JP2011105184A - Cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device using a refrigerant in which a capsule enclosing a latent heat storage material is dispersed, which circulates a refrigerant with a transferrable amount of heat grasped. <P>SOLUTION: The cooling device 1 includes: a refrigerant 10 in which a microcapsule 11 enclosing the latent heat storage material is dispersed; a refrigerant passage which is formed by connecting a water jacket 4 formed in an engine body 2 with a radiator 3 so that the refrigerant 10 may circulate; a temperature sensor 9 disposed at the downstream side of the water jacket 4, and measuring temperature of the refrigerant 10; a water pump 7 disposed in the water jacket 4, and pressure-feeding the refrigerant 10 of which an amount of pressure feeding is variable; and an ECU 8. ECU 8 detects the transferrable amount of heat of the refrigerant 10 by decreasing the amount of pressure feeding of the water pump 7 prior to controlling an amount of circulation of the refrigerant 10 in the refrigerant passage. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a cooling device using a refrigerant in which microcapsules filled with a latent heat storage material are dispersed.

  A cooling device for cooling an engine or the like and circulating a refrigerant mixed with a latent heat storage material is known. In the internal combustion engine device disclosed in Patent Document 1, a medium containing capsule particles covering a latent heat storage material circulates through a liquid flow path and a radiator in the internal combustion engine body.

  In the cooling device disclosed in Patent Document 2, the latent heat storage material enclosed in the resin capsule is mixed in the cooling water and circulated between the engine and the radiator, and the refrigerant is circulated based on the melting rate of the latent heat storage material. The flow rate is controlled.

  In such a cooling system in which a latent heat storage material is enclosed in a capsule and dispersed in a cooling path, warm-up is promoted during cold start by selecting a latent heat storage material having a specific heat smaller than that of cooling water. Furthermore, the latent heat storage material changes from the solid phase to the liquid phase in the temperature range of the object to be cooled (heat generation part), and absorbs from the heat generation part by changing from the liquid phase to the solid phase in the temperature range during heat dissipation. The amount of heat released to the outside (the amount of heat that can be transported) is greatly increased, and the cooling capacity of the cooling system is improved.

JP 2003-129844 A JP 2007-21657 A

  However, when the latent heat storage material undergoes a phase change from the liquid phase to the solid phase, no temperature change is observed, and thus the amount of heat absorbed by the latent heat storage material from the heat generating portion cannot be detected based on the temperature change of the refrigerant. That is, the amount of heat that can be transported by the refrigerant when the latent heat storage material undergoes a phase change from the liquid phase to the solid phase cannot be grasped. Therefore, in a cooling device using a refrigerant in which a capsule enclosing a latent heat storage material is dispersed, the refrigerant may be circulated without knowing the amount of heat that can be transported by the refrigerant. For this reason, the merit using a latent heat storage material may not be fully utilized.

  Accordingly, an object of the present invention is to provide a cooling device using a refrigerant in which a capsule enclosing a latent heat storage material is dispersed, and circulating the refrigerant whose amount of heat that can be transported is circulated.

  The cooling device of the present invention that solves such a problem includes a refrigerant in which microcapsules encapsulating a heat storage material are dispersed, a refrigerant passage formed by connecting a heat generating part and a heat radiating part so that the refrigerant circulates, and A refrigerant temperature measuring means that is arranged downstream of the heat generating part and measures the temperature of the refrigerant; a pressure feeding means that is arranged on the refrigerant passage and that varies a pumping amount of the refrigerant; and the refrigerant in the refrigerant passage And detecting means for detecting the amount of heat that can be transported by the refrigerant by reducing the pumping amount of the pumping means before controlling the circulation amount of the refrigerant.

  With such a configuration, the amount of heat that can be transported by the refrigerant can be detected. Since the amount of refrigerant pumped by the pumping means decreases, the movement of the refrigerant slows, so the amount of heat absorbed by the refrigerant in the heat generating portion increases. As the amount of heat absorbed by the refrigerant increases, the amount of heat absorbed by the heat storage material also increases, and the phase change of the heat storage agent from the solid phase to the liquid phase is completed. While the phase change is being performed, the temperature change of the refrigerant is not observed, but when the phase change is completed, an increase in the temperature of the refrigerant can be detected. Based on the temperature rise of the refrigerant, the amount of heat that can be transported by the refrigerant can be detected, and the amount of refrigerant pumped by the pumping means can be determined.

