JP7131500B2 - heat exchanger cooler - Google Patents

Description

The present invention relates to heat exchanger cooling devices.

Patent Literature 1 listed below discloses a technique related to an apparatus for spraying water on the front surface of a heat exchanger and utilizing latent heat of vaporization when the water evaporates to cool the heat exchanger. Briefly, as shown in FIG. 1 of Patent Document 1, this prior art includes a main tank and a sub-tank having a smaller capacity than the main tank, and directs the water in the main tank to the spraying device. and a second spraying pump for pressure-feeding the water in the sub-tank toward the main tank or the spraying device via the three-way valve.

JP 2019-43385 A

However, in the above prior art, the pump for pressure-feeding the water in the main tank toward the spraying device is only the first spraying pump. However, there is room for improvement in terms of suppressing excessive use of the first spray pump without increasing the number of pumps.

In consideration of the above facts, the present invention is capable of suppressing the excessive use of dedicated pumps for sending the water in the main tank to the water discharge part while suppressing the number of pumps while sufficiently using the water in the main tank. It is an object to obtain a heat exchanger cooling device.

The heat exchanger cooling device of the present invention described in claim 1 comprises a water discharge section for discharging water toward a heat exchanger, a main tank for storing water supplied to the water discharge section, and a sub-tank that has a small capacity to store water; a first flow path that connects the first outlet of the main tank and the water discharge section; and a second flow path that connects the inlet of the main tank and the water discharge section. two flow paths, a third flow path connecting the second outlet of the main tank and the outlet of the sub-tank, a connecting flow path connecting the second flow path and the third flow path, a first pump provided in the first flow path for sending water to the water discharge part; a second pump provided in the connecting flow path for sending water to the second flow path; A first three-way valve provided at a connection portion with a second flow path and switching between a state in which the second pump and the main tank are communicated and a state in which the second pump and the water discharge portion are communicated. and a state in which the sub-tank and the second pump are communicated with each other, and a state in which the main tank and the second pump are communicated with each other. and a switching second three-way valve.

According to the above configuration, the water discharge section discharges water toward the heat exchanger. The main tank stores the water to be supplied to the water discharge part, the first outlet of the main tank and the water discharge part are connected by the first flow path, and the water is supplied to the water discharge part by the first pump provided in the first flow path. Sent. On the other hand, the inlet of the main tank and the water discharge part are connected by a second channel, the second outlet of the main tank and the outlet of the sub-tank are connected by a third channel, and the second channel and the third The channels are connected by connecting channels. A second pump provided in the connecting channel sends water to the side of the second channel. In addition, the first three-way valve provided at the connecting portion between the connecting flow path and the second flow path has a state in which the second pump and the main tank are communicated, and a state in which the second pump and the water discharge portion are communicated. and switch to Furthermore, the second three-way valve provided at the connecting portion between the third flow path and the connecting flow path has a state in which the sub-tank and the second pump are communicated, and a state in which the main tank and the second pump are communicated. switch to

As described above, the second three-way valve allows communication between the sub-tank and the second pump, and the first three-way valve allows communication between the second pump and the main tank. water is sent to Further, the second three-way valve communicates the main tank and the second pump, the first three-way valve communicates the second pump and the water discharge section, and the second pump is operated. Water is sent to the water discharge part. As a result, it is possible to suppress the excessive use of the first pump while suppressing the number of pumps while sufficiently using the water in the main tank.

As described above, according to the heat exchanger cooling device of the present invention, a dedicated pump is provided to send the water in the main tank to the water discharge part while sufficiently using the water in the main tank and reducing the number of pumps. It has an excellent effect of suppressing excessive use of the first pump.

1 is a diagram schematically showing the configuration of a fuel cell system including a heat exchanger cooling device according to one embodiment as viewed from the side of a vehicle; FIG. 1 is a block diagram showing part of a control system of a fuel cell system according to one embodiment; FIG. FIG. 4 is a diagram schematically showing the flow of water when water is stored in a main tank; FIG. 4 is a diagram schematically showing the flow of water when the first pump is operated to send water in the main tank to the water discharge section; FIG. 4 is a diagram schematically showing the flow of water when the second pump is operated to send water in the main tank to the water discharge section; It is a figure which shows an example of the pump applicable to a 1st pump and a 2nd pump.

A heat exchanger cooling device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. FIG. 1 schematically shows the configuration of a fuel cell system 10 including a heat exchanger cooling device 30 according to the present embodiment as viewed from the side of a vehicle. A fuel cell system 10 shown in FIG. 1 is mounted on an electric vehicle and has a fuel cell 12 .

