JP2013105686A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save space of a humidifier tank and control water temperature in the humidifier tank with good responsiveness.SOLUTION: A fuel cell system includes: a solid polymer fuel cell 2 and a humidifier tank 9 which humidifies hydrogen by bubbling and supplies hydrogen to the fuel cell 2. The fuel cell system includes: a water supply tank 10 having a heater 14 heating water supply to the humidifier tank 9; a humidification water circulation path 11 supplying water supply in the water supply tank 10 while circulating the water supply to the humidifier tank 9; a coolant circulation path 12 heating the water supply in the water supply tank 10 with heat obtained by a cooling part 7 of the fuel cell 2; and a control unit which energizes the heater 14 and drives a first circulation pump 17 of the humidification water circulation path 11 when the fuel cell 2 is activated, the control unit which drives a second circulation pump 18 of the coolant circulation path 12 after the fuel cell 2 is activated.

Description

  The present invention relates to a fuel cell system using a polymer electrolyte fuel cell.

  A fuel cell system comprising a solid polymer fuel cell that takes out electricity using a chemical reaction between hydrogen and oxygen, and a humidification tank that bubbles and humidifies hydrogen and supplies the fuel cell to the fuel cell is disclosed in Patent Document 1 and the like. Are known.

  In this patent document 1, it is comprised so that hydrogen gas may be heated by energizing the heater provided in the humidification tank at the time of starting, and heating the water in a humidification tank. Moreover, in patent document 1, the heat exchanger which heats the water in a humidification tank with the heat obtained in the cooling part of the fuel cell is provided in the humidification tank.

  In the configuration of Patent Document 1, since it is necessary to incorporate a heater and heat exchanger having a large capacity in the humidification tank, the humidification tank becomes large and space saving cannot be achieved.

JP 2007-250326 A

  The problem to be solved by the present invention is to reduce the size of the humidification tank to save space and to control the water temperature in the humidification tank with good responsiveness.

  The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 is directed to a polymer electrolyte fuel cell that takes out electricity using a chemical reaction between hydrogen and oxygen, and hydrogen is bubbled. A fuel cell system comprising a humidification tank that humidifies and supplies the fuel cell, wherein the water supply tank includes a water supply tank that stores water supplied to the humidification tank and that heats the water supply, and a first circulation pump. A humidification water circulation path for supplying the water supply in the tank while circulating it to the humidification tank; and a cooling water circulation path for heating the water supply in the water supply tank with heat obtained by the cooling section of the fuel cell, the second circulation pump When the fuel cell is started, the heater is energized and the first circulation pump is driven to heat the water supply in the water supply tank. By driving the second circulation pump is characterized by comprising a controller for heating the water in the water supply tank to cool the fuel cell.

  According to the first aspect of the present invention, compared with the prior art disclosed in Patent Document 1, the humidification tank is not provided with the heater and the heat exchanger, and the humidification is performed at and after the start of the fuel cell. Since the water in the tank can be heated, the humidification tank can be downsized to save space. Further, since the water supply tank and the humidification tank are connected by the humidification water circulation path, the water temperature change in the water supply tank can be quickly transmitted to the humidification tank, and the water temperature control in the humidification tank is responded. There is an effect that it can be performed with good performance.

According to a second aspect of the present invention, in the first aspect, the cooling water circulation path includes a heat radiator having a heat radiation amount adjusting unit, and the controller rotates the second circulation pump after the fuel cell is started. The temperature of the cooling water at the outlet of the cooling unit is controlled by control and / or control of the heat radiation amount adjusting means.

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the temperature of the cooling water at the outlet of the cooling unit is controlled, so that the fuel cell can be effectively cooled. There is an effect that can be done.

  The invention according to claim 3 further comprises water supply means to the water supply tank and water level detection means for detecting the water level of the water supply tank according to claim 1 or claim 2, wherein the controller is The water level is controlled by the water level detection unit and the water level in the water supply tank is controlled to a set water level, whereby the water level in the humidification tank is controlled to the set water level.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the water level control means provided in the water supply tank can appropriately control the water level in the humidification tank. In addition to being able to perform stable humidification, there is no need to newly provide a water level detection means, so that the system configuration can be simplified and the humidification tank can be further reduced in size.

  According to the present invention, the humidification tank can be reduced in size to save space, and the water temperature in the humidification tank can be controlled with good responsiveness.

It is explanatory drawing explaining the schematic structure of embodiment of this invention. It is a flowchart figure explaining the control procedure of the embodiment.

An embodiment of a fuel cell system of the present invention will be described with reference to the drawings.
<Configuration of the embodiment>
The fuel cell system 1 of this embodiment supplies a solid polymer fuel cell (hereinafter simply referred to as a fuel cell) 2 that takes out electricity using a chemical reaction between hydrogen and oxygen, and supplies hydrogen to the fuel cell 2. A hydrogen supply path 3 and an oxygen supply path 4 for supplying oxygen to the fuel cell 2 are provided.

