Охолоджуючі рідини з покращеними екологічними та експлуатаційними властивостями

Abstract

The analysis of modern water-glycol coolants / antifreezes for internal combustion engines and some technical coolants has been carried out. Attention is focused on the physicochemical properties of glycols (density, freezing point, heat capacity, thermal conductivity, viscosity) and the possibility of their use in various machines and mechanisms. The dependence of the freezing temperature of water-glycol solutions on their concentration has been shown. Depending on the metals (alloys) for cooling the cylinder blocks and radiators of internal combustion engines (ICE), the classification has been carried out with the indication of modern corrosion inhibitors. It has been shown the formation of the organic acids of various chemical nature during oxidation of glycols in the course of their long-term operation. It has been noted that acid corrosion and scale formation on the working surfaces of the ICE are the main negative factors that reduce engine power, increase gas emissions from the combustion products of the ICE into the atmosphere which leads to environmental degradation. Depending on the chemical component, the classification of used inhibitors has been carried out according to their international designation: inorganic — IAT (Inorganic Acid Technology); organic (carboxylate) OAT (Organic Acid Technology); "hybrid" (mixed) — HOAT (Hybrid Organic Acid Technology). The toxicological and ecological properties of coolants (antifreezes) depending on the composition of water-glycol mixtures have been considered. The high toxicity of antifreezes based on ethylene glycol for the environment and the absence of such for antifreezes based on propylene glycol and glycerin has been emphasized. Emphasis has been placed on the possibility of improving the physicochemical (operational) characteristics of antifreezes by changing the main (basic) components of water-glycol mixtures, changing their ratio and introducing new more effective additives