Air containing oxygen is supplied to the fuel cell 12 through an air passage 14 and hydrogen is supplied through a hydrogen passage 15 . The fuel cell 12 generates heat and moisture-containing exhaust gas during output (power generation). A cooling water circuit 18 is provided in the fuel cell system 10 to maintain the temperature of the fuel cell 12 within a predetermined allowable range.

The cooling water circuit 18 has a cooling water circulation flow path 20 , a water pump 22 , a radiator 24 as a heat exchanger, and a blower fan 26 . The coolant circulation flow path 20 is configured to circulate through the fuel cell 12 and the radiator 24 . The water pump 22 is provided in the cooling water circulation flow path 20 and circulates the cooling water by pumping the cooling water. The radiator 24 exchanges heat between the cooling water flowing inside the heat exchange section and the air flowing from the front side of the electric vehicle to the rear side of the vehicle (see the direction of arrow D), thereby generating heat in the fuel cell 12. release heat. A blower fan 26 is arranged on the vehicle rear side of the radiator 24 . The blower fan 26 generates an airflow from the front side of the vehicle to the rear side of the vehicle.

Further, the fuel cell system 10 is provided with a gas-liquid separator 16 on the downstream side of the fuel cell 12 in the air passage 14 . The gas-liquid separator 16 recovers the exhaust gas containing moisture generated during the output of the fuel cell 12, separates the exhaust gas into gas and water, and stores the water whose temperature has been lowered. The water stored in the gas-liquid separator 16 has a very high purity. The gas-liquid separator 16 is connected to a sub-tank 36 via a liquid feed path 28 so that water stored in the gas-liquid separator 16 is supplied to the sub-tank 36 . Since the sub-tank 36 collects the wastewater in the exhaust gas generated from the fuel cell 12, the viewpoint of drainage performance and power saving (that is, the viewpoint of using the pressure of the exhaust gas as a liquid feeding force to the sub-tank 36). Therefore, it is preferable to place the fuel cell 12 directly under or substantially directly under the fuel cell 12, and it is required to avoid an increase in size from the viewpoint of freedom of mounting.

On the other hand, a water discharge portion 32 for discharging water W (liquid water) toward the radiator 24 is arranged on the front side of the vehicle with respect to the upper portion of the radiator 24 . The water discharge part 32 has a cylindrical housing that extends in the width direction of the vehicle and into which water can flow. is formed. Water W discharged (also referred to as jet) from the water discharge portion 32 rides on an air flow from the front side of the vehicle to the rear side of the vehicle, and is sprayed on the heat radiating surface of the heat exchange portion of the radiator 24. It is

A main tank 34 and the aforementioned sub-tank 36 are connected to the water discharge portion 32 . The main tank 34 stores water to be supplied to the water discharge portion 32 . At the top of the main tank 34, a water inlet (not shown) is provided in addition to an inlet 34B, which will be described later, through which water can be supplied into the main tank 34. Further, the sub-tank 36 stores water supplied from the gas-liquid separator 16 described above through the liquid feed path 28 . The sub-tank 36 has a smaller capacity than the main tank 34 .

The heat exchanger cooling device 30 has a first flow path 40 connecting a first outflow port 34A in the lower part of the main tank 34 and the water discharge part 32, and an inflow port 34B in the upper part of the main tank 34 and the water discharge part 32. has a second flow path 42 that connects the The downstream part of the first flow path 40 and the downstream part of the second flow path 42 are combined together to form a confluence flow path part 43 . Further, as an example, a check valve (not shown) for backflow prevention is provided at the first outflow port 34A of the main tank 34 . A first pump 50 for sending water to the water discharge section 32 is provided in the first flow path 40 . The first pump 50 is an electric pump, and as an example, can be operated at a variable speed by an inverter.

The heat exchanger cooling device 30 has a third channel 44 connecting the second outlet 34C at the bottom of the main tank 34 and the outlet 36A of the sub-tank 36, and the second channel 42 and the third channel 44 It has a connecting channel 46 that connects the . In addition, as an example, the second outlet 34C of the main tank 34 and the outlet 36A of the sub-tank 36 are each provided with a check valve (not shown) for backflow prevention. The connecting channel 46 is provided with a second pump 52 that sends water to the second channel 42 side. The second pump 52 is an electric pump like the first pump 50, and as an example, can be operated at a variable speed by an inverter.

A first three-way valve 54 is provided at the connecting portion between the connecting channel 46 and the second channel 42 . The first three-way valve 54 switches between a state in which the second pump 52 and the main tank 34 are communicated and a state in which the second pump 52 and the water discharge section 32 are communicated.