  The fuel cell 2 is a known one, and includes an oxygen electrode 5, a hydrogen electrode 6, and a fuel cell cooling unit 7 sandwiching an ion exchange membrane (not shown), and the oxygen electrode 5 has oxygen as an oxidant. Is configured to generate electricity by supplying hydrogen as a reducing agent to the hydrogen electrode 6.

  The hydrogen supply path 3 is provided with a humidification tank 9 for humidifying the hydrogen from the blowing portion 8 by bubbling and supplying the hydrogen to the fuel cell 2.

  Further, the fuel cell system 1 includes a water supply tank 10, a humidified water circulation path 11, a cooling water circulation path 12, and a controller 13 as main parts.

  The water supply tank 10 stores water supplied to the humidification tank 9, a heater 14 for heating the water supply, a water level sensor 15 as water level detection means for detecting the water level of the water supply tank 10, and water supply means for the water supply tank 10. And a pure water producing device 16 comprising a reverse osmosis membrane filtration apparatus. The pure water producing device 16 has a function of purifying raw water and supplying it into the water supply tank 10.

The humidification water circulation path 11 includes a first circulation pump 17 and is configured to supply the supply water in the supply water tank 10 while circulating it to the humidification tank 9.

  The cooling water circulation path 12 includes a second circulation pump 18 and is configured to cool the fuel cell 2 with the cooling unit 7 of the fuel cell 2 and to heat the water in the water supply tank 10 with the heat obtained by the cooling unit 7. Has been. Further, the cooling water circulation path 12 is provided with a radiator 20 having a fan 19 as a heat radiation amount adjusting means.

  The controller 13 receives signals from the water level sensor 15 and the water temperature sensor 21 for detecting the water temperature at the outlet of the cooling unit 7 of the cooling water circulation path 12 and the like, and based on the control procedure stored in advance, the heater 14 and the pure water producing device 16. , The first circulation pump 17, the second circulation pump 18, the fan 19 and the like are configured to be controlled.

  The control procedure of the controller 13 includes a water supply temperature control procedure when the fuel cell 2 is started, a battery cooling / feed water heating control procedure after the startup, and a water level control procedure for the water supply tank 10 and the humidification tank 9. . An example of the water supply temperature control procedure and the battery cooling / water supply warming control procedure is shown in FIG. 2, but is not limited thereto.

  The feed water temperature control procedure is a procedure for heating the feed water in the feed water tank 10 by energizing the heater 14 and driving the first circulation pump 17 when the fuel cell 2 is started.

  The battery cooling / feed water heating control procedure is a procedure for cooling the fuel cell 2 by driving the second circulation pump 18 after starting the fuel cell 2 and heating the feed water in the feed water tank 10. is there. The second circulation pump 18 can be driven when the fuel cell 2 is started. In this battery cooling / feed water heating control procedure, the cooling of the outlet of the cooling unit 7 is controlled by the fan 19 after the fuel cell 2 is started so that the cooling of the fuel cell 2 has priority over the heating of the feed water in the water tank 10. It includes a cooling adjustment procedure that controls the temperature of the water within a certain range. This cooling adjustment procedure is performed by controlling the rotational speed of the second circulation pump 18 instead of the control of the fan 19, or by combining the control of the fan 19 and the rotational speed control of the second circulation pump 18. The temperature can be controlled within a certain range.

Although the water level control procedure is not shown, the pure water producing device 16 is controlled by the water level sensor 15 (water supply starts when it is turned on, water supply stops when it is turned off), and the water level H1 in the water tank 10 is controlled to the first set water level H10. In addition, the water level H2 in the humidification tank 9 is indirectly controlled to the second set water level H20 by controlling the water level in the water supply tank 10. The principle of indirect water level control of the humidifying tank 9 is as follows. The water level difference ΔH between the water supply tank 10 and the humidification tank 9 can be obtained by the following equation.
ΔH (= H1-H2) ∝P1
However, P1 is the pressure in the humidification tank 9 and can be calculated by the sum of the pressure loss in the hydrogen supply path 3 after the humidification tank 9 and the pressure loss in the hydrogen electrode 6.

<Operation of the embodiment>
The operation of the embodiment having the above configuration will be described with reference to the drawings.
(When starting the fuel cell)
Referring to FIG. 2, it is determined whether or not an operation start switch (not shown) is operated in process step S1 (hereinafter, process step SN is simply referred to as SN). If YES is determined, the process proceeds to S2, and the first circulation pump 17, the second circulation pump 18, and the heater 14 are turned on. In addition, before S2, the control which makes the water level in the water supply tank 10 a setting water level is performed. In S <b> 2, the water supply in the water supply tank 10 is heated by the heater 14, and the water supply in the water supply tank 10 circulates in the humidified water circulation path 11 and the cooling water circulation path 12 in parallel.

