JP7024570B2 - Heat transport system - Google Patents

Description

The present invention relates to a heat transport system through which a heat transport fluid flows.

In the heat transport system disclosed in Patent Document 1 below, fine particles are mixed in the base fluid constituting the heat transport fluid, and the heat transport fluid flows through the flow path. By the way, in such a heat transport system, the flow of the heat transport fluid is stopped, so that fine particles remain in the flow path or the like.

Japanese Unexamined Patent Publication No. 2013-249981

In consideration of the above facts, an object of the present invention is to obtain a heat transport system capable of suppressing the remaining of fine particles in a flow path or the like when the flow of the heat transport fluid is stopped.

The heat transport system according to claim 1 is located between a heat transport fluid in which fine particles that can flow together with the base fluid are mixed in the base fluid, a flow path through which the heat transport fluid flows inside, and the flow path. When the heat exchange section provided and the heat transport fluid flows through the flow path to exchange heat with the heat transport fluid and the flow of the heat transport fluid in the flow path is stopped. A control means for flowing a low-concentration fluid having a concentration of the fine particles lower than the average dispersed state of the fine particles in the heat transport fluid to the flow path, and passage of the fine particles having a particle size of a predetermined size or more. The heat transport fluid is provided with a filter through which the heat transport fluid flows from one side to the other, the heat transport fluid having a predetermined size larger than the fine particles having a particle size smaller than the predetermined size. The low-concentration fluid is produced by containing a large amount of the fine particles having the above particle size and passing the heat transport fluid through the filter .

According to the first aspect of the heat transport system, when the flow of the heat transport fluid in the flow path is stopped, the low concentration fluid is flowed into the flow path by the control means. The low concentration fluid has a lower concentration of fine particles than the average dispersed state of the fine particles in the heat transport fluid. Therefore, it is possible to prevent fine particles from remaining in the flow path, the heat exchange portion, etc. in the state where the flow of the heat transport fluid is stopped due to the flow of such a low-concentration fluid through the flow path.
Further, in the present invention, the heat transport fluid passes through the filter, but among the fine particles contained in the heat transport fluid, fine particles having a particle size larger than a predetermined size cannot pass through the filter. Here, the heat transport fluid contains more fine particles smaller than a predetermined size than fine particles having a predetermined size or more. Therefore, the heat transport fluid that has passed through the filter can be made into a low-concentration fluid in which the concentration of the fine particles is lower than the average dispersed state of the fine particles in the heat transport fluid.

The heat transport system according to claim 2 has a heat transport fluid in which fine particles that can flow together with the base fluid are mixed in the base fluid, a flow path through which the heat transport fluid flows inside, and a flow path between the flow paths. When the heat exchange section provided and the heat transport fluid flows through the flow path to exchange heat with the heat transport fluid and the flow of the heat transport fluid in the flow path is stopped. A control means for flowing a low-concentration fluid having a concentration of the fine particles lower than the average dispersed state of the fine particles in the heat transport fluid into the flow path is provided, and the fine particles having a particle size of a predetermined size or larger are provided. A filter is provided inside to allow the particles to pass through and flow from one side to the other, and the heat transport fluid flowing from the heat exchange section is on one side of the filter inside. It is provided with a tank that can be flowed in and stored, and can individually discharge the heat transport fluid from each of one side and the other side of the filter to the heat exchange portion side of the flow path.

According to the second aspect of the present invention, when the flow of the heat transport fluid in the flow path is stopped, the low concentration fluid is flowed into the flow path by the control means. The low concentration fluid has a lower concentration of fine particles than the average dispersed state of the fine particles in the heat transport fluid. Therefore, it is possible to prevent fine particles from remaining in the flow path, the heat exchange portion, etc. in the state where the flow of the heat transport fluid is stopped due to the flow of such a low-concentration fluid through the flow path.
Further, in the present invention, a filter through which the heat transport fluid flows is provided inside, and among the fine particles contained in the heat transport fluid, fine particles having a particle size larger than a predetermined size cannot pass through the filter.
Further, in the present invention, a tank is provided, and a filter is provided inside the tank. The heat transport fluid flowing from the heat exchange section flows in and is stored on one side of the filter inside the tank. Further, the tank is allowed to flow out the heat transport fluid individually from each of one side and the other side of the filter. As a result, when the heat transport fluid flows out from the tank that stores the heat transport fluid, the heat transport fluid can be separated into a low concentration fluid and a high concentration fluid having a higher concentration of fine particles than the low concentration fluid.

The heat transport system according to claim 3 is the heat transport system according to claim 1 or 2, wherein the filter cannot pass the fine particles.

According to the heat transport system according to claim 3, the filter is a filter in which fine particles cannot pass through. Therefore, the low concentration fluid, which is the heat transport fluid that has passed through the filter, does not contain fine particles. When such a low-concentration fluid containing no fine particles flows through the flow path, it is possible to effectively prevent the fine particles from remaining in the flow path, the heat exchange portion, or the like in the state where the heat transport fluid is stopped flowing.

The heat transport system according to claim 4 is the heat transport system according to claim 1 or 3, wherein the filter is provided inside, and the heat transport fluid flowing from the heat exchange unit is inside the filter. It is provided with a tank that can flow into and be stored in one side, and can individually flow the heat transport fluid from each of the one side and the other side of the filter inside to the heat exchange portion side of the flow path. ing.

The heat transport system according to claim 4 includes a tank, and a filter is provided inside the tank. The heat transport fluid flowing from the heat exchange section flows in and is stored on one side of the filter inside the tank. Further, the tank is allowed to flow out the heat transport fluid individually from each of one side and the other side of the filter. As a result, when the heat transport fluid flows out from the tank that stores the heat transport fluid, the heat transport fluid can be separated into a low concentration fluid and a high concentration fluid having a higher concentration of fine particles than the low concentration fluid.

