JP2010223116A - Engine cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine whether or not cooling of an engine is realized, in the boiling/cooling engine using vaporizing latent heat. <P>SOLUTION: This cooling system 1 of the engine 100 includes a water jacket 2 formed inside the engine 100 and vaporizing a refrigerant passing through the inside through the waste heat of the engine 100, a gas-liquid separator 3 for returning a liquid phase refrigerant to a refrigerant passage by separating the refrigerant discharged from the inside of this water jacket 2 into the liquid phase refrigerant and a gaseous phase refrigerant, a second flowmeter 15 for acquiring flow rate information on the gaseous phase refrigerant separated by the gas-liquid separator 3, and an ECU 16. The ECU 16 determines a cooling shortage of the engine by comparing a predictor of a flow rate of the gaseous phase refrigerant calculated based on items of the refrigerant passing through the inside of the water jacket 2, with a measured value of the flow rate of the gaseous phase refrigerant acquired by the second flowmeter 15. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling device that cools an engine by removing heat from the engine by boiling a refrigerant used for engine cooling.

  Liquid phase refrigerant absorbs thermal energy as latent heat when vaporized. The amount of heat absorbed as the latent heat of vaporization of the refrigerant is considerably larger than the amount of heat absorbed in the cooling method that does not use the latent heat of vaporization that has been conventionally used (hereinafter referred to as “water cooling method”). For this reason, the cooling method using latent heat of vaporization can recover more heat with the same amount of refrigerant as compared with the water cooling method. That is, the cooling method using the latent heat of vaporization can reduce the amount of refrigerant necessary for cooling the same amount of heat as compared with the case of the water cooling method. A boiling cooling system using such latent heat of vaporization is employed for cooling the engine. For example, Patent Document 1 discloses an engine boiling cooling device.

  In a water jacket of an engine that employs boiling cooling, when the refrigerant is boiling, the liquid phase refrigerant and the gas phase refrigerant are stagnant, and the exact liquid level cannot be determined. For this reason, in the apparatus which detects a static liquid level, since the refrigerant | coolant amount in a water jacket cannot be grasped | ascertained appropriately, it is difficult to maintain a liquid level. The engine boiling cooling device of Patent Document 1 is provided with a detector for detecting a void ratio (volume ratio of vapor bubbles in the liquid phase) at a predetermined level of the water jacket, and a refrigerant so that the detected value becomes a predetermined value. Control the supply amount. Thus, the engine boiling cooling device of Patent Document 1 keeps the amount of refrigerant in the water jacket constant.

JP 61-83444 A

  By the way, in the water cooling system, it is possible to calculate the amount of cooled heat from the supply amount of the refrigerant and the temperature difference before and after the cooling of the refrigerant. Therefore, a coolant capable of cooling the amount of cooling heat required by the engine can be supplied into the water jacket, and the engine can be cooled.

  On the other hand, in the boiling cooling system using vaporization latent heat, the amount of heat absorbed by vaporization is absorbed as latent heat and does not appear as a temperature change of the refrigerant, and therefore cannot be detected as a temperature difference before and after cooling. Therefore, the boiling cooling engine cannot calculate the amount of heat cooled by the refrigerant from the refrigerant supply amount and the temperature information before and after the refrigerant cooling. For this reason, it cannot be determined whether or not the amount of heat absorbed by the refrigerant matches the amount of heat that needs to be cooled in the engine. As described above, when it cannot be determined whether or not the amount of heat of cooling of the engine is absorbed by the refrigerant, the cooling of the engine may be insufficient, and the engine may be overheated.

  Therefore, an object of the present invention is to determine whether or not engine cooling is established in a boiling cooling engine that uses latent heat of vaporization.

  An engine cooling device of the present invention that solves such a problem includes a refrigerant passage formed inside the engine, through which refrigerant evaporated by waste heat of the engine passes, and refrigerant discharged from the refrigerant passage in a liquid phase. A gas-liquid separator that separates the refrigerant and the gas-phase refrigerant; a gas-phase refrigerant amount obtaining unit that obtains an actual value of the flow rate of the gas-phase refrigerant separated by the gas-liquid separator; and the refrigerant passage. Control means for calculating a predicted value of the flow rate of the gas-phase refrigerant based on the specifications of the refrigerant, comparing the predicted value with the measured value, and determining the cooling state of the engine. .