A second three-way valve 56 is provided at the connecting portion between the third flow path 44 and the connecting flow path 46 . The second three-way valve 56 switches between a state in which the sub-tank 36 and the second pump 52 are communicated and a state in which the main tank 34 and the second pump 52 are communicated.

FIG. 2 shows a block diagram of part of the control system of the fuel cell system 10 according to this embodiment. As shown in FIG. 2 , the fuel cell system 10 has a controller 60 . The control device 60 includes a CPU, RAM, ROM, and an input/output interface (I/O), which are communicably connected to each other via a bus. Also, the input/output interface unit communicates with an external device.

As shown in FIG. 2, the fuel cell 12 and the water temperature sensor 62 are connected to the controller 60 . The water temperature sensor 62 is provided in the cooling water circulation flow path 20 (see FIG. 1). The control device 60 can acquire the output of the fuel cell 12 and the temperature of the cooling water in the cooling water circulation passage 20 .

Control target devices such as the water pump 22 , the blower fan 26 , the first pump 50 , the second pump 52 , the first three-way valve 54 and the second three-way valve 56 are connected to the control device 60 . The control device 60 functions as a control unit by reading a control program from the ROM and developing it in the RAM, and executing the control program developed in the RAM by the CPU, and controls the operation of each device to be controlled. It's like

The control device 60 also has a timer 60T. The timer 60T measures the continuous operating time of the first pump 50 when the first pump 50 is operating (operating state), and measures the continuous operating time of the second pump 52 when the second pump 52 is operating (operating state). is doing. The timer 60T resets the value of the continuous operation time of the first pump 50 when the first pump 50 is stopped, and resets the value of the continuous operation time of the second pump 52 when the second pump 52 is stopped. Further, the control device 60 stores in advance an upper limit value of the time allowed for continuous operation of each of the first pump 50 and the second pump 52 (hereinafter abbreviated as "upper limit value of continuous operation time"). .

Next, regarding the operation of the fuel cell system 10, the operation of the heat exchanger cooling device 30 shown in FIG. 1 and the like will be mainly described.

When water is stored in the main tank 34, the water is made to flow as indicated by the two-dot chain line arrow in FIG. That is, first, the water generated when the fuel cell 12 outputs is passed through the gas-liquid separator 16 and the liquid feed path 28 in this order, and stored in the sub-tank 36 . Next, the sub-tank 36 and the second pump 52 are communicated by the second three-way valve 56, the second pump 52 and the main tank 34 are communicated by the first three-way valve 54, and the second pump 52 is operated. Let Water is thereby sent from the sub-tank 36 to the main tank 34 .

When sending water from the main tank 34 to the water discharge part 32, the first mode in which water flows as shown by the two-dot chain line arrow in FIG. and a second mode of flowing water to. In the first mode shown in FIG. 4, the first pump 50 is operated. In the second mode shown in FIG. 5, the main tank 34 and the second pump 52 are communicated by the second three-way valve 56, and the second pump 52 and the water discharge section 32 are communicated by the first three-way valve 54. and the second pump 52 is operated.

An example of control processing executed when water is sent from the main tank 34 to the water discharge section 32 will be described below.

First, when the normal cooling capacity (cooling load) is required for the heat exchanger cooling device 30 shown in FIG. ), the CPU of the control device 60 controls such that the above-described first mode shown in FIG. 4 is executed. When the continuous operation time of the first pump 50 measured by the timer 60T shown in FIG. 2 exceeds the preset upper limit value of the continuous operation time of the first pump 50, the CPU of the control device 60 It controls to stop the operation of the first pump 50 and controls to switch to the second mode shown in FIG. 5 described above.

After that, when the continuous operation time of the second pump 52 measured by the timer 60T shown in FIG. 2 exceeds the preset upper limit value of the continuous operation time of the second pump 52, the CPU of the control device 60 It controls to stop the operation of the second pump 52 and controls to switch to the first mode shown in FIG. 4 described above.

Thereafter, the CPU of the control device 60 shown in FIG. 2 controls the second mode shown in FIG. 5 and the first mode shown in FIG. 4 to be alternately executed so as to repeat the above control processing. do. Then, the CPU of the control device 60 shown in FIG. As an example, both the first pump 50 and the second pump 52 are controlled to be temporarily stopped when the lower limit of the range is exceeded. After that, the CPU of the control device 60, as an example, controls so that water is sent from the sub-tank 36 to the main tank 34 until a predetermined amount of water is stored in the main tank 34 shown in FIG.