The heat transport system according to claim 5 is the heat transport system according to any one of claims 1 to 4, wherein the heat transport fluid flowing from the heat exchange unit is stored inside and the heat transport system is described. A tank capable of allowing the heat transport fluid to flow out to the heat exchange portion side of the flow path, and by being operated, the heat transport fluid is moved inside the tank to suppress precipitation of the fine particles inside the tank. It is provided with a means for suppressing sedimentation.

In the heat transport system according to claim 5, when the precipitation suppressing means is activated, the heat transport fluid is moved inside the tank. This makes it possible to suppress the precipitation of fine particles of the heat transport fluid inside the tank.

As described above, in the heat transport system according to claim 1, it is possible to prevent fine particles from remaining in the flow path, the heat exchange section, etc. in the state where the heat transport fluid is stopped flowing.

It is a circuit diagram of the heat transport system heat transport fluid which concerns on 1st Embodiment. It is a block diagram which shows the outline of the control of the heat transport system which concerns on 1st Embodiment. It is a flowchart which shows the outline of the control of the heat transport system which concerns on 1st Embodiment. It is a circuit diagram of the heat transport system heat transport fluid which concerns on 2nd Embodiment. It is a block diagram which shows the outline of the control of the heat transport system which concerns on 2nd Embodiment.

Next, each embodiment of the present invention will be described with reference to the drawings of FIGS. 1 to 3. The heat transport system 10 according to each of the following embodiments is configured to be used for cooling the fuel cell stack 14 as a heat exchange unit of the fuel cell system 12 mounted on a vehicle (not shown). The left-right direction of the paper, the up-down direction of the paper, etc. in the figure are basically unrelated to each direction with respect to the vehicle, such as the front-rear direction of the vehicle and the width direction of the vehicle. In addition, in explaining each of the following embodiments, the same parts as those of the above-described embodiments are given the same reference numerals as compared with the described embodiments, and detailed explanations thereof will be given. Omit.

<Structure of the first embodiment>
As shown in FIG. 1, the heat transport system 10 includes a first tank 16 constituting a tank, and the heat transport fluid 18 is stored inside the first tank 16. As shown by the chain A of the two-dot chain line, which is an enlarged view of the heat transport fluid 18 in FIG. 1, the heat transport fluid 18 includes a base fluid 20. The base fluid 20 is composed of, for example, an organic solvent such as ethylene glycol or water.

Further, the heat transport fluid 18 includes a large number of fine particles 22. The fine particles 22 are formed of, for example, carbon-based powder particles such as graphite and diamond, and the particle size of the fine particles 22 is, for example, 100 μm or more and 1000 μm or less. The heat transport fluid 18 is mixed with fine particles 22 having a predetermined volume with respect to the total volume of the base fluid 20 in the heat transport system 10. For example, the volume of the fine particles 22 with respect to the total volume of the base fluid 20. The ratio of is about 10%.

The first tank 16 is provided with wings 26 of a stirring device 24 as a means for suppressing precipitation. The wing 26 is provided in the vicinity of the bottom wall portion 28 inside the first tank 16, and the wing 26 can rotate in an axial direction with the vertical direction of the first tank 16 as the axial direction. The stirring device 24 includes a motor 30 (see FIG. 2), and when the motor 30 is operated, the wings 26 are rotated. As a result, the heat transport fluid 18 is agitated, and for example, the fine particles 22 that have settled on the bottom wall portion 28 side of the first tank 16 are dispersed in the upper portion of the base fluid 20 and the like.

As shown in FIG. 2, the motor 30 of the stirring device 24 is electrically connected to the motor driver 32. The motor driver 32 is electrically connected to a control device 34 constituting the control means, and is also electrically connected to a battery (not shown) mounted on the vehicle, and is output from the control device 34 to be a motor. When the motor control signal Ms input to the driver 32 is switched from the Low level to the High level, the motor 30 is operated and the wings 26 are rotated.

Further, the first tank 16 includes a first outflow port 36. The first outflow port 36 is provided, for example, at the lower end in the vertical direction of the first tank 16 in the peripheral wall portion 38 of the first tank 16, and the heat transport fluid 18 stored in the first tank 16 is provided. It can flow out from the first outflow port 36 to the outside of the first tank 16. One end of the first flow path 42 constituting the circulation flow path 40 as the flow path is connected to the first outflow port 36.

The other end of the first flow path 42 is connected to the first inflow port of the three-way valve 44 constituting the control means together with the control device 34 as the adjusting means of the concentration adjusting means. The three-way valve 44 includes two inflow ports, a first inflow port and a second inflow port, and one outflow port, and a valve is provided between one of the first inflow port and the second inflow port and the outflow port. When blocked by the body, the space between the other of the first inflow port and the second inflow port and the outflow port is opened.

As shown in FIG. 2, the first valve drive unit 46 that moves the valve body in the three-way valve 44 is electrically connected to the first valve drive driver 48. The first valve drive driver 48 is electrically connected to the control device 34 and is also electrically connected to a battery (not shown) mounted on the vehicle. For example, the first valve drive driver 48 is output from the control device 34. When the first valve control signal Vs1 input to the first valve drive driver 48 is switched from the Low level to the High level, the valve body is moved, the space between the first inflow port and the outflow port is opened, and the second inflow port is opened. And the outflow port are blocked. Further, when the first valve control signal Vs1 is switched from the high level to the low level, the valve body is moved, the space between the second inflow port and the outflow port is opened, and the space between the first inflow port and the outflow port is blocked. Will be done.

