JPH11173146A - Cooling system for vehicular engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce energy loss and attain the power reduction of a water pump, etc., by decreasing turbulent flow frictional resistance of coolant in a circulation channel and the like. SOLUTION: A cooling system for vehicular engine is provided with a main circulation channel (main water channel 3) which circulates coolant at least between a main water jacket and a radiator 4 of an engine 1 and can be opened and closed by a thermostat 5, and an auxiliary circulation channel (first and second auxiliary channels 6 and 9) which circulates coolant at least between the main water jacket and a heater core 10 of the engine 1. In the cooling system, surfactant which can form a giant structure among plural bar micells is contained in the coolant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle engine cooling system that cools an engine with a coolant and uses the heat of the coolant to heat a passenger compartment.

[0002]

2. Description of the Related Art In a general vehicle engine cooling system, a main water jacket of the engine is connected to at least a radiator, a heater core, and a circulation path such as a hose, and a water pump provided integrally with the engine. The internal coolant is circulated. Therefore, the cold coolant cools the engine, and the coolant heated by the cooling of the engine is used for heating the vehicle compartment by the heater core. The heated coolant is cooled by the radiator.

In such an engine cooling system, it is common to use water as a coolant circulating in a circulation path. Further, in order to prevent freezing of the coolant in a cold region or the like, antifreeze is added to the coolant. In addition, ethylene glycol, glycerin, methyl alcohol, ethyl alcohol, and the like are used for the antifreeze.

[0004]

By the way, in a hose or the like as a circulation path, the flow of the coolant is considered to be a turbulent flow accompanied by irregular turbulent motion of the fluid particles. For this reason, in the engine cooling system, it is considered that energy is lost due to turbulent frictional resistance (pressure loss) due to turbulent motion of the fluid particles in the circulation path and the like. Also, if the turbulent frictional resistance in the circulation path or the like is large, there is a concern that the coolant may leak from a connection portion of a hose as the circulation path due to vibration or the like, and noise due to the vibration into the vehicle interior cannot be ignored. . Furthermore, if the flow of the coolant is turbulent in the circulation path, etc., the heat transfer coefficient increases due to turbulent diffusion, and the heat release from the circulation path, etc. increases, resulting in a large heat loss during transportation. As a result, there is a problem that the warming of the engine and the heating efficiency of the passenger compartment are reduced.

[0005] In particular, in the above-mentioned engine cooling system, when a heat generator is interposed between the heater core and the main water pump of the engine as an auxiliary heat source in order to increase the efficiency of warming up the engine and heating the passenger compartment, The pressure loss is further increased due to water flow resistance (pressure loss) due to fins and the like provided in the water jacket of the heat generator to improve the heat exchange rate. For this reason, when an auxiliary heat source having a water jacket is added to the engine cooling system, it is necessary to increase the size of the water pump in order to compensate for the pressure loss while ensuring an effective heat exchange rate in the auxiliary heat source. However, there is a problem that the effective space in the engine room is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and aims to reduce the power of a water pump by reducing the turbulent frictional resistance of a coolant in a circulation path or the like, and to suppress the vibration and the like to prevent the coolant from leaking and the like. A technical problem to be solved is to provide a vehicle engine cooling system that can prevent noise transmission into a room and that can avoid an increase in the size of a water pump even when an auxiliary heat source is added. Things.

[0007]

According to a first aspect of the present invention, there is provided a cooling system for a vehicle engine, wherein a coolant is circulated at least between a main water jacket of the engine and a radiator and opened and closed by a thermostat. In a cooling system for a vehicle engine having a circulation path and at least a sub-circulation path for circulating the coolant between the main water jacket and the heater core of the engine, the coolant has a huge structure between a plurality of rod-shaped micelles. Characterized by containing a surfactant capable of forming (2) cooling system for a vehicle engine according to claim 2, wherein, in the cooling system of the vehicle engine according to claim 1 wherein the surfactant is, n- tetradecyl trimethylammonium Sarishireito (C ₁₄ TASal), n- Hexadecyltrimethylammonium salicylate (C ₁₆
TASal), n-dodecyltrimethylammonium.
Salicylate (C ₁₂ TASal) and trimethylstearyl ammonium salicylate (C ₁₈ TASal). (3) In the cooling system for a vehicle engine according to the third aspect, in the cooling system for a vehicle engine according to the first or second aspect, the concentration of the surfactant in the coolant is determined by at least association of molecules of the surfactant. It is characterized in that the formed spherical micelles have a concentration higher than the critical concentration at which the micelles change into rod-like micelles or the above-mentioned giant structure. (4) The vehicle engine cooling system according to claim 4, wherein the Reynolds number in the flow field of the coolant is in the range of 8000 to 35000 in the vehicle engine cooling system according to claim 1, 2, or 3. In addition, the concentration of the surfactant is adjusted so that a phenomenon in which a macrostructure of the surfactant is formed or collapsed occurs. (5) The vehicle engine cooling system according to claim 5, wherein the surfactant concentration in the coolant is 50% by weight in the vehicle engine cooling system according to claim 4.
It is characterized by being in the range of 0 to 1000 ppm. (6) The cooling system for a vehicle engine according to the sixth aspect is the cooling system for a vehicle engine according to the first, second, third, fourth or fifth aspect, wherein the auxiliary circulation path includes a heater core and a main water jacket of the engine. And an auxiliary heat source is connected between the first heat source and the second heat source. (7) In the vehicle engine cooling system according to the seventh aspect, in the vehicle engine cooling system according to the sixth aspect, the auxiliary heat source may include a heating chamber inside and a sub-circulating coolant adjacent to the heating chamber. A housing forming a water jacket, a drive shaft rotatably supported by the housing via a bearing device, a rotor rotatably provided by the drive shaft in the heating chamber, and a wall surface of the heating chamber And a viscous fluid that is interposed in a liquid-tight gap between the rotor and the outer surface of the rotor and that generates heat by being sheared by the rotation of the rotor.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the cooling system for a vehicle engine according to the present invention, the coolant contains a surfactant capable of forming a huge structure, for example, a mesh structure (see FIG. 9C), between a plurality of rod-shaped micelles. ing. When a plurality of rod-shaped micelles of a surfactant form a giant structure in the coolant, the effect of reducing turbulent frictional resistance (hereinafter referred to as drag reduction effect).
As a result, the effect of suppressing the turbulence of the flow (turbulence suppression) is obtained. Therefore, by adding a surfactant capable of forming a giant rod structure to the coolant, energy loss due to turbulent frictional resistance (pressure loss) can be reduced, and the water pump can be downsized and the power of the pump can be reduced. A reduction effect can be obtained.

