JPH0831436A - Package type fuel cell power generation plant - Google Patents

Abstract

PURPOSE:To determine concentration of combustible gas to be under explosion lower limit by detecting leak of the combustible gas from devices and pipings in a package into inner space in the package when it occurs, and increasing air ventilation quantity of the package at the time. CONSTITUTION:When combustible gas leaks from a fuel cell main body 2 or its peripheral elements of devices and pipings into a package 6 during power generation operation by the fuel cell main body 2, this leak is detected by a combustible gas detector 8, and this detection signal is inputted to a control device 10. When the control device 10 determines that concentration of the combustible gas increases to be closer to an allowable limit based on the detection signal from the detector 8, it outputs a control signal to an automatically opening door to open the automatically opening door 9, so ventilation air quantity of the package 6 is increased. The concentration of the combustible gas can thus be set to be under explosion lower limit.

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 plant of a package type in which a fuel cell main body and its peripheral elements are housed inside a package, and more particularly from a package internal device and piping to a package internal space. The present invention relates to a packaged fuel cell power plant capable of detecting the leakage of flammable gas and dealing with it.

[0002]

2. Description of the Related Art A fuel cell power plant directly converts the chemical energy of a fuel such as natural gas or methanol into electric energy. Usually, a fuel cell and a fuel electrode are sandwiched by an electrolyte layer such as phosphoric acid. A pair of porous electrodes of the oxidizer electrode are arranged, and a fuel gas such as hydrogen is brought into contact with the back surface of the fuel electrode, and an oxidant gas such as oxygen is brought into contact with the back surface of the oxidizer electrode. It is composed of a fuel cell main body that takes out electric energy generated by a dynamic reaction from a pair of electrodes, and its peripheral elements.

Further, since this fuel cell power generation plant also generates heat during chemical / electrical conversion, it has recently been utilized as a cogeneration facility. FIG. 3 is a schematic diagram showing a configuration example of a conventional phosphoric acid type fuel cell power generation plant of this type.

That is, as shown in FIG. 3, in a fuel cell power plant, a fuel processor 1 for converting natural gas, methanol or the like into hydrogen, a fuel gas (hydrogen or the like) and an oxidant (oxygen or the like in the atmosphere) are used. And a fuel supply valve 4 for supplying a fuel gas and an oxidant to the fuel cell main body 2, an electric / control device 3, and the fuel cell main body 2 through pipes, respectively. It is composed of the agent supply valve 5. Further, in the on-site use which is a demand location, each of these elements is housed inside the package 6 to form a package type, which has a structure convenient for installation.

On the other hand, since flammable gases such as natural gas and hydrogen are handled, the package 6 is carefully ventilated, and the ventilation fan 7 is provided so that the atmosphere inside the package 6 is constantly exhausted and fresh outside air is discharged. Is taken in,
Even if flammable gas leaks into the package 6 from the equipment and piping, it is designed so as not to reach the combustion / explosion concentration due to its retention and accumulation.

By the way, such a package type fuel cell power plant is basically designed for unmanned operation for on-site use, and when the ventilation fan 7 is stopped, the fuel supply valve 4 is fully closed immediately, Fuel cell body 2
It is designed to stop power generation.

Therefore, even if there is a leak of combustible gas, it can be repaired without stopping, or the amount of leak of the combustible gas is extremely low, and the concentration can be sufficiently suppressed by natural ventilation. In this case, or in the case of a malfunction of the sensor, although the power generation operation can be continued, the current technology cannot continue the operation and the power generation operation rate is low.

Further, since it is necessary to cause the protective operation only by the loss of the ventilation function without knowing the presence or absence of the combustible gas itself, the fuel supply valve 4 is immediately fully closed to stop the operation of the fuel cell power plant. The fuel cell main body 2 is deficient in hydrogen and the unnecessary load on the fuel cell main body 2 is increased, resulting in deterioration of operating performance.

[0009]

As described above, in the conventional packaged fuel cell power plant, attempting to ensure safety not only lowers the power generation operating rate but also deteriorates the operating performance. There was a problem.

