JP5003725B2 - Boiling cooler - Google Patents

Description

  The present invention relates to a boiling cooling device.

  2. Description of the Related Art Conventionally, as a cooling device for an internal combustion engine, a boiling cooling device that performs cooling using boiling heat of vaporization of a refrigerant flowing in a refrigerant passage (for example, a water jacket) included in the internal combustion engine is known. In such a boiling cooling device, the refrigerant passage is not filled with a liquid refrigerant. Therefore, for example, when the acceleration of the vehicle changes, the refrigerant may be biased in the refrigerant passage. As a result, there may be a place where a refrigerant shortage occurs locally in the refrigerant passage.

  Patent Document 1 discloses boiling cooling that suppresses excessive supply of cooling water into the refrigerant passage by limiting the amount of refrigerant supplied to the refrigerant passage based on an acceleration sensor that acquires the swing state of the vehicle. An apparatus is disclosed. This technique attempts to make the temperature in the cooling passage uniform by suppressing excessive cooling water from being supplied into the cooling passage.

Japanese Utility Model Publication No. 61-128332

  However, in the technique of Patent Document 1, when a refrigerant shortage occurs locally in the refrigerant passage, this cannot be solved. Therefore, it is difficult to make the temperature in the refrigerant passage uniform.

  The present invention provides a boiling cooling device capable of bringing the temperature in the refrigerant passage close to a uniform state.

  A boiling cooling device according to the present invention is formed in an internal combustion engine, and is disposed corresponding to each of a refrigerant passage having a plurality of refrigerant supply ports into which refrigerant supplied by a refrigerant supply pump is introduced, and the refrigerant supply ports. A plurality of temperature acquisition means, an inclination angle acquisition means for acquiring a liquid surface inclination angle of the refrigerant in the refrigerant passage, an acquisition result of the inclination angle acquisition means, and an acquisition result of the temperature acquisition means, Based on the undercooling rate calculating means for calculating the undercooling rate at the location where the temperature acquisition means is arranged, and the cooling undersupply rate calculated by the undercooling rate calculating means, the refrigerant supply pump introduces each of the refrigerant supply ports. And a refrigerant amount adjusting means for adjusting the refrigerant amount to be adjusted.

  According to the boiling cooling device according to the present invention, the refrigerant amount adjusting means introduces a large amount of refrigerant into the refrigerant supply port at a location where the cooling insufficient rate is large, and a small amount at the refrigerant supply port at a location where the cooling insufficient rate is small. A refrigerant can be introduced. Thereby, the temperature in the refrigerant passage can be brought close to a uniform state. In addition, since the liquid level inclination angle and the temperature near the refrigerant supply port are reflected in the undercooling rate, the cooling underpercentage rate is lower than when only one of them is reflected in the undercooling rate. The calculation accuracy is good. Thereby, the temperature in the refrigerant passage is brought closer to a uniform state with higher accuracy than when adjusting the refrigerant amount to each refrigerant supply port based on the undercooling rate reflecting only one of them. Can do.

  The said structure may be provided with the superheater which superheats the said refrigerant | coolant which flowed through the said refrigerant | coolant channel | path with the waste heat of the said internal combustion engine, and the turbine driven with the said refrigerant | coolant which passed through the said superheater.

  According to this configuration, the turbine can be driven by the refrigerant superheated by the waste heat of the internal combustion engine. Thereby, the power of the internal combustion engine can be recovered. As a result, the fuel consumption of the internal combustion engine can be improved. Further, even when a vehicle equipped with an internal combustion engine is in an uphill state or in an accelerated state, the power of the turbine can be recovered even when the coolant level is inclined and local insufficient cooling is likely to occur. .

  ADVANTAGE OF THE INVENTION According to this invention, the boiling cooling device which can make the temperature in a refrigerant path close to a uniform state can be provided.

FIG. 1 is a schematic diagram showing a configuration of a boiling cooling device. FIG. 2A is a schematic diagram showing the arrangement state of the temperature sensor. FIG. 2B is a schematic diagram showing a rectangular parallelepiped. FIG. 3 is a diagram illustrating an example of a flowchart of the ECU.

  Hereinafter, modes for carrying out the present invention will be described.

  The boiling cooling device 10 according to the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the configuration of the boiling cooling device 10. The boiling cooling device 10 includes a refrigerant passage 22 formed in the internal combustion engine 20, a gas-liquid separator 30, a first pump 40, a refrigerant distributor 50, a superheater 60, a turbine 70, and a condenser 80. A refrigerant tank 90, a second pump 100, a plurality of temperature sensors 110, an acceleration sensor 112, and an ECU 120. These components form a Rankine cycle.