  In such a cooling device, the detecting means estimates the rising temperature of the refrigerant in advance before changing the pumping amount of the pumping means, the rising temperature of the refrigerant to be measured after changing the pumping amount by the pumping means, and the preliminarily estimated refrigerant The amount of heat that can be transported by the refrigerant can be detected by comparing the rising temperature of the refrigerant.

  Thereby, the amount of pumping by a pumping means can be determined. For example, when the measured rising temperature of the refrigerant coincides with the pre-estimated rising temperature of the refrigerant, it is possible to adopt the pumping amount in that state, assuming that the target heat of transportation is obtained. On the other hand, when the measured rising temperature of the refrigerant is different from the estimated rising temperature of the refrigerant, the predicted heat transport capability of the refrigerant can be corrected.

  In such a cooling apparatus, the detection means includes a heat generation estimation means for estimating a heat flux generated from the heat generating portion, a heat release estimation means for estimating a heat flux released in the heat dissipation portion, and the heat generation. Thermal storage material state estimation means for estimating the latent heat and solid phase ratio of the thermal storage material enclosed in the microcapsule from the generated heat flux estimated by the estimation means and the released heat flux estimated by the emitted heat estimation means And before the change of the pumping amount of the pumping means, the rising temperature of the refrigerant is estimated from the state of the heat storage material estimated by the heat storage material state estimation means, and the actual refrigerant after the pumping amount change by the pumping means The amount of heat that can be transported by the refrigerant can be detected by comparing the rising temperature of the refrigerant.

  With such a configuration, the state of the heat storage material can be estimated from the heat flux, the rising temperature of the refrigerant can be estimated from the state of the heat storage material, and the pumping amount by the pumping means can be determined.

  In such a cooling device, the detection means may be configured to perform fail-safe control when the difference between the estimated rising temperature and the actually measured rising temperature exceeds a threshold value. For example, when the difference between the actually measured temperature and the estimated temperature exceeds a threshold value, control is performed to reduce the amount of heat generated in the heat generating portion, and the heat generating portion can be protected from high heat. On the other hand, if the difference between the measured temperature and the estimated temperature exceeds the threshold, deterioration of the microcapsules, tampering, cooling water addition, etc. are assumed. Can be encouraged.

  In such a cooling device, it is possible to adopt a configuration in which the heat generating part is an engine body, the heat radiating part is a radiator, and the pressure feeding means is a water pump. According to such a configuration, the cooling device of the present invention can be used as an engine cooling device.

  In such a cooling device, the generated heat estimation means can estimate the heat flux generated from the engine body based on the engine speed, the fuel injection amount, or the supply air amount. Further, the released heat estimation means can estimate the heat flux emitted from the radiator based on the water pump rotation speed, the outside air temperature, or the cooling water temperature.

  The cooling device of the present invention can grasp the amount of heat that can be transported by the refrigerant, and can supply an amount of the refrigerant that is suitable for the amount of heat to be absorbed from the heat generating portion.

It is explanatory drawing which showed the cooling device of the Example. It is explanatory drawing of the flow which showed the optimization control of the refrigerant | coolant pumping amount of the water pump of Example 1. FIG. It is a map used for prediction of the temperature change by the stop of a water pump. It is explanatory drawing which showed the time response about the measured value of the temperature sensor at the time of switching ON / OFF of driving | operation of a water pump during the driving | operation of an engine. It is explanatory drawing which compared the present Example and the prior art about the refrigerant | coolant temperature during engine operation. It is explanatory drawing which showed the relationship between the heat amount which can be transported, and the temperature difference of the entrance / exit of a water jacket. It is explanatory drawing of the flow which showed optimization control of the refrigerant | coolant pumping amount of the water pump of Example 2. FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a cooling device 1 of this embodiment. The cooling device 1 includes an engine main body 2 corresponding to a heat generating portion and a radiator 3 corresponding to a heat radiating portion. Further, a water jacket 4 is formed in the engine body 2. The water jacket 4 and the radiator 3 are connected by a first passage 5 and a second passage 6, and the radiator 3, the water jacket 4, the first passage 5, and the second passage 6 form a refrigerant passage. A refrigerant 10 is sealed in the refrigerant passage. Further, a water pump 7 corresponding to the pressure feeding means of the present invention is arranged in the water jacket 4. By operating the water pump 7, the refrigerant 10 passes through the water jacket 4, the first passage 5, the radiator 3, and the second passage 6 in this order and circulates in the refrigerant passage. The water pump 7 is electrically connected to an ECU (Electronic Control Unit) 8 and can change the pumping amount in accordance with a command signal from the ECU 8. Further, a temperature sensor 9 that measures the temperature of the refrigerant is disposed in the first passage 5. The temperature sensor 9 is electrically connected to the ECU 8.