As shown in FIG. 1, one end of the second flow path 50 constituting the circulation flow path 40 is connected to the outflow port of the three-way valve 44. The other end of the second flow path 50 is connected to the supply port of the pump 52 as a fluid feeding device, and when the pump 52 is operated, the heat transport fluid 18 is transferred from the second flow path 50 side to the pump 52. Be sucked in.

As shown in FIG. 2, the pump 52 is electrically connected to the pump driver 54. The pump driver 54 is electrically connected to the control device 34 and is also electrically connected to a battery (not shown) mounted on the vehicle. For example, the pump driver 54 is output from the control device 34. When the pump control signal Ps input to is switched from the Low level to the High level, the pump 52 is operated, and when the pump control signal Ps is switched from the High level to the Low level, the pump 52 is stopped.

On the other hand, as shown in FIG. 2, the control device 34 is electrically connected to the ignition switch 56 of the vehicle. When the ignition device is operated to turn on the ignition switch 56 and the ignition signal Is output from the ignition switch 56 is switched from the low level to the high level, power generation in the fuel cell stack 14 of the fuel cell system 12 is started. To. On the other hand, when the ignition device is operated to turn off the ignition switch 56 and the ignition signal Is output from the ignition switch 56 is switched from the high level to the low level, the fuel cell stack 14 of the fuel cell system 12 is used. Power generation is stopped.

Further, the control device 34 is electrically connected to the speed sensor 58 that detects the speed of the vehicle. When the vehicle starts running (that is, when the running speed of the vehicle becomes greater than 0), the speed detection signal Ss output from the speed sensor 58 switches from the Low level to the High level, and when the vehicle is stopped (that is, when the running speed of the vehicle becomes higher than 0). That is, when the traveling speed of the vehicle becomes 0), the speed detection signal Ss output from the speed sensor 58 switches from the High level to the Low level. The ignition signal Is output from the ignition switch 56 and the speed detection signal Ss output from the speed sensor 58 are input to the control device 34.

On the other hand, one end of the third flow path 60 constituting the circulation flow path 40 is connected to the discharge port of the pump 52 shown in FIG. 1, and when the pump 52 is operated, the second flow path 50 side is connected. The heat transport fluid 18 sucked into the pump 52 is sent out from the discharge port of the pump 52 to the third flow path 60.

The intermediate portion of the third flow path 60 (between one end and the other end of the third flow path 60) passes through the fuel cell stack 14 as a heat exchange portion of the fuel cell system 12. The fuel cell stack 14 includes a plurality of cells. Hydrogen as a fuel gas flows between the positive electrode (anode, fuel electrode) of the cell and the separator on the positive electrode side, and air containing oxygen as an oxidizing agent flows between the negative electrode (cathode, air electrode) of the cell and the separator on the negative electrode side. An electrochemical reaction occurs by flowing between them, thereby generating electricity.

The fuel cell stack 14 is electrically connected to a vehicle drive motor as a drive device via a drive driver mounted on the vehicle, and the fuel cell stack 14 supplies power to the vehicle drive motor to drive the vehicle. The motor is driven. The output shaft of the vehicle drive motor is mechanically connected to the drive wheels of the vehicle, and the vehicle can travel by transmitting the driving force of the vehicle drive motor to the drive wheels.

When an electrochemical reaction between hydrogen and oxygen occurs in the cell of the fuel cell stack 14, the fuel cell stack 14 generates heat. Since the intermediate portion of the third flow path 60 passes through the fuel cell stack 14, heat is exchanged between the fuel cell stack 14 and the heat transport fluid 18 flowing in the third flow path 60. As a result, the fuel cell stack 14 is cooled and the heat transport fluid 18 is heated.

The other end of the third flow path 60 is connected to the radiator 62 as a heat exchange portion, and the heat transport fluid 18 flowing through the third flow path 60 is supplied to the radiator 62. The radiator 62 is arranged, for example, on the vehicle rear side of the radiator grill in the engine room of the vehicle. When the vehicle runs, the running wind passes through the radiator grill and enters the engine room. The traveling wind that has entered the engine room in this way passes through the radiator 62. When the traveling wind passes through the radiator 62, heat is exchanged between the traveling wind and the heat transport fluid 18 passing through the radiator 62, so that the heat transport fluid 18 is cooled. One end of the fourth flow path 64 constituting the circulation flow path 40 is connected to the radiator 62, and the heat transport fluid 18 flowing through the radiator 62 is fed to the fourth flow path 64 to be supplied to the fourth flow path 64. It flows through 64.

The other end of the fourth flow path 64 is connected to the inflow port 66 provided in the first tank 16. The inflow port 66 is provided on the upper portion of the first tank 16, such as the upper wall portion of the lid of the first tank 16 and the upper end portion of the peripheral wall of the first tank 16, and flows through the fourth flow path 64. The heat transport fluid 18 is supplied to the inside of the first tank 16 through the inflow port 66, and the heat transport fluid 18 is accumulated inside the first tank 16.

Here, inside the first tank 16, a plurality of filters 68 constituting the concentration adjusting means are provided as the separating means. Each filter 68 is formed in a cylindrical shape, and the central axis direction of the filter 68 is the vertical direction of the first tank 16. Each of the upper wall, the peripheral wall, and the bottom wall of the filter 68 has a mesh shape, for example, and each of the upper wall, the peripheral wall, and the bottom wall of the filter 68 has a large number of holes communicating inside and outside the filter 68. Has been done. The diameter of the pores of the filter 68 is smaller than the minimum particle size of the fine particles 22 described above. For example, as described above, the particle size of the fine particles 22 is 100 μm or more and 1000 μm or less. For example, the diameter of the hole of the filter 68 is less than 100 μm. Therefore, the fine particles 22 cannot pass through the filter 68.