  The refrigerant passage 22 is a passage through which the refrigerant flows. The internal combustion engine 20 is cooled by the refrigerant in the refrigerant passage 22. For example, the refrigerant in the refrigerant passage 22 boils by absorbing the heat of the internal combustion engine 20. Thereby, the internal combustion engine 20 is cooled. The refrigerant passage 22 is not particularly limited as long as the internal combustion engine 20 can be cooled by the refrigerant in the refrigerant passage 22. In the present embodiment, the refrigerant passage 22 is a water jacket formed around the cylinder of the internal combustion engine 20. The refrigerant is not particularly limited as long as it is a fluid that absorbs the heat of the internal combustion engine 20 and boils.

  A plurality of refrigerant supply ports 24 are formed in the refrigerant passage 22. The refrigerant flowing through the refrigerant distributor 50 is introduced into the refrigerant supply port 24. The refrigerant introduced into the refrigerant supply port 24 is supplied to the refrigerant passage 22. The refrigerant supplied to the refrigerant passage 22 flows through the refrigerant passage 22, is then discharged from the refrigerant discharge port, and flows into the gas-liquid separator 30.

  The gas-liquid separator 30 is a device that separates an inflowing fluid into a gas component and a liquid component. The liquid component flows into the first pump 40. The gas component flows into the superheater 60.

  The first pump 40 pumps the liquid refrigerant flowing from the gas-liquid separator 30 to the refrigerant distributor 50. As the first pump 40, for example, a water pump can be used.

  In response to an instruction from the ECU 120, the refrigerant distributor 50 distributes the refrigerant pressure-fed from the first pump 40 and introduces it into each refrigerant supply port 24. Accordingly, the amount of refrigerant introduced from the first pump 40 to each refrigerant supply port 24 is adjusted. As a result, the amount of refrigerant supplied from the refrigerant supply port 24 to the refrigerant passage 22 is adjusted. That is, the refrigerant distributor 50 and the ECU 120 have a function as refrigerant quantity adjusting means. The refrigerant distributor 50 is not particularly limited as long as it can adjust the amount of refrigerant introduced into each refrigerant supply port 24 in response to an instruction from the ECU 120. For example, a refrigerant distributor having a plurality of flow rate adjustment valves that adjust the communication rate between the first pump 40 and each refrigerant supply port 24 in response to an instruction from the ECU 120 can be used.

  The superheater 60 turns the gaseous refrigerant flowing from the gas-liquid separator 30 into superheated steam using the waste heat of the internal combustion engine 20. The refrigerant that has passed through the superheater 60 flows into the turbine 70.

  The turbine 70 is driven by the refrigerant that has passed through the superheater 60. For example, a generator that generates power using the driving force of the turbine 70 is connected to the turbine 70. In this case, electric power can be generated by driving the turbine 70 with the refrigerant superheated by the waste heat of the internal combustion engine 20. Thereby, the power of the internal combustion engine 20 can be recovered.

  The condenser 80 is a device that returns the refrigerant that has passed through the turbine 70 to a liquid. For example, a radiator can be used as the condenser 80. The refrigerant that has passed through the condenser 80 is stored in the refrigerant tank 90.

  The second pump 100 is a pump that pumps the refrigerant in the refrigerant tank 90 to the gas-liquid separator 30. For example, a water pump can be used as the second pump 100.

  The temperature sensor 110 is disposed in the vicinity of the refrigerant supply port 24 in the internal combustion engine 20. That is, the temperature sensor 110 is arranged corresponding to the refrigerant supply port 24. The temperature sensor 110 acquires the temperature of the arrangement location (in this embodiment, the temperature of the wall portion of the water jacket of the internal combustion engine 20), and transmits the acquisition result to the ECU 120.

  It is preferable that the temperature sensor 110 is disposed in the internal combustion engine 20 so that the temperature change of the internal combustion engine 20 can be quickly acquired. FIG. 2A is a schematic diagram showing an arrangement state of the temperature sensor 110. For example, a protruding portion 27 that protrudes from the wall portion 26 of the internal combustion engine 20 that defines the refrigerant passage 22 is provided. Here, since the heat capacity of the protruding portion 27 is smaller than the heat capacity of portions other than the protruding portion 27, the temperature of the protruding portion 27 reacts sensitively to the temperature change of the refrigerant passage 22. Therefore, the temperature sensing part of the temperature sensor 110 is arranged on the protruding part 27. Thereby, the temperature sensor 110 can quickly acquire the temperature change of the internal combustion engine 20.

