RU2470059C1 - Liquid coolant for internal combustion engine - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to antifreeze liquid coolants and can be used to cool internal combustion engines of vehicles and stationary power generators, as well as a heat carrier in heat-exchange apparatus. Disclosed is a liquid coolant for internal combustion engines which contains the following, wt %: ethylene glycol - 40-69, disubstituted sodium phosphate - 0.31-0.35, potato dextrin- 1.2-1.3, polyacrylamide - 0.05-0.1, polyvinyl alcohol - 0.05-0.1, surfactant - Sintanol DS-10 - 0.05-0.1, distilled water or steam condensate - the balance.

EFFECT: high efficiency of protecting structural materials from cavitation erosion and lower heat loss through the cooling system, which enables to reduce the warm up time of an internal combustion engine, low cost of the product owing to low concentration of additives and a higher water component.

3 tbl, 5 ex

Description

The invention relates to low-freezing coolants (antifreezes) and can be used to cool internal combustion engines (ICE) of transport and stationary energy systems, as well as a coolant in heat exchangers. The proposed substance was obtained by specialists of the St. Petersburg State University of Water Communications in the development of a cooling system for marine internal combustion engines with liquid cooling.

Most of the coolants for internal combustion engines and heat exchangers are based on an aqueous solution of ethylene glycol (see, for example, Pat. RU 2219216 IPC C09K 5/00, Pat. US 4759864 IPC C09K 5/00, etc.). Compared with antifreeze agents of other classes, they are the cheapest compositions and have large heat capacity and thermal conductivity. In addition, they have a low freezing point, which allows safe operation of the refrigerated equipment at almost any negative ambient temperature. The disadvantage of these fluids is the high corrosiveness to structural materials, to prevent which special additives are introduced into the mixture: corrosion inhibitors, buffer additives, etc.

In the territory of the Russian Federation, Tosol (Tosol-AM, Tosol-A40M, Tosol-A65M, TU 2422-001-526000940-00, GOST 28084-89) is most widely used as a coolant. The anticorrosive additive of commercially available antifreezes is disubstituted sodium phosphate of the first grade (disodium phosphate Na ₂ HPO ₄ · 12H ₂ O) and extra grade dextrin (general formula (C ₆ H ₁₀ O ₅ ) _x ). Disodium phosphate protects cast iron, steel and copper parts from corrosion, while dextrin protects solder, aluminum and copper. The disadvantage of these compositions is the tendency to foaming, enhanced by additives. To prevent foaming, antifoam agents (for example, siloxane) are added to the antifreeze, which complicates the composition of the substance and, accordingly, the technology for its preparation and, thus, increases the cost of the product.

Of the known solutions, the closest analogue to the proposed substance is a coolant for cooling internal combustion engines based on an aqueous solution of ethylene glycol according to US Pat. RU 2206591, IPC C09K 5/00, publ. 06/20/2003. The composition contains, wt.%: Ethylene glycol - 65-69; disubstituted sodium phosphate - 0.31-0.35; potato dextrin - 1.2-1.3; morpholine paranitrobenzoic acid - 0.7-0.8; glycerin - 8-10; sodium oleic acid - 0.11-0.13; distilled water or steam condensate - the rest.

As shown by the results of laboratory tests, this fluid is not inferior to most analogues in physico-chemical properties, while providing high corrosion protection of structural materials. However, it has a complex composition, high concentration of additives (11 ... 12%) and a low coefficient of protection against cavitation erosion. In addition, the known liquid does not effectively control the heat transfer processes inside the engine, which limits its use as a coolant.

The technical result from the use of the invention is to increase the efficiency of protection of structural materials from cavitation erosion while reducing the concentration of additives and increasing the influence on the heat transfer processes inside the internal combustion engine.