  With such a configuration, it is possible to determine whether or not engine cooling has been established in a boiling cooling engine that uses latent heat of vaporization. Here, it is assumed that cooling of the engine has been established when the temperature rise can prevent damage or the like and the engine is cooled to such an extent that the operation of the engine can be maintained. The specifications of the refrigerant can include information indicating the state of the refrigerant flowing into the cooling passage and information indicating the state of the refrigerant discharged from the cooling passage.

  In such an engine cooling device, supply refrigerant amount acquisition means for acquiring the flow rate of the refrigerant supplied into the refrigerant passage, and supply refrigerant temperature acquisition means for acquiring the temperature of the refrigerant supplied into the refrigerant passage. An exhaust refrigerant temperature acquisition means for acquiring the temperature of the refrigerant discharged from within the refrigerant passage; and a gas phase refrigerant pressure acquisition means for acquiring the pressure of the gas phase refrigerant discharged from within the refrigerant passage, The specifications are the refrigerant amount Gin acquired by the supply refrigerant amount acquisition means, the temperature T_in acquired by the supply refrigerant temperature acquisition means, the temperature T_out acquired by the exhaust refrigerant temperature acquisition means, and the gas phase Pressure P_s acquired by the refrigerant pressure acquisition means.

  The amount of gas-phase refrigerant generated can be predicted from each piece of refrigerant information acquired by these acquisition means. The predicted value calculated here can be compared with the actual measurement value to determine whether or not the engine has been cooled.

  In the engine cooling apparatus, the specifications may include a heat release amount Q_loss in a pipe connecting the refrigerant passage and the gas-liquid separator.

  When the refrigerant passes through the pipe connecting the passage and the gas-liquid separator, the heat recovered from the engine by the refrigerant is released to the atmosphere through the pipe. In the present invention, the engine cooling device may calculate the predicted value of the generation amount of the gas-phase refrigerant in consideration of the heat radiation amount in the pipe when measuring the specifications of the discharged refrigerant with the gas-liquid separator. it can.

  In the engine cooling apparatus described above, a Rankine cycle system including power recovery means for recovering waste heat energy from the gas-phase refrigerant separated by the gas-liquid separator may be incorporated.

  Steam generated by cooling the boiling cooling engine recovers engine waste heat and has effective thermal energy. The engine cooling device of the present invention can recover the thermal energy of such steam by the power recovery means of the Rankine cycle. Thereby, energy can be used effectively and fuel consumption can be improved.

  The engine cooling apparatus includes a tank that stores liquid phase refrigerant, and a supply unit that supplies the liquid phase refrigerant in the tank to the refrigerant passage, wherein the control unit has insufficient cooling of the engine. When determining, it can be set as the structure which supplies the liquid phase refrigerant | coolant in the said tank to the said refrigerant | coolant channel | path based on the difference of the said measured value and the said estimated value.

  If the measured value of the amount of the gas-phase refrigerant (steam) does not reach the predicted value calculated by the control means, the engine has not been sufficiently cooled. That is, heat recovery by the refrigerant is insufficient. For this reason, the coolant can be supplied into the engine to cool the engine. Thereby, damage to the engine can be avoided and operation can be maintained.

  In the engine cooling apparatus, when the control unit determines that the engine is insufficiently cooled, it can stop the engine or limit the output of the engine.

  When the actual value of the amount of gas-phase refrigerant (steam) does not reach the predicted value calculated by the control means, the engine is stopped or the output is restricted to prevent engine overheating and avoid engine damage. be able to.

  The engine cooling apparatus includes a refrigerant leakage detection unit that detects a leakage of a gas-phase refrigerant, and the control unit determines whether the engine is insufficiently cooled based on a detection result of the refrigerant leakage detection unit. It can be.

  When detecting the leakage of the gas-phase refrigerant, the engine cooling device can calculate the predicted value in consideration of this and determine whether or not the engine has been cooled. Thus, for example, it is possible to avoid excessive supply of the refrigerant to the engine by misidentifying a decrease in the measured value of the gas-phase refrigerant due to leakage as an insufficient heat recovery amount, and to maintain the engine temperature.

  The present invention predicts whether or not engine cooling has been established in a boiling-cooled engine that uses latent heat of vaporization by predicting the flow rate of the vapor-phase refrigerant that has been vaporized by absorbing the heat of the engine and comparing it with actual measurement values. Can be judged.

