JP3100768B2 - Distributed fuel cell power plant and operation control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed arrangement type fuel cell power plant which can be preferably used for, for example, an electric utility and a method of controlling the operation thereof.

[0002]

2. Description of the Related Art At present, the development of phosphoric acid type fuel cells is several hundred K.
Commercial on-site type installed adjacent to customers up to W class, 5M
The development of both W-10MW class suburban distributed installation type electric utilities is being promoted. In such a situation, the single-unit capacity configuration of the distributed power plant is described in, for example, “FUJI SIGNAL”, Vol. 63, No. 11 (1990, published by “Fuji SIGNAL” editorial department of Fuji Electric Co., Ltd.). P. 745
As described on page 776, the usual idea was to make the module a module of about 5 MW or more. Also,
“Future Prospects of Phosphoric Acid Fuel Cell Power Generation Technology”, 2nd Report (Appendix) (published by the Ministry of International Trade and Industry in January 1986)
Page 7 also states that the capacity of a single unit is planned to be about 6.7 MW.

For example, FIGS. 8, 9 and 10 show the aforementioned “Prospects for Power Generation Technology for Phosphoric Acid Fuel Cells” 3-22 to 3-24.
The first floor of the 20MW class distributed power plant shown in the page,
FIG. 2 is a plan view and an elevation view of the second floor, in which 1 is a 6 MW fuel cell power generation module which is a unit of power generation, 2 is a fuel cell stack, 3 is a reformer, 4 is the gas of battery cooling water and raw material steam. A steam separator for water separation, 5 is an orthogonal converter for converting DC from battery output to AC, 6 is a water treatment device for purifying make-up water for raw material steam, and 7 is a cooling tower.

Next, the operation will be described. 8 to 1
At 0, the natural gas of the raw fuel and the steam generated by the steam separator 4 are mixed and charged into the reformer 3, and the hydrogen-rich gas generated by the reformer 3 is guided to the fuel cell stack 2, and is fed to the fuel cell stack 2. The generated DC output is converted into an AC output by the orthogonal transformer 5 and the power is transmitted to a power system (not shown). Here, the power transmission unit is for each 6 MW module 1, and when it is necessary to stop the blunt at the time of periodic inspection or failure, the unit is stopped for each 6 MW module.

The fuel cell stack 2 needs to be cooled at the time of power generation, and cell cooling water for that purpose is guided to the fuel cell stack 2 from the liquid phase portion of the steam separator 4. Since the above-mentioned raw material steam is consumed together with power generation, make-up water is required, and a facility for purifying make-up water is a water treatment device 6. Further, since nitrogen is used for the heating medium in the plant when the plant is started and the purge in the plant when the plant is stopped, a nitrogen supply facility (not shown) is required. Since these make-up water and nitrogen are utilities that are required in common for all 6 MW modules 1, the water treatment device 6 and the nitrogen supply equipment are 6 M in total.
It is a common facility with a capacity of one W module.
The size of each component device that covers the capacity of 6 MW,
It becomes a quite large size, the equipment arrangement is naturally limited,
For example, the equipment layout is as shown in FIGS. 9 and 10, and the site size corresponding to the 6 MW module is 28 m / 3 × 42 m (39
2m2) and the height of the building is about 15m.

Next, an example of a characteristic curve with respect to the output of the power generation efficiency of the 5 MW class module 1 is shown in FIG. Power generation efficiency 3
The output region where the efficiency is higher than 6% is the case where the load is 60% or higher, and the power generation efficiency is significantly reduced in a low load zone lower than 60%. Since power is transmitted in units of 5 MW class modules, improvement in power generation efficiency cannot be expected due to devised operation methods.
The power generation efficiency is uniquely determined by the characteristic curve.

[0007]

As described above, the conventional distributed-type fuel cell power plant is a module having a single unit capacity of about 5 MW class or more. However, the layout was decided uniquely, and there was no flexibility in the site shape. In addition, the plant must be stopped in units of 5 MW even in the case of periodic inspections and failures, resulting in a large decrease in output as a power plant and a problem in reliability. Furthermore, when evaluated in units of 5 MW class modules, the power generation efficiency in the low load zone was low, determined by the characteristics of the module itself, and there was no room for improvement by the operation method.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and the layout of a plant can be freely selected. The purpose is to obtain a portable fuel cell power plant. It is another object of the present invention to provide a partial load high efficiency operation control method suitable for this power plant.

[0009]

According to a first aspect of the present invention, there is provided a distributed fuel cell power plant comprising a plurality of small power fuel cell power generation units having a package structure accommodating all component devices required for power generation. On the first floor
Of utilities related to fuel cell power generation units
It is three-dimensionally arranged in a building with a hierarchical structure in which facilities are arranged . According to a second aspect of the present invention, there is provided a method for controlling operation of a distributed arrangement type fuel cell power plant, wherein the number of low power fuel cell power generation units to be operated is set in advance in accordance with an electric power load, and The power generation unit is controlled so as to operate at a load factor with high power generation efficiency. According to a second aspect of the present invention, there is provided an operation control method for a distributed fuel cell power plant, wherein a plurality of low power fuel cell power generation units are grouped into groups, and the group of the low power fuel cell power generation units to be operated according to an electric power load. Are set in advance, and each of the low-power fuel cell power generation units to be operated is controlled to operate at the same load factor.