  The ECU 8 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a known type digital computer in which an input / output port is connected by a bidirectional bus, and grasps the engine operating state. Therefore, the engine is controlled by exchanging signals with various sensors and actuators provided for the purpose. Further, the ECU 8 corresponds to the detection means of the present invention, and detects the amount of heat that can be transported by the refrigerant 10 by changing the amount of the refrigerant 10 pumped by the water pump 7 before controlling the circulation amount of the refrigerant 10 in the refrigerant passage. .

  The refrigerant 10 is engine cooling water in which the microcapsules 11 are dispersed. The microcapsule 11 is a capsule particle having a particle diameter of 1 to 100 μm, and is formed of a melanin resin that does not dissolve in a temperature range that the refrigerant 10 can take. The microcapsule 11 is sealed with a latent heat storage material. The latent heat storage material employs a substance that causes a phase change between a solid phase and a liquid phase in a temperature range when the engine body 2 is warmed up. Moreover, it is desirable that the latent heat storage material has a specific heat lower than that of water below the temperature range when the engine body 2 is warmed up. As such a latent heat storage material, for example, stearic acid, n-octacosane (straight chain) or the like can be selected. For example, when stearic acid is used as the latent heat storage material, the amount of heat absorbed while 1 g of water rises by 1 ° C. is 4.2 J, whereas 1 g of stearic acid undergoes a phase change from solid to liquid. The amount of heat absorbed is 203J. That is, stearic acid can absorb 50 times the amount of heat of the same mass of water when changing from a solid phase to a liquid phase. Moreover, LLC (Long Life Coolant) generally used as a coolant for engines can be used as the cooling water.

  Next, optimization control of the refrigerant pumping amount of the water pump 7 will be described. FIG. 2 is an explanatory diagram of a flow showing the optimization control of the coolant pumping amount of the water pump 7. When the ECU 8 controls the circulation amount of the refrigerant 10 in the refrigerant passage, in other words, when determining the pumping amount of the water pump 7, the ECU 8 executes the control. Hereinafter, description will be made according to the flow of FIG.

  In step S11, the ECU 8 estimates the generated heat flux generated from the engine body 2. The generated heat flux from the engine body 2 is estimated with reference to a generated heat map prepared in advance. Here, the generated heat map is created so as to estimate the generated heat flux from the engine body 2 based on the engine speed. The generated heat map is created so as to estimate the generated heat flux from the engine body 2 based on the specifications that can determine the operating state of the engine, such as the fuel injection amount or the supply air amount, instead of the engine speed. May be.

  When the ECU 8 finishes the process of step S11, the process proceeds to step S12. In step S12, the ECU 8 assumes the concentration of the microcapsules 11 in the refrigerant 10.

  When the ECU 8 finishes the process of step S12, the process proceeds to step S13. In step S13, the ECU 8 estimates the released heat flux released in the radiator 3. The discharge heat flux in the radiator 3 is estimated with reference to a discharge heat map prepared in advance. Here, the heat release map is created so as to estimate the heat release heat flux in the radiator 3 based on the rotational speed of the water pump 7. Note that the heat release map is based on specifications that allow the heat exchange amount between the refrigerant and air in the radiator 3 such as the outside air temperature or the cooling water temperature to be estimated instead of the rotation speed of the water pump 7. You may make so that a heat flux may be estimated.

  When the ECU 8 finishes the process of step S13, the process proceeds to step S14. In step S14, the ECU 8 estimates the solid phase ratio of the latent heat storage material enclosed in the microcapsules 11 in the refrigerant 10. Here, the solid phase ratio of the latent heat storage material will be described. The solid phase ratio is a value indicating the ratio of the solid phase latent heat storage material in the latent heat storage agent sealed in all the microcapsules 11 in the refrigerant 10. For example, in the case where only the microcapsules 11 in which the latent heat storage material is in the liquid phase exist in the refrigerant 10, the solid phase ratio is 0%. On the other hand, when only the microcapsule 11 in which the latent heat storage material is in a solid phase exists in the refrigerant 10, the solid phase ratio is 100%.