It is explanatory drawing which showed schematic structure of the engine in which the cooling device of Example 1 was integrated. 3 shows a flow of control for determining whether cooling is insufficient in the first embodiment. It is explanatory drawing which showed schematic structure of the engine in which the cooling device of Example 2 was integrated. The flow of determination control of insufficient cooling in Example 2 is shown. It is explanatory drawing which showed schematic structure of the engine in which the cooling device of Example 3 was integrated. 10 shows a flow of control for determining whether cooling is insufficient in the third embodiment. It is explanatory drawing which showed schematic structure of the engine in which the cooling device of Example 4 was integrated.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for implementing 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 diagram showing a schematic configuration of an engine 100 in which the cooling device 1 of this embodiment is incorporated. In the main body 101 of the engine 100, a water jacket 2 through which a cooling refrigerant passes is formed. The engine 100 is an engine that performs boiling cooling and water cooling. When the engine 100 performs boiling cooling, the engine main body 101 is cooled when the liquid phase refrigerant in the water jacket 2 absorbs heat from the engine main body 101 and vaporizes. Here, the water jacket 2 functions as a refrigerant passage of the present invention.

  The cooling device 1 includes a gas-liquid separator 3, a tank 4, a first pipe 5, a second pipe 6, a third pipe 7, and a fourth pipe 8. Each of the first pipe 5 and the second pipe 6 communicates the gas-liquid separator 3 and the water jacket 2. The first pipe 5 is a pipe that transports the liquid-phase refrigerant from the gas-liquid separator 3 into the water jacket 2. The second pipe 6 is a pipe that transports liquid-phase and gas-phase refrigerant from the water jacket 2 to the gas-liquid separator 3. Further, the gas-liquid separator 3 and the tank 4 are communicated with each other by a third pipe 7, and the liquid-phase refrigerant stored in the tank 4 can be supplied to the gas-liquid separator 3. The gas-liquid separator 3 separates the refrigerant that has flowed into the liquid phase refrigerant and the gas phase refrigerant. The separated liquid-phase refrigerant is sent to the water jacket 2 through the first pipe 5. On the other hand, the separated gas-phase refrigerant is sent to the condenser 9 through the fourth pipe 8 and condensed to become a liquid-phase refrigerant, which is sent to the tank 4 and stored.

  Furthermore, an electrically driven pump 10, a first flow meter 11, and a first temperature sensor 12 are disposed in the first pipe 5. The first flow meter 11 is disposed on the downstream side of the pump 10 and acquires flow rate information of the refrigerant that passes through the pump 10 and is supplied into the water jacket 2. This 1st flow meter 11 is an example of the supply refrigerant | coolant amount acquisition means of this invention. The first temperature sensor 12 is disposed in the vicinity of the engine body 101 of the first pipe 5 and acquires temperature information of the refrigerant supplied to the water jacket 2. This 1st temperature sensor 12 is an example of the supply refrigerant temperature acquisition means of the present invention. Since the first temperature sensor 12 is disposed in the vicinity of the engine main body 101, the temperature information of the refrigerant immediately before being supplied into the water jacket 2 is acquired. Thereby, the information of the temperature of the refrigerant | coolant supplied to the water jacket 2 is acquired accurately.

  The second pipe 6 is provided with a second temperature sensor 13 for measuring the temperature of the refrigerant discharged from the water jacket 2. The second temperature sensor 13 is an example of an exhaust refrigerant temperature acquisition unit of the present invention. Further, the gas-liquid separator 3 is provided with a pressure sensor 14 for measuring pressure information of the gas-phase refrigerant in the gas-liquid separator 3, that is, a vapor pressure. The pressure sensor 14 is an example of a gas-phase refrigerant pressure acquisition unit of the present invention. A second flow meter 15 is disposed immediately after the gas / liquid separator 3 of the fourth pipe 8. The second flow meter 15 acquires the flow rate information of the gas-phase refrigerant separated by the gas-liquid separator 3. This 2nd flow meter 15 is an example of the gaseous-phase refrigerant | coolant amount acquisition means of this invention. Engine 100 also includes an outside air temperature sensor 17 that detects an ambient temperature Tair around engine 100.

  The engine 100 includes an ECU (Electronic Control Unit) 16. The ECU 16 is electrically connected to each of the first flow meter 11, the first temperature sensor 12, the second temperature sensor 13, the pressure sensor 14, the second flow meter 15, and the outside air temperature sensor 17. The ECU 16 determines whether the engine is insufficiently cooled based on the specifications of the refrigerant obtained from these sensors and the outside air temperature. Further, the ECU 16 is electrically connected to the pump 10, controls the driving of the pump 10, and adjusts the flow rate of the refrigerant supplied into the water jacket 2.