An object of the present invention is to provide a packaged fuel cell power plant which is capable of improving the power generation operation rate while ensuring sufficient safety and which is excellent in drivability without imposing an unnecessary burden on the fuel cell body. To provide.

[0011]

In order to achieve the above object, a fuel gas such as hydrogen is brought into contact with the fuel electrode, and
The fuel cell body and its peripheral elements are brought into contact with an oxidant electrode such that oxygen and other oxidant gas are brought into contact with each other, and electrical energy generated by an electrochemical reaction that occurs at this time is taken out from the pair of electrodes. Further, in a package type fuel cell power plant configured to include a ventilating means for exhausting the atmosphere in the package to the outside and taking the outside air into the package, first, in the invention according to claim 1, the exhaust part of the package or the vicinity thereof. And a combustible gas leakage detecting means for detecting a combustible gas leaking into the package from the fuel cell main body and its peripheral elements.

According to the second aspect of the invention, there is provided a flammable gas leak detecting means provided at or near the exhaust portion of the package for detecting the flammable gas leaking into the package from the fuel cell main body and its peripheral elements. And a control means for controlling to increase the ventilation air volume of the package based on the combustible gas detection signal from the combustible gas leakage detection means.

Here, in particular, as the control means for controlling to increase the ventilation air volume of the package, the automatic opening door provided in the package is controlled to be opened, or the ventilation volume by the ventilation means is increased. I'm trying to control it.

On the other hand, in the invention according to claim 5, combustible gas leakage detection means for detecting combustible gas leaking into the package from the fuel cell main body and its peripheral elements is provided at or near the exhaust portion of the package. And a control means for controlling the power generation output of the fuel cell main body to decrease to a predetermined value based on the combustible gas detection signal from the combustible gas leakage detection means.

Further, in the invention according to claim 6, there is provided a flammable gas leakage detecting means which is provided at or near the exhaust portion of the package and which detects the flammable gas leaking into the package from the fuel cell main body and its peripheral elements. When the flammable gas concentration detection signal is monitored and processed over time based on the flammable gas detection signal from the flammable gas leak detection means, and the flammable gas concentration has a time margin up to an allowable limit. And a control means for controlling the power generation output of the fuel cell main body to gradually decrease to a predetermined value and then shifting to stop the power generation of the fuel cell main body.

Here, in particular, as the control means for controlling the power generation output of the fuel cell main body to decrease to a predetermined value, the opening of the fuel supply valve for supplying the fuel gas to the fuel electrode of the fuel cell main body is controlled. It is controlled in the closing direction.

[0017]

Therefore, in the packaged fuel cell power plant of the present invention, flammable gas leak detection is performed at the exhaust portion of the package or in the vicinity thereof to detect the flammable gas leaking from the fuel cell main body and its peripheral elements into the package. By providing the means, it is possible to determine whether the flammable gas from the device or the piping is actually leaking into the package, and it is possible to detect the abnormal state at an early stage.

In the package type fuel cell power plant according to the second aspect of the present invention, the ventilation air volume of the package is controlled to increase based on the flammable gas detection signal from the flammable gas leakage detection means ( By opening the automatic opening door provided in the package or controlling so that the ventilation amount by the ventilation means is increased), it is possible to suppress the increase in the concentration of the combustible gas by increasing the ventilation air amount.

On the other hand, in the package type fuel cell power generation plant of the invention according to claim 5, the power generation output of the fuel cell main body is reduced to a predetermined value based on the flammable gas detection signal from the flammable gas leakage detection means. By controlling in this way, when the concentration of the combustible gas increases, the operation can be performed so as to reduce the opening amount of the fuel supply valve to suppress the leakage amount.

