This volume consists of 14 manuscripts from the Fifth International Symposium on Engine Coolant Technology sponsored by the American Society for Testing and Materials Committee D15 on Engine Coolants, held in Toronto, Canada, in May 2006. Papers cover advances in system components, experimental testing, uses, and users' experience of automotive and heavy-duty applications. They focus on international coolant development, field testing of additives, recycling, additive compatibility, alternate coolant base technology, extended life oxidation and thermal stability, and new testing methods of cavitation, erosion, and localized corrosion. Contributors are international technical representatives from OEM and engine coolant producers. There is no index.
Annotation Emerging from a November 1991 symposium in Scottsdale, Arizona, 19 papers report on advances in developing, testing, and applying engine cooling fluids for automobiles and heavy duty engines. Among the topics are carboxylic acids as corrosion inhibitors in engine coolant, phosphate-molybdate supplements to heavy duty diesel engines, the toxicity and disposal of engine coolants, and the characterization of used engine coolant by statistical analysis. Annotation copyright by Book News, Inc., Portland, OR.
Collection of papers from the 2001 SAE World Congress, held March 5-8 in Detroit, Michigan. Paper topics are: a round robin study of freezing point of coolants using manual and automatic methods; a new tool for corrosion inhibitor research; elastomer service life prediction in organic acid coolants; the effects of contaminated engine coolants on the service life of elastomers; standard test method for cavitation and erosion-corrosion characteristics of aluminum pumps with engine coolants; a chemical base for engine coolant/antifreeze with improved thermal stability properties; the role of carboxylate-based coolants in cast iron corrosion protection; and heat exchange characteristics of silicate and carboxylate-based coolants in air-cooled engine parts.
Recently there has been interest by motor vehicle manufacturers in developing longer-lived automotive engine coolants with an emphasis on organic acid technology (OAT) [1]. Paradoxically, the lifetime of conventional technology remains largely undefined. Concerns arising from the depleting nature of silicate have led to modern conservative change recommendations of 30 000 to 50 000 miles (~48 279 to 80 464 km) [2].
Significant advances have been made in heavy duty diesel engine technology to meet increasingly stringent environmental regulations for emissions. Today's heavy duty diesel engines are being designed with lighter and softer metals, greater turbocharging, increased combustion controls, and new emission reduction equipment. The cooling systems contained in these vehicles are similarly being impacted by smaller designs, new cooling system configurations, and increased usage of lighter, softer metals. Vehicle thermal loads have significantly increased due to increased power densities, higher engine temperatures, and greater metal-coolant fluxes which places greater emphasis on oxidation/thermal stability, and high temperature corrosion protection performance of the coolant. Other operating conditions (coolant flow rates, turbulence, pressure drops, deaeration) are also becoming more severe calling for improved erosion-corrosion protection, cavitation protection, and elastomer, seal, hose compatibility. This paper reviews the changes in heavy duty diesel engine technology and provides information on coolant performance in 2002-4 emission compliant engines. Predictions are also made on future engine technology and next generation engine coolants.
Recycling of used engine coolants containing ethylene glycol and other glycols would appear to be well established, particularly for reverse osmosis and nanofiltration membrane, electrodialysis, and distillation-based processes. Both literature and recycling facilities indicate success in employing these techniques. However, many recyclers, particularly those employing a single treatment technology, are not capable of producing recycled product meeting original equipment manufacturer (OEM) requirements for coolant, and these typically fall far short of approaching virgin (nonrecycled) coolant quality. In addition, some recycling facilities have produced and marketed product that led to coolant system damage and engine failure, either as a result of not sufficiently removing contaminants or inadequately reformulating with corrosion inhibitors and other additives. The danger of process upsets resulting in inadequate product is particularly high for those facilities that receive feeds with varying contaminant levels and coolants containing a range of corrosion inhibitors and additives (silicates, organic acids, etc.). However, no study to date has focused on a fundamental assessment of the separation characteristics and interactions of the various classes of coolant technologies with the commercially available reverse osmosis, nanofiltration, and electrodialysis ion exchange membranes typically seen in recycling operations. This study presents results of a comprehensive evaluation of the separation characteristics of a wide range of these membranes with a wide range of coolant types. In particular, the study examined production rate characteristics, inhibitor and other additive separation, and contaminant removal for reverse osmosis, nanofiltration, and electrodialysis. Residual inhibitors remaining in the recycled coolant are examined, with guidance provided on how these residuals might affect coolant reformulation and performance.
A brief history of ethylene glycol application as an engine coolant is presented. Concurrent engine cooling system corrosion problems and coolant corrosion inhibition requirements are reported. Comments on current engine system corrosion problems are provided. Resistance to corrosion failure is shown to depend upon the correct combination of cooling system design, materials, coolant inhibition, and coolant retention.
Over the years, new performance requirements and environmental regulations have driven engine manufacturers to design new engines. The new engine technologies have resulted in different operating conditions in cooling systems. In general, a trend towards higher coolant temperatures is observed, which is expected to have an implication on the coolant stability and corresponding lifetime. In heavy duty applications, this trend is even more pronounced as engines are running longer and under more severe conditions. In this paper, a selection of different current coolant technologies available in the market have been tested to obtain more information on the influence of the coolant additive package on the thermal stability of the most commonly used coolant base fluid, mono ethylene glycol (MEG). For this reason glycol oxidation products have been measured after subjecting the coolants to high temperature oxidative conditions. In addition the physical/chemical stability of the coolants and corrosion protection level of the additive packages have been evaluated.