Further, if the turbulent frictional resistance is reduced, the vibration in the circulation path or the like can be suppressed, so that it is possible to effectively prevent the leakage of the coolant and the propagation of the noise into the vehicle interior. The surfactant capable of forming such a huge structure is formed by adding a base material of the surfactant and an electrolyte capable of forming the surfactant by reacting with the base material into a coolant. can do.

The base material of the above surfactant is represented by the following chemical formula 1.
Having the chemical structure shown in Formula n- tetradecyltrimethylammonium bromide (C ₁₄ TABr), n- tetradecyl trimethyl ammonium chloride (C ₁₄ TA
Cl), n-hexadecyl trimethyl ammonium bromide (C ₁₆ TABr), cetyltrimethylammonium chloride (C ₁₆ TACl), n- dodecyl trimethyl ammonium bromide (C ₁₂ TABr), trimethyl stearyl ammonium chloride (C ₁₈ T
AC1) can be preferably used.

[0011]

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As the electrolyte, sodium salicylate (NaSal, molecular weight = 160.10) having a chemical structure represented by the following chemical formula 2 can be suitably used. Examples of the electrolyte other than sodium salicylate include those having the chemical formula shown in the following chemical formula ₃ , and those having the chemical formulas of C ₃ F ₇ COONa and C ₇ H ₁₅ SO ₃ Na.

[0013]

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[0014]

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The above C ₁₄ TABr, the above C ₁₄ TACl, the above C ₁₆ TABr, the above C ₁₆ TACl, the above C ₁₂ TABr
And the chemical reaction between the above C ₁₈ TACl and the above sodium salicylate is shown below. In the _{C 14 TABr + NaSal → C 14} TASal + NaBr C 14 TACl + NaSal → C 14 TASal + NaCl C 16 TABr + NaSal → C 16 TASal + NaBr C 16 TACl + NaSal → C 16 TASal + NaCl C 12 TABr + NaSal → C 12 TASal + NaBr C 18 TACl + NaSal → C 18 TASal + NaCl Thus, the macrostructures surfactants which can form, i.e. n- tetradecyl trimethylammonium Sarishireito (C ₁₄ TASal), n- hexadecyl trimethyl ammonium Sarishireito (C ₁₆ TASal),
n- dodecyl trimethyl ammonium Sarishireito (C ₁₂ TASal) or trimethyl stearyl ammonium Sarishireito (C ₁₈ TASal) can be obtained.

It is preferable that the addition ratio of the surfactant to the base material and the electrolyte to the coolant be adjusted so as to be equal to each other. This is because, even if the other is added more than the other, the added amount is wasted.
Incidentally, a commercially available detergent, which is an anionic surfactant, cannot exert the above-described drag reduction effect.

Here, the formation of a giant structure by the surfactant changes the spherical micelles formed by the association of the surfactant molecules (ions) into rod-like micelles, and such rod-like micelles are present in the coolant. It is assumed that
If rod-shaped micelles are present in the coolant, a plurality of rod-shaped micelles will be aggregated to form a giant mesh structure, and the coolant flow conditions will be adjusted. Specifically, the Reynolds number of the flow field will be a value within a predetermined range. This (the degree of shear in the flow field) produces a turbulence suppression effect due to the elastic effect of the network structure.

Whether or not the spherical micelle formed by the association of the surfactant molecules changes into a rod-like micelle is determined as follows.
It is affected by the concentration of the surfactant added to the coolant and the coolant temperature. That is, when the concentration of the surfactant in the coolant is extremely low, the surfactant is molecularly dispersed (or ion-dispersed), but when the concentration of the surfactant exceeds the critical micelle concentration, several molecules (a few ions)
From one hundred and several hundreds of ions (one hundred and several tens of ions) rapidly associate to form stable micelles. The micelle of this surfactant is first formed as an entropically stable spherical micelle structure (see FIG. 9A). When the surfactant concentration is further increased, the micelle concentration also increases, and as a result, the distance between micelles gradually decreases. When the distance between micelles decreases, the electrostatic energy increases on the micelle surface, and when the excess energy becomes equal to the energy difference between the spherical micelles and rod-like micelles, the average micelle distance is large compared to the spherical micelles, and therefore the static electricity between micelles A rod-shaped micelle with low energy is formed (see FIG. 9B). The rod-shaped micelle has a circular cross-sectional shape having the extended hydrocarbon chain as a radius.
Here, the surfactant concentration when the micelle changes from a spherical shape to a rod shape is referred to as a critical concentration Ct. In order to change the spherical micelles into rod-shaped micelles, the concentration of the surfactant in the coolant must be at least higher than the critical concentration Ct.