Further, in the package type fuel cell power plant of the invention according to claim 6, the change with time of the combustible gas concentration is monitored based on the combustible gas detection signal from the combustible gas leakage detection means. If processing is performed and the combustible gas concentration has a time margin up to the allowable limit, the power generation output of the fuel cell body is gradually reduced to a predetermined value and then the power generation of the fuel cell body is stopped. If there is a time margin to the allowable limit of the combustible gas concentration, the output of the fuel cell will be gradually decreased to fully close the rear fuel supply valve. Deterioration can be kept to a minimum.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIG. 1 is a schematic diagram showing a structural example of a packaged fuel cell power plant according to the first embodiment of the present invention. The same elements as those in FIG. Description is omitted, and only different parts will be described here.

That is, in the packaged fuel cell power plant of this embodiment, as shown in FIG. 1, the fuel cell main body 2 and its peripheral elements (devices, pipes) are provided in or near the exhaust portion of the package 6. A combustible gas detector 8 for detecting combustible gas leaking into the package 6 is provided,
Any location in the package 6 where flammable gas leaks can be detected. The combustible gas detector 8 can measure the combustible gas concentration in the air as an analog value.

Further, an automatic opening door 9 is provided at the illustrated portion of the package 6 so that the ventilation air volume of the package 6 can be increased as required. Further, a control device 10 is provided which controls to open the automatic opening door 9 based on the flammable gas detection signal from the flammable gas detector 8 to increase the ventilation air volume of the package 6. ing.

Next, the operation of the packaged fuel cell power plant according to this embodiment having the above-described structure will be described. In FIG. 1, if a flammable gas leaks from the fuel cell main body 2 and its peripheral elements (devices, pipes) into the package 6 during the power generation operation of the fuel cell main body 2, this leak of the flammable gas Is detected by the combustible gas detector 8, and a combustible gas detection signal is input to the control device 10.

On the other hand, the control device 10 automatically opens when it is determined that the concentration of the combustible gas increases and approaches the allowable limit based on the combustible gas detection signal from the combustible gas detector 8. A control signal is output to the door 9 to open the automatic release door 9.

As a result, the ventilation air volume of the package 6 is increased to suppress the increase in the concentration of the combustible gas, that is, the purge amount is increased, and the concentration of the combustible gas can be made lower than the lower explosion limit. .

As described above, in this embodiment, a fuel gas such as hydrogen is brought into contact with the fuel electrode, and an oxidant gas such as oxygen is brought into contact with the oxidant electrode, which is generated by an electrochemical reaction occurring at this time. Fuel cell main body 2 and peripheral elements for extracting electric energy from a pair of electrodes (fuel processing device 1, fuel supply valve 4, oxidant supply valve 5, and piping)
In a package type fuel cell power plant including an exhaust fan 7 for exhausting the atmosphere in the package 6 to the outside and taking the outside air into the package 6. A flammable gas detector 8 provided at or near the exhaust portion of the fuel cell body 2 for detecting flammable gas leaking into the package 6 from the fuel cell body 2 and its peripheral elements; and an automatic opening door 9 provided in the package 6. , And a control device 10 for controlling to open the automatic opening door 9 based on the flammable gas detection signal from the flammable gas detector 8 to increase the ventilation air volume of the package 6. It was done like this.

Therefore, the following effects can be obtained. (A) By grasping the presence or absence and the concentration of the flammable gas leaking into the atmosphere inside the package 6 of the package type fuel cell power plant, it is possible to more rationally operate the power plant according to the situation.

That is, since the combustible gas detector 8 measures the combustible gas concentration in air as an analog value, when the combustible gas concentration approaches the allowable limit, the automatic release door 9 is opened, It is possible to suppress the concentration increase by increasing the ventilation air volume.

As a result, the reliability of the plant that handles combustible gas is enhanced and the power generation operating rate can be improved. (B) Among the power generation plants, it is possible to operate the plant in which the burden on the fuel cell main body 2 is particularly small, and it is possible to contribute to the prevention of operational performance deterioration.

(Second Embodiment) FIG. 2 is a schematic diagram showing a structural example of a packaged fuel cell power plant according to a second embodiment of the present invention. The same elements as those in FIG. 3 are designated by the same reference numerals. The description thereof will be omitted, and only different parts will be described here.