The specific process of step S14 is as follows. The ECU 8 estimates the amount of latent heat absorbed by the latent heat storage material from the generated heat flux from the engine main body 2 estimated in step S11 and the released heat flux in the radiator 3 estimated in step S13. That is, the amount of heat received by the refrigerant is estimated from the generated heat flux and the emitted heat flux, and the latent heat amount Q ₁ absorbed by the latent heat storage material is estimated by referring to this and the temperature of the refrigerant measured from the temperature sensor 9. Subsequently, ECU 8 estimates the solid phase ratio of the latent heat storage material from the latent heat quantity Q ₁ of latent heat storage material is absorbed. Since the latent heat storage material is considered to have changed from the solid phase to the liquid phase by the amount of heat absorbed, the amount of latent heat absorbed from the heat amount Q ₀ required to change all the latent heat storage materials from the solid phase to the liquid phase. min obtained by subtracting the Q ₁ is still a solid phase state latent heat storage material is equivalent to the amount of heat Q ₂ required for a phase change to the liquid phase. That is, the amount of heat Q ₂ required for the solid phase state latent heat storage material is a phase change to a liquid phase, much against heat Q ₀ for changing all the latent heat storage material from the solid phase into the liquid phase Is calculated. The value Q ₂ / Q ₀ obtained here is the solid phase ratio of the latent heat storage material.

When the ECU 8 finishes the process of step S14, the process proceeds to step S15. In step S15, the ECU 8 predicts a change in the temperature of the refrigerant 10 when the pumping amount of the water pump 7 is changed. Here, the temperature change is predicted using a map created in advance. The map used for predicting the temperature change is created by acquiring the temperature change when the water pump 7 is stopped for a certain period of time and then operating for each heat flux obtained from the engine body 2. This map is created based on data acquired by operating the engine under the same conditions as in actual driving. FIG. 3 is an explanatory diagram showing an example of such a map. The solid line in the map of FIG. 3 shows the case where the latent heat storage material in the microcapsule 11 acts as expected 100%, and the broken line shows the case where the latent heat storage material in the microcapsule 11 only works 50%. The ECU 8 divides the sensor value based on these values, so that the ratio between these values, for example, the case where the latent heat storage material in the microcapsule 11 functions 60%, 75%, 90%, etc. Can be estimated. And ECU8 acquires the value of the peak in a curve as an estimated value of a temperature rise with reference to the value of the solid phase ratio of the latent heat storage material acquired at Step S14.
The calculation mechanism of the temperature rise amount ΔT is as shown in the following formula (1). However, since it is difficult to acquire the refrigerant amount M, in this embodiment, an estimated value of the temperature rise is calculated using the map.
ΔT = (Q ₁ −Q ₂ ) / M / C (1)
Q ₁ : Amount of heat input to the refrigerant while the water pump is stopped Q ₂ : Amount of heat that can be absorbed in the phase change of the refrigerant
C: Specific heat of fluid (when there is no phase change)
M: Amount of refrigerant (in the heat generation part)

  When the ECU 8 finishes the process of step S15, the process proceeds to step S16. In step S16, the ECU 8 temporarily stops the water pump 7. When the ECU 8 finishes the process of step S16, the process proceeds to step S17. In step S17, the ECU 8 resumes the operation of the water pump 7. When the ECU 8 finishes the process of step S17, the process proceeds to step S18. In step S18, the ECU 8 detects a temperature change of the temperature sensor 9.