  Next, the control for determining whether the engine 100 is insufficiently cooled in the cooling device 1 will be described. This determination control is performed when the engine 100 is performing boiling cooling, and the processing is performed by the ECU 16. FIG. 2 shows a flow of determination control for insufficient cooling performed by the ECU 16.

In step S1, the ECU 16 takes in the specifications of the refrigerant that passes through the water jacket 2. What are refrigerant specifications?
(A) The amount of refrigerant supplied to the water jacket 2 acquired by the first flow meter 11, that is, the supplied refrigerant amount Gin,
(B) The temperature of the refrigerant supplied to the water jacket 2 acquired by the first temperature sensor 12, that is, the supply refrigerant temperature T_in,
(C) The temperature of the refrigerant discharged from the water jacket 2 acquired by the second temperature sensor 13, that is, the discharged refrigerant temperature T_out,
(D) Pressure information of the gas-phase refrigerant in the gas-liquid separator 3 acquired by the pressure sensor 14, that is, the vapor pressure P_s,
(E) The flow rate of the gas-phase refrigerant separated in the gas-liquid separator 3 obtained by the second flow meter 15, that is, the gas-phase refrigerant amount Gs,
(F) The ambient temperature Tair around the engine 100 acquired from the outside air temperature sensor 17,
It is. When the ECU 16 finishes the process of step S1, the ECU 16 proceeds to step S2.

Ｑ_Ｗ：冷却熱量
Ｑ_{Ｗ＿ｌｏｓｓ}：第２配管における熱損失
ｈ_ｗ＿ｉｎ：ウォータジャケットへ供給される冷媒の比エンタルピー
ｈ_{ｗ＿ｏｕｔ}：ウォータジャケットから排出された液相冷媒の比エンタルピー
ｈ_ｓ：ウォータジャケットから排出された気相冷媒（蒸気）の比エンタルピー In step S2, the ECU 16 calculates an estimated gas phase refrigerant amount Gs_c, which is a predicted value of the flow rate of the gas phase refrigerant, based on the refrigerant specifications and the outside air temperature acquired in step S1. The calculation formula is as follows (Formula 1).

Q _W : Cooling heat quantity Q _{W_loss} : Heat loss in second pipe h _{w_in} : Specific enthalpy of refrigerant supplied to water jacket h _{w_out} : Specific enthalpy of liquid refrigerant discharged from water jacket h _s : Exhausted from water jacket Specific enthalpy of vapor phase refrigerant (vapor)

Here, the enthalpies of h _s , h _{w_in} , and h _{w_out} are calculated from (b) supply refrigerant temperature T_in, (c) exhaust refrigerant temperature T_out, and (d) vapor pressure P_s, which are the above acquisition information. Q _W is a required amount of heat for cooling the engine calculated in advance from the operating conditions of the engine 100. Q _{W_loss} is _calculated from the surface area A_pipe of the second pipe 6 and (c) the discharged refrigerant temperature T_out and (f) the ambient temperature Tair, which are the above acquisition information.

  The ECU 16 proceeds to step S3 after completing the process of step S2. In step S3, the ECU 16 calculates a difference ΔGs between the estimated gas phase refrigerant amount Gs_c and the actually measured gas phase refrigerant amount Gs. After finishing the process of step S3, the ECU 16 proceeds to step S4.

  In step S4, the ECU 16 determines whether or not ΔGs calculated in step S3 exceeds the threshold value α. This α is a preset value. If the ECU 16 determines YES, that is, if the difference ΔGs exceeds α, the process proceeds to step S5.

  In step S5, the ECU 16 determines that the cooling state is abnormal. Next, the ECU 16 increases the amount of cooling water supplied into the water jacket 2 by increasing the pumping amount by the pump 10 in step S6. Thereby, the cooling system of engine 100 is switched from boiling cooling to a cooling system that does not use vaporization latent heat, that is, a water cooling system. Thus, when the value of ΔGs exceeds α, boiling cooling is stopped. Thereby, it is suppressed that the engine 100 becomes high temperature too much, and the deformation | transformation by a heat | fever is prevented. At this time, a process for limiting the output of the engine 100 can also be performed. The ECU 16 returns after completing the process of step S6.