That is, in the packaged fuel cell power plant of this embodiment, as shown in FIG. 2, the fuel cell main body 2 and its peripheral elements (devices, pipes) are provided at or near the exhaust portion of the package 6. A combustible gas detector 8 for detecting combustible gas leaking into the package 6 is provided,
Any location in the package 6 where flammable gas leaks can be detected. The combustible gas detector 8 can measure the combustible gas concentration in the air as an analog value.

The opening of the fuel supply valve 4 for supplying the fuel gas to the fuel electrode of the fuel cell body 2 is controlled in the closing direction based on the combustible gas detection signal from the combustible gas detector 8. Control unit 11 for controlling the power generation output of the fuel cell main body 2 to decrease to a predetermined value.
Is provided.

Next, the operation of the packaged fuel cell power plant according to this embodiment having the above-mentioned structure will be described. In FIG. 2, if a flammable gas leaks from the fuel cell body 2 and its peripheral elements (devices, pipes) into the package 6 during the power generation operation by the fuel cell body 2, the flammable gas leaks. Is detected by the combustible gas detector 8, and a combustible gas detection signal is input to the control device 10.

On the other hand, the control device 10 supplies the fuel when it determines that the concentration of the combustible gas increases and approaches the allowable limit based on the combustible gas detection signal from the combustible gas detector 8. A control signal is output to the valve 4 to control the opening degree of the fuel supply valve 4 in the closing direction so that the power generation output of the fuel cell main body 2 is reduced to a predetermined value.

As a result, when the concentration of the combustible gas increases, the fuel supply valve 4 can be narrowed to operate so as to suppress the leakage amount of the combustible gas. That is, when a leak of flammable gas is detected, the ventilation volume is not increased as described above, and the operating load of the fuel cell power plant is reduced to reduce the amount of process gas and the amount of leak of flammable gas. The effect similar to the above-mentioned case can be acquired by reducing.

More specifically, the leakage of the combustible gas from the equipment and the piping is influenced by the flow rate of the fuel gas, that is, the power generation output. Therefore, when the concentration of the combustible gas increases, the fuel is supplied. The operation can be performed by reducing the opening degree of the valve 4 to suppress the leakage amount of the combustible gas.

As described above, in this embodiment, a fuel gas such as hydrogen is brought into contact with the fuel electrode, and an oxidant gas such as oxygen is brought into contact with the oxidant electrode, which is generated by an electrochemical reaction occurring at this time. Fuel cell main body 2 and peripheral elements for extracting electric energy from a pair of electrodes (fuel processing device 1, fuel supply valve 4, oxidant supply valve 5, and piping)
In a package type fuel cell power plant including an exhaust fan 7 for exhausting the atmosphere in the package 6 to the outside and taking the outside air into the package 6. Combustible gas detector 8 for detecting combustible gas leaking into the package 6 from the fuel cell main body 2 and its peripheral elements, and the combustible gas from the combustible gas detector 8 Based on the detection signal, the opening of the fuel supply valve 4 for supplying the fuel gas to the fuel electrode of the fuel cell main body 2 is controlled to be controlled in the closing direction, so that the power generation output of the fuel cell main body 2 is predetermined. A control device 11 for controlling so as to reduce the value is provided.

Therefore, the following effects can be obtained. (A) By grasping the presence or absence and the concentration of the flammable gas leaking into the atmosphere inside the package 6 of the package type fuel cell power plant, it is possible to more rationally operate the power plant according to the situation.

That is, since the combustible gas detector 8 measures the combustible gas concentration in the air as an analog value, when the combustible gas concentration approaches the allowable limit, the opening of the fuel supply valve 4 is reduced. Thus, the amount of flammable gas leaked can be suppressed.

As a result, the reliability of the plant that handles combustible gas is enhanced and the power generation operating rate can be improved. (B) Among the power generation plants, it is possible to operate the plant in which the burden on the fuel cell main body 2 is particularly small, and it is possible to contribute to the prevention of operational performance deterioration.

