JP3375345B2 - Fuel cell generator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a replenishing water recovery system in which battery cooling water is sent by a pump to a heat exchanger provided in a fuel cell cooler, and the replenishment is performed. The water recovery apparatus relates to a fuel cell power generation apparatus provided with a water path having a pump and a water path having a blowdown valve for supplying low-temperature make-up water. 2. Description of the Related Art FIG. 1 is a view showing an embodiment of the present invention. Of these, well-known portions will be described for better understanding of the present invention. A fuel cell generally designated by reference numeral 1 is provided with an anode 2 to which fuel gas A is supplied, a cathode 3 to which air B is supplied, and a cooler 4. The heat exchanger 5 of the cooler 4 is interposed in a cooling water passage L1, and a pump 6 and a makeup water recovery device 7 for storing battery cooling water C are interposed in the cooling water passage L1. The makeup water recovery device 7 is connected to a fuel reformer (not shown) by a water path L2, and is connected to exhaust heat utilization equipment (not shown) by a water path L3. The bottom of the make-up water recovery device 7 is provided with a water passage L4
Is connected to a replenishing water source (not shown) of the replenishing water D via a replenishing water pump 8, and is connected to a water treatment device provided with an ion exchange resin (not shown) via a blowdown valve 9 via a water passage L5. When the level of the battery cooling water C in the makeup water recovery device 7 is reduced to a predetermined level,
The pump 8 is operated to replenish the replenishing water D, and to maintain the quality of the battery cooling water C, the blowdown valve 9 is opened to discharge the water to the water treatment device. In the conventional fuel cell power generator, if blowdown is performed during replenishment of make-up water D, low-temperature replenishment of high-temperature battery cooling water C, whose amount has been reduced by blowdown, is performed. The water D is mixed, the temperature of the make-up water C decreases as a whole, and the pressure fluctuates. Therefore, the cooling performance of the cooler 4 decreases, and the output characteristics of the fuel cell 1 fluctuate. It is an object of the present invention to provide a fuel cell power generator that reduces output fluctuations during blowdown. According to the present invention, the battery cooling water (C) of the makeup water recovery device (7) is supplied to the cooler (4) of the fuel cell (1) by the pump (6). A water passage (L4) having a pump (8) for supplying cold make-up water (D) to the make-up water recovery device (7) and a blowdown valve ( In the fuel cell power generation device provided with the water channel (L5) having the configuration (9), when the battery cooling water (C) falls to a predetermined water level, the makeup water recovery device requires the makeup signal that requires the makeup water (D). And a control unit (1) for controlling a pump (8) and a blowdown valve (9) for the makeup water (D).
1), the control unit (11) operates the pump (8) for a predetermined time based on the make-up signal to supply make-up water, closes the blow-down valve (9), and when there is no make-up signal Has a function of turning off the pump (8) for a predetermined time and opening the blowdown valve (9). It is preferable to use an electromagnetic valve as the blowdown valve and connect the level sensor to the blowdown valve and the pump via a control unit. Further, a mechanical valve may be used as the blowdown valve, and the blowdown valve may be connected to the pump by a mechanical link. Therefore, when the level sensor lowers the battery cooling water in the make-up water recovery device to a predetermined level and outputs a make-up signal, the control unit operates the pump to replenish the make-up water in a predetermined amount, that is, for a predetermined time. . When the supply of makeup water is stopped, blowdown is performed using a blowdown valve. As described above, when blowing down the high-temperature battery cooling water in the make-up water recovery device, if the low-temperature make-up water is supplied, the blow-down amount is further replenished, and the low-temperature make-up water amount increases. , Resulting in pressure fluctuations. However, according to the present invention, since the blowdown and the supply of makeup water are performed separately, the supply amount of low-temperature makeup water due to a decrease in the level can be minimized, and the temperature change in the makeup water recovery device is small. , Stable operation. Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a level sensor 10 is provided in the make-up water recovery device 7, and when the battery cooling water C drops to a predetermined water level, a makeup signal that requires the supply of make-up water D is output. ing. The level sensor 10 is connected to the control unit 11 by an electric circuit L11.
L13 is connected to the pump 8 and the operating portion 9a of the blowdown valve 9 composed of a solenoid valve. Next, the operation will be described with reference to FIGS. When the level of the battery cooling water C in the makeup water recovery device 7 drops to a predetermined level and the level sensor 10 outputs a makeup signal (YES in step S1), the control unit 11 performs a certain period of time (FIG. 3) based on the makeup signal. (T1), the pump 8 is operated to supply the makeup water C (step S2), and the blowdown valve 9 is closed (step S2).
3). If no makeup signal is output (NO in step S1), the control unit 11 turns off the pump 8 for a certain time (T2 in FIG. 3) (step S4).
The blowdown valve 9 is opened, and the electric cooling water C flows out to the water treatment device. Therefore, since the blowdown is performed while the low-temperature replenishing water D is not supplied, the replenishing water recovery device 7
The temperature drop of the battery cooling water C in the inside is small, and thus the pressure fluctuation is reduced. As described above, according to the present invention, the following excellent effects can be obtained. (A) Since the signal from the level sensor provided in the makeup water recovery device is sent to the control unit, and the control unit operates the blowdown and the makeup water pump, the configuration is simple. (B) It is sufficient to provide a level sensor and a control unit in the conventional product, and the improvement is easy. (C) When the make-up water pump is stopped, the blow-down valve can be reliably opened, and pressure fluctuation and output fluctuation can be reliably prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing one embodiment of the present invention. FIG. 2 is a control flowchart. FIG. 3 is an ON / OFF timing chart of a pump and a blowdown valve. [Description of Signs] A: Fuel gas B: Air C: Battery cooling water D: Makeup water 1: Fuel cell 2: Anode 3 ... Cathode 4: Cooling Unit 5 Air 6 Pump 7 Makeup water recovery device 8 Makeup water pump 9 Blowdown valve 9a Actuator 10 Level sensor 11 Control unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 8/04 H01M 8/06

Claims (1)

(1) Heat exchange in which the battery cooling water (C) of the makeup water recovery device (7) is provided in the cooler (4) of the fuel cell (1) by the pump (6). Sent to the vessel (5), and the makeup water recovery device (7) has a water channel (L4) having a pump (8) for supplying cold makeup water (D) and a blowdown valve (9). In a fuel cell power generator provided with a water channel (L5), the makeup water recovery device outputs a makeup signal that requires makeup water (D) when the battery cooling water (C) drops to a predetermined water level. Sensor (1
0), the level sensor (10) is connected to a control unit (11) for controlling a pump (8) and a blowdown valve (9) for make-up water (D), and the control unit (11) is Based on the makeup signal, the pump (8) is operated for a predetermined time to supply replenishing water to close the blow-down valve (9), and when there is no makeup signal, the pump (8) is turned off for a predetermined time to blow down the valve. (9) A fuel cell power generator having a function of opening (9).