Here, the critical concentration Ct increases with temperature. For example, if the coolant temperature rises,
Since the critical concentration Ct increases, the micelles cannot be changed from spherical to rod-like unless the surfactant concentration is higher than when the temperature of the coolant is low. And the temperature of the coolant used for the cooling system of the vehicle engine usually changes within a range of about -40 to 80 ° C. For this reason, it is necessary to adjust the concentration of the surfactant in the coolant to exceed the critical concentration Ct in at least a certain temperature range of the temperature range of the coolant that changes during the operation of the engine. Over the entire temperature range of the coolant,
The concentration of the surfactant in the coolant may be adjusted so as to always exceed the critical concentration Ct.

For example, if the temperature of the coolant is between -40 and 80
When the median temperature around 20 ° C. is around 20 ° C., n-tetradecyltrimethylammonium salicylate (C ₁₄ TA
If Sal) is used as the surfactant, the surfactant concentration in the coolant is preferably 250 ppm or more by weight (hereinafter the same) so as to exceed the critical concentration Ct.

The upper limit of the surfactant concentration in the coolant is preferably about 1000 to 1500 ppm so that normal turbulent heat transfer is performed in a heat exchanger (heater core, radiator). By adding the surfactant at the above concentration, the viscosity of the coolant does not increase significantly, and the flow resistance becomes extremely large due to the increase in the viscosity due to the addition of the surfactant. Absent.

As described above, when the rod-shaped micelles are formed and the coolant has a giant mesh structure in which a plurality of rod-shaped micelles are aggregated, as described above, the conditions for the flow of the coolant are adjusted. When the Reynolds number of the flow field falls within a predetermined range (the degree of shear in the flow field), the above-described drag reduction effect is exerted by the elastic effect of the network structure.

That is, when the flow of the coolant is a flow having a low shear rate gradient (Reynolds number is about 2300 or less), the coolant is equivalent to the Newtonian fluid. For this reason, when the flow field of the coolant is in a low shear state with a Reynolds number of about 2300 or less, the effect of the elastic effect of the huge structure (network structure) is small, so that the drag reduction effect by the surfactant cannot be obtained. Then, the flow rate of the coolant in the circulation path increases, and the flow of the coolant is in a predetermined turbulent state (for example, if n-tetradecyltrimethylammonium salicylate (500 ppm) as shown in FIG. 2 is used as a surfactant, Reynolds The number is 3000-11000
At moderate shear, the coolant has a greater effect of the elastic effect and exerts the drag reduction effect as described above.

However, the flow velocity of the coolant increases due to a decrease in the cross-sectional area in the circulation path, and the flow field becomes high shear, and the Reynolds number becomes a predetermined value (11000 to 14000).
Above) and exceeds the critical wall shear stress τ _WC , the above-mentioned drag reduction effect rapidly attenuates (hereinafter, the phenomenon where the drag reduction effect abruptly attenuates due to the increase in Reynolds number, or the Reynolds number The point at which the phenomenon in which the drag reduction effect is suddenly exhibited by the reduction occurs is referred to as a transition point.) This is because the Reynolds number is the critical wall shear stress τ
_{When the WC} is exceeded, the giant structure is destroyed, and the separated rod-like micelles begin to rotate in turbulent shear, whereby the drag reduction effect starts to attenuate. Note that the critical wall shear stress τ _WC refers to a wall shear stress when the drag reduction effect starts to attenuate.
However, since the individual rod-shaped micelles thus divided are not destroyed, the Reynolds number becomes critical shear stress τ.
_By returning to a value smaller than _{WC, the} giant structure is formed again, and the drag reduction effect is reproduced without hysteresis.

Therefore, in the circulation system having a large cross-sectional area in the cooling system for a vehicle engine, the above-described drag reduction effect is easily exerted because the flow is relatively low and the Reynolds number is small. In a radiator such as a radiator or a heater core having a small diameter, a relatively high shear flow and a large Reynolds number tend to make it difficult for the drag reduction effect to be exerted. If this is the case, it is considered desirable because a turbulent flow transmission effect as in the past is expected.

As described above, when the above-described drag reduction effect is obtained by forming a giant structure, a turbulence suppression effect is also exerted. When the turbulence of the coolant flow is suppressed in this manner, heat transfer due to turbulent diffusion can be suppressed. For this reason, in a circulation path or the like in which the cross-sectional area of the flow path is large and the above-described drag reduction effect tends to be easily exerted, the heat transfer coefficient can be reduced by the turbulence suppression effect to suppress the heat release. Therefore, heat loss in the circulation path or the like can be reduced, which is advantageous for improving warm-up of the engine and heating efficiency of the vehicle compartment. On the other hand, in a heat radiating portion such as a radiator or a heater core in which the cross-sectional area of the flow passage is small and the above-described drag reducing effect is hard to be exerted, it acts in the same manner as the conventional coolant (water) which does not exhibit the drag reducing effect. The heat transfer coefficient does not decrease due to the suppression effect. Therefore, the same heat exchange rate as that of the related art can be maintained in the radiator such as the radiator and the heater core.

