1. Blue is better 1 Eng. Marco Caldara Frascold R&D laboratory manager COMPRESSOR TECNOLOGY FOR THE LOW GWP REFRIGERANTS London - 26° April 2012 RAC question time

2. Frascold Research Philosophy Compressor Technology Manufacturing and Process Engineering Material Sciences Forensic Engineering Compressor Design Refrigerants and Application Engineering Frascold Research Philosophy Compressor Technology Manufacturing and Process Engineering Material Sciences Forensic Engineering Compressor Design Refrigerants and Application Engineering Blue is better 2 Introduction

3. Blue is better 3 HFO R407F CO2 Refrigerants Design evaluation for drop-in allowance Design evolution for performance increasing Application envelope extensions Compressor design Suggest refrigerant choice Hybrid system Field test in different location for seasonal TEWI calculation purposes Validating application Current activities

4. Blue is better R1234ze TESTING EXPERIENCE R1234ze TESTING EXPERIENCE 4 R&D case study

5. Blue is better 5 Summary  Testing routine instruction  Testing equipment and methods  Refrigerant properties databases  Results  Operations  Current state of test program  Design evolution  Selection software update

6. Blue is better 6 TEST PLAN 1.Measure compressor parts 2.Assembling compressor 3.Tightness test 4.Oil charge 5.Installing on test rig and evacuate for 12 h 6.Test and record time + working condition 7.Recover refrigerant and uninstall from test rig 8.Taking oil sample for analysis 9.Dismantle compressor 10.Measure compressor part (500 h). Each test result contributes to the entire project final result Testing routine instruction

7. Blue is better 7 TEST RIG: 300kW Test equipment and methods

8. Blue is better 8 TEST RIG: 300kW  Built by ILK Dresden in 2004.  Test according to EN13771-1  Two Coriolis mass flow meter  LP side, method D1  HP side, method D2  Oil separator  Power supply from stabilized grid  Four independent PID controllers  Pressure measurement uncertainty lower than 1%  Temperature measurement uncertainty lower than 0,3 K  Power measurement uncertainty lower than 1%  Water cooled condenser and subcooler  Performance uncertainty lower than 5% Test equipment and methods

9. Blue is better 9 PERFORMANCE DATA PROCESSING STEP 1.Placing testing point 2.Expect limits 3.Break-in time (24 h) 4.Reproduce conditions 5.Go outside limits 6.Check results 7.Use interpolation software 8.Evaluate efficiency curve 9.Create performance model Test equipment and methods

10. Blue is better REFRIGERANT PROPERTIES DATABASE:  NIST refprop 9.0  ILK REFLIB for MS Excel 2.1 10 Refrigerant databases

11. Blue is better 11  Compressor performance  Performance test  Numeric simulation  Refrigerant comparison  Oil behavior  Compressor parts wearing Results – key points

12. Blue is better 12 Results – performance test

13. Blue is better 13 Results – Numeric simulation

14. Blue is better 14 Results – Refrigerant Comparison

15. Blue is better 15 EVALUATED OIL:  POE 68 cst  PAG 68 cst  POE 170 cst (screw)  POE 68 cst Oil level was regulated at half of the sight glass on compressor crankcase by an optical level switch. LUBRICATION AT COLD START UP SUDDEN PRESSURE DECREASE (FOAM) FORCED LUBRICATION – PUMP DIFFERENTIAL PRESSURE GAS TRAPPING WHEN DISCARDED Results – Oil behavior

16. Blue is better 16 EVALUATED COMPONENTS:  PISTON AND PISTON RINGS  SHAFT  RODS  BUSHES  VALVE PLATE REEDS LIGHT WEARING (NORMAL) NO OVERHEATING SIGN ON VALVE REEDS AND ROTATING PARTS ABSENCE OF DIRT OR PARTICLES Results – compressor parts wearing

17. Blue is better 17 NEEDING ADDITIONAL CARE FOR:  LOADING – UNLOADING OF THE REFRIGERANT  FLAMMABILITY ISSUE: VENTILATION OF AREA  STOCK AND HANDLING  VACUUM OPERATION No difference in loading operation, but lower pressure at given temperature Same ambient condition Same stock area and procedure Additional vacuum time to sample oil after test Operations ?

18. Blue is better 18  1° step: drop in of refrigerant in standard model  2° step: Evaluated R134a model range  3° step: HFO dedicated model to enhance favorable behavior  4° step: field test running and confirmation test 99% compatible with standard model (dedicated oil) different performances requires technology adaption Test program

19. Blue is better 19 Design evolution Motor optimized for HFOMotor optimized for HFO New valve plateNew valve plate Reduced clearancesReduced clearances Optimized bore-stroke ratioOptimized bore-stroke ratio

20. Blue is better 20 Thanks to lower power consumption motor efficiency improvement is possible and necessary Shorter stroke compression helps with low density refrigerant in suction stage Valve plate for higher specific volume Design evolution  Different motor size tested to catch higher efficiency  different bore-stroke solutions will be evaluated in future.  New design of valve plate under evaluation

21. Blue is better 21  Refrigerant model available  Compressor efficiencies available for tested models  Other models could be calculated having tested performaces with HFC and conversion tools  Models need confirmation test on oher sizes Thanks to similarity with R134a conversion is plausible and tested to define accuracy Performance calculation in progress. Selection software update

22. Blue is better 22 COMPRESSOR TECNOLOGY FOR THE LOW GWP REFRIGERANTS Thanks !