The entire area of the filter 68 in the central axis direction or the portion below the intermediate portion in the center axis direction is immersed in the heat transport fluid 18 stored in the first tank 16. Therefore, in the portion below the liquid level of the heat transport fluid 18 in the first tank 16 inside the filter 68, the base fluid 20 of the heat transport fluid 18 is outside the filter 68 (one side of the filter 68). From inside (the other side of the filter 68) to the inside of the filter 68.

Further, each filter 68 is provided with a fifth flow path 70 constituting the circulation flow path 40. One end side of the fifth flow path 70 is branched into a plurality of parts on the outside of the filter 68 inside the first tank 16, and each one end side portion of the fifth flow path 70 thus branched is the first tank. From the outside of the filter 68 inside the 16 to the inside of the filter 68 through the upper wall of each filter 68, and further, each end of the fifth flow path 70 is the bottom wall of the filter 68 inside each filter 68. It is located in the vicinity of.

On the other hand, the first tank 16 includes a second outflow port 72. In the second outflow port 72, in the vertical upper portion of the first tank 16 in the peripheral wall portion of the first tank 16, for example, in the peripheral wall portion of the first tank 16, all the heat transport fluid 18 is stored in the first tank 16. It is provided above the liquid level of the heat transport fluid 18 in the state of being. A portion on the other end side of the branch portion of the fifth flow path 70 passes through the second outflow port 72 and extends to the outside of the first tank 16, and the other end of the fifth flow path 70 is described above. It is connected to the second inflow port of the three-way valve 44 of.

<Actions and effects of the first embodiment>
Next, the operation and effect of the present embodiment will be described based on a schematic flowchart of control of the stirring device 24, the three-way valve 44, and the pump 52 by the control device 34 of FIG.

In this heat transport system 10, when the ignition device of the vehicle is operated and the ignition signal Is output from the ignition switch 56 is switched from the Low level to the High level, the stirring device 24 by the control device 34, the three-way valve 44, and the pump 52 Control is started (step 150). Next, in step 152, it is determined whether or not the speed detection signal Ss output from the speed sensor 58 has switched from the Low level to the High level.

When the vehicle starts traveling and the speed detection signal Ss is switched from the Low level to the High level, it is determined in step 154 whether or not the first valve control signal Vs1 output from the control device 34 is at the High level. When the first valve control signal Vs1 is at the Low level in this state, the first valve control signal Vs1 output from the control device 34 in step 156 is switched from the Low level to the High level. When the high level first valve control signal Vs1 output from the control device 34 is input to the first valve drive driver 48 in this way, the valve of the three-way valve 44 is moved. As a result, in the three-way valve 44, the space between the first inflow port and the outflow port is opened, and the space between the second inflow port and the outflow port is closed.

Next, in step 158, the motor control signal Ms output from the control device 34 is switched from the Low level to the High level. As a result, the motor 30 of the stirring device 24 is operated to rotate the wings 26 of the stirring device 24. By rotating the blades 26 of the stirring device 24, the heat transport fluid 18 in the first tank 16 is stirred, and the fine particles 22 that have sunk and accumulated on the bottom wall side of the first tank 16 are on the upper side of the first tank 16. The fine particles 22 are dispersed in the first tank 16 over the entire heat transport fluid 18 except for the inner portion of the filter 68.

Further, in step 158, the pump control signal Ps output from the control device 34 is switched from the Low level to the High level. As a result, when the pump 52 is operated, a negative pressure is generated in the second flow path 50 connected to the supply port of the pump 52, and the heat transport fluid 18 is sucked from the second flow path 50 into the pump 52. In this state, in the three-way valve 44, the space between the first inflow port and the outflow port is opened, and the space between the second inflow port and the outflow port is blocked. Therefore, the heat transport fluid 18 on the second flow path 50 side is sucked into the pump 52, so that the heat transport fluid 18 in the first tank 16 becomes the first outflow port 36 of the first tank 16 and the first flow path. 42, it flows into the second flow path 50 through between the first inflow port and the outflow port of the three-way valve 44.

Further, the heat transport fluid 18 sucked into the pump 52 is discharged from the discharge port of the pump 52 to the third flow path 60. The heat transport fluid 18 discharged to the third flow path 60 passes through the fuel cell stack 14 of the fuel cell system 12 at the intermediate portion of the third flow path 60. In this state, power is generated in the cells of the fuel cell stack 14, which causes the fuel cell stack 14 to generate heat.

In this state, when the heat transport fluid 18 passes through the fuel cell stack 14, heat is exchanged between the heat transport fluid 18 and the fuel cell stack 14. In particular, in the present embodiment, the fine particles 22 are mixed in the base fluid 20 of the heat transport fluid 18, and when the fine particles 22 come into contact with the inner peripheral portion of the third flow path 60 in the fuel cell stack 14. , The base fluid 20 containing the fine particles 22 is more efficient than the base fluid 20 alone (that is, the base fluid 20 not containing the fine particles 22), the heat of the third flow path 60, and thus the heat generated in the fuel cell stack 14. To absorb. As a result, the fuel cell stack 14 can be efficiently cooled.

