Cummins Power - Insulating Materials Mentor: Robert Rossini Patrick Cleaver Justin Fernandez Ethan Taylor
Cummins Inc. Headquarters: Columbus, IN Employees: 33,000+ worldwide Earnings: $11.4 billion (2006) Business Units Engine, Power Generation, Components Distribution
Cummins Power Generation Products: Generators for RVs, Yachts, and residential standby Emergency standby power Stationary, mobile, open, and sound attenuated enclosures offered for all generator sets
Anatomy of a Generator Set Turbocharger Air Filtration Control System Fan Engine Alternator
Enclosures Air Intake Exhaust Sound Insulation Recessed doors
Current Insulating Material Mineral Wool In used because: Cheap, operating temperature Disadvantages Difficult to work with, Requires supporting material, Requires extra manufacturing
Needs/Wants Needs Operation at high temperatures (900 °F), must not burn or degrade Must not absorb water, must resist mold Wants Higher thermal resistance (R > 4.3) Better acoustic dampening (STC > 10) Better workability Self Supporting Material Fewer Processing steps
Product Design Specifications 1. Thermal Continuous operation at 900 °F Acceptable surface burning, 5/5 or better (ASTM E-84) 2. Sound Sound Transfer Coefficient comparable to mineral wool (STC 10) 3. Mechanical Compressive strength greater than mineral wool is desired (>1.7 psi) 4. Environmental Must not adsorb water (<1 % by volume) Must not allow for mold growth 5. Workability One step installation process Reduction in manufacturing steps 6. Cost No more than 2x cost of mineral wool ($14.8/ft3)
Weighting Factors Original Updated Selection Criteria Weight Thermal 0.2 Acoustic 0.3 Mechanical 0.05 Environmental Workability Cost 0.1 Selection Criteria Weight Thermal 0.4 Acoustic 0.1 Mechanical 0.05 Environmental Workability 0.3 Cost
Candidate Materials Sound Proof Foam Acoustiblok® Calcium Silicate Expanded Perlite
Selection Matrix
Design Solution For a 35kW level II enclosure: 11 pieces are to be cut from received board Installed into walls/doors Installed above generator and around exhaust system
Insulation board dimensions
Cutting/Forming Done with circular saws 57.5 feet of cutting per enclosure Ventilation is required to eliminate spread of dust
Insulation of door panels
Insulation of exhaust area
Elimination of perforated steel
Exhaust box installation Insulation block Small bolts Perforated steel
Thickness will remain the same Thermal conductivity of expanded perlite: .85 Btu in/hr ft2 °F Thermal conductivity of mineral wool: 1.06 Btu in/hr ft2 °F Same thickness will be used Thermal insulation will improve
Thermal conductivity ∆T = 735 °F ∆T = 590 °F heat flow rate thickness *Assuming a heat flow of 3000 Btu/hr area thermal conductivity ∆T = 735 °F For mineral wool with k = 1.06 Btu in/hr ft2 °F ∆T = 590 °F
Further Testing Acoustical testing Mechanical testing Ability for material to withstand vibrations Impact testing
Regional Market Worldwide leader in auxiliary generator sets for RVs, commercial vehicles and recreational marine applications. Caterpillar and Volvo are the primary competitors $2.42 billion in 2006 9.1 % increase
Potential Increase Increase earnings due to new products and manufacturing efficiency gains 7-9% of sales Potential increase of $170-218 million
Capital Investment Ventilation System: $75,000 Circular Saws (5): $5,000 Engineering Testing: $14,000 Total: $94,000
Variable Costs Assumptions: Energy used for ventilation: $3,000 per year Energy costs for operating saws: $540 per year Blade costs $10 each 30% overhead
Variable Cost per Enclosure
Breakeven Analysis II
Cost Comparison
Breakeven Analysis I
Project Timeline
Going Forward Potential Material Identified Potential Cost savings Mock-up Enclosure Materials Testing