  The acceleration sensor 112 acquires the acceleration of the vehicle on which the internal combustion engine 20 is mounted, and transmits the acquisition result to the ECU 120. In the present embodiment, the ECU 120 calculates the inclination angle of the refrigerant level in the refrigerant passage 22 using the result obtained by the acceleration sensor 112. That is, in the present embodiment, the acceleration sensor 112 and the ECU 120 function as an inclination acquisition unit that acquires the inclination angle of the coolant level in the coolant passage 22. The acceleration sensor 112 and the ECU 120 are not limited as long as the inclination angle of the coolant level in the coolant passage 22 can be acquired.

  The ECU 120 is a microcomputer having a CPU, a ROM, and a RAM. In the present embodiment, the ECU 120 receives the acquisition results of the temperature sensor 110 and the acceleration sensor 112 and calculates an insufficient cooling rate at a location where the temperature sensor 110 described later is disposed. Then, ECU 120 controls refrigerant distributor 50 based on the undercooling rate. That is, in this embodiment, the ECU 120 has a function as an insufficient cooling rate calculation unit in addition to the functions as the inclination angle acquisition unit and the refrigerant amount adjustment unit described above.

Next, the insufficient cooling rate will be described. In the present embodiment, when calculating the undercooling rate, a rectangular parallelepiped 200 having a volume and height (H _j ) equivalent to that of the refrigerant passage 22 (water jacket) is used as the undercooling rate calculation model. FIG. 2B is a schematic diagram showing a rectangular parallelepiped 200. A liquid refrigerant is stored in the rectangular parallelepiped 200. A temperature sensor 110 is disposed on the top of the rectangular parallelepiped 200. The temperature sensor 110 from the reference surface of the rectangular parallelepiped 200 to the i-th surface is referred to as a temperature sensor i (when the number of temperature sensors 110 is n _sen , i is a natural number between 1 and n _sen ).

A representative width that is a distance from the reference plane of the rectangular parallelepiped 200 is W _j, and a representative height that is a height from the reference bottom surface of the rectangular parallelepiped 200 is H _j . The arrangement position of the rectangular parallelepiped 200 of the temperature sensor i is _{defined as Wsen_i} . Let _{Hw be} the height of the coolant level when the tilt of the coolant level is 0 degrees. Here, for example, when the acceleration of the vehicle changes or when the vehicle enters an uphill state, it is assumed that the coolant level is inclined by θ degrees. At this time, the distance H _{sen —} i from the temperature sensor i to the virtual liquid surface is _expressed by the following _{equation (} 1).

Here, as H _{sen —} i is larger, the degree of shortage of the refrigerant amount in the vicinity of the temperature sensor i is larger. That is, H _{sen — i} is an index indicating the degree of refrigerant shortage based on the inclination angle of the liquid level at the location where each temperature sensor 110 is disposed.

Then, as an index G _i indicating the insufficient cooling degree based on a temperature of a portion of each temperature sensor 110 is arranged to define the number 2 or less. In _Formula 2, K th — _i is a coefficient. T _{des_i} is a target temperature of the temperature sensor i. T _i is the temperature acquired by the temperature sensor i. As G _i greater deviation from the target temperature of the temperature of the temperature sensor i is acquired increases. That is, as the G _i is larger, insufficient cooling degree of the portion where the temperature sensor i is placed is large.

Using the above formulas 1 and 2, the undercooling rate α _i is set so that the rate of locations where cooling is insufficient is relatively high and the rate of locations where cooling is not low is relatively small. Defined in In this embodiment, α _i is defined as shown in Equation 3. The denominator of Equation 3 is an index indicating the degree of insufficient cooling of the entire location where the temperature sensor 110 of the internal combustion engine 20 is disposed. The numerator of Equation 3 is an index indicating the degree of insufficient cooling at the location where each temperature sensor 110 of the internal combustion engine 20 is disposed. Therefore, it can be said that α _i is an index indicating the degree of insufficient cooling in the entire location where the temperature sensors 110 are arranged in the internal combustion engine 20 where the temperature sensors 110 are arranged.

The ECU 120 according to the present embodiment calculates H _{sen — i} based on the detection result of the acceleration sensor 112, and calculates G _i based on the detection result of the temperature sensor 110. Next, the ECU 120 calculates α _i using H _{sen — i} and G _i . Next, the ECU 120 controls the refrigerant distributor 50 based on α _i . Specifically, ECU 120 controls refrigerant distributor 50 by using undercooling rate α _i as the refrigerant distribution rate. More specifically, the ECU 120 introduces a large amount of refrigerant into the refrigerant supply port 24 in the vicinity of the temperature sensor 110 having a small α _i among the temperature sensors 110, and in the vicinity of the temperature sensor 110 having a large α _i . The refrigerant distributor 50 is controlled so that a small amount of refrigerant is introduced into the refrigerant supply port 24.

