Use of hydrocarbon refrigerants in commercial refrigeration and air conditioning equipment

Transcription

1 UNEP South America Regional Workshop Low-GWP, Energy-Efficient HCFC Replacement Technologies in the Refrigeration and Air Conditioning Sector Use of hydrocarbon refrigerants in commercial refrigeration and air conditioning equipment Daniel Colbourne RE PHRIDGE 22 nd 23 rd April, 2010, Bogota, Columbia

2 Introduction HC refrigerants being used fairly widely Good properties (excellent efficiency), no ODP, negligible GWP, good material and oil compatibility almost ideal Flammability the obvious problem! Flammability risk can be handled by use of standards Also good engineering design, considering relevant hazards Various end-users and manufacturers provide a range of RAC equipment using HC refrigerants Will describe examples of commercial refrigeration products Will describe examples of air conditioning products (air conditioners and chillers)

3 Refrigerant composition Commonly used/available HC refrigerants Many other (similar) blends available Refrigerant Name Normal boiling point R-600a iso-butane -11 C R600a/R290 (50%/50%) iso-butane/propane mix -31 C R-290 propane -42 C R-1270 propylene -48 C R290/R170 (94%/6%) propane/ethane mix -49 C Other hydrocarbons n-butane (R-600) not normally used Ethane (R-170), methane (R-50) in low temp industrial only Numerous other mixtures being sold

4 Classification Basis of addressing safety requirements is a refrigerants safety classification ISO 817 details refrigerant safety classification Based on 2 toxicity criteria 3 flammability criteria Higher toxicity + higher flammability = more onerous requirements No flame propagation Lower flammability Higher flammability Lower (chronic) toxicity A1 (HFCs) A2 A3 (HCs) Higher (chronic) toxicity B1 B2 B3 onerous requirements onerous requirements

5 Overview of safety standards Standard Title Application HC charge limits IEC and EN IEC and EN IEC and EN EN 378 ISO (DIS) 5149 Particular requirements for refrigerating appliances, ice-cream appliances and ice-makers Particular requirements for electrical heat pumps airconditioners, and dehumidifiers Particular requirements for commercial refrigerating appliances with an incorporated or remote refrigerant condensing unit or compressor Refrigeration systems and heat pumps safety and environmental requirements Mechanical refrigerating systems used for cooling and heating safety requirements Domestic refrigeration Any air conditioning and heat pump appliances Any refrigeration appliances used for commercial situations All refrigeration, air conditioning and heat pumps; domestic, commercial, industrial All refrigeration, air conditioning and heat pumps; domestic, commercial, industrial Up to 150 g Up to ~ 1kg and ~ 5 kg, depending upon application Up to 150 g Variable, depending upon application Variable, depending upon application

6 Maximum and allowable HC charges sizes Location of refrigerant containing parts Human occupied space which is not a machinery room In an unoccupied machinery room or in the open air or a special vented enclosure Notes: System type Direct Indirect Refrigerant mass Allowable (M al ) Max (M max ) Allowable (M al ) Max (M max ) Category A (general occupancy) Occupancy type Category B (supervised occupancy) Category C (only authorised access) RHPAC Comfort HPAC RHPAC Comfort HPAC All types PL V rm 2.5 LFL 1.25 h A rm or 0.55 A rm LFL 1.5 kg, or 1 kg 5 kg, or 1 kg 5 kg, or 1 kg 26 LFL, or 1 kg 130 LFL, or 1 kg 130 LFL, or 1 kg PL V rm 2.5 LFL 1.25 h A rm or 0.55 A rm LFL 2.5 kg, or 1 kg 10 kg, or 1 kg 10 kg, or 1 kg 26 LFL, or 1 kg 130 LFL, or 1 kg 130 LFL, or 1 kg PL V rm 10 kg (or 25 kg*), or 1 kg No limit, or 1 kg No limit, or 1 kg RHPAC = Refrigeration, heat pumps and air conditioning; Comfort HPAC = heat pumps and air conditioning (specifically for human comfort); Allowable and maximum refrigerant charge sizes in kg; = below ground; PL = Practical Limit = kg/m 3 ; LFL = lower flammability limit = kg/m 3 ; * 25 kg if compressor and liquid receiver are in an unoccupied machinery room or in the open air

7 Overall risk levels with application of HCs Equipment considered to have the least risk have the following characteristics: Smaller refrigerant charges Fewer number of potential SOI Similar equipment characteristics across the installed base Refrigerant-containing parts outside No additional modifications to make to the system System categories Overall risk Domestic refrigeration level 2 Retail refrigeration Air conditioning Transport Integral (stand-alone) level 2 Split (condensing unit) level 4 [Central direct expansion] [level 4] Central indirect level 2 Integral (window/portable) level 1 Split level 1 Close control level 3 Rooftop unit level 3 [Ducted direct expansion] [level 4] [Multi-split] [level 4] Chiller level 2 Car air conditioning level 1 Transport a/c level 3 Truck refrigeration level 2 Fishing vessels level 3 Food processing, bespoke level 4