Further, the heat transport fluid 18 that has passed through the fuel cell stack 14 further flows through the third flow path 60, and is supplied to the radiator 62 from the other end of the third flow path 60. When the heat transport fluid 18 is fed to the radiator 62, the base fluid 20 containing the fine particles 22 flows in the radiator 62. In this state, the vehicle is running. Therefore, the traveling wind passes through the radiator 62 arranged on the rear side of the radiator grill in the engine room of the vehicle. When the traveling wind passes through the radiator 62, heat is exchanged between the traveling wind and the heat transport fluid 18 passing through the radiator 62. In particular, in the present embodiment, the fine particles 22 are mixed in the base fluid 20 of the heat transport fluid 18, and the fine particles 22 are in the flow path of the heat transport fluid 18 in the radiator 62 in the fuel cell stack 14. Upon contact with the inner circumference, the base fluid 20 containing the fine particles 22 can transfer heat to the radiator 62 more efficiently than the base fluid 20 alone (ie, the base fluid 20 not containing the fine particles 22), thereby transferring heat to the radiator 62. , The heat transport fluid 18 can be efficiently cooled.

Further, the heat transport fluid 18 that has flowed through the radiator 62 flows through the fourth flow path 64, and flows from the inflow port 66 of the first tank 16 to the inside of the first tank 16. In this way, the heat transport fluid 18 is circulated.

On the other hand, as shown in FIG. 3, when the pump control signal Ps and the motor control signal Ms output from the control device 34 are switched from the Low level to the High level in step 158, the timer program of the control device 34 is set in step 160. Is activated. Next, it is determined whether or not the speed detection signal Ss output from the speed sensor 58 is switched from the High level to the Low level in step 162, that is, whether or not the vehicle has stopped, and the vehicle running state is continued. For example, in step 164, it is determined whether or not the elapsed time T in the timer program is less than the predetermined first set time Ts1.

When the elapsed time T becomes the first set time Ts1 or more, the motor control signal Ms output from the control device 34 in step 166 is switched from the High level to the Low level, and the elapsed time T in the timer program is reset. (That is, the elapsed time T is set to 0). As a result, the stirring device 24 is stopped.

Next, it is determined in step 162 whether or not the speed detection signal Ss output from the speed sensor 58 has switched from the High level to the Low level, that is, whether or not the vehicle has stopped, and in this state, the vehicle is stopped. When the speed detection signal Ss is switched from the high level to the low level, the first valve control signal Vs1 output from the control device 34 in step 170 is switched from the high level to the low level. Further, when the vehicle is stopped at the stage of step 162 and the speed detection signal Ss is switched from the high level to the low level, the same processing as in step 166 is performed in step 172, and the first valve control signal Vs1 is performed in step 170. Switches from the High level to the Low level.

As described above, when the first valve control signal Vs1 output from the control device 34 is switched from the high level to the low level in step 170, the valve body of the three-way valve 44 is operated by the first valve drive driver 48, whereby the valve body of the three-way valve 44 is operated. The space between the second inflow port and the outflow port of the three-way valve 44 is opened, and the space between the first inflow port and the outflow port is closed. In this state, the heat transport fluid 18 on the second flow path 50 side is sucked into the pump 52, so that the heat transport fluid 18 in the first tank 16 becomes the second outflow port 72 and the fifth flow of the first tank 16. It flows to the second flow path 50 through the path 70, between the second inflow port and the outflow port of the three-way valve 44.

Here, each end of the fifth flow path 70 is arranged in the vicinity of the bottom wall of the filter 68 inside each filter 68. Therefore, the heat transport fluid 18 is sucked from the inside of each filter 68 from each end of the fifth flow path 70. When the heat transport fluid 18 is sucked from each end of the fifth flow path 70 inside each filter 68, the heat transport fluid 18 flows from the outside of each filter 68 inside the first tank 16 to the inside of each filter 68. The diameter dimension of the large number of holes communicating inside and outside the filter 68 is smaller than the minimum particle diameter dimension of the fine particles 22 of the heat transport fluid 18.

Therefore, the base fluid 20 of the heat transport fluid 18 can pass through the filter 68, but the fine particles 22 cannot pass through the filter 68. As a result, the heat transport fluid 18 outside the filter 68 is a high-concentration fluid in which fine particles 22 are mixed with the base fluid 20, and the heat transport fluid 18 inside the filter 68 is composed of only the base fluid 20 (). That is, it is a low-concentration fluid (that is, the concentration of the fine particles 22 is low). Therefore, in a state where the space between the second inflow port and the outflow port of the three-way valve 44 is opened and the space between the first inflow port and the outflow port is closed, the pump 52 heat transports the base fluid 20 only. The fluid 18 (low concentration fluid) flows through the circulation flow path 40 and the radiator 62.

Further, in step 174, the timer program of the control device 34 is operated, and in step 176, it is determined whether or not the elapsed time T in the timer program is less than the predetermined second set time Ts2. When it is determined in step 176 that the elapsed time T becomes equal to or greater than the predetermined second set time Ts2, the pump control signal Ps output from the control device 34 in step 178 is switched from the High level to the Low level. , Pump 52 is stopped.

Here, in the second set time Ts2 described above, the heat transport fluid 18 (low concentration fluid) sucked from each end of the fifth flow path 70 by the operation of the pump 52 is transferred to the circulation flow path 40 and the circulation flow path 40. It is set to be longer than the time required to return from the inflow port 66 of the first tank 16 to the inside of the first tank 16 through the radiator 62.

Therefore, from the time when the space between the second inflow port and the outflow port of the three-way valve 44 is opened and the space between the first inflow port and the outflow port is closed until the pump 52 is stopped. The heat transport fluid 18 (low concentration fluid) composed of only the base fluid 20 is sucked from each end of the fifth flow path 70, flows through the circulation flow path 40 and the radiator 62, and further returns to the inside of the first tank 16. (That is, the fine particles 22 of the circulation flow path 40 and the radiator 62 are collected in the first tank 16). As a result, after the pump 52 is stopped (that is, after the flow of the heat transport fluid 18 in the circulation flow path 40 and the radiator 62 is stopped), the fine particles 22 are transferred into the circulation flow path 40 and the radiator 62. It can be suppressed from remaining inside.