  Here, the processing from step S16 to step S18 will be described. FIG. 4 is an explanatory diagram showing a time response for the measured value of the temperature sensor 9 when the operation of the water pump 7 is switched ON / OFF during the operation of the engine. When the water pump 7 is stopped, the circulation of the refrigerant 10 is delayed. As a result, the refrigerant 10 remaining in the water jacket 4 receives a greater amount of heat from the engine body 2 than when the refrigerant 10 circulates in the refrigerant passage. In this state, the heat received by the refrigerant 10 remaining in the water jacket 4 from the engine body 2 exceeds the amount of heat received by the phase change of the latent heat storage material from the solid phase to the liquid phase, and all of the latent heat storage material of the microcapsule 11 is liquid. Change to phase. In this state, the refrigerant 10 cannot recover the heat received from the engine body 2 as latent heat, but recovers it as sensible heat. That is, the temperature of the refrigerant 10 increases. In other words, the ECU 8 stops the water pump 7 to give the refrigerant 10 an amount of heat exceeding the amount of heat received (the amount of heat that can be transported) at which the solid-phase ratio of the latent heat storage agent becomes zero, and the engine 8 as sensible heat. The heat from the main body 2 is absorbed. When the operation of the water pump 7 is resumed from this state, the refrigerant 10 whose temperature has risen flows, and the temperature sensor 9 detects an increase in the temperature of the refrigerant.

  That is, the refrigerant whose temperature has risen due to the stop of the operation of the water pump 7 in step S16 flows through the refrigerant passage by the resumption of the operation of the water pump 7 in step S17, and the temperature of the refrigerant is detected by the temperature sensor 9 in step S18. .

  When the ECU 8 finishes the process of step S18, the process proceeds to step S19. In step S19, the ECU 8 compares the temperature change predicted in step S15 with the temperature change of the temperature sensor 9 detected and acquired in step S18, and determines whether or not they match. Here, it can be recognized that the temperature change predicted in step S15 and the actually measured temperature change in step S18 coincide with each other to some extent. For example, a difference of 5% may be regarded as a match. When the ECU 8 determines that the predicted temperature change matches the temperature change detected by the temperature sensor 9, the ECU 8 detects the amount of heat given to the refrigerant 10 by stopping the water pump 7 as the transportable heat amount of the refrigerant 10. To do. If the ECU 8 determines that the temperature change detected in step S18 matches the temperature change predicted in step S15, the ECU 8 proceeds to step S20.

  In step S20, the ECU 8 optimizes the water pump 7. That is, the pumping amount of the water pump 7 is determined based on the detected transportable heat amount, and the operation is performed according to the determined pumping amount. If it is determined that the detected temperature change matches the predicted temperature change in step S15, it indicates that the estimation model is correct. For this reason, the operation of the water pump 7 can be maintained in this state, and the refrigerant 10 can be maintained at the target temperature. Thereby, the merit of the heat transport by the phase change of a latent heat storage material can be utilized, and a fuel consumption can be improved. When the ECU 8 finishes the process of step S20, the ECU 8 finishes the control process and returns.

  On the other hand, when the ECU 8 determines in step S19 that the temperature change predicted in step S15 is different from the temperature change detected in step S18, the process proceeds to step S11, and this control process is performed again. That is, when it is determined that the temperature change detected in step S15 does not match the predicted temperature change, it indicates that the estimation model is incorrect. Therefore, the assumption of the concentration of the microcapsule 11 in step S12 is changed to correct the estimation model.

  By the above control, the cooling device 1 of the present embodiment estimates the generated heat flux from the engine body 2 and the released heat flux from the radiator 3, and estimates the latent heat and solid phase ratio of the latent heat storage material from these heat fluxes. And the temperature change at the time of changing the pumping amount of the water pump 7 is estimated. In the cooling device 1, the predicted temperature change is compared with the actual temperature change, and if they match, it can be confirmed that the temperature prediction estimation model functions correctly. Thereby, the water pump 7 can be appropriately controlled using the estimation model.

  The flow rate may be reduced without stopping the operation of the water pump 7. By reducing the flow rate, it takes time for the refrigerant 10 to pass through the water jacket 4, so that the amount of heat from the engine body 2 cannot be absorbed only by the phase change of the latent heat storage material. Thereby, since the temperature of the refrigerant | coolant 10 rises, the effect similar to the case where the water pump 7 is stopped is acquired.

  Next, the effect of using the refrigerant 10 in which the microcapsules 11 are dispersed will be described. FIG. 5 is an explanatory diagram comparing the present embodiment and the conventional example with respect to the refrigerant temperature during engine operation. In FIG. 5, the solid line indicates the present embodiment, and the broken line indicates the conventional example. The conventional example is the same as the present embodiment except that a refrigerant of 100% LLC is sealed in the refrigerant passage. In FIG. 5, both the present example and the conventional example were operated in the EC mode at the beginning of operation, and then operated in WOT (Wide Open Throttle).