The claimed technical result is achieved in that the coolant for internal combustion engines based on an aqueous solution of ethylene glycol (containing, as well as the prototype, sodium phosphate disubstituted and potato dextrin), in contrast to the prototype, additionally contains polyacrylamide, polyvinyl alcohol and surface-active a substance, for example, syntanol DS-10, in the following ratio, wt.%:

Ethylene glycol 40-69 Sodium Phosphoric Acid Disubstituted 0.31-0.35 Potato dextrin 1.2-1.3 Polyacrylamide (PAA) 0.05-0.1 Polyvinyl alcohol (PVA) 0.05-0.1 Surfactant (Syntanol DS-10) 0.05-0.1 Distilled water or steam condensate Rest

Thus, the difference between the proposed composition from the prototype is the introduction of water-soluble polymers and a surfactant into its composition and the selection of the appropriate ratio of all components.

Comparison of the proposed substance and the prototype showed that the task is to increase the efficiency of protection against cavitation damage to structural materials of internal combustion engines with a decrease in the concentration of additives and increase the influence on the heat transfer processes inside the internal combustion engine - it is solved as a result of a new set of features, which proves that the proposed invention meets the patentability criterion of "novelty" .

In turn, the information search in the field of chemical technology did not reveal any distinctive features of the claimed invention (the content of surfactants and soluble polymers in water-glycol solutions in the recommended proportions), which allows us to conclude that the proposed method meets the criterion of "inventive step".

The essence of the invention is to obtain a low-temperature liquid coolant with high efficiency protection against corrosion and erosion of structural materials. In addition, the proposed solution improves the heat transfer properties of the substance. To do this, in the solution containing sodium phosphate disubstituted and potato dextrin, instead of morpholine paranitrobenzoate (0.7-0.8), glycerin (8-10) and sodium oleic acid (0.11-0.13), polyacrylamide (0.05) is introduced -0.1), polyvinyl alcohol (0.05-0.1) and syntanol (0.05-0.1).

The presence of polymers in the coolant leads to a change in the rheological properties of the coolant, prevents the transfer of momentum across the flow, that is, laminates it and thereby reduces the hydraulic resistance of the cooling system, reduces the rate of growth and collapse of cavitation bubbles and the rate of scale formation.

In turn, the surfactant contributes to: reducing surface tension at the gas-liquid phase boundary, hydrophobizing surfaces as a result of oriented adsorption of molecules and creating a barrier between the metal and the medium, the occurrence of proppant pressure and separation of contaminant particles from surfaces, preventing the formation of scale, creating protective films on surfaces and reducing the intensity of erosion and corrosion processes, increasing the thickness of the laminar sublayer on a heat transfer ited, thereby reducing the coefficient of heat transfer from the wall to the fluid. At the same time, a decrease in heat losses contributes to an increase in indicator operation and a decrease in fuel consumption, and also provides faster warming up of the engine after its start.

With the joint introduction of all components due to their synergistic action, the goal is achieved - the effectiveness of protection against cavitation damage to the structural materials of the internal combustion engine and the influence on the heat transfer processes inside the internal combustion engine are increased. The increase in the coefficient of protection of steels and cast irons is 30-40%, for non-ferrous metals: 5-25%. Thus, the proposed composition of the coolant not only allows us to produce a product that exceeds the prototype in terms of its anti-corrosion and consumer properties, but also provides high anti-erosion protection and the ability to directionally affect the heat exchange processes in the internal combustion engine, and thereby increase the fuel efficiency of the internal combustion engine.

Characteristics of the components.

Ethylene glycol premium or first grade according to GOST 19710-83 is a colorless transparent liquid. Formula HOCH ₂ CH ₂ OH. It is used as an intermediate in the production of antifreezes.

Disubstituted sodium phosphate according to TU 113-25-110-90 - vitreous and white crystals. Formula NaHPO ₄ · 12H ₂ O. Used as an emulsifier, bleach.

Potato dextrin according to GOST 6034-74 - is used as a corrosion inhibitor.

Polyacrylamide (PAA) according to TU 6-01-1049-92. Formula [-CH ₂ CH (CONH ₂ ) -] _n , a solid, amorphous, white, or partially transparent, odorless substance. It is used as effective flocculants, dressing additives, flotation reagents, dispersants, thickeners, hydrodynamic drag reducing agents.