In this way, it is possible to prevent the fine particles 22 from remaining in the circulation flow path 40 and the radiator 62 in the state where the flow of the heat transport fluid 18 is stopped, so that the fine particles 22 are in the circulation flow path 40 and in the radiator 62. When the flow of the heat transport fluid 18 is resumed, the heat transport fluid 18 can smoothly flow in the circulation flow path 40 and the radiator 62, and the heat transport system 10 can be prevented from sinking and accumulating. Durability can be improved. This facilitates maintenance of the heat transport system 10 and reduces maintenance costs.

Further, in the present embodiment, when the flow of the heat transport fluid 18 in the circulation flow path 40 and the radiator 62 is started (including at the time of restart), the stirring device 24 is operated and the inside of the first tank 16 is operated. The fine particles 22 are dispersed in the entire heat transport fluid 18 except for the inner portion of the filter 68. As a result, at the start of the flow of the heat transport fluid 18, it is possible to prevent the fine particles 22 that greatly exceed the average concentration of the fine particles 22 in the heat transport fluid 18 from flowing from the first tank 16 to the circulation flow path 40 or the like.

<Second embodiment>
As shown in FIG. 4, in the second embodiment, the filter 68 as the separating means has a plate shape. The thickness direction of the filter 68 is the vertical direction of the first tank 16, and is arranged near the lower end portion of the first tank 16 inside the first tank 16. Further, the first outflow port 36 of the first tank 16 is provided on the peripheral wall portion 38 of the first tank 16 above the first tank 16 with respect to the filter 68.

Further, the second outflow port 72 of the first tank 16 is provided on the bottom wall portion 28 of the first tank 16, and the second outflow port 72 of the first tank 16 constitutes a circulation flow path 40. One end of 6 flow paths 82 is connected. Therefore, when the heat transport fluid 18 in the first tank 16 flows from the second outflow port 72 of the first tank 16 to the outside of the first tank 16 by its own weight, the heat transport fluid 18 passes through the filter 68. As a result, below the filter 68 in the first tank 16, the heat transport fluid 18 becomes a low-concentration fluid containing no fine particles 22.

On the other hand, the heat transport system 10 according to the present embodiment includes a second tank 84 that constitutes a tank together with the first tank 16. In the present embodiment, the second tank 84 is provided below the first tank 16. An inflow port 88 is provided on the upper wall portion 86 (or a lid) of the second tank 84, and the other end of the sixth flow path 82 is connected to the inflow port 88.

Therefore, the heat transport fluid 18 which has passed through the filter 68 and becomes a low-concentration fluid containing no fine particles 22 has the second outflow port 72 of the first tank 16, the sixth flow path 82, and the inflow port 88 of the second tank 84. It passes through and is stored in the second tank 84. The outflow port 92 of the second tank 84 is provided near the lower end portion of the second tank 84 in the peripheral wall portion 90 of the second tank 84, and one end of the fifth flow path 70 is connected to the outflow port 92. ..

Further, the heat transport system 10 according to the present embodiment includes a sluice valve 94. The sluice valve 94 is provided in the middle portion of the sixth flow path 82, and the heat transport fluid 18 flowing from the first tank 16 to the second tank 84 flows through the sluice valve 94. The sluice valve 94 is composed of, for example, a solenoid valve having two ports (a structure having one inflow port and one outflow port), and the flow path of the heat transport fluid 18 in the sluice valve 94 is the sluice valve 94. The second valve drive unit 96 (see FIG. 5) is operated to move the valve body in the sluice valve 94 to open and close the valve body.

As shown in FIG. 5, the second valve drive unit 96 of the sluice valve 94 is electrically connected to the second valve drive driver 98. The second valve drive driver 98 is electrically connected to the control device 34 and is also electrically connected to a battery (not shown) mounted on the vehicle. For example, the second valve drive driver 98 is output from the control device 34 and has a second valve drive driver 98. When the second valve control signal Vs2 input to the two-valve drive driver 98 is switched from the Low level to the High level, the valve body is moved, the flow path of the heat transport fluid 18 in the sluice valve 94 is blocked, and the second valve control is performed. When the signal Vs2 is switched from the High level to the Low level, the valve body is moved and the flow path of the heat transport fluid 18 in the sluice valve 94 is opened.

Further, the heat transport system 10 according to the present embodiment includes a liquid level sensor 100 as a storage amount detecting means. The liquid level sensor 100 is provided in the second tank 84, and detects whether or not the liquid level of the heat transport fluid 18 (low concentration fluid) in the second tank 84 has reached a predetermined height. There is. On the other hand, as shown in FIG. 5, the liquid level sensor 100 is electrically connected to the control device 34, and the liquid level detection signal Fs output from the liquid level sensor 100 is input to the control device 34. ..

When the liquid level of the heat transport fluid 18 (low concentration fluid) in the second tank 84 becomes equal to or higher than a predetermined height, the liquid level sensor 100 switches the liquid level detection signal Fs from the Low level to the High level. When the high level liquid level detection signal Fs is input to the control device 34, the control device 34 switches the second valve control signal Vs2 from the low level to the high level. On the other hand, when the liquid level of the heat transport fluid 18 (low concentration fluid) in the second tank 84 becomes less than a predetermined height, the liquid level sensor 100 changes the liquid level detection signal Fs from the High level to the Low level. Switch to. When the low level liquid level detection signal Fs is input to the control device 34, the control device 34 switches the second valve control signal Vs2 from the high level to the low level.

