Shortcut to Improved Efficiency: Research Points to Hydraulic Fluid

Transcription

1 Shortcut to Improved Efficiency: Research Points to Hydraulic Fluid Frank-Olaf Mähling Michaël Alibert Evonik Industries AG, Germany Thomas Schimmel Evonik Oil Additives USA, Inc.

2 Outline 1. Trends in industrial and mobile hydraulics 2. Advanced hydraulic fluids: Basis for efficiency improvement 3. Performance demonstration - Plastic injection molding - Excavator 4. Conclusion STLE 2015 Page Page 2 2

3 Hydraulic equipment is working harder than ever. Smaller and Lighter Equipment Higher Operating Temperature Demand for Higher Efficiency Reduced Noise Levels More Stringent Emission Regulations Higher Pressure and Increased Power Output z.b. Kraftsymbol STLE 2015 Public Page 3

4 Examples for growing hydraulic equipment markets. Sales of hydraulic construction equipment Thousand Units / year Sales of injection molding equipment Sales of Injection Molding Equipment Year Source: Off-Highway Research data base Source: Plastics Today, Growing markets result in increasing fleet size with demand for higher quality hydraulic fluids: Typical oil drain intervals: Mid size excavator: 2,500 hours Plastic injection molding machine: >10,000 hours STLE 2015 Public Page 4

5 Outline 1. Trends in industrial and mobile hydraulics 2. Advanced hydraulic fluids: Basis for efficiency improvement 3. Performance demonstration - Plastic injection molding - Excavator 4. Conclusion STLE 2015 Page Page 5 5

6 Hydraulic fluid selection and pump approvals. Example of a fluid selection diagram for an axial piston pump Monogrades ONLY Source: Bosch Rexroth A10 pump documentation STLE 2015 Public Page 6

7 Hydraulic pump efficiency. The overall pump efficiency is the product of volumetric and mechanical efficiency. a) Volumetric efficiency: Ratio of the actual flow delivered by a pump to its nominal flow rate Q ηv = Q Volumetric power losses correspond to internal leakage of the pump b) Mechanical efficiency: Ratio of theoretical to actual input torque η HM actual nominal M = M theoretical actual Q = nominal Q = M Q nominal M theoretical leakage theoretical + M friction Hydromechanical losses (or frictional losses) are proportional to viscosity, flow velocity and pressure. They correspond to the extra input torque required to overcome the frictional losses within the pump STLE 2015 Public Page 7

8 Benefits of high VI hydraulic fluids. 1) Same ISO viscosity grade Two oils meeting ISO 46 viscosity requirements Improved cold start Maximum Start-up Viscosity Kinematic Viscosity, mm²/s High VI Oil ISO VG 46 Mechanical benefits at low temperature HM Oil ISO VG 46 Optimum Efficiency Minimum Operating Viscosity Volumetric Benefits at High Temperature 3.0 Minimum Operating Temperature Maximum Operating Temperature Temperature, C STLE 2015 Public Page 8

9 Benefits of high VI hydraulic fluids. 2) Lower ISO viscosity grade Two oils with identical maximum operating temperature Improved cold start Maximum Start-up Viscosity Kinematic Viscosity, mm²/s High VI Oil ISO 32 Minimum Operating Temperature Mechanical benefits at all temperatures Temperature, C HM Oil ISO 46 Optimum Efficiency Minimum Operating Viscosity Maximum Operating Temperature Protection at high temperature STLE 2015 Public Page 9

10 Fluid examples. VI Improver None Non-shear stable VII Shear stable VII Highly shear stable VII After KRL 20hr VII Treat rate 0% 8.2% 11.0% 14.6% KV 40 C mm²/s KV 100 C mm²/s VI KV 100 C mm²/s Shear loss % Some polymers survive mechanical stress better than others STLE 2015 Public Page 10

11 Vane pump efficiency with high VI hydraulic fluids (all ISO VG 46). Efficiency Improvement in a Parker Denison vane pump T6CM, [%] bar, 80 C! Only shear-stable, high VI fluids deliver significant efficiency improvements. -3 non shear stable medium shear stable highly shear stable Source: Alibert et al., IFK 2006 STLE 2015 Public Page 11

12 In-service viscosity in a hydraulic pump. Shear stable high VI fluid Non-shear stable fluid Shear stable high VI fluids retain their viscosity under severe conditions, under heavy loads and over time. This guarantees high overall efficiency and protection. STLE 2015 Public Page 12

13 Outline 1. Trends in industrial and mobile hydraulics 2. Advanced hydraulic fluids: Basis for efficiency improvement 3. Performance demonstration - Plastic injection molding - Excavator 4. Conclusion STLE 2015 Page Page 13

14 Field tests for efficiency in hydraulic equipment: literature reports. Lead author Neveu Firm name Forum OEM Equipment Reported efficiency improvement Evonik Industries STLE 2007 Guerzoni Shell Hydraulics and Pneumatics, 2009 Mid-sized excavator Hannon ExxonMobil STLE 2010 Small excavator, Injection molding Skid steer loader up to 18% Injection molding 14% up to 6% up to 2.2% up to 4% - Hydrotex Press release 2010 Injection molding 13% Battersby Shell NFPA 2011 Telehandler 4% Schimmel Schrode Evonik Industries Schrode GmbH ivt International Off- Highway - China Edition 2013 DYNAVIS Testimonial, Youtube 2013 Mid-sized excavator Mid-sized excavator up to 27% 10% (up to 25%) STLE 2015 Public Page 14

