JPH11250927A - Fuel cell power generating set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a fuel cell so as not to supply a reformed gas containing much of drain water or steam to the fuel cell. SOLUTION: In a fuel cell power generating set generating electric power with reformed gas steam-reformed in fuel reformer 1 and oxygen in air, a first temperature sensor 11 is arranged in a drain separator 6 and a second temperature sensor 12 is arranged in the inlet of a fuel cell 8, when at least one of conditions that the detected value with the temperature sensor 11 is in the specified value or higher, and the detected value with the temperature sensor 12 is in the specified value or lower is satisfied, it shows that the content of drain water or steam in the reformed gas is increased, an on-off valve 10 is closed, and supply of the reformed gas is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell power generator for generating power using a hydrogen-rich gas as fuel, and particularly to a means for introducing a reformed gas into a fuel cell at the start of power generation and during power generation operation. The present invention relates to a fuel cell power generation device having:

[0002]

2. Description of the Related Art As is well known, a fuel cell power generator introduces hydrogen-rich gas obtained by steam reforming oxygen in air and raw fuel (natural gas) in a reformer into a fuel cell. Power is generated by an electrochemical reaction.

FIG. 3 is a system diagram showing a conventional example of a fuel cell power generator. 1 is a fuel reformer, 2 is a steam separator, 3 is a steam flow control valve, and 4 is raw fuel LNG (liquefied natural gas). And an ejector that mixes and compresses a raw material gas such as gas (gas), LPG (liquefied petroleum gas) and water vapor, and supplies the mixture to the fuel reformer 1. That is, by injecting the steam as the driving gas from the nozzle of the ejector 4, the sucked natural gas is mixed with the steam and compressed, and then supplied to the fuel reformer 1, where the natural gas is steam-reformed into a hydrogen-rich gas. . Then, the fuel gas reformed in the reformer 1 is supplied to the fuel cell 8 via the heat exchanger 5 for condensing the reformed gas, the drain separator 6 and the drain trap 7. The fuel cell 8 generates power by an electrochemical reaction between the fuel gas supplied to the anode and the air supplied from the atmosphere to the cathode by means of a blower or the like, and supplies power to the load.

FIG. 4 is a system diagram showing another conventional example of a fuel cell power generator. This is achieved by adding a heat exchanger 5 and an integral heat exchanger 9 to the one shown in FIG. 3 and transferring the fuel gas reformed by the reformer 1 to the heat exchanger 5, the drain separator 6, and the drain trap. 3 is the same as FIG. 3 except that it is supplied to the fuel cell 8 through the heat exchanger 9 and the heat exchanger 9, and the description is omitted.

[0005]

By the way, the hydrogen-rich gas supplied to the fuel cell contains a large amount of steam during reforming. Therefore, in the case of FIG. The dry reformed gas is supplied to the fuel cell 8 by condensing the water vapor therein. In the case of FIG. 4, the steam in the reformed gas is condensed by the heat exchanger 5 and the temperature is raised by the second heat exchanger 9 provided at the subsequent stage, so that the dry reformed gas 4 The battery 8 is supplied.

In FIGS. 3 and 4, if the heat exchange performance of the heat exchanger 5 is reduced or if a malfunction occurs in the drain trap 7 provided downstream of the heat exchanger 5, a large amount of water vapor is contained. The hydrogen-rich reformed gas or drain water is supplied to the fuel cell 8. When a hydrogen-rich reformed gas containing a large amount of water vapor is supplied to the fuel cell 8, the volume of phosphoric acid in the cells of the fuel cell 8 expands and loses gas diffusion performance, leading to deterioration in the characteristics of the fuel cell. .
Further, when a large amount of drain water flows into the fuel cell 8, the operation cannot be continued due to lack of gas due to submergence of the gas passage of the fuel cell or poor insulation, and eventually leads to breakage.
Therefore, an object of the present invention is to prevent the introduction of drain water or a hydrogen-rich reformed gas containing a large amount of water vapor into a fuel cell.

[0007]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a raw fuel containing LNG and LPG is steam reformed by a reformer, and a heat exchanger for condensing reformed gas is provided. A fuel cell that generates power using reformed gas, in which drain water and excess water vapor are separated by a drain separator, and oxygen in the air, the drain separator is provided with a first temperature sensor while the fuel cell inlet A second temperature sensor for detecting gas temperature is provided, and when at least one of the following conditions is satisfied: a value detected by the first temperature sensor is equal to or more than a predetermined value, and a value detected by the second temperature sensor is equal to or less than a predetermined value. The supply path of the reformed gas into the fuel cell is shut off.