Polyvinyl alcohol (PVA) according to GOST 10779-78. Formula [-CH ₂ CH (OH) -] _n . Colorless solid. They are used for the production of fibers as protective removable coatings on parts, a binder in foundry molds, an emulsifier, and a thickener for aqueous solutions in the manufacture of adhesives. Low molecular weight polyvinyl alcohol, thoroughly purified from impurities, is used in pharmacology and medicine.

Surfactant (Syntanol DS-10) - a mixture of fractions of alcohols C10-C20 and ethylene oxide according to TU 6-14-577-88. It is a paste of white or white-yellow color. It is used in the manufacture of detergents.

The specified mixture is prepared as follows.

In a water-ethylene glycol solution, sodium phosphate disubstituted, potato dextrin, polyacrylamide, polyvinyl alcohol and syntanol are successively dissolved with stirring. To speed up the dissolution process, the temperature of the liquid is raised to 50-55 ° C.

To justify the quantitative composition of the components, samples of the claimed composition were prepared, are presented in table 1.

Samples and prototype according to US Pat. RU 2206591 (coolant brand "Tosol-AM") was tested in laboratory conditions. Studies of the anti-corrosion and anti-erosion properties of coolants were carried out in accordance with the requirements of GOST 28084-84. The research results are given in table.2. The influence of liquids on heat transfer processes in cooling systems and fuel efficiency was studied during laboratory and bench tests. The test results are shown in table.3.

As can be seen from the test results, the proposed liquid has the following advantages compared to the prototype:

more effective protection of the metals of which the equipment is made from corrosion and erosion (table 2),

higher heat transfer properties. So, the use of a liquid provides a reduction in heat loss through the cooling system, as evidenced by a more rapid warming up of the engine (Table 3),

a lower concentration of additives, and, therefore, a higher water component (table 1). This accordingly reduces the cost of the resulting product.

Conducted laboratory, bench and operational tests showed high performance qualities of the liquid, which allows us to conclude that industrial applications of the invention are possible, including in cooling systems for stationary and transport internal combustion engines, as well as in heat exchangers operating in both positive and and negative temperatures.

Table 1 No. Component Name Sample Number Prototype one 2 3 four 5 one Ethylene glycol 40 44.7 49.5 60 69 67 2 Disubstituted sodium phosphate 0.31 0.32 0.33 0.34 0.35 0.32 3 Potato dextrin 1,2 1.22 1.25 1.27 1.3 1.25 four Polyacrylamide (PAA) 0.05 0,067 0,075 0,087 0.1 - 5 Polyvinyl alcohol (LAN) 0.05 0,067 0,075 0,087 0.1 - 6 Surfactant (Syntanol DS-10) 0.05 0,067 0,075 0,087 0.1 - 7 Distilled water or steam condensate 58.35 53.6 48.7 39.13 29.15 21.61

table 2 Material GOST Tosol-A40M (prototype) The inventive liquid (sample 3) ΔG _k , g / (m ² · day) ΔG _k , g / (m ² · day) ΔG _p , g / (m ² · day) Steel St20 No more than 0.1000 0.0572 0.0418 Cast iron SCH24 No more than 0.1000 0.0511 0.0372 Al-9 alloy No more than 0.1000 0.0440 0.0415 Brass L63 No more than 0.1000 0.0600 0.0512 Copper M-1 No more than 0.1000 0.0579 0.0452 POS-40 solder No more than 0.2000 0.0901 0.0744

Table 3 Antifreeze A40M (prototype) The inventive liquid (sample 3) heat transfer coefficient Warm-up time, min heat transfer coefficient Warm-up time, min one hundred% 8.5 one hundred% 7.5

Claims (1)

Coolant for internal combustion engines based on an aqueous solution of ethylene glycol containing sodium phosphate disubstituted and potato dextrin, characterized in that it additionally contains polyacrylamide, polyvinyl alcohol and a surfactant - Syntanol DS-10 in the following ratio, wt.%:
ethylene glycol 40-69 disubstituted sodium phosphate 0.31-0.35 potato dextrin 1.2-1.3 polyacrylamide (PAA) 0.05-0.1 polyvinyl alcohol (LAN) 0.05-0.1 surfactant - Syntanol DS-10 0.05-0.1 distilled water or steam condensate rest