Here, during the operation of the engine, the Reynolds number in the flow field of the coolant in the circulation path is 40.
The Reynolds number in a coolant flow field in a heat radiating section such as a radiator or a heater core is about 35,000 to 70,000. Therefore, in the circulation path, energy loss and vibration based on the turbulent frictional resistance can be suppressed by the drag reduction effect, and heat loss can be suppressed by the turbulence suppression effect. On the other hand, in the radiator such as the radiator and the heater core, the turbulence is reduced. In order to more reliably exert the effect of suppressing the flow suppression effect from being exhibited and maintaining the same heat exchange rate as that of the conventional coolant (water), the following aspects are preferably employed. .

That is, for example, at 20 ° C. during operation of the engine.
At the coolant temperature before and after, when the Reynolds number in the flow field of the coolant is in the range of 8000 to 35000, a phenomenon in which the macrostructure of the surfactant is formed or collapse occurs, that is, the Reynolds number of 8000 to 35000 It is preferable that the transition point exists within the range.

Such an embodiment can be achieved by appropriately adjusting the surfactant concentration in the coolant. That is, although it depends on the type of surfactant added to the coolant, the surfactant concentration in the coolant is 5
The above aspect can be achieved by setting the amount to about 00 to 1000 ppm. Note that the surfactant is unlikely to undergo mechanical deterioration due to shearing while the coolant circulates in a circulation path or the like. For this reason, the above-mentioned drag reduction effect and the like by the surfactant can be continuously maintained without periodically adding the surfactant to the coolant.

In a preferred embodiment of the vehicle engine cooling system according to the present invention, an auxiliary heat source is connected to a sub-circulation path between the heater core and the main water jacket of the engine. Since the coolant introduced into the auxiliary heat source is heated by the auxiliary heat source, the heating efficiency of the vehicle interior in the heater core can be improved, and the warming efficiency of the engine in the main water jacket of the engine can be improved. Further, since the turbulent frictional resistance in the coolant is reduced by the addition of the surfactant, it is possible to adopt a fin or the like having a better heat exchange rate as the auxiliary heat source while avoiding an increase in the size of the water pump. Become.

As the auxiliary heat source, a housing forming an exothermic chamber and a sub-water jacket adjacent to the exothermic chamber for circulating a coolant, and a drive rotatably supported by the housing via a bearing device are provided. A shaft, a rotor provided rotatably by the drive shaft in the heating chamber,
A heat generator may be provided having a viscous fluid that is interposed in a liquid-tight gap between the wall surface of the heat generating chamber and the outer surface of the rotor and that generates heat by being sheared by the rotation of the rotor.

[0032]

EXAMPLES Hereinafter, examples embodying the present invention will be described.
This will be described with reference to the drawings. In the vehicle engine cooling system of the present embodiment, as shown in FIG. 1, a main water jacket (not shown) is formed on a cylinder block or the like of the engine 1. This main water jacket is
A main water passage (transportation pipe) 3 as a main circulation passage in which the water pump 2 is disposed communicates with the radiator 4 so that the coolant can circulate with the radiator 4. A thermostat three-way valve 5 is provided in the main waterway 3 between the main water jacket of the engine 1 and the radiator 4. The thermostat three-way valve 5 is connected to a first sub-water channel (transport pipe) 6 which forms a part of a sub-circulation channel, and the first sub-water channel 6 is connected to the main water channel 3 on the downstream side of the radiator 4. The cooling fan 7 faces the radiator 4. The cooling fan 7 receives the operation control of the cooling control unit 8, and the cooling control unit 8 performs cooling based on temperature detection information obtained from a temperature sensor 14 provided in a second sub-channel (transport pipe) 9 described later. The operation of the fan 7 is controlled.

On the other hand, the main water jacket of the engine 1 is connected to a second sub-water passage 9 which constitutes a part of a sub-circulation passage, and the second sub-water passage 9 is provided with a viscous heater 10 as a heat generator as an auxiliary heat source. It is connected. Viscous heater 1
The heater core 11 is connected to the second sub-channel 9 on the downstream side of the first sub-channel 6, and the second sub-channel 9 on the downstream side of the heater core 11 is downstream of the first sub-channel 6 (the first sub-channel 6 and the water pump 2). ) Is connected to the main waterway 3). The heater core 11 faces the vehicle interior heating fan 12. The cabin heating fan 12 receives the operation control of the control unit 13, and the control unit 13 is obtained from the temperature sensor 14 provided in the second sub-water passage 9 located between the viscous heater 10 and the engine 1. The operation of the cabin fan 12 is controlled based on the temperature detection information.

Thus, between the connection point of the main water jacket of the engine 1 and the connection point of the three-way thermostat valve 5 in the main waterway 3 and between the connection point of the main water jacket of the engine 1 and the junction of the first sub waterway 6. The space constitutes a part of the main circuit and the rest of the sub circuit. Then, coolant as a circulating fluid is put into the main water jacket, the main water channel 3, the radiator 4, the first sub water channel 6, the second sub water channel 9, the water jacket WJ of the viscous heater 10, and the heater core 11, which will be described later. , This coolant is the main channel 3
As shown by arrows in FIG. 1, the directions of the flows in the first sub-channel 6 and the second sub-channel 9 can be circulated by the operation of the water pump 2.

Here, in the present embodiment, the above-mentioned coolant has the same moles of n-tetradecyltrimethylammonium bromide (C ₁₄ TABr) as a surfactant base material and sodium salicylate (NaSal) as an electrolyte. in an amount, and the concentration in the coolant serving surfactant formed by both n- tetradecyl trimethylammonium Sarishireito (C ₁₄ TASal) 500
What was adjusted to be ppm and added to tap water was used.