(Fuel cell operation)
In S3, when the temperature detected by the water temperature sensor 21 reaches the set temperature T1, the process proceeds to S4, where hydrogen supply through the hydrogen supply path 3 and oxygen supply through the oxygen supply path 4 are performed, and the fuel cell 2 generates power ( Operation) is started.

  In the humidification tank 9, hydrogen is supplied into the feed water from the blowing part 8 by bubbling to humidify the hydrogen. This humidification is governed by the water level and water temperature in the humidification tank 9. That is, when the water level is low, the humidifying effect is deteriorated, and when the water temperature is low, the humidifying effect is deteriorated. In this embodiment, by controlling the water level in the water supply tank 10, the water level in the humidification tank 9 is controlled within the set range, and the water in the humidification tank 9 is circulated by the circulation of the humidification water through the humidification water circulation path 11. Is stably heated, so that stable humidification is performed.

  When the set time t1 has elapsed since YES is determined in S3, YES is determined in S5, the heater 14 is turned off, the fan 19 that has been turned off is turned on, and the heat radiation amount control is started.

  This heat radiation amount control is performed by controlling the rotation speed of the fan 19 so that the detected temperature of the water temperature sensor 21 at the outlet of the cooling unit 7 becomes the set temperature T1. By this heat radiation amount control, the fuel cell 2 can be effectively cooled by the cooling water passing through the cooling unit 7, and failure of the fuel cell 2 due to poor cooling can be prevented.

(Fuel cell shutdown)
When the operation stop switch (not shown) is operated, YES is determined in S7, and the processes in S8 and S9 are executed. In S8, hydrogen supply and oxygen supply are stopped, and in S9, the first circulation pump 17, the second circulation pump 18, and the fan 19 are turned off.

  According to the above embodiment, the water in the humidification tank 9 can be heated at the start and after the start of the fuel cell 2 without providing a heater and a heat exchanger for heating in the humidification tank 9. it can. For this reason, the humidification tank 9 can be miniaturized and space saving can be realized. Moreover, since the water supply tank 10 and the humidification tank 9 are connected by the humidification water circulation path 11, the water temperature change in the water supply tank 10 can be given to the humidification tank 9 rapidly. As a result, the water temperature control in the humidification tank 10 can be performed with good responsiveness.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, the circulating water in the cooling water circulation path 12 is configured to pass directly through the water supply tank 10, but the circulating water in the cooling water circulation path 12 and the water in the water supply tank 10 are included in the water supply tank 10. A heat exchanging unit (not shown) for indirectly exchanging heat with the water supply can be provided, and the heat obtained by the cooling unit 7 can be transmitted to the water supply in the water supply tank 10. Further, the water level in the humidifying tank 9 is indirectly controlled by the water level of the water supply tank 10, but the water level sensor (not shown) may be provided in the humidifying tank 9 to control the water level. Furthermore, the radiator 20 can be a water-cooled heat exchanger, and in this case, the heat radiation amount adjusting means adjusts the cooling water amount of the radiator 20.

DESCRIPTION OF SYMBOLS 1 Fuel cell system 2 Polymer electrolyte fuel cell 3 Hydrogen supply means 7 Cooling part 9 Humidification tank 10 Water supply tank 11 Humidification water circulation path 12 Cooling water circulation path 13 Controller 16 Pure water production device (water supply means)
17 1st circulation pump 18 2nd circulation pump 19 Fan (heat dissipation amount adjustment means)
20 Heatsink

Claims (3)

In a fuel cell system comprising a solid polymer fuel cell that extracts electricity using a chemical reaction between hydrogen and oxygen, and a humidification tank that humidifies hydrogen by bubbling and supplies the fuel cell to the fuel cell system,
A humidification water circulation path comprising a first circulation pump and supplying the water supply in the water supply tank while circulating it to the humidification tank;
A cooling water circulation path that includes a second circulation pump and heats the feed water in the feed water tank with heat obtained by the cooling unit of the fuel cell;
When the fuel cell is started, the heater is energized and the first circulation pump is driven to heat the water supply in the water tank, and after the fuel cell is started, the second circulation pump is driven. And a controller for cooling the fuel cell and heating the water supply in the water supply tank. A radiator having a heat radiation amount adjusting means in the cooling water circulation path,
The controller controls the temperature of the cooling water at the outlet of the cooling unit by controlling the number of revolutions of the second circulation pump and / or controlling the heat dissipation amount after the fuel cell is started. Item 4. The fuel cell system according to Item 1. Water supply means to the water supply tank;
Water level detection means for detecting the water level of the water supply tank,
The controller controls the water supply means by the water level detection means, and controls the water level in the humidification tank to a set water level by controlling the water level in the water supply tank to a set water level. The fuel cell system according to claim 1 or 2.

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