evaluation is focused on Supermarket MT and LT applications (NH 3 and Hydrocarbons are not considered) 18

19 Köldmedium jämförelse GWP Tb (C) Tc (C) PEL, ppm LFL-UFL vol%, 23C Base: 134a ze(E) * yf * Isobutane < CO (extrapolated) Ammonia ~ ze(E) 1234yf * Honeywell preliminary values 19

20 Vapour Pressure (kpa) Ångtryckskurvor R134a 1234ze Isobutane 1234yf Temperature (Deg. C) Atmospheric Pressure 20

21 Heat of Combustion, MJ/kg HFO-1234yf Brännbarhet Flammability is evaluated by Chance of Flame occurring and Effect of Flame occurring Effect of Flame occurring -> Burning Velocity, Heat of Combustion methane propane butane gasoline Ammonia HFO-1234yf R134a R32 Class 2L (proposed) R152a ASHRAE Class 3 ASHRAE Class Burning Velocity, cm/s HFO-1234yf will be classified in Class 2L (Low Burning Velocity) 21

22 Klassificering av Komprimerad gas* Flammable Gas Classification Gas EU Japan US Propane Flammable Flammable Flammable HFC-152a Flammable Flammable Flammable Ammonia Flammable Flammable Nonflammable HFC-32 Flammable Nonflammable Flammable 1234yf Flammable Flammable Flammable 1234ze(E) Nonflammable TBD Nonflammable 22 * Normal transportklassificering

23 HFO R1234yf för mobil AC Stort arbete har lagts ned på att finna en ersättare till R134a HFO-1234yf motsvarar R-134a på de flesta punkter HFO-1234yf ger bästa sammanlagda effekten (ekonomi, miljö och säkerhet) i nya fordon vars AC har konstruerats för HFO 23

24 Egenskaper medium temperatur Cycle Initial Information Thermodynamic Analysis Relative Properties to R-134a Other Parameter R134a 1234ze 1234yf Evap Temp, C Super Heat, C Cond Temp, C Sub Cool, C Comp eff P_evap, kpa P_cond, kpa Discharge Temperature, C COPc Density, kg/m Compression Ratio Capacity 100% 73% 94% COP 100% 100% 96% Suction Pressure 100% 71% 109% Discharge Pressure 100% 75% 98% Discharge Temperature GWP Flammability 1 2L* 2L* Toxicity A A* A* * Estimated based on Honeywell data and proposed ISO 817 standard 24

25 HFO R1234ze för stora slagvolymer Refrigerant Parameter Units R-12 R-134a 1234ze(E) 1234yf Delta hevap kj/kg Delta hs,comp kj/kg Head m mdot kg/s density kg/m Vdot m3/s N (Impeller Speed) rpm D (Impeller Dia.) m u2 (tip speed) m/s Pr (Pressure Ratio) COP COP Rel to 134a 100.6% 97.6% Assumptions 5 C Evaporator Temperature 35 C Condensing Temperature 500 Tons (1760 kw) Refrigeration Capacity Both 1234ze(E) and 1234yf show promise as a refrigerant for centrifugal compressor applications Only minor increases in impeller diameter are needed and speed can be reduced. 25

26 Vitvaror med suggasväxling Assumptions Evaporation Temperature: -23 C Evaporator outlet superheat: 0 C Superheat Superheat in the suction line: 1 C Compressor inlet Temperature: 32 C Condensing Temperature: 55 C Subcooling at the outlet of Condenser: 5 C Compressor: 70% Isentropic Efficiency, 100% Volumetric Efficiency Refrigerant GWP Capacity (%) Cycle Analysis Efficiency (%) Suction Pressure Discharge Pressure Discharge Temp. Flow (%) (%) (%) Change ( C) R134a % 100% 100% 100% % 1234yf 4 102% 99% 115% 96% % 1234ze(E) 6 72% 101% 70% 75% % Isobutane ~5 56% 107% 54% 52% % Performance differences are small with commonly used internal heat exchanger All new refrigerants have lower discharge temperature than R134a (helps reliability) 26