That is, in the present embodiment, when a predetermined amount of the heat transport fluid 18 (low concentration fluid) is accumulated in the second tank 84, the flow path of the heat transport fluid 18 in the sluice valve 94 is blocked. As a result, it is possible to prevent the heat transport fluid 18 from flowing from the first tank 16 to the second tank 84 in a state where a predetermined amount of the heat transport fluid 18 (low concentration fluid) is accumulated in the second tank 84.

Further, in the present embodiment, the control of the stirring device 24, the three-way valve 44, and the pump 52 by the control device 34 is basically the same as that of the first embodiment. Therefore, this embodiment can basically obtain the same effect as that of the first embodiment.

Although the present embodiment has a configuration in which the sluice valve 94 is provided in the sixth flow path 82, it is not necessary to provide a configuration that has the same effect as the sluice valve 94 or the sluice valve 94.

Further, in the present embodiment, the second tank 84 is provided, but the second tank 84 is not provided, and one end of the fifth flow path 70 is connected to the second outflow port of the first tank 16. May be.

Further, in the present embodiment, the thickness direction of the filter 68 is the vertical direction of the first tank 16, but the thickness direction of the filter 68 is the direction inclined with respect to the vertical direction of the first tank 16. The inside of the tank 16 may be partitioned by the filter 68 in a direction inclined with respect to the vertical direction of the first tank 16.

Further, in each of the above embodiments, the adjusting means of the concentration adjusting means constituting the controlling means is a three-way valve 44. However, for example, two ports (one inflow port and one outflow port) are provided in each of the portion between the other end of the first flow path 42 and one end of the second flow path 50 and the intermediate portion of the fifth flow path 70. A sluice valve such as a solenoid valve (with a structure having) may be provided as an adjusting means, and the other end of the fifth flow path 70 may be connected to the intermediate portion of the second flow path 50. That is, as the adjusting means, the heat transport fluid 18 sucked by the pump 52 in the operating state of the pump 52 flows through the heat transport fluid 18 (high concentration fluid) flowing through the first flow path 42 and the heat transport fluid 18 flowing through the fifth flow path 70. If it is possible to switch from one of 18 (low concentration fluid) to the other, it can be widely applied without being limited to the specific embodiment.

Further, in each of the above embodiments, when the traveling vehicle is stopped, the heat transport fluid 18 (low concentration fluid) composed of only the base fluid 20 flows to the circulation flow path 40 and the radiator 62. Met. However, even if the vehicle is not stopped, the heat transport fluid 18 (low concentration fluid) may flow to the circulation flow path 40 and the radiator 62 when the traveling speed of the vehicle becomes less than a certain value.

Further, in each of the above embodiments, the first valve drive unit 46 of the three-way valve 44 as the adjusting means is controlled based on the traveling speed of the vehicle. However, for example, the liquid temperature of the heat transport fluid 18 in the first tank 16 is detected by a temperature detection means such as a liquid temperature detection sensor, and when the liquid temperature is above a certain temperature, the first inflow of the three-way valve 44 is performed. The first valve drive unit 46 of the three-way valve 44 is controlled so as to open the space between the port and the outflow port and close the space between the second inflow port and the outflow port. The configuration is also such that the first valve drive unit 46 of the three-way valve 44 is controlled so as to open the space between the second inflow port and the outflow port of the three-way valve 44 and close the space between the first inflow port and the outflow port. good.

Further, for example, a power generation amount detecting means for detecting the power generation amount in the fuel cell system 12 is provided, and when the power generation amount in the fuel cell system 12 is a certain size or more, the first inflow port of the three-way valve 44 is provided. The first valve drive unit 46 of the three-way valve 44 is controlled so as to open the space between the outflow port and block the space between the second inflow port and the outflow port, and the amount of power generated by the fuel cell system 12 is constant. If it is less than the above, the first valve drive unit 46 of the three-way valve 44 is opened so as to open the space between the second inflow port and the outflow port of the three-way valve 44 and close the space between the first inflow port and the outflow port. It may be configured to control.

In this way, the timing for changing the concentration of the fine particles 22 in the heat transport fluid 18 flowing through the circulation flow path 40 and the radiator 62 is before the circulation of the heat transport fluid 18 in the circulation flow path 40 and the radiator 62 is stopped. For example, the specific timing is not limited to the specific timing and the specific configuration for detecting the timing.

Further, in each of the above embodiments, the heat transport fluid 18 sucked by the pump 52 in the operating state of the pump 52 is the heat transport fluid 18 (high concentration fluid) flowing through the first flow path 42 or the fifth flow path 70. It was a flowing heat transport fluid 18 (low concentration fluid). However, for example, the heat transport fluid 18 (high concentration fluid) flowing through the first flow path 42 and the heat transport fluid 18 composed of only the base fluid 20 flowing through the fifth flow path 70 are mixed to form the first flow path 42. The heat transport fluid 18 (low concentration fluid) having a smaller concentration of the fine particles 22 than the flowing heat transport fluid 18 (high concentration fluid) may be formed.

Further, in the present embodiment, the heat transport fluid 18 passes through the filter 68 to become a low concentration fluid in which the concentration of the fine particles 22 in the heat transport fluid 18 is low. However, for example, after the main heat transport system 10 is stopped, the fine particles 22 in the heat transport fluid 18 are waited to settle in the first tank 16, and then the heat transport fluid 18 in the first tank 16 is waited for. The supernatant liquid may be used as a low-concentration fluid and flowed through the circulation flow path 40.