In the viscous heater 10, as shown in FIG. 1, a front housing 21, a rear plate 22, and a rear housing main body 23 are laminated between the rear plate 22 and the rear housing main body 23 via a gasket 24. In this state, it is fastened by a plurality of through bolts 25. Here, the rear plate 22 and the rear housing main body 23 constitute a rear housing 26. And
The recess formed in the rear end surface of the front housing 21 forms a heat generating chamber 27 together with the flat front end surface of the rear plate 22.

An auxiliary water jacket WJ is formed in the outer peripheral area between the rear end surface of the rear plate 22 and the inner surface of the rear housing body 23 as a heat radiating chamber adjacent to the heat generating chamber 27. In the outer region of the rear surface of the rear housing body 23, a water inlet port 28 for taking in coolant from the second sub-channel 9 and a water outlet port 29 for sending out coolant to the second sub-channel 9 are formed adjacent to each other.
The water port 29 communicates with the sub-water jacket WJ. Further, in an inner peripheral area between the rear end surface of the rear plate 22 and the inner surface of the rear housing main body 23, a storage communicating with the heat generating chamber 27 via a recovery hole 22 a and a supply hole 22 b penetrating through the rear plate 22. A chamber SR is formed.

A heating chamber 27 is provided in the front housing 21.
A shaft sealing device 30 and a bearing device 31 are provided adjacent to
The drive shaft 3 is connected via the shaft sealing device 30 and the bearing device 31.
2 is rotatably supported. A flat-plate-shaped rotor 33 rotatable in the heat generating chamber 27 is press-fitted into the rear end of the drive shaft 32, and a silicone oil as a viscous fluid is interposed in a gap between the wall surface of the heat generating chamber 27 and the outer surface of the rotor 33. ing.

An electromagnetic clutch MC is mounted on the boss 21a of the front housing 21. Here, in the electromagnetic clutch MC, a pulley 42 is rotatably supported by the boss 21 a via a bearing device 41, and an excitation coil 43 is provided to be located in the pulley 42. The hub 45 is fixed by screwing a bolt 44 to the drive shaft 32, and the hub 45 is connected to an armature 47 via an elastic member 46. Pulley 42
Is rotated by a belt 48 by an engine 1 of the vehicle.

The main channel 1, the first sub channel 6 and the second sub channel 9 are rubber hoses having a circular cross section (inner diameter: 10
mm) is used, and the radiator 4 and the heater core 1 are used.
A metal pipe having a circular cross section (inner diameter: 1.5
mm). In the cooling system for the engine 1 configured as described above, when the engine 1 is started, the coolant is still cold at the initial stage of the start, and the three-way thermostat valve 5 is connected to the radiator 4 in the main waterway 3.
Close the side opening. For this reason, the water pump 2 transfers the coolant in the main water jacket of the engine 1 to the second
Circulation is performed only in the sub waterway 9, the viscous heater 10, the heater core 11, a part of the main waterway 3, and the first sub waterway 6.

In the viscous heater 10, the driving shaft 3
2 is driven by the engine 1 via the electromagnetic clutch MC, the rotor 33 rotates in the heat generating chamber 27 and the silicone oil is sheared by a liquid-tight gap between the wall surface of the heat generating chamber 27 and the outer surface of the rotor 33. Fever. This heat is exchanged with the coolant in the sub water jacket WJ, and the heated coolant is led out to the heater core 11 through the second sub water passage 9 to be used for heating the vehicle interior. 9 and the main water channel 3, the air is led out to the main water jacket of the engine 1 and is used for warming up the engine 1.

When the coolant is warmed by the waste heat of the viscous heater 10 and the engine 1, the thermostat three-way valve 5 opens the opening on the radiator 4 side in the main water channel 3. Therefore, the water pump 2 circulates the coolant in the main water jacket of the engine 1 also to the main water passage 3 and the radiator 4. Therefore, the heated coolant is removed by the cooling fan 7 releasing the heat of the coolant in the radiator 4. Further, the coolant removed by the radiator 4 cools the engine 1.

As described above, the coolant used for warming the engine, heating the vehicle compartment and cooling the engine is supplied to the circulation pipe (main water path 3, first sub water path 6, and second sub water path 9) as a transport pipe. The turbulent air flows in the heat radiating portion of each heat exchange means (radiator 4, viscous heater 10, heater core 11, etc.), and energy loss due to turbulent frictional resistance becomes a problem.

In this regard, in this embodiment, a specific surfactant and an electrolyte are added at a specific concentration. For this reason,
During the operation of the engine, in a circulation path in which the Reynolds number in the flow field of the coolant is about 4000 to 8000, the turbulent frictional resistance can be reduced by the drag reduction effect of the surfactant to suppress the turbulent flow. Accordingly, the energy loss in the circulation path can be reduced, and the water pump 2 can be downsized and the power of the pump 2 can be reduced. If the turbulent frictional resistance is reduced, the vibration in the circulation path can be suppressed, so that it is possible to effectively prevent the leakage of the coolant and the propagation of the noise into the vehicle interior. Further, since the heat transfer coefficient of the coolant can be reduced by the turbulence suppressing effect, the heat loss due to the heat radiation from the circulation path can be suppressed, which is advantageous for improving the warm air of the engine 1 and the heating efficiency of the passenger compartment. Becomes

On the other hand, during the operation of the engine, in a radiator such as a radiator or a heater core having a Reynolds number of about 35,000 to 70,000 in the flow field of the coolant, the turbulence suppressing effect is suppressed from being exhibited, and the conventional coolant ( The same heat exchange rate as that of (water) can be maintained. Further, since the turbulent frictional resistance in the coolant is reduced by the addition of the above-mentioned surfactants, fins and the like having a better heat exchange rate are adopted for the viscous heater 10 while avoiding an increase in the size of the water pump 2. It becomes possible. For this reason, the heat exchange rate in the viscous heater 10 can be improved while effectively utilizing the mounting space in the engine room.