By the way, when the ECU 16 determines NO, that is, when the difference ΔGs exceeds α, the process proceeds to step S7. In step S7, the ECU 16 determines that there is no abnormality in the cooling state. Therefore, boiling cooling in engine 100 is continued. Next, the ECU 16 proceeds to step S8. In step S8, the ECU 16 calculates an increase ΔGin of the supply refrigerant amount Gin and a target supply refrigerant amount Gin_des. The calculation formulas are as shown in the following formulas (1) and (2).
ΔGin = fs (ΔGs) (1)
Gin_des = Gin + ΔGin (2)
Here, fs (x) represents a function for calculating ΔGin.

After finishing the process of step S8, the ECU 16 proceeds to step S9. In step S9, the ECU 16 calculates the drive torque Tq_w / p of the pump 10. The calculation formula is as shown in formula (3) below.
Tq_w / p = ft (Gin, Gin_des, T_in) (3)
Here, ft (x, y, z) is a function for calculating Tq_w / p. Note that the influence of cavitation is added to the value of T_in. The ECU 16 returns after completing the process of step S9.

  The ECU 16 corrects the value of the supplied refrigerant amount Gin based on the estimated value Gs_c of the gas-phase refrigerant and the actually measured value Gs by the processing from step S7 to step S9. Thereby, the amount of refrigerant corresponding to the amount of cooling heat is supplied into the water jacket 2, and boiling cooling suitable for the operating state of the engine 100 is performed.

  In the present embodiment, the ECU 16 of the cooling device 1 compares the predicted value of the flow rate of the gas-phase refrigerant that is vaporized by absorbing the heat of the engine 100 with the measured value of the flow rate of the gas-phase refrigerant. The ECU 16 determines whether or not the cooling of the engine 100 is established based on the result of this comparison, and performs control so that the cooling is suitable for the amount of gas-phase refrigerant generated. Thereby, an excessive temperature rise of engine 100 is suppressed, and damage due to heat of engine 100 is suppressed.

Next, a second embodiment of the present invention will be described. FIG. 3 is an explanatory diagram showing a schematic configuration of the engine 100 in which the cooling device 20 of the present embodiment is incorporated. The cooling device 20 of the present embodiment has substantially the same configuration as the cooling device 1 of the first embodiment. However, the cooling device 20 of the present embodiment is the cooling device of the first embodiment in that an O ₂ sensor 21 is disposed between the second flow meter 15 on the fourth pipe 8 and the condenser 9. 1 and different. The O ₂ sensor 21 measures the oxygen concentration in the fourth pipe 8. The O ₂ sensor 21 is electrically connected to the ECU 16, and the ECU 16 determines the leakage of the refrigerant in the fourth pipe 8 from the oxygen concentration acquired by the O ₂ sensor 21. That is, the ECU 16 and the O ₂ sensor 21 function as the refrigerant leakage detection means of the present invention. In addition, since the other structure is the same as Example 1, about the component same as Example 1, the same reference number is attached | subjected in drawing and the detailed description is abbreviate | omitted.

  Next, control for determining whether the engine 100 is insufficiently cooled in the cooling device 20 of this embodiment will be described. This determination control is performed by the ECU 16. The determination control in the present embodiment is different from the determination control in the first embodiment in that the leakage of the refrigerant from the pipe is detected. FIG. 4 is an explanatory diagram showing a flow of determination control in the present embodiment. The determination control of this embodiment is performed when boiling cooling is executed. In the flow of FIG. 4, processes similar to those in the control flow of the first embodiment illustrated in FIG. 2 are denoted by the same step numbers, and detailed description thereof is omitted.

After finishing the process of step S1, the ECU 16 proceeds to the process of step S11. In step S11, the ECU 16 acquires the oxygen concentration in the fourth pipe 8 from the O ₂ sensor 21. Next, ECU16 judges the leakage of a refrigerant | coolant based on the oxygen concentration acquired in step S11 by step S12. When the refrigerant leaks in the pipe through which the refrigerant passes, outside air is mixed. When the oxygen concentration exceeds the threshold value, the ECU 16 determines that outside air is mixed and determines that the refrigerant leaks. If the ECU 16 determines YES in step S12, that is, determines that the refrigerant is leaking, the ECU 16 proceeds to step S13. On the other hand, if the ECU 16 determines NO in step S12, that is, determines that the refrigerant is not leaking, the ECU 16 proceeds to step S14.

In step S13, the ECU 16 sets the refrigerant leakage correction coefficient η _leak to 0, and proceeds to step S15. In step S14, the ECU 16 sets the refrigerant leakage correction coefficient η _leak to 1, and proceeds to step S15.