Further, the fine particles 22 contained in the heat transport fluid 18 had a structure formed by carbon-based powder particles such as graphite and diamond. However, the fine particles 22 may be formed of metal oxide powder particles such as silica (silicon dioxide) and alumina, ceramic powder particles such as aluminum nitride, and metal powder particles such as copper. That is, regarding the material of the fine particles 22, the specific specifications of the heat transport system 10, for example, the volume of the first tank 16, the performance of the pump 52, the material and size of the circulation flow path 40, and the fuel cell system 12. It can be appropriately selected based on the calorific value of the fuel cell stack 14, the cooling capacity of the radiator 62, and the like.

Further, in the present embodiment, the particle size of the fine particles 22 is 100 μm or more and 1000 μm or less, but the particle size of the fine particles 22 is also the specific specification of the heat transport system 10 as described above. It can be selected as appropriate based on.

Further, the particle size of the fine particles 22 may be constant, or may have a predetermined range such as, for example, 100 μm or more and 300 μm or less. Further, when the particle size of the fine particles 22 has a predetermined range, the filter 68 may be configured so that the smallest fine particles 22 cannot pass through, or may be within the range of the particle size of the fine particles 22. Therefore, the structure may be such that the fine particles 22 having a particle size larger than a certain size cannot pass through.

Further, in each of the above embodiments, the ratio of the volume of the fine particles 22 to the total volume of the base fluid 20 is about 10%. However, the ratio of the volume of the fine particles 22 to the total volume of the base fluid 20 can be appropriately selected based on the specific specifications of the main heat transport system 10 as described above.

Further, in each of the above-described embodiments, the stirring device 24 for rotating the wings 26 to stir the heat transport fluid 18 is used as the precipitation suppressing means. However, for example, in the portion where the heat transport fluid 18 containing the fine particles 22 is stored in the first tank 16, the heat transport fluid 18 or a jet of air or the like is generated, and the fine particles 22 in the heat transport fluid 18 settle. You may suppress doing so. That is, the precipitation suppressing means is limited to a specific embodiment as long as it can suppress the precipitation of the fine particles 22 in the heat transport fluid 18 by moving the heat transport fluid 18 in the first tank 16. It's not a thing.

Further, the above embodiment is a heat transport system 10 applied for cooling the fuel cell stack 14 of the fuel cell system 12. However, for example, the present invention may be applied to a heat transport system for cooling a gasoline engine, a diesel engine or the like applied as a drive source of a vehicle or the like, or installed in a building such as a house or a factory, a ship or the like. The present invention may be applied for cooling a fuel cell system, an engine, or the like. That is, if it is a heat transport system having a configuration in which heat is exchanged between a cooling target or a heating target and a heat transport fluid by flowing a heat transport fluid containing fine particles in a flow path, the specific embodiment is used. There is no limitation.

10 Heat transport system 14 Fuel cell stack (heat exchange section)
16 1st tank (tank)
18 Heat transport fluid 20 Base fluid 22 Fine particles 24 Stirrer (precipitation suppressing means)
40 Circulation flow path (flow path)
68 Filter 84 2nd tank (tank)

Claims (5)

A heat transport fluid in which fine particles that can flow with the base fluid are mixed in the base fluid,
The flow path through which the heat transport fluid flows inside,
A heat exchange unit provided in the middle of the flow path and capable of exchanging heat with the heat transport fluid by allowing the heat transport fluid to flow through the flow path.
When the flow of the heat transport fluid in the flow path is stopped, a low-concentration fluid having a concentration of the fine particles lower than the average dispersed state of the fine particles in the heat transport fluid is flowed in the flow path. Control means and
A filter that prevents the passage of the fine particles having a particle size larger than a predetermined size and allows the heat transport fluid to flow from one side to the other.
Equipped with
The heat transport fluid contains more of the fine particles having a particle size of a predetermined size or larger than the fine particles having a particle size of less than the predetermined size.
A heat transport system in which the low concentration fluid is produced by passing the heat transport fluid through the filter . A heat transport fluid in which fine particles that can flow with the base fluid are mixed in the base fluid,
The flow path through which the heat transport fluid flows inside,
A heat exchange unit provided in the middle of the flow path and capable of exchanging heat with the heat transport fluid by allowing the heat transport fluid to flow through the flow path.
When the flow of the heat transport fluid in the flow path is stopped, a low-concentration fluid having a concentration of the fine particles lower than the average dispersed state of the fine particles in the heat transport fluid is flowed in the flow path. Control means and
Equipped with
A filter is provided inside to allow the fine particles having a particle size of a predetermined size or larger to pass through, and the heat transport fluid flows from one side to the other, and the heat transport flows from the heat exchange unit. The fluid flows into and is stored on one side of the filter on the inside, and the heat transport fluid is individually transferred from each of one side and the other side of the filter on the inside to the heat exchange portion side of the flow path. A heat transport system with an outflowable tank . The heat transport system according to claim 1 or 2, wherein the filter is impassable for the passage of the fine particles. The filter is provided on the inner side, and the heat transport fluid flowing from the heat exchange unit flows into and is stored on one side of the filter on the inner side, and is stored on one side and the other side of the filter on the inner side, respectively. The heat transport system according to claim 1 or 3, further comprising a tank capable of allowing the heat transport fluid to flow out to the heat exchange portion side of the flow path individually. A tank in which the heat transport fluid flowing from the heat exchange section is stored inside and the heat transport fluid can flow out to the heat exchange section side of the flow path.
A precipitation suppressing means for suppressing the precipitation of the fine particles inside the tank by moving the heat transport fluid inside the tank by being operated.
The heat transport system according to any one of claims 1 to 4.

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