An Analysis of Energy Savings Possible Through Advances in Automotive Tooling Technology

Rick Schmoyer, RLS

Oak Ridge National Laboratory

关键词: Thermodynamics;    Sensitivity;    02 Petroleum;    Energy Audits;    Potential Energy;   

DOI  :  10.2172/885655
RP-ID  :  ORNL/TM-2004/115
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  885655

美国|英语

来源: UNT Digital Library

【 摘 要 】

The use of lightweight and highly formable advanced materials in automobile and truck manufacturing has the potential to save fuel. Advances in tooling technology would promote the use of these materials. This report describes an energy savings analysis performed to approximate the potential fuel savings and consequential carbon-emission reductions that would be possible because of advances in tooling in the manufacturing of, in particular, non-powertrain components of passenger cars and heavy trucks. Separate energy analyses are performed for cars and heavy trucks. Heavy trucks are considered to be Class 7 and 8 trucks (trucks rated over 26,000 lbs gross vehicle weight). A critical input to the analysis is a set of estimates of the percentage reductions in weight and drag that could be achieved by the implementation of advanced materials, as a consequence of improved tooling technology, which were obtained by surveying tooling industry experts who attended a DOE Workshop, Tooling Technology for Low-Volume Vehicle Production, held in Seattle and Detroit in October and November 2003. The analysis is also based on 2001 fuel consumption totals and on energy-audit component proportions of fuel use due to drag, rolling resistance, and braking. The consumption proportions are assumed constant over time, but an allowance is made for fleet growth. The savings for a particular component is then the product of total fuel consumption, the percentage reduction of the component, and the energy audit component proportion. Fuel savings estimates for trucks also account for weight-limited versus volume-limited operations. Energy savings are assumed to be of two types: (1) direct energy savings incurred through reduced forces that must be overcome to move the vehicle or to slow it down in braking. and (2) indirect energy savings through reductions in the required engine power, the production and transmission of which incur thermodynamic losses, internal friction, and other inefficiencies. Total savings for an energy use component are estimated by scaling up the direct savings with an approximate total-to-direct savings ratio. Market penetration for new technology vehicles is estimated from projections about scrappage. Retrofit savings are assumed negligible, but savings are also assumed to accrue with increases in the fleet size, based on economic growth forecasts. It is assumed that as vehicles in the current fleet are scrapped, they are replaced with advanced-technology vehicles. Saving estimates are based on proportions of new vehicles, rather than new-vehicle mileages. In practice, of course, scrapped vehicles are often replaced with used vehicles, and used vehicles are replaced with new vehicles. Because new vehicles are typically driven more than old, savings estimates based on count rather than mileage proportions tend to be biased down (i.e., conservative). Savings are expressed in terms of gallons of fuel saved, metric tons of CO2 emissions reductions, and percentages relative to 2001 levels of fuel and CO2. The sensitivity of the savings projections to inputs such as energy-audit proportions of fuel consumed for rolling resistance, drag, braking, etc. is assessed by considering different scenarios. Though based on many approximations, the estimates approximate the potential energy savings possible because of improvements in tooling. For heavy trucks, annual diesel savings of 2.4-6.8 percent, and cumulative savings on the order of 54-154 percent, of 2001 consumption could accrue by 2050. By 2050, annual gasoline savings of 2.8-12 percent, and cumulative savings on the order of 83-350 percent of 2001 consumption could accrue for cars.