In the invention of claim 2, LNG, LP
The raw fuel containing G is reformed by steam using a reformer, and the reformed gas from which drain water and excess steam are separated by a heat exchanger for condensing reformed gas, a heat exchanger for preheating reformed gas, and a drain separator. A fuel cell that generates power using oxygen in the air, a first temperature sensor is provided in the drain separator, and a second temperature sensor is provided in the heat exchanger for preheating reformed gas. When at least one of the conditions that the value detected by the temperature sensor is equal to or more than a predetermined value and the value detected by the second temperature sensor is equal to or less than a predetermined value is satisfied, the supply path of the reformed gas into the fuel cell is shut off. I have to.

[0009]

FIG. 1 is a system diagram showing a first embodiment of the present invention, which is different from that shown in FIG. 3 in that a drain separator 6 at a stage subsequent to a heat exchanger 5 for condensing reformed gas is provided. A temperature sensor 11 is provided at the inlet of the fuel cell 8, and a temperature sensor 12 is provided at the inlet of the fuel cell 8. Further, values detected by these sensors are input, and the on / off valve 10 is controlled based on the input signal under predetermined conditions. It is characterized in that a control unit (not shown) for generating an appropriate output signal is provided. That is, at the time of power generation startup, the temperature sensor 11 that can be used to evaluate the performance of the heat exchanger 5 for condensing reformed gas is at or below the set temperature, and a temperature sensor that detects the presence or absence of drain water due to a malfunction of the drain trap 7 The hydrogen-rich reformed gas is supplied to the fuel cell 8 for the first time by opening the on / off valve 10 provided on the subsequent stage under the condition that the temperature of the fuel cell 12 is equal to or higher than the set temperature. At this time, the performance of the heat exchanger 5 and the performance of the drain trap 7 can be monitored by the temperature sensors 11 and 12 installed as shown in FIG. 1 to detect an abnormality at an early stage.

During the power generation operation, the heat exchanger 5
If the temperature sensor 11 capable of detecting a decrease in the performance is equal to or higher than the set temperature, and the temperature sensor 12 for detecting the presence or absence of drain water due to a malfunction of the drain trap 7 has at least one condition equal to or lower than the set temperature, the on-off valve To prevent the reformed gas from being introduced into the fuel cell 8. By doing as described above, it is possible to prevent the drain water and the reformed gas containing a large amount of water vapor from being introduced into the fuel cell.

FIG. 2 is a system diagram showing a second embodiment of the present invention. In contrast to the system shown in FIG. 4, a temperature sensor 1 is connected to a drain separator 6 at the subsequent stage of a heat exchanger 5 for condensing reformed gas.
1. The feature is that a temperature sensor 12 is provided at the subsequent stage of the heat exchanger 9, and the other parts are the same as those in FIG. The heat sensor 9 can be monitored by the temperature sensor 12.

[0012]

According to the present invention, when introducing a hydrogen-rich reformed gas into a fuel cell, drain water and water vapor that may be contained in the reformed gas are removed. The advantage of avoiding the danger of breakage and lowering of output characteristics and providing a fuel cell power generation device having an excellent protection effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a system diagram showing a conventional example of a fuel cell power generator.

FIG. 4 is a system diagram showing another conventional example of a fuel cell power generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel reformer, 2 ... Steam separator, 3 ... Flow control valve,
4 ejector, 5, 9 heat exchanger, 6 drain separator, 7 drain trap, 8 fuel cell, 10 on / off valve, 11, 12 temperature sensor.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toshiya Omura 3-3-2 Shiomidai, Isogo-ku, Yokohama-shi, Kanagawa Prefecture 72) Inventor Takuro Hagino 1-33 Maeda-cho, Mizuho-ku, Nagoya, Aichi Prefecture

Claims (2)

[Claims] 1. A reformed gas obtained by steam reforming a raw fuel containing LNG and LPG by a reformer and separating drain water and excess steam by a heat exchanger for condensing the reformed gas and a drain separator. A fuel cell power generation device that generates power from oxygen in the fuel cell, comprising: a first temperature sensor provided on the drain separator; a second temperature sensor for detecting a fuel cell inlet gas temperature; When at least one of the conditions in which the value detected by the temperature sensor is equal to or more than a predetermined value and the value detected by the second temperature sensor is equal to or less than a predetermined value is satisfied, the control to cut off the supply path of the reformed gas into the fuel cell is performed. A fuel cell power generator comprising means. 2. A raw fuel containing LNG and LPG is steam reformed by a reformer, and drain water and excess steam are formed by a heat exchanger for condensing reformed gas, a heat exchanger for preheating reformed gas, and a drain separator. In the fuel cell power generation device that generates power by using the reformed gas separated from oxygen and oxygen in the air, a first temperature sensor is provided for the drain separator, and a second temperature is provided for the heat exchanger for preheating the reformed gas. A fuel for the reformed gas when at least one of the following conditions is satisfied: a value detected by the first temperature sensor is equal to or more than a predetermined value and a value detected by the second temperature sensor is equal to or less than a predetermined value. A fuel cell power generator comprising: a control unit that cuts off a supply path into a battery.