27 Cooling Capacity 4000 Översikt av utvecklingsprogrammet Mildly Flammable 2L Refrigerants Non-Flammable Refrigerants 3500 L-41 R410A Unitary Air Conditioning N-40 L-40 Performax LT N-20 R22 Commercial Refrigeration L-20 R404A 1500 L-YF N-13 R134a Plug-ins & Large Chillers 1000 L-ZE GWP< Ultra Low GWP Reduced GWP GWP GWP<500 Low GWP 27

28 HC CO 2 NH 3 Oorganiska eller naturliga köldmedium

29 Oorganiska köldmedium Köldmedium kategori 29

30 Relative Cooling Capacity [%] Compressor types: to +5 C, tc 50 C to -10 C, tc 45 C to -35 C, tc 40 C Relative Compressor Cooling Capacity HFCs, HCs & NH 3 vs. R22 HFCs & HCs vs. R22 Semi-hermetic recips (screws) NH 3 vs. R22 Open drive screws EN / t oh 20 C / *NH 3 Dt oh 5 K R22 R134a R134a Screw + ECO R407C (Dew) R404A R507A R410A R32 R290 R600a R1270 NH3* Screw NH3* Screw + ECO 30

31 Relative COP [%] Relative Compressor COP HFCs, HCs & NH 3 vs. R Compressor types: to +5 C, tc 50 C to -10 C, tc 45 C to -35 C, tc 40 C HFCs & HCs vs. R22 Semi-hermetic recips (screws) NH 3 vs. R22 Open drive screws EN / t oh 20 C / *NH 3 Dt oh 5 K R22 R134a R134a Screw R134a Screw + ECO R407C R417A R404A R507A R410A R32 R290 R1270 NH3 NH3 Screw + ECO 31

32 Discharge Gas Temperature [ C] 260 Comparison of Discharge Gas Temperatures with Single Stage Operation to +5 C, tc 50 C to -10 C, tc 45 C to -35 C, tc 40 C outside operating limits t oh 20 C / *NH 3 Dt oh 5 K Isentropic Efficiency: HFCs + HCs 0.7 (semi-hermetic) NH (open type compressor) outside operating limits R22 R 134a R 407C R404A / R507A R 410A R32 R 290 R 600a R 1270 NH3* 32

33 Design Pressure Levels, Safety Classification & Global Warming Potential Refrigerant Design Pressures [bar] Lower Flammability Limit [kg/m 3 ] Safety Group Practical Limit [kg/m 3 ] GWP [100 years] HFCs 28 (42) A HFC R A2(L) HCs A NH B2(L) CO 2 42 ( 150) A valid for non flammable refrigerants used in standard applications according to EN bar with R410A 42 (53) bar with subcritical, up to 150 bar with trans-critical systems Practical limit (EN378) represents highest concentration level in a humanly occupied space which will not result in any impairing (i.e. acute) effects. 33

34 Pressure [bar] CO 2 A Special Refrigerant with Unique Properties and Specific Requirements Critical temperature C CO 2 R410A R404A R Temperature [ C] 34

35 Förenklad bild på en Booster Drifttryck 90 bar 35 bar (+2) 25 bar (-10) 12 bar (-33 Maxtryck PS 120 bar 60 bar (+22) 52 bar (+17) 30 bar (-5) Rekommenderat Program för rördimensionering en är DirCalc [Danfoss] 35

36 Sammanfattning R407F för kommersiell kyla (tryckrörstemperatur) R407C för AC och VP R410A för AC och VP R134a + R744 för hybridanläggning (bäst i test) R1234yf för mobil AC R1234ze för stora Chillers R290 i Chillers för MT och AC (Brännbart) R600a i vitvaror (Brännbart) R744 i kommersiell kyla (höga tryck, transkritisk drift) R717 för industriell kyla (klassning B2) 36

37 Tack för visat intresse! Frågor? DISCLAIMER Although all statements and information contained herein are believed to be accurate and reliable, they are presented without guarantee or warranty of any kind, expressed or implied. Information provided herein does not relieve the user from the responsibility of carrying out its own tests and experiments, and the user assumes all risks and liability for use of the information and results obtained. Statements or suggestions concerning the use of materials and processes are made without representation or warranty that any such use is free of patent infringement and are not recommendations to infringe on any patents. The user should not assume that all toxicity data and safety measures are indicated herein or that other measures may not be required. 37