  As shown in FIG. 5, in this embodiment, the temperature rise immediately after the start of operation is faster than in the conventional example. This is because the heat storage material in the microcapsule 11 has a specific heat lower than that of LLC. Further, in the conventional example, the temperature of the refrigerant is increased when operated by the WOT, whereas in the present embodiment, the temperature does not increase even when operated by the WOT, and the refrigerant 10 is suitable for the operation of the engine. Maintained at a constant temperature. That is, according to this embodiment, the engine can be warmed up early by using the refrigerant 10 in which the microcapsules 11 are dispersed. In addition, the engine can be maintained at an optimum temperature even during high load operation.

  FIG. 6 is an explanatory diagram showing the relationship between the amount of heat that can be transported and the temperature difference between the inlet and outlet of the water jacket. The vertical axis in FIG. 6 indicates the heat transferable heat quantity, that is, the conventional ratio of the heat quantity that can be absorbed from the engine body 2 and released by the radiator 3. On the other hand, the horizontal axis in FIG. 6 indicates the difference obtained by subtracting the temperature at the inlet of the water jacket 4 from the temperature at the outlet of the water jacket 4, that is, the rising temperature of the refrigerant when passing through the water jacket 4.

  FIG. 6 shows a case where the latent heat storage material is n-octacosane and the mixing ratio in the refrigerant is changed. The solid line in FIG. 6 indicates a conventional refrigerant, that is, LLC that does not include a latent heat storage material, the dotted line indicates a refrigerant mixed with 10% of n-octacosane, and the broken line indicates a refrigerant mixed with 20% of n-octacosane. The alternate long and short dash line indicates a refrigerant mixed with 30% n-octacosane, and the two-dot chain line indicates a refrigerant mixed with 40% n-octacosane.

  FIG. 6 shows the operating conditions of a conventional engine obtained with a water jacket inlet refrigerant temperature of 95 ° C., a water jacket outlet refrigerant temperature of 102 ° C., an oil temperature of 118 ° C., and a towing condition upper limit of 105 ° C. In addition, assuming that the weight of the microcapsules enclosing n-octacosane is 44%, in the case of the refrigerant mixed with octacosane, the calculation was made assuming that the transportable heat amount due to the latent heat of octacosan is added to the conventional transportable heat amount.

  The upper left side in FIG. 6, that is, the smaller the temperature difference between the inlet and outlet of the water jacket 4 and the greater the amount of heat that can be transported, the more ideal the refrigerant. In the case where only the LLC in which the conventional microcapsules are not mixed is used as the refrigerant, the difference in refrigerant temperature between the outlet and the inlet of the water jacket is 7 ° C. (point A in FIG. 6). As shown in FIG. 6, the refrigerant mixed with microcapsules improves the transportable heat amount compared to the LLC-only refrigerant not mixed with microcapsules, while reducing the difference in refrigerant temperature between the water jacket outlet and the inlet. Can be reduced. In particular, with a refrigerant mixed with 40% of n-octacosane, the temperature difference between the outlet and the inlet of the water jacket is substantially suppressed (about 1 ° C.), and more than twice the amount of heat that can be transported is obtained compared to the conventional case. .

  By using the refrigerant 10 in which the microcapsules 11 are dispersed, the warm-up property is improved and the fuel consumption can be reduced. Moreover, the structure of the cooling system can be reviewed by changing the refrigerant 10. Thereby, a cooling loss is reduced and the loss of the water pump 7 can be reduced. Furthermore, since the warm-up property is improved, the heater performance is also improved. In addition, since the temperature rise can be suppressed under high-load operating conditions, the oil temperature used for sealing, lubrication, etc. can be lowered, and the oil viscosity can be maintained high. For this reason, low-viscosity oil can be used, startability at low temperatures such as during cold start can be improved, and fuel consumption can be reduced. Similarly, since the temperature rise can be suppressed under high-load operating conditions, the cooling system in the engine can be downsized. The water jacket, water piping, radiator, EGR cooler, and heater core can be made compact, and the engine body can be made compact. Since the engine body becomes compact in this way, the heat capacity is reduced, and variations in mountability can be increased.

  Next, a second embodiment of the present invention will be described. The cooling device of the present embodiment has the same configuration as the cooling device 1 of the first embodiment. The present embodiment is different from the first embodiment in that a part of the optimization control of the coolant pumping amount of the water pump 7 is different. FIG. 7 is an explanatory diagram of a flow showing the optimization control of the refrigerant pumping amount of the water pump 7 of the present embodiment. Note that the description of the same steps as the control of the first embodiment is omitted.