なお、文字列が示す諸元は、実施例１と同様である。ここで、ステップＳ１２で冷媒の漏洩を判断した場合、Ｇｓ＿ｃ´の値は０である。ＥＣＵ１６はステップＳ１５の処理を終えると、ステップＳ１６へ進む。 In step S15, the ECU 16 is a predicted value of the flow rate of the gas-phase refrigerant based on the refrigerant specifications and the outside air temperature acquired in step S1, and the refrigerant leakage correction coefficient η _leak calculated in step S13 or step S14. An estimated gas phase refrigerant amount Gs_c ′ is calculated. The calculation formula is as follows (Formula 2).

The specifications indicated by the character string are the same as those in the first embodiment. Here, when it is determined in step S12 that the refrigerant has leaked, the value of Gs_c ′ is zero. When the ECU 16 finishes the process of step S15, the process proceeds to step S16.

  In step S16, the ECU 16 calculates a difference ΔGs ′ between the estimated gas phase refrigerant amount Gs_c ′ and the actually measured gas phase refrigerant amount Gs. After finishing the process of step S16, the ECU 16 proceeds to step S17.

  In step S17, the ECU 16 determines whether or not ΔGs ′ calculated in step S16 exceeds the threshold value α. This α is a preset value. When the ECU 16 determines YES, that is, when the difference ΔGs ′ exceeds α, the process proceeds to step S5. On the other hand, if the ECU 16 determines NO, that is, if the difference ΔGs ′ does not exceed α, the process proceeds to step S18.

  In step S18, the ECU 16 determines whether ΔGs is −Gs. From the calculation formula (Equation 2) in step S15, when it is determined in step S12 that the refrigerant has leaked, the value of Gs_c ′ is zero. Therefore, ΔGs ′ in step S16 is −Gs. If the ECU 16 determines YES in step S18, that is, determines that the refrigerant is leaking and ΔGs ′ is −Gs, the ECU 16 proceeds to step S19.

  In step S <b> 19, the ECU 16 increases the pumping amount by the pump 10 and increases the amount of cooling water supplied into the water jacket 2. That is, the boiling cooling system is switched to the water cooling system. Moreover, ECU16 restrict | limits the output of an engine by step S19. In step S19, the ECU 16 turns on a warning lamp that informs the user (driver) that the refrigerant is leaking. When the ECU 16 determines YES in step S18, since the refrigerant is leaking, a measure is taken in consideration of safety. In addition, by warning the user, it is possible to prompt early shutdown and repair. The ECU 16 returns after completing the process of step S19.

  On the other hand, if the ECU 16 determines NO in step S18, that is, if ΔGs ′ is not −Gs and it is determined that the refrigerant is not leaking, the ECU 16 proceeds to step S7.

  In the present embodiment, the cooling device 20 determines the leakage of the refrigerant, stops boiling cooling when the refrigerant leaks, and maintains the safety of the engine 100. Further, similarly to the first embodiment, the cooling device 20 compares the predicted value of the flow rate of the gas-phase refrigerant vaporized by absorbing the heat of the engine 100 with the actual measurement value, and based on the result of this comparison, It is determined whether or not cooling is established, and control is performed so that the cooling is suitable for the amount of gas-phase refrigerant generated. Thereby, excessive temperature rise of engine 100 is suppressed and engine 100 is protected.

  Next, Embodiment 3 of the present invention will be described. FIG. 5 is an explanatory diagram showing a schematic configuration of the cooling device 30 of the present embodiment. The cooling device 30 of the present embodiment has substantially the same configuration as the cooling device 1 of the first embodiment. However, the cooling device 30 of the present embodiment differs from the cooling device 1 of the first embodiment in that a third flow meter 31 is disposed between the condenser 9 on the fourth pipe 8 and the tank 4. Is different. Since the refrigerant condensed in the condenser 9 flows to the tank 4, the third flow meter 31 acquires the amount of refrigerant condensed in the condenser 9. The third flow meter 31 is electrically connected to the ECU 16, and the ECU 16 acquires the amount of refrigerant condensed by the condenser 9. In addition, since the other structure is the same as Example 1, about the component same as Example 1, the same reference number is attached | subjected in drawing and the detailed description is abbreviate | omitted.

  Next, control for determining whether the engine 100 is insufficiently cooled in the cooling device 30 of the present embodiment will be described. This determination control is performed by the ECU 16. The determination control in the present embodiment differs from the determination control in the first embodiment in that the amount of gas-phase refrigerant generated is determined from the condensate amount. FIG. 6 is an explanatory diagram showing a flow of determination control in the present embodiment. In the flow of FIG. 6, processes similar to those in the control flow of the first embodiment illustrated in FIG. 2 are denoted by the same step numbers, and detailed description thereof is omitted.