(Test Example 1) The coolant used in the above embodiment was passed through a brass tube having an inner diameter (d) of 16.2 mm with a smooth inner surface at a predetermined flow rate (v) and a length of 1620.
mm, the pressure loss (p ₁ −p ₂ ) due to friction in the pressure measurement section having a length (L) of 650 mm is measured in a region where the flow is sufficiently developed after completion of the approach section of mm. It measured using.

Here, if the loss head is h, the pipe friction coefficient is λ, the coolant density is ρ, and the gravitational acceleration is g,
According to the Darcy-Weissbach equation, there is a relationship of h = (p ₁ −p ₂ ) / ρg = λLv ² / 2gd. In addition, ₀ the wall shear stress τ, if the Reynolds number and Re, a relationship of τ ₀ = λρv ^2/8. If the kinematic viscosity of the coolant is ν, the Reynolds number (Re) is represented as follows.

[0048] Re = vd / ν Then, in the measurement of the pressure loss, the coolant in which the C ₁₄ TASal concentration in the coolant was prepared so as 1000 ppm, the above C ₁₄ TASal concentration 500
ppm of the above-mentioned C ₁₄ TA
For the coolant prepared to have a Sal concentration of 250 ppm and the coolant (tap water) to which C ₁₄ TABr and NaSal were not added, the Reynolds number (Re) and the pipe friction coefficient were changed by appropriately changing the flow rate (v). The relationship with (λ) was examined. The result is shown in FIG.

FIG. 2 (the same applies to FIGS. 3 to 8).
A line shown in the following) is a straight line represented by the following Hagen-Poiseuille equation, which is a theoretical equation of laminar flow of water. λ = 64 / Re The line B shown in FIG. 2 is an empirical equation for turbulent flow of water, and is a curve represented by the following formula of the resistance of Blasius shown in the following equation.

[0050] λ = 0.3164Re ^-1/4 Further, C line shown in FIG. 2 is a slightly corrected equation coefficients theoretical formula of water turbulence, wherein the Prandtl-Karman shown in equation (1) below Is a curve represented by

[0051]

(Equation 1)

The line D shown in FIG. 2 is a maximum drag reduction asymptote.
This is a curve obtained by Virk based on a number of experimental data relating to a decrease in resistance of a dilute polymer solution in a circular tube flow, and is a curve represented by the following equation (Virk P. et al.).
S. , AICHE J .; , 21-4 (1975), 62
5).

[0053]

(Equation 2)

As is apparent from FIG. 2, the coolant is C
_It can be seen that the addition of TABr and NaSal reduces the coefficient of friction of the pipe and exerts a drag reduction effect.
Further, the C ₁₄ TASal concentration in the coolant 500 to 1
3,000 ppm, 8000 to 35000
It can be seen that the above transition point exists within the range of Reynolds number. Further, in a circuit having a Reynolds number of 8000 or less, the C ₁₄ TASal concentration in the coolant is reduced to 50%.
A pipe friction coefficient of 0 ppm or 250 ppm can be greatly reduced as compared with 1000 ppm.

Therefore, C ₁₄ TASa in the coolant
The l concentration is preferably 500 to 1000 ppm, and most preferably 500 ppm. (Test Example 2) In the measurement of the pressure loss, the C ₁₄ T
With respect to the coolant having an ASal concentration of 500 ppm and the coolant (tap water) to which C ₁₄ TABr and NaSal were not added, the Reynolds number (Re) was changed by appropriately changing the flow rate (v) while changing the coolant temperature. The effect of coolant temperature on the relationship with the pipe friction coefficient (λ) was investigated. The result is shown in FIG.

As is clear from FIG. 3, when the coolant temperature increases, the transition point shifts to the side where the Reynolds number is large accordingly. If the coolant temperature is in the range of 15.0 to 31.1 ° C., 800
It can be seen that the transition point always exists within the range of Reynolds number of 0 to 35000. As described above, the range of the coolant temperature that changes during operation of the engine is −40.
８０80 ° C., and around 20 ° C. of the median value, 8
It can be seen that the above transition point exists within the range of Reynolds number of 000 to 35000.

Further, from the results of FIG.
₁₄The upper limit of TASal concentration should be around 1500 ppm
For example, the above transition within the Reynolds number of 35,000 or less
A point is expected to exist. (Test Example 3) In the measurement of the pressure loss, a surfactant was used.
N-tetradecyltrimethylammonium as base material for
・ Chloride (C₁₄TAC)
C₁₄Courant with TASal concentration of 1000ppm
G, above C₁₄Cool with TASal concentration of 500 ppm
Runt, C above₁₄The TASal concentration was 250 ppm
Coolant, C above₁₄TASal was 125 ppm
Coolant and above C ₁₄Add TACl and NaSal
Flow rate of coolant (tap water) not added
By appropriately changing (v), the Reynolds number (R
The relationship between e) and the pipe friction coefficient (λ) was examined. The result
As shown in FIG.