The present invention is not limited to the above embodiments, but can be implemented in the same manner as described below. (A) In the first embodiment, the package 6 is provided as the control device 10 for controlling the ventilation air volume of the package to increase based on the combustible gas detection signal from the combustible gas detector 8. The case of increasing the ventilation air volume by opening the automatic opening door 9 has been described.
Not limited to this, the ventilation fan 7 is controlled by an inverter to control the number of revolutions of the ventilation fan 7 as a control device 10 that controls to increase the ventilation air volume of the package based on a combustible gas detection signal from the combustible gas detector 8. When the combustible gas detector 8 detects a combustible gas, even if the ventilation air volume is increased by increasing the rotation speed of the ventilation fan 7, as in the case described above, It is possible to suppress an increase in concentration.

(B) In the second embodiment, the fuel supply valve 4 for supplying the fuel gas to the fuel electrode of the fuel cell main body 2 based on the combustible gas detection signal from the combustible gas detector 8. By controlling the opening degree of to control in the closing direction,
The case of providing the control device 11 for controlling the power generation output of the fuel cell main body 2 to decrease to a predetermined value has been described, but the present invention is not limited to this, and based on the combustible gas detection signal from the combustible gas detector 8, A fuel for supplying the fuel gas to the fuel electrode of the fuel cell main body 2 when the combustible gas concentration is monitored and processed over time and the combustible gas concentration has a time margin up to an allowable limit. By controlling the opening degree of the supply valve 4 to be controlled in the closing direction, the power generation output of the fuel cell main body 2 is gradually reduced to a predetermined value and then the power generation output of the fuel cell main body 2 is shifted to stop. Even if the control device 11 for controlling is provided, it is possible to obtain the same effect as in the above case.

As a result, it is possible to perform an operation in which the deterioration of the operating performance of the fuel cell power generation plant 2 is minimized. (C) In each of the above embodiments, the combustible gas detector 8 is
Needless to say, by increasing the number and disposing the positions in a dispersed manner, early detection of flammable gas leakage or a malfunction signal prevention measure for only one combustible gas detector 8 may be performed.

[0045]

As described above, according to the present invention, a fuel gas such as hydrogen is brought into contact with the fuel electrode and an oxidant gas such as oxygen is brought into contact with the oxidant electrode, and an electrochemical reaction that occurs at this time The fuel cell main body and its peripheral elements that take out the electrical energy generated by the pair of electrodes from the pair of electrodes are housed inside the package, and provided with ventilation means for exhausting the atmosphere inside the package to the outside and taking the outside air into the package. In the package type fuel cell power plant configured, a combustible gas leakage detection means for detecting a combustible gas leaking into the package from the fuel cell body and its peripheral elements, which is provided at or near the exhaust portion of the package, Based on the flammable gas detection signal from the flammable gas leak detection means, control is performed to increase the ventilation air volume of the package. Means, or control means for controlling the power generation output of the fuel cell main body to decrease to a predetermined value based on the flammable gas detection signal from the flammable gas leakage detection means, or flammability from the flammable gas leakage detection means. Based on the gas detection signal, monitor and process the change in the flammable gas concentration over time, and if the flammable gas concentration has a time margin to the allowable limit, the power generation output of the fuel cell main body to the specified value. Since it is provided with a control means for controlling so as to stop the power generation of the fuel cell main body after gradually lowering, while ensuring sufficient safety,
It is possible to provide a packaged fuel cell power plant that can improve the power generation operating rate and that does not impose an unnecessary burden on the fuel cell body and has excellent operability.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of a packaged fuel cell power plant according to the present invention.

FIG. 2 is a schematic diagram showing a second embodiment of the packaged fuel cell power plant according to the present invention.

FIG. 3 is a schematic diagram showing a configuration example of a conventional packaged fuel cell power plant.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel processing device, 2 ... Fuel cell main body, 3 ... Electricity / control device, 4 ... Fuel supply valve, 5 ... Oxidizing agent supply valve, 6 ... Package, 7 ... Ventilation fan, 8 ... Combustible gas detector, 9 ... automatic opening door, 10 ... control device, 11 ... control device.