8 Availability of equipment Sector Equipment type System type Available Domestic refrigeration Retail refrigeration Cold storage and food processing Transport refrigeration Chiller cabinets Integral Freezer cabinets Integral Chiller, freezer cabinets Integral Chiller, freezer cabinets Remote Chiller, freezer cabinets Distributed Chiller, freezer cabinets Indirect Storage cabinets Integral Coldstores Remote Coldstores Distributed Coldstores Indirect Process cooling/freezing Remote Process cooling/freezing Distributed Process cooling/freezing Indirect Road transport trucks Integral Refrigerated railcars Integral Reefer containers Integral Marine refrigeration Integral

9 Availability of equipment Sector Equipment type System type Available Air conditioners, dehumidifiers and heat pumps Transport air conditioning Portable units Integral Window units Integral ( ) Through-wall units Integral Split units Remote Multi-split/VRV Distributed Packaged ducted Remote Central packaged Remote Positive displace chillers Integral/Indirect Centrifugal chillers Integral/Indirect Hot water heating Integral Central heating Integral/indirect Cars Remote Converted only Buses Remote Trains Remote Aeroplanes Remote

10 Commercial refrigeration Williams refrigeration ( Commercial stand-alone cabinets (also supplied with R134a and R404A) Safety aspects Designed to EN 378 Charge size up to 150 g of R290 Cost of R290 systems same as HFC products Energy consumption R290 gives 15% lower kwh/24h than HFC options R290 provides lower noise levels, operates efficiently up to +43 C ambient

11 Commercial refrigeration Foster Refrigerator ( Commercial stand-alone cabinets (also supplied with R404A and R134a) Safety aspects Designed to EN Charge size up to 150 g of R290 Cost of R290 systems same as HFC products Energy consumption R290 gives 15% lower kwh/24h than R134a/R404A option

12 Commercial refrigeration Verco ( Commercial display cabinets (also supplied with R404A) Safety aspects Designed to EN 378 Charge size up to 500 g of R290 Cost of R290 systems similar to HFC products Energy consumption R290 gives 15-20% lower power than HFC options

13 Commercial refrigeration Gram refrigeration ( Commercial stand-alone cabinets (also supplied with R134a; R290 is standard) Safety aspects Designed to EN Charge size up to 150 g of R290 and R600a Cost of R290 systems same as HFC products R290 has lower energy consumption than HFC options

14 Commercial refrigeration Palfridge ( All types of commercial stand-alone cabinets (and domestic fridge/freezers) Factory based in Swaziland, southern Africa Completed conversion to R600a, R290 January 2010 By GTZ, funded by German finance ministry Complete conversion of production line Charge size up to 300 g of R290 and R600a Cost of R290 models lower than HFC (R134a, R404A) models Better production facilities Energy consumption much lower than HFC options Between 8 24% lower Partly due to refrigerant, partly due to improved design

15 Commercial refrigeration Waitrose supermarket (UK) All new refrigeration installations to use HCs Safety aspects Designed to EN 378 Charge size of cabinets up to 500g Charge size of chiller ~ 5 kg per circuit System based on chilled water-circuit, removing heat from water-cooled condensing units in display cases

16 Small commercial refrigeration Various multi-national end-users only utilising natural-refrigerant appliances Many stand-alone commercial units on HCs (R600a, R290) Numerous manufacturers Range from mini glass door bottle coolers, vending machines, icecream freezers, catering units, to multi-deck cabinets

17 Air conditioning Benson air conditioning ( Single cooling-only, reversible and heat-recovery splits Safety aspects Designed to AS/NZS 1677 (similar to EN 378) Charge size up to 1000 g of R290 Cost of R290 systems less than R410A Efficiency (cooling and heating) better than competing R410A and R22 products

18 Air conditioning De Longhi ( Portable type air conditioners Safety aspects Designed to EN Charge size up to 400 g of R290 Cost of R290 systems same as HFC products Energy consumption R290 gives 5-10% higher efficiency than HFC options

19 Air conditioning York/JCI ( Air-cooled chillers Safety aspects Designed to EN 378 Charge size up to 25 kg of R290 Cost of R290 systems marginally more than HFC products ( green premium ) Energy consumption R290 gives >15% higher COP than R407C and R410A products Frequency-controlled screw compressor

20 Air conditioning Frigadon ( Air-cooled chillers (also supplied with R404A) Safety aspects Designed to EN 378 Charge size up to 15 kg of R1270 Cost of R1270 systems marginally more than HFC products (~3% more) Energy consumption R1270 gives higher efficiency

21 Air conditioning Earthcare ( Air-cooled chillers Safety aspects Designed to EN 378 Charge size up to 25 kg of R290 (per circuit) Cost of R290 systems marginally more than HFC products (~3% more) Energy consumption R290 gives 15% higher efficiency

22 Final remarks Success of HCs in domestics can be extrapolated to other applications/systems Only minor technical hurdles, knowledge transfer, training Safety an issue in some systems with some alternatives Safety standards, codes and experience used to overcome this More and more products becoming available with HCs Product cost is rarely higher than HFC products (often suppliers charge a green premium ) Many end-users are demanding natural refrigerants Feedback is that there is insufficient product availability and variety