Giacomo Pisano, Dorin

2. CO2 TRANS-CRITICAL SYSTEM FOR A FRESH FROZEN
FOOD PRODUCTION FACILITY
GIACOMO PISANO - DORIN S.P.A.

3. 1. INTRODUCTION
2. JOBSITE DESCRIPTION
3. PRACTICING WITH (ALMOST) ALL REFRIGERANTS KINDS
4. CONCLUSIONS

4. 1. INTRODUCTION: DORIN SPA
• 1995: DEVELOPMENTS ON NATURAL REFRIGERANTS COMPRESSORS
NH3HCsCO2

5. 2. JOBSITE DESCRIPTION
• SURGITAL: ITALIAN EXCELLENCE IN HIGH QUALITY FROZEN FOOD
• GENCOLD: LOCAL ITALIAN RACK BUILDER & REFR. CONTRACTOR

6. 3. PRACTICING WITH (ALMOST) ALL REFRIGERANTS KINDS
• 1980: PLANT COMMISSIONED FOR THE 1ST TIME
• 1.2 MW TOTAL REFRIGERATION CAPACITY
• FREEZING TUNNELS (-40°C) - COLD ROOMS (-30°C) - CHILLERS (0°C)
• REFRIGERANT: R22 ~ 2.000 kg CHARGE
• N. 50 SCREW COMPRESSORS
• COP ~ 0.65
SURGITAL

7. • YEARS 1980 ÷ 2000
• TUNNELS RETROFIT TO LOTS OF FUNKY STUFF
( R409, R422B, R422D, R424A )
3. PRACTICING WITH (ALMOST) ALL REFRIGERANTS KINDS
SURGITAL
• YEAR 2000
• 8 NEW TUNNELS WERE NEEDED
• PROGRESSIVELY TEAR DOWN AND REFURBISH EXISTING TUNNELS
• DECISION TO DECREASE CHEMICAL REFRIGERANTS CHARGE
• OPTIONS:
• 2 STAGE AMMONIA: SEVERAL THOUSANDS kg CHARGE
• LOCAL AUTHORITIES DENIED PERMISSIONS
• FIRST R22 NESTLÉ PLANTS CONVERTED FROM R22 TO CO2 / NH3
( DRY OPERATED QUIRI COMPRESSORS )
• SIMILAR SOLUTION PROPOSED TO LOCAL AUTHORITIES:
• 5.000 kg CO2 CHARGE + 500 kg NH3 CHARGE
• COMPLEX AUTHORIZATION PROCESS
• FINALLY IT ALL WENT THROUGH: COP ~ 1.16

8. 3. PRACTICING WITH (ALMOST) ALL REFRIGERANTS KINDS
SURGITAL
• YEARS 2000 ÷ 2017
• SINGLE TUNNELS RETROFITS ~ 300 kW LT EACH
• CO2 / NH3 NOT SO PRACTICABLE ( TOO SMALL )
• NEED TO AVOID AND / OR LIMIT HFCs CHARGE
• TRANSITION TO NATURAL REFRIGERANTS
• CO2 / R507: COP ~ 0.90
• CO2 / R134a: COP ~ 0.94
• CO2 / GLYCOLE / R134a: : COP ~ 0.85
• REMEMBER - CO2 / NH3: COP ~ 1.16
• COP DROP: (-27%) ÷ (-19%) USING CO2 CASCADE WITH HFCs
• A DIFFERENT SOLUTION WAS NEEDED
• CO2 TRANSCRITICAL BOOSTER WITH PARALLEL COMPRESSION

9. 3. PRACTICING WITH (ALMOST) ALL REFRIGERANTS KINDS
SURGITAL
• YEARS 2018 ÷ 2019
• SINGLE TUNNELS RETROFITS ~ 300 kW LT DUTY
• NEW TECHNOLOGY IMPLEMENTED
• CO2 BOOSTER WITH PARALLEL COMPRESSION

10. 3. PRACTICING WITH (ALMOST) ALL REFRIGERANTS KINDS
SURGITAL
• CO2 BOOSTER WITH PARALLEL COMPRESSION
• REMOTE DATA MONITORING
• VERY QUICK COMMISSIONING PERIOD ( ~ 2 DAYS )
• EXTRA SHORT PULL DOWN TIME
• NO MAIN ALARMS REPORTED IN 12 MONTHS OPERATION
• END USER IS EXTREMELY SATISFIED

11. 3. PRACTICING WITH (ALMOST) ALL REFRIGERANTS KINDS
SURGITAL
• CO2 BOOSTER WITH PARALLEL COMPRESSION
• REFRIGERATION CAPACITY: 271 kW
• COMPRESSORS - DORIN: N. 4 CDS3001B + N. 4 CD5201M
• MEASURED POWER CONSUMPTION AT PEAK TEMP: 235 kW
• COP = 1.15
• VERY SMOOTH
PRESSURES
BEHAVIORS
• SYSTEM IS EASY
TO HANDLE

12. 4. CONCLUSIONS
SURGITAL
• SAME JOBSITE: DIFFERENT COP LEVELS DEPENDING ON TECHNOLOGY
• R22: COP ~ 0.65
• CO2 / GLYCOLE / R134a: : COP ~ 0.85
• CO2 / R507: COP ~ 0.90
• CO2 / R134a: COP ~ 0.94
• CO2 / NH3: COP ~ 1.16
• CO2 BOOSTER: COP ~ 1.15
• NATURAL REFRIGERANT ARE ENERGY EFFICIENT
• NATURAL REFRIGERANTS ARE EASY TO HANDLE