As is apparent from FIG. 4, the coolant is C
_It can be seen that the addition of ₁₄ TACl and NaSal reduces the coefficient of friction of the tube and exerts a drag reducing effect, and the drag reducing effect is similar to that of the above-mentioned C ₁₄ TABr. Further, the C ₁₄ TASal concentration in the coolant 500 to
By setting the content to 00 ppm, it can be seen that the above transition point exists within the range of Reynolds number of 8000 to 35000. Further, in a circuit having a Reynolds number of 8000 or less, the C ₁₄ TASal concentration
1000 ppm when 00 ppm or 250 ppm
The pipe friction coefficient can be greatly reduced as compared with the above.

Therefore, C in the coolant₁₄TASa
l concentration is C in Test Example 1.₁₄Like TABr, 500-
Preferably 1000 ppm, and 500 ppm
It is best to do. (Test Example 4) In the measurement of the pressure loss, a surfactant was used.
N-hexadecyltrimethylammonium as base material
・ Bromide (C₁₆TABr) in the coolant
C₁₆A coolant with a TASal concentration of 500 ppm,
The above C₁₆Courant with TASal concentration of 250ppm
G, above C₁₆Cool with TASal concentration of 125 ppm
Runt, C above₁₆A TASal concentration of 60 ppm
And the above C ₁₆Add TABr and NaSal
Flow rate (v) for coolant (tap water) not used
Is appropriately changed, so that the Reynolds number (Re) and
The relationship with the pipe friction coefficient (λ) was examined. Fig. 5 shows the results.
Show.

As is apparent from FIG. 5, the coolant has C
_It can be seen that the addition of 16TABr and NaSal reduces the coefficient of friction of the pipe and exerts a drag reduction effect.
In addition, the C ₁₆ TASal concentration in the coolant was set to 500 pp.
By setting m or more, it is understood that the transition point exists within the range of 8000 to 35000 Reynolds number.

From the results shown in FIG. 5, it is clear that C in the coolant
If the upper limit of the ₁₆ TASal concentration is about 1500 ppm, it is expected that the above transition point exists within the range of Reynolds number of 35,000 or less. Therefore, the concentration of C ₁₆ TASal in the coolant is 500 to 1500 ppm.
It is preferable that

In C ₁₆ TASal, the above transition point appears even at a low concentration of 250 ppm, but the Reynolds number is 8
The effect of decreasing the drag in the circulation path of not more than 000 is slightly smaller than that of C ₁₄ TABr of Test Example 1 or C ₁₄ TACl of Test Example 3. (Test Example 5) in the measurement of the pressure loss, using cetyl trimethyl ammonium chloride (C ₁₆ TaCl) as Motozai surfactant, C ₁₆ in the coolant TAS
coolant with an al concentration of 500 ppm, the above C ₁₆ T
Coolant with an ASal concentration of 250 ppm, C
_With respect to the coolant having a ₁₆ TASal concentration of 125 ppm and the coolant (tap water) to which the C ₁₆ TACl and NaSal were not added, the Reynolds number (Re) and the pipe friction coefficient (λ) were changed by appropriately changing the flow rate (v). And examined the relationship. FIG. 6 shows the result.

As is clear from FIG. 6, the coolant is C
_It can be seen that the addition of ₁₆ TACl and NaSal reduces the friction coefficient of the pipe and exerts a drag reduction effect.
In addition, the C ₁₆ TASal concentration in the coolant was set to 500 pp.
By setting m or more, it is understood that the transition point exists within the range of 8000 to 35000 Reynolds number.

It should be noted that, from the results of FIG.
If the upper limit of the ₁₆ TASal concentration is about 1500 ppm, it is expected that the above transition point exists within the range of Reynolds number of 35,000 or less. Therefore, the concentration of C ₁₆ TASal in the coolant is 500 to 1500 ppm.
It is preferable that

In C ₁₆ TASal, the above transition point appears even at a low concentration of 250 ppm, but the Reynolds number is 8
The effect of decreasing the drag in the circulation path of not more than 000 is slightly smaller than that of C ₁₄ TABr of Test Example 1 or C ₁₄ TACl of Test Example 3. In the measurement of (Test Example 6) the pressure loss, using as Motozai surfactant n- dodecyl trimethyl ammonium bromide (C ₁₂ TABr), C ₁₂ in the coolant
Coolant was TASal concentration 1000 ppm, for the C ₁₂ TASal concentration without the addition of coolant and the C ₁₂ TaBr and NaSal was 500ppm coolant (tap water), by appropriately changing the flow velocity (v), the Reynolds number The relationship between (Re) and the pipe friction coefficient (λ) was examined. FIG. 7 shows the result.

As is apparent from FIG. 7, the coolant is C
_It can be seen that the addition of 1000 ppm or more of TABr and NaSal reduces the coefficient of friction of the pipe and exerts a drag reduction effect. In addition, C ₁₂ TASa in the coolant
If the l concentration is about 1000 ppm,
It can be seen that the transition point exists within the range of Reynolds number of 000.