Claims (7)

[Claims] 1. A fuel gas such as hydrogen is brought into contact with a fuel electrode and an oxidant gas such as oxygen is brought into contact with an oxidant electrode, and electric energy generated by an electrochemical reaction occurring at this time is generated from the pair of electrodes. A package type fuel cell, which is formed by housing a fuel cell main body to be taken out and its peripheral elements inside a package, and is provided with a ventilating means for exhausting the atmosphere in the package to the outside and taking the outside air into the package. In a power generation plant, a combustible gas leakage detection means is provided which is provided at or near an exhaust portion of the package and detects combustible gas leaking into the package from the fuel cell main body and its peripheral elements. Packaged fuel cell power plant. 2. A fuel gas such as hydrogen is brought into contact with the fuel electrode and an oxidant gas such as oxygen is brought into contact with the oxidant electrode, and electric energy generated by an electrochemical reaction occurring at this time is generated from the pair of electrodes. A package type fuel cell, which is formed by housing a fuel cell main body to be taken out and its peripheral elements inside a package, and is provided with a ventilating means for exhausting the atmosphere in the package to the outside and taking the outside air into the package. In a power plant, a combustible gas leakage detection unit that is provided at or near the exhaust portion of the package and that detects combustible gas leaking into the package from the fuel cell body and its peripheral elements, and the combustible gas leakage. Control for controlling to increase the ventilation air volume of the package based on the flammable gas detection signal from the detection means Package fuel cell power plant which characterized in that it comprises a stage, a. 3. The package according to claim 2, wherein the control means for controlling to increase the ventilation air volume of the package controls to open an automatic opening door provided in the package. Type fuel cell power plant. 4. The packaged fuel cell according to claim 2, wherein the control unit for controlling to increase the ventilation air volume of the package is to control to increase the ventilation amount by the ventilation unit. Power plant. 5. A fuel gas such as hydrogen is brought into contact with the fuel electrode and an oxidant gas such as oxygen is brought into contact with the oxidant electrode, and electric energy generated by an electrochemical reaction occurring at this time is generated from the pair of electrodes. A package type fuel cell, which is formed by housing a fuel cell main body to be taken out and its peripheral elements inside a package, and is provided with a ventilating means for exhausting the atmosphere in the package to the outside and taking the outside air into the package. In a power plant, a combustible gas leakage detection unit that is provided at or near the exhaust portion of the package and that detects combustible gas leaking into the package from the fuel cell body and its peripheral elements, and the combustible gas leakage. Based on the flammable gas detection signal from the detection means, the power generation output of the fuel cell body is reduced to a predetermined value. Package fuel cell power plant which characterized in that it comprises a Gosuru control means. 6. A fuel gas such as hydrogen is brought into contact with the fuel electrode and an oxidant gas such as oxygen is brought into contact with the oxidant electrode, and electric energy generated by an electrochemical reaction occurring at this time is generated from the pair of electrodes. A package type fuel cell, which is formed by housing a fuel cell main body to be taken out and its peripheral elements inside a package, and is provided with a ventilating means for exhausting the atmosphere in the package to the outside and taking the outside air into the package. In a power plant, a combustible gas leakage detection unit that is provided at or near the exhaust portion of the package and that detects combustible gas leaking into the package from the fuel cell body and its peripheral elements, and the combustible gas leakage. Based on the flammable gas detection signal from the detection means, the change with time of the flammable gas concentration is monitored and processed, and When the combustible gas concentration has a time margin up to an allowable limit, control for gradually decreasing the power generation output of the fuel cell main body to a predetermined value and then shifting to stop power generation of the fuel cell main body A packaged fuel cell power plant comprising: 7. The control means for controlling the power generation output of the fuel cell main body to decrease to a predetermined value includes closing an opening of a fuel supply valve for supplying a fuel gas to a fuel electrode of the fuel cell main body. 7. The package type fuel cell power plant according to claim 5, wherein the package type fuel cell power plant is controlled in a direction.