15 Injection molding field trial: Test design. Equipment and materials Plastic injection molding machines of various size Without plastic or with standard plastics Set-up and measurements Oil change, including sample analysis Redundant measurement of energy consumption Oil Temperature (steady-state conditions) Pressure and flow rate Multiple replication of runs Test parameter variations Fluid temperature Cycle time STLE 2015 Public Page 15

16 Injection molding field trials: Variation of fluid and temperature. Measure electric power consumption according to EUROMAP 60.1 over the whole cycle and for individual process steps Reference oil Shear Stable high VI Fluid Reference oil low three test temperatures medium high STLE 2015 Public Page 16

17 Injection molding field trial: Improvement of energy efficiency. Efficiency Gain [%] % Shear stable high VI HF vs Conventional monograde HF Temperature / C Efficiency was improved by using a shear stable high VI fluid Power consumption was reduced by 6..9% Lower viscosity grades show largest benefits allowing for apparent viscosities of 20 cst at process operating temperature Reference Test Fluid ISO VG VI KV100 * /cst *after sonic shear, 40 min. UNITI Energy Efficient Hydraulic Fluids for Industrial and Mobile Applications Public Page 17

18 Excavator field trial: Test equipment. Hydraulic Excavator (Liebherr R 924 LC) 2 axial hydraulic piston pumps, 380 bar 3 hydraulic pistons that operate the boom A single hydraulic piston for the arm A single hydraulic piston for the bucket 0.75 and 1.75 mt buckets 2 Dump trucks (18 mt) 1 Wheel loader On-site truck scale Site: Stone quarry in Southern Germany Gravel: Ø ~1 inch STLE 2015 Public Page 18

19 Excavator field trial: Test protocol. Three test phases plus 2 minutes idling test 1. Truck Loading (Loading time for 20 big scoops / 40 small scoops) 2. Traveling (Travel 200 meters -- 4 times 50 meters) 3. Digging (Mass of stones buckets - moved in 10 minutes) Parameter variations 1. Two operators: A / B 2. Engine mode: Slow / Power+ 3. Initial oil temperature: 50 C / 70 C 4. Scoop size: small / large Efficiency (mt / kg fuel) or (m / kg fuel) Average amount of work done in relation to average amount of fuel or energy consumed Productivity (mt / hr) or (m / hr) Average tons of material moved in relation to time spent STLE 2015 Public Page 19

20 Excavator field trial: Test fluids Hydraulic fluid data Reference Fluid 1 Fluid 2 Fluid 3 Fluid 4 Fluid 5 KV40 / cst KV70 / cst KV100 / cst VI KV70 / cst after shear* KV100 Shear loss* <1% <1% <1% 7% 5% 9% *Ultrasonic shear, 40 min STLE 2015 Public Page 20

21 Excavator field trial: Efficiency test results - Digging Efficiency Improvement / % (S) Efficiency Improvement / % (P+) 5% 12% 18% Digging and truck loading are the most demanding operations Up to 18% diesel fuel can be saved with shear-stable, high VI hydraulic fluids % -8% -3% The viscosity group should be selected according to climate conditions and typical operation temperature of the excavator (here 70 C oil temperature) *After ultrasonic shear, 40 min.. STLE 2015 Public Page 21

22 Excavator field trial: Productivity test results - Digging 25 21% Productivity Improvement / % (S) 20 Productivity Improvement / % (P+) 15% % 5 0% 0-9% -3% KV40/ cst Digging and truck loading are the most demanding operations Up to 21% more work per unit of time can be completed with shearstable, high VI hydraulic fluids The viscosity group should be selected according to climate conditions and typical operation temperature of the excavator (here 70 C oil temperature) VI KV70/ cst * After ultrasonic shear 40 min STLE 2015 Public Page 22

23 Excavator field trial: Efficiency and productivity. 200 ISO VG 46 monograde High VI, very high shear stability fluid + 15 % 3,000 kg fuel / day % 2,500 2,000 1,500 mt / day 50 1, Fuel consumption (Efficiency) Productivity STLE 2015 Public Page 23

24 Outline 1. Trends in industrial and mobile hydraulics 2. Advanced hydraulic fluids: Basis for efficiency improvement 3. Performance demonstration - Plastic injection molding - Excavator 4. Conclusion STLE 2015 Page Page 24

25 Conclusion selection parameters for energy efficient hydraulic fluids Define typical operating conditions Investigate extreme operating conditions (T and p) Evaluate importance of volumetric and mechanical efficiency Choose ISO VG and VI (consider reliability, protection and efficiency) Select highly shear-stable fluid to maintain high volumetric efficiency of hydraulic pumps, motors and actuators STLE 2015 Public Page 25

26 Conclusion 1. Methods to measure the efficiency of hydraulic equipment were developed and applied to an excavator and to plastic injection molding equipment. Shear-stable, high viscosity index hydraulic fluids offer: 2. Significant energy savings Potentials for productivity increase Reduction of GHG emissions. 3. Cost advantages and emission reductions make the use of shear-stable, high VI hydraulic fluids very attractive. STLE 2015 Public Page 26

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