  After finishing the process of step S1, the ECU 16 proceeds to step S21. The ECU 16 acquires the condensate amount from the third flow meter 31 in step S21. Further, in step S21, the ECU 16 calculates an estimated gas phase refrigerant amount Gs_c ″ from the acquired condensate amount. After finishing the process of step S21, the ECU 16 proceeds to step S22. The estimated gas-phase refrigerant amount Gs_c ″ calculated here may be calculated from the amount of heat released by the refrigerant in the condenser 9.

  In step S22, the ECU 16 determines whether or not the difference between the estimated gas phase refrigerant amount Gs_c ″ calculated in step S21 and the gas phase refrigerant amount Gs that is an actual measurement value exceeds a threshold value β. This β is a preset value. If the ECU 16 determines YES in step S22, that is, if the difference exceeds β, the ECU 16 proceeds to step S23.

  In step S23, the ECU 16 increases the pumping amount by the pump 10 to increase the amount of cooling water supplied into the water jacket 2. That is, the boiling cooling system is switched to the water cooling system. Moreover, ECU16 restrict | limits the output of an engine by step S23. In step S23, the ECU 16 turns on a warning lamp that informs the user (driver) that the refrigerant is leaking. The ECU 16 returns after completing the process of step S23.

  On the other hand, if the ECU 16 determines NO in step S22, that is, if the difference does not exceed β, the ECU 16 proceeds to step S2. The following processing is the same as in the first embodiment.

  In the present embodiment, the failure determination of the second flow meter 15 can be performed by comparing the estimated gas phase refrigerant amount Gs_c ″ calculated from the condensate amount with the actually measured value Gs of the gas phase refrigerant. Similarly to the first embodiment, the cooling device 30 compares the predicted value of the flow rate of the gas-phase refrigerant vaporized by absorbing the heat of the engine 100 with the actual measurement value, and based on the result of this comparison, It is determined whether or not cooling is established, and control is performed so that the cooling is suitable for the amount of gas-phase refrigerant generated. Thereby, excessive temperature rise of engine 100 is suppressed and engine 100 is protected. In addition, the cooling device 30 of the present embodiment can include a sensor that detects a steam leak, and can perform a control process incorporating the steam leak control of the second embodiment.

  Next, a fourth embodiment of the present invention will be described. FIG. 7 is an explanatory diagram showing a schematic configuration of an engine 200 in which the cooling device 40 of this embodiment is incorporated. The cooling device of the present embodiment has a configuration in which the Rankine cycle system is incorporated in the cooling device 1 of the first embodiment. That is, a three-way valve 41, a superheater 42, and a power recovery machine 43 are arranged in this order from the second flow meter 15 side between the second flow meter 15 and the condenser 9 on the fourth pipe 8. .

  One end of a fifth pipe 44 is connected to the three-way valve 41, and the other end of the fifth pipe 44 is connected between the power recovery machine 43 on the fourth pipe 8 and the condenser 9. The fifth pipe 44 is a passage through which the refrigerant bypasses the superheater 42 and the power recovery machine 43. The three-way valve 41 is electrically connected to the ECU 16. The three-way valve 41 switches between supply of the refrigerant to the superheater 42 and the power recovery machine 43 side and supply of the refrigerant to the fifth pipe 44 that bypasses these, based on a signal from the ECU 16. The superheater 42 is drawn in an exhaust pipe through which the exhaust discharged from the engine body 101 passes, and superheats the gas-phase refrigerant by the heat of the exhaust. The power recovery machine 43 includes a turbine 431 driven by a high-temperature gas-phase refrigerant and a converter 432 that converts the rotational force of the turbine 431 into electric power, auxiliary power, and the like. The waste heat energy is recovered from the phase refrigerant. In addition, a Rankine pump 45 is disposed on the third pipe 7, and pumps the liquid-phase refrigerant from the tank 4 to the gas-liquid separator 3 based on a drive signal from the electrically connected ECU 16. .

Further, an O ₂ sensor 21 that measures the oxygen concentration in the fourth pipe 8 is disposed between the power recovery machine 43 and the condenser 9 on the fourth pipe 8. A third flow meter 31 that measures the amount of condensate in the condenser 9 is disposed between the condenser 9 on the fourth pipe 8 and the tank 4. In addition, since the other structure is the same as Example 1, about the component same as Example 1, the same reference number is attached | subjected in drawing and the detailed description is abbreviate | omitted.