FIG. 3 is a diagram illustrating an example of a flowchart of the ECU 120. ECU 120 repeatedly executes the flowchart of FIG. 3 at predetermined intervals. In step S10, the ECU 120 acquires the inclination angle (θ) of the coolant level based on the acquisition result of the acceleration sensor 112. In addition, the ECU 120 acquires the acquisition result (T _i ) of the temperature sensor 110.

Next, the ECU 120 calculates α _i (step S20). Specifically, the ECU ₁₂₀ calculates H _{sen — i} using the tilt angle (θ), and calculates G _i using the temperature (T _i ) acquired by the temperature sensor 110. Then, ECU 120 calculates α _i using H _{sen — i} and G _i .

Next, the ECU 120 controls the refrigerant distributor 50 based on α _i (step S30). Next, the ECU 120 ends the execution of the flowchart.

According to the boiling cooling device 10 according to the present embodiment, the ECU 120 can introduce the refrigerant amount based on the undercooling rate α _i into the refrigerant supply ports 24 in the vicinity of each temperature sensor 110. Thereby, for example, a large amount of refrigerant can be supplied to a portion of the refrigerant passage 22 where the cooling insufficient rate is high, and a small amount of refrigerant can be supplied to a portion where the cooling insufficient rate is low. As a result, the temperature of the refrigerant passage 22 can be brought close to a uniform state. Moreover, it can suppress that local insufficient cooling arises. As a result, damage to the internal combustion engine 20 due to local insufficient cooling is suppressed.

In addition, H _{sen — i} that is an index based on the tilt angle (θ) of the liquid level and G _i that is an index based on the temperature (T _i ) are used to calculate the undercooling rate α _i . Thereby, the undercooling rate is the refrigerant amount shortage (H _{sen — i} ) due to the liquid level inclination, and the undercooling (G _i ) due to factors other than the liquid level inclination (for example, stagnation of the refrigerant vapor), Can be reflected. As a result, the temperature of the refrigerant passage 22 is brought closer to a uniform state with higher accuracy than when only one of the liquid surface inclination angle (θ) and the temperature (T _i ) is reflected in the insufficient cooling rate. be able to.

  In addition, although the boiling cooling device 10 comprises the Rankine cycle, it is not restricted to this. For example, the boiling cooling device 10 of FIG. 1 may not include the superheater 60 and the turbine 70. In this case, the structure of the boiling cooling device 10 can be simplified.

  On the other hand, when the boiling cooling device 10 forms a Rankine cycle as shown in FIG. 1, the power of the internal combustion engine 20 can be recovered, so that the fuel efficiency of the internal combustion engine 20 can be improved. Further, in the boiling cooling device 10 according to the present embodiment, even when the liquid level of the refrigerant in the refrigerant passage 22 is inclined, the temperature of the refrigerant passage 22 can be brought close to a uniform state. Therefore, the power of the turbine 70 can be recovered even in a situation where the coolant level is inclined and local insufficiency is likely to occur, such as when the vehicle is in an uphill state, an acceleration state, or the like.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 10 Boiling cooler 20 Internal combustion engine 22 Refrigerant passage 24 Refrigerant supply port 26 Wall part 27 Protrusion part 30 Gas-liquid separator 40 1st pump 50 Refrigerant distributor 60 Superheater 70 Turbine 80 Condenser 90 Refrigerant tank 100 2nd pump 110 Temperature sensor 112 Acceleration sensor 120 ECU
200 rectangular parallelepiped

Claims (2)

A refrigerant passage formed in an internal combustion engine and having a plurality of refrigerant supply ports into which refrigerant supplied by a refrigerant supply pump is introduced;
A plurality of temperature acquisition means arranged corresponding to each of the refrigerant supply ports;
An inclination angle obtaining means for obtaining a liquid surface inclination angle of the refrigerant in the refrigerant passage;
Based on the acquisition result of the tilt angle acquisition unit and the acquisition result of the temperature acquisition unit, an undercooling rate calculation unit that calculates an undercooling rate at an arrangement location of the temperature acquisition unit;
Refrigerant amount adjusting means for adjusting the amount of refrigerant introduced from the refrigerant supply pump to each of the refrigerant supply ports based on the undercooling rate calculated by the undercooling rate calculating means. Boiling cooler. A superheater that superheats the refrigerant flowing through the refrigerant passage with waste heat of the internal combustion engine;
A boiling cooling device according to claim 1, further comprising: a turbine driven by the refrigerant via the superheater.

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