  The ECU 8 performs the processes from step S11 to step S18, and when the process of step S18 is completed, the process proceeds to step S101.

  In step S101, the ECU 8 compares the temperature change predicted in step S15 with the temperature change of the temperature sensor 9 detected and acquired in step S18, and determines whether or not the difference between the two is equal to or less than a threshold value. Here, when the difference between the predicted temperature change and the temperature change detected by the temperature sensor 9 is equal to or smaller than the threshold value, it is determined that the prediction of the temperature change is correct. In this case, the ECU 8 proceeds to step S20.

  On the other hand, when the ECU 8 determines in step S101 that the difference between the temperature change predicted in step S15 and the temperature change detected in step S18 exceeds the threshold value, the process proceeds to step S102.

  In step S102, the ECU 8 executes fail safe control. When the actual temperature change is lower than the predicted temperature change, low calorific value control is executed to protect the engine. The low heat generation amount control is realized by setting a maximum allowable value for the fuel injection amount, limiting the injection amount, performing EGR cut, and the like. Further, when the difference between the predicted temperature change and the temperature change detected by the temperature sensor 9 exceeds the threshold value, it is assumed that the performance of the microcapsule is deteriorated and tampering (mixing of water in the refrigerant) is assumed. A warning is issued to prompt inspection. The engine can be protected by such processing. When the ECU 8 finishes the process of step S102, the ECU 8 finishes the control process and returns.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope. For example, the cooling device of the present invention can be used not only as an engine but also as a device for cooling a heating element that requires cooling, by the same configuration as described above.

DESCRIPTION OF SYMBOLS 1 Cooling device 2 Engine main body 3 Radiator 4 Water jacket 5 1st channel | path 6 2nd channel | path 7 Water pump 8 ECU
9 Temperature sensor

Claims (7)

A refrigerant in which microcapsules encapsulating a heat storage material are dispersed;
A refrigerant passage formed by connecting the heat generating portion and the heat radiating portion so that the refrigerant circulates;
A refrigerant temperature measuring means arranged downstream of the heat generating unit and measuring the temperature of the refrigerant;
A pumping means disposed on the refrigerant passage, wherein the pumping amount of the refrigerant is variable;
Detecting means for detecting the amount of heat that can be transported by the refrigerant by reducing the pumping amount of the pumping means before controlling the circulation amount of the refrigerant in the refrigerant passage;
A cooling device comprising: The detection means includes
Estimating the rising temperature of the refrigerant in advance before changing the pumping amount of the pumping means,
The cooling device according to claim 1, wherein the amount of heat that can be transported by the refrigerant is detected by comparing the rising temperature of the refrigerant measured after the pumping amount is changed by the pumping means and the rising temperature of the refrigerant estimated in advance. The detection means includes
Generated heat estimating means for estimating a heat flux generated from the heat generating portion;
Emission heat estimation means for estimating the heat flux emitted in the heat radiating portion;
The heat storage material state for estimating the latent heat of the heat storage material enclosed in the microcapsules and the solid phase ratio from the generated heat flux estimated by the generated heat estimation means and the released heat flux estimated by the emitted heat estimation means An estimation means,
Before the pumping amount change of the pumping means, the rising temperature of the refrigerant is estimated from the state of the heat storage material estimated by the heat storage material state estimating means, and the actual rising temperature of the refrigerant after the pumping amount change by the pumping means, The cooling device according to claim 1, wherein the amount of heat that can be transported by the refrigerant is detected by comparing the two.   The cooling device according to any one of claims 1 to 3, wherein the detection unit performs fail-safe control when a difference between the estimated rising temperature and the actually measured rising temperature exceeds a threshold value.   The cooling device according to any one of claims 1 to 4, wherein the heat generating unit is an engine body, the heat dissipating unit is a radiator, and the pressure feeding unit is a water pump.   The cooling device according to claim 5, wherein the generated heat estimation means estimates a heat flux generated from the engine body based on an engine speed, a fuel injection amount, or a supply air amount.   The cooling device according to claim 5, wherein the released heat estimating means estimates a heat flux released in the radiator based on a water pump rotation speed, an outside air temperature, or a cooling water temperature.

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