[0010]

The low power fuel cell power generation units according to the present invention are three-dimensionally arranged, so that the required area of the site is reduced, and the degree of arbitrariness is increased even when selecting the site shape. Further, the operation control method of the present invention performs start and stop operations for each unit unit or for each unit group in the operation control method according to another invention, thereby generating power for the entire plant at a low load. Improving efficiency.

[0011]

[Embodiment 1] FIG. 1 is an elevation view showing a 5MW-class distributed fuel cell power plant according to an embodiment of the present invention. In the figure, reference numeral 11 denotes a 200 kW class on-site fuel cell power generation unit (hereinafter simply referred to as 200 kW) as a low power fuel cell power generation unit.
This is a unit having a package structure in which all component devices necessary for power generation corresponding to the 6 MW fuel cell power generation module shown in FIG. 8 are stored.
Reference numeral 12 denotes a building for arranging the 200 kW units 11 in a hierarchical manner. The 200 kW units 11 are arranged on the second to fifth floors, and the first floor is common to all units corresponding to the nitrogen supply equipment, the water treatment device 6, and the like. Utility-related common facilities are provided (details not shown). FIG. 2 is a plan view of the fifth floor portion of the power plant according to the first embodiment, in which six 200 kW units 11 are arranged.

In addition, 13 is a collective piping tower, 14 is a cooling tower,
15 is a distribution board, 16 is an elevator tower, 17 is a machine room, 1
8 is a crane, 19 is a city gas pipe, 20 is a water supply pipe, 21
Is a steam pipe, 22 is an exhaust pipe, 23 is a drain pipe, 24 is a conduit pipe, 25 is a hot water pipe, 26 is a nitrogen supply pipe, and 27 is a piping / wiring route.

Next, the operation will be described. As shown in FIGS. 1 and 2, in this embodiment, a low power 200 KW unit 11 used as an on-site fuel cell power generator
Are three-dimensionally arranged on the second to fifth floors of the building 12, and the assembly forms a 5 MW class power plant. In this case, the power transmission unit is every 200 KW unit 11, and this 200
The KW units 11 can be arranged alone or freely in groups, and can be freely arranged in a two-dimensional or three-dimensional manner. In this case, the required site size is about 32m
× 13 m (420 square meters), which is almost equivalent to the case of FIG. Furthermore, if there are constraints such as a small site area, the number of 200 KW units to be arranged per floor can be reduced, and if the building level is raised, a power plant can be constructed according to the site conditions. High degree.
The site shape can be arbitrarily selected.

Since the power transmission unit is 200 KW unit 11 as described above, 200 KW unit 11
It is only necessary to stop the power supply in units of the W unit 11, so that the power output of the whole plant is small and a highly reliable power plant can be obtained. Further, by using the on-site type unit, the cost reduction effect can be expected because the number of on-site type units becomes large in the distributed power plant based on practical equipment.

In the above-described embodiment, the on-site fuel cell power generation unit having an output of 200 KW is used as the low power fuel cell power generation unit 11. However, the present invention is not limited to this, and has an output of, for example, about 500 KW. Similar effects can be expected with a power generation unit.

Next, an operation control method of the power plant according to the embodiment configured as described above will be described. FIG. 3 shows the power generation efficiency characteristics of the 200 kW unit 11 in the embodiment shown in FIG. 1. As in the case of the power generation efficiency characteristics of the 5 MW class module shown in FIG.
The power generation efficiency is significantly reduced as the load becomes smaller.

FIG. 4 shows an example of an operation control method for the entire plant, in which all the 200 KW units are temporarily set to the same output in accordance with the plant output. In FIG. 4, the operation control method is such that the load factor is linearly proportional to the plant output in all the 25 units under the same conditions in accordance with the output of the plant. In this operation control curve 31, all 20
Since the plant output is configured using the 0 KW unit, as can be seen from the line indicated by hatching A in FIG.
It is possible to increase the output up to the W output, and it is a flexible operation method that is strong against load changes. However, the power generation efficiency of the entire plant is exactly the same as the power generation efficiency of the 200 kW basic unit itself, and low power generation efficiency in the low load zone Is the same as FIG. 11 showing the power generation efficiency characteristics of the conventional 6 MW module.

Embodiment 2 FIG. FIG. 5 is a diagram illustrating an embodiment of the operation control method of the present invention. In FIG. 5, the number of 200 KW units to be operated is set finely in accordance with the plant output, and all the operated 200 KW units are operated at a load factor of 75% or more with high power generation efficiency (but 500 KW or less) The operation control method in this case is as shown in 32. In the method of the operation control curve 32, since the load factor of the operating 200 KW unit is 75% or more, the power generation efficiency curve of the whole plant is 36% over the entire plant output region except for the ultra-low load zone of 500 KW or less.
The above high power generation efficiency can be obtained.