  The cooling device 40 of the present embodiment performs the control process shown in the first to third embodiments. In this control process, the ECU 16 switches the three-way valve 41 and causes the refrigerant to flow through the fifth pipe 44 when the boiling cooling is stopped. This is because it is impossible to supply a gas-phase refrigerant that only drives the turbine 431.

In the present embodiment, the cooling device 40 preferably includes both the O ₂ sensor 21 and the third flow meter 31, but may have a configuration that does not include either or both.

  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.

なお、文字列が示す諸元は、実施例１と同様であり、実施例１における図２の制御フローにおいて（数３）の算出式を用いることができる。 For example, the heat loss Q _{W_loss} in the second pipe 6 can be removed in the calculation of the estimated gas phase refrigerant amount Gs_c by performing a process of covering the second pipe 6 with a heat insulating material. Hereinafter, the formula (Equation 3) is a formula for calculating the estimated gas phase refrigerant amount Gs_c in this case.

The specifications indicated by the character string are the same as those in the first embodiment, and the calculation formula (Equation 3) can be used in the control flow of FIG.

DESCRIPTION OF SYMBOLS 1, 20, 30, 40 Cooling device 2 Water jacket 3 Gas-liquid separator 4 Tank 5 1st piping 6 2nd piping 7 3rd piping 8 4th piping 9 Condenser 10 Pump 11 1st flow meter 12 1st temperature Sensor 13 Second temperature sensor 14 Pressure sensor 15 Second flow meter 16 ECU
17 Outside air temperature sensor 21 O ₂ sensor 42 Superheater 43 Power recovery machine 100, 200 Engine

Claims (7)

A refrigerant passage formed inside the engine and through which the refrigerant vaporized by the waste heat of the engine passes,
A gas-liquid separator that separates the refrigerant discharged from the refrigerant passage into a liquid-phase refrigerant and a gas-phase refrigerant;
A gas phase refrigerant amount acquisition means for acquiring an actual measurement value of a flow rate of the gas phase refrigerant separated by the gas-liquid separator;
Control means for calculating a predicted value of the flow rate of the gas-phase refrigerant based on the specifications of the refrigerant passing through the refrigerant passage, comparing the predicted value with the measured value, and determining the cooling state of the engine;
An engine cooling system comprising: The engine cooling device according to claim 1,
Supply refrigerant amount acquisition means for acquiring the flow rate of the refrigerant supplied into the refrigerant passage;
Supply refrigerant temperature acquisition means for acquiring the temperature of the refrigerant supplied into the refrigerant passage;
Exhaust refrigerant temperature acquisition means for acquiring the temperature of the refrigerant discharged from within the refrigerant passage;
Gas phase refrigerant pressure acquisition means for acquiring the pressure of the gas phase refrigerant discharged from the refrigerant passage;
With
The specifications are:
Refrigerant amount Gin acquired by the supplied refrigerant amount acquisition means,
A temperature T_in acquired by the supply refrigerant temperature acquisition means;
A temperature T_out acquired by the discharged refrigerant temperature acquisition means;
Pressure P_s acquired by the gas-phase refrigerant pressure acquisition means;
An engine cooling device comprising: The engine cooling device according to claim 2,
The engine cooling apparatus according to claim 1, wherein the specifications include a heat release amount Q_loss in a pipe connecting the refrigerant passage and the gas-liquid separator. The engine cooling device according to any one of claims 1 to 3,
An engine cooling apparatus comprising a Rankine cycle system including power recovery means for recovering waste heat energy from a gas-phase refrigerant separated by the gas-liquid separator. The engine cooling device according to any one of claims 1 to 4,
A tank for storing liquid phase refrigerant;
Supply means for supplying liquid refrigerant in the tank to the refrigerant passage;
With
The control means causes the liquid-phase refrigerant in the tank to be supplied to the refrigerant passage based on a difference between the actually measured value and the predicted value when determining that the engine is insufficiently cooled. Cooling system. The engine cooling device according to any one of claims 1 to 4,
The engine cooling device characterized in that, when it is determined that the engine is insufficiently cooled, the control means stops the engine or restricts the output of the engine. The engine cooling device according to any one of claims 1 to 6,
Refrigerant leakage detection means for detecting refrigerant leakage,
The engine cooling apparatus according to claim 1, wherein the control means determines whether the engine is insufficiently cooled based on a detection result by the refrigerant leakage detection means.

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