Unless the concentration of C ₁₂ TASal is set to a high concentration of 1000 ppm or more, the effect of decreasing the drag is not exhibited and the manner of transition is gradual. Therefore, the C ₁₂ TASal concentration in the coolant is preferably set to about 1000 ppm. In addition, comparing the results of Test Examples 1, 3, 4, 5, and 6, the drag reduction effect was large in the circulation path having a Reynolds number of 8000 or less, and 8
C ₁₄ T used in Test Example 1 from the viewpoint that the transition point exists within the range of Reynolds number of 000 to 35000.
It can be seen that it is optimal to add ABr or C ₁₄ TACl used in Test Example 3 so that the C ₁₄ TASal concentration in the coolant becomes 500 ppm.

(Test Example 7) In the measurement of the pressure loss, as the surfactant, a commercially available anionic surfactant, specifically, a household detergent (trade name “Hi-To”) was used.
p ", manufactured by Lion Corporation, composition: 42% polyoxyethylene fatty acid ester + alkyl ether esral sodium sulfate + fatty acid sodium), and a coolant in which 4000 ppm of this household detergent is added by weight%; Coolant added with 2000ppm in water and coolant without the above household detergent (tap water)
For, the relationship between the Reynolds number (Re) and the pipe friction coefficient (λ) was examined by appropriately changing the flow velocity (v). FIG. 8 shows the result.

As is clear from FIG. 8, it can be seen that the household detergent does not exhibit the drag reduction effect.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle engine cooling system according to an embodiment.

FIG. 2 is a graph showing how the relationship between the pipe friction coefficient and the Reynolds number changes according to the concentration of C ₁₄ TASal in the coolant.

FIG. 3 is a diagram showing how a relationship between a pipe friction coefficient and a Reynolds number changes depending on a coolant temperature.

FIG. 4 is a diagram showing how the relationship between the pipe friction coefficient and the Reynolds number changes according to the concentration of C ₁₄ TASal in the coolant.

FIG. 5 is a graph showing how the relationship between the pipe friction coefficient and the Reynolds number changes depending on the C ₁₆ TASal concentration in the coolant.

FIG. 6 is a graph showing how the relationship between the pipe friction coefficient and the Reynolds number changes depending on the C ₁₆ TASal concentration in the coolant.

FIG. 7 is a graph showing how the relationship between the pipe friction coefficient and the Reynolds number changes depending on the C ₁₂ TASal concentration in the coolant.

FIG. 8 is a diagram showing how the relationship between the pipe friction coefficient and the Reynolds number changes depending on the concentration of the household detergent in the coolant.

FIG. 9 is a diagram schematically illustrating micelles formed by association of surfactant ions (molecules), (a) is a schematic diagram of a spherical micelle, (b) is a schematic diagram of a rod-shaped micelle, (c) is a schematic diagram of a network structure as a giant structure formed by collecting rod-shaped micelles.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Water pump 3, 6, 9 ... Circulation path (3 ... Main waterway as main circulation path, 6)
1st sub-waterway as a sub-circulation path, 9 2nd sub-waterway as a sub-circulation path) 4 ... radiator 5 ... thermostat three-way valve 10 ... auxiliary heat source (heat generator (viscus heater)) 11 ... heater cores 21 and 22 , 23 ... housing (21 ... front housing, 22 ... rear plate, 23 ... rear housing main body) 27 ... heating chamber WJ ... sub water jacket 30 ... shaft sealing device 31 ... bearing device 32 ... drive shaft 33 ... rotor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Takenaka 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Motoyuki Ito 2-10 Mitake, Togo-cho, Aichi-gun, Aichi Prefecture −15

Claims (7)

[Claims] A coolant is circulated between at least a main water jacket of the engine and a radiator, and the coolant is provided at least between the main water jacket and the heater core of the engine which can be opened and closed by a thermostat. A cooling system for a vehicle engine having a sub-circulation path for circulating water, wherein the coolant contains a surfactant capable of forming a giant structure between a plurality of rod-shaped micelles. Cooling system. 2. A surfactant, n- tetradecyl trimethylammonium Sarishireito (C ₁₄ TASal), n
- hexadecyl trimethyl ammonium Sarishireito (C ₁₆ TASal), n- dodecyl trimethylammonium Sarishireito (C ₁₂ TASal), trimethyl stearyl ammonium Sarishireito (C ₁₈ TASA
1) The cooling system for a vehicle engine according to claim 1, wherein the cooling system is one selected from the group consisting of: 3. The surfactant concentration in the coolant is at least a critical concentration at which spherical micelles formed by association of the surfactant molecules change into rod-like micelles or the above-mentioned macrostructure. The cooling system for a vehicle engine according to claim 1 or 2, wherein 4. When the Reynolds number in the flow field of the coolant is in the range of 8000 to 35000, the concentration of the surfactant is adjusted so that a large structure of the surfactant may be formed or collapsed. The cooling system for a vehicle engine according to claim 1, wherein the cooling system is adjusted. 5. The method according to claim 5, wherein the concentration of the surfactant in the coolant is% by weight.
5. The cooling system for a vehicle engine according to claim 4, wherein the concentration is 500 to 1000 ppm. 6. The vehicle engine according to claim 1, wherein an auxiliary heat source is connected to the auxiliary circulation path between the heater core and a main water jacket of the engine. Cooling system. 7. An auxiliary heat source includes a housing that forms a heating chamber and a sub-water jacket that circulates a coolant adjacent to the heating chamber, and a drive that is rotatably supported by the housing via a bearing device. A shaft, a rotor rotatably provided by the drive shaft in the heating chamber, and a liquid-tight gap between a wall surface of the heating chamber and an outer surface of the rotor, which is sheared by the rotation of the rotor. The cooling system for a vehicle engine according to claim 6, wherein the heat generator includes a viscous fluid that generates heat.