As can be seen from the line shown by hatching B, since the number of 200 KW units to be operated is set in detail for the plant output, there is an upper limit to the amount that can be increased by the operating unit alone. It is difficult to respond instantaneously to a load increase beyond the changeable region. That is, it is necessary to increase the number of operating units for a large load increase, and it takes three hours to start the units. Therefore, it is difficult to cope with an instantaneous load increase. Therefore, this operation control method 32 can be said to be optimal for a power plant in which the plant output can be programmed in a planned manner.

Embodiment 3 FIG. Next, as another embodiment of another operation control method according to the present invention, a plurality of 200 kW units are grouped, and
FIG. 6 shows an example of an operation control method in which a group to be operated according to the plant output is set. In the embodiment of FIG. 6, all the 25 units are divided into 5 groups of 5 units, and 10 units of 2 groups are operated up to 2 MW corresponding to the plant output.
In the 2.5MW area, 4 groups operate 20 units, 2.5-5
In the MW area, the operation of 25 units in 5 groups is set, and the units in operation are operated at substantially the same load factor.
In this embodiment, the load ratio of the basic unit to the plant output is as shown in the operation control curve 33.
FIG. 7 is a flowchart for briefly explaining the operation control method shown in FIG.

When the control is performed as in this embodiment, the load factor becomes 50% or more in a region where the plant output is 1 MW or more, and a high power generation efficiency of about 35.5% or more can be obtained.
In this case, the difference from the embodiment shown in FIG. 5 is that the number of operating units in FIG. 6 is equal to or greater than that in FIG. The upper limit that can handle is raised. Therefore, the operation control method 33 can be said to be an operation control method which slightly sacrifices power generation efficiency but is resistant to load changes.

In this specification, the low-power fuel cell power generation unit is not particularly limited, but is, for example, several kW used as a so-called on-site type fuel cell power plant.
Any of up to several hundred KW class can be preferably used. Further, in the above-described embodiment, the description has been given of the 5 MW class distributed fuel cell power plant and the operation control method thereof. However, the output of the power plant, the method of grouping the power generation units, and the like are not limited to those of the embodiment. Needless to say.

As described above, claim 1 of the present invention
According to the distributed arrangement type fuel cell power plant according to the above, a plurality of small power fuel cell power generation units having a package structure containing all the component devices necessary for power generation are placed on the first floor.
Is a utility common to small power fuel cell power generation units
The three-dimensional layout of the building has a hierarchical structure with common facilities related to it, so the site shape can be selected arbitrarily, and even when periodic inspections or breakdowns need to be stopped, there is little reduction in plant output. A highly reliable power plant can be obtained. Further, according to the operation control method of the distributed fuel cell power plant according to the second aspect of the present invention, the number of low power fuel cell power generation units to be operated is set in advance according to the power load, and the operation is performed. Since the small power fuel cell power generation unit is controlled so as to operate at a high power generation efficiency load factor, high power generation efficiency can be obtained as a whole plant. Further, according to the operation control method for a distributed fuel cell power plant according to claim 3 of the present invention, a plurality of low power fuel cell power generation units are grouped together, and the small power fuel cell operated according to the power load. The number of groups of power generation units is set in advance, and each small-power fuel cell power generation unit to be operated is controlled so as to operate at the same load factor. Can be dealt with flexibly.

[Brief description of the drawings]

FIG. 1 is an elevational view showing a distributed fuel cell power plant according to one embodiment of the present invention.

FIG. 2 is a plan view of the embodiment shown in FIG.

FIG. 3 is a characteristic diagram showing a power generation efficiency curve measured for the embodiment shown in FIG.

FIG. 4 is a diagram illustrating an operation control method according to the conventional system of the embodiment shown in FIG. 1;

FIG. 5 is a diagram for explaining an operation control method of a distributed fuel cell power plant according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating an operation control method of a distributed fuel cell power plant according to a third embodiment of the present invention.

FIG. 7 is a flowchart showing an example of the operation control method of the embodiment shown in FIG.

FIG. 8 is an overall plan view of a conventional distributed power plant.

FIG. 9 is a plan view of a 5 MW module section of a conventional distributed power plant.

FIG. 10 is an elevation view of a 5 MW module section of a conventional distributed power plant.

FIG. 11 is a characteristic diagram illustrating the power generation efficiency of a conventional distributed power plant.

[Explanation of symbols]

11 Low power fuel cell power generation unit 12 Building with hierarchical structure 32 Operation control curve in which operation pattern for each unit is set according to power load 33 Operation in which operation pattern for each unit group grouped according to power load Control curve

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-304581 (JP, A) JP-A-62-150664 (JP, A) JP-A-3-270651 (JP, A) JP-A 61-304 232569 (JP, A) "Fuji Jiho" Vol. 63, No. 11 (published by the editorial department of "