As described above, while alternately operating the first pump 50 and the second pump 52 shown in FIGS. The time for continuously (or almost continuously) discharging water from the main tank 34 from the water discharging portion 32 is lengthened compared to the case where water is discharged from the water discharging portion 32 only by operating one pump 50. can do. In addition, since the continuous operation time of the first pump 50 is limited, the durability and reliability of the first pump 50 are also improved.

Here, with reference to FIG. 6, supplementary explanation will be given on the advantage of limiting the continuous operation time of each of the first pump 50 and the second pump 52. FIG.

FIG. 6 shows an example of a pump 70 applicable to the first pump 50 and the second pump 52. As shown in FIG. As shown in FIG. 6, the pump 70 includes a casing 72 forming a flow path, an electric motor 74 disposed outside the casing 72 and having an output shaft 75, and an electric motor 74 housed within the casing 72. It includes an impeller 76 fixed to an axial shaft 75 and a cylindrical axial seal 78 that seals a gap between the casing 72 and the axial shaft 75 . When the electric motor 74 is driven, the impeller 76 rotates and the fluid in the casing 72 can be moved (see arrow A direction and arrow B direction).

On the other hand, the electric motor 74 generates heat at this time, and the heat is transferred to the shaft seal 78 via the shaft shaft 75 . If the shaft seal 78 receives more heat than expected when the pump 70 is continuously operated under a high load, the durability of the shaft seal 78 may deteriorate.

However, in this embodiment, the first mode shown in FIG. 4 and the second mode shown in FIG. 5 are alternately executed, and the continuous operation time of the first pump 50 and the continuous operation time of the second pump 52 are both limited. Therefore, for example, the influence on the durability of the portion corresponding to the shaft seal 78 shown in FIG. 6 can be suppressed.

On the other hand, when the heat exchanger cooling device 30 shown in FIG. above the upper limit), the CPU of the control device 60 shown in FIG. 2 controls so that both the first mode shown in FIG. 4 and the second mode shown in FIG. 5 are executed.

If the first mode shown in FIG. 4 and the second mode shown in FIG. 5 are executed simultaneously, the amount of water discharged per unit time increases, so only the first mode shown in FIG. 4 is executed. Cooling capacity (kW) is improved compared to the case where From a different point of view, the load on the first pump 50 can be reduced and the life of the first pump 50 can be extended as compared with the case where the cooling capacity is increased only by the first pump 50 .

As described above, according to the present embodiment, the first pump 50 and the second pump 52 are controlled according to the cooling load so as to alternately operate, simultaneously operate, or stop. As a result, the excessive use of the first pump 50, which is a dedicated pump for sending the water in the main tank 34 to the water discharge section 32, can be suppressed while reducing the number of pumps while sufficiently using the water in the main tank 34. can.

In addition, as a modification of the above embodiment, the pressure loss from each of the first pump 50 and the second pump 52 to the water discharge part 32 is adjusted to A configuration is also possible in which the CPU of the control device 60 shown in FIG. 2 controls to switch the operating pumps according to the required cooling capacity. In such a modified example, it is possible to control the discharge amount without requiring an inverter for controlling the output of the pump.

An example of the present invention has been described above, but the present invention is not limited to the above, and it goes without saying that it is possible to implement various modifications without departing from the gist of the present invention. .

24 radiator (heat exchanger)
30 heat exchanger cooling device 32 water discharge part 34 main tank 34A first outlet of main tank 34B inlet of main tank 34C second outlet of main tank 36 sub-tank 36A outlet of sub-tank 40 first channel 42 second channel 44 third channel 46 connecting channel 50 first pump 52 second pump 54 first three-way valve 56 second three-way valve

Claims (1)

a water discharge unit that discharges water toward the heat exchanger;
a main tank for storing water to be supplied to the water discharge part;
a sub-tank having a smaller capacity than the main tank and storing water;
a first flow path connecting the first outlet of the main tank and the water discharge part;
a second flow path connecting the inlet of the main tank and the water discharge part;
a third channel connecting the second outlet of the main tank and the outlet of the sub-tank;
a connecting channel that connects the second channel and the third channel;
a first pump that is provided in the first flow path and sends water to the water discharge section;
a second pump provided in the connecting channel for sending water to the second channel;
a state in which the second pump and the main tank are communicated with each other, and a state in which the second pump and the water discharge section are communicated with each other; a switching first three-way valve;
A second switch is provided at the connecting portion between the third flow path and the connecting flow path, and switches between a state in which the sub-tank and the second pump are communicated and a state in which the main tank and the second pump are communicated. two three-way valves;
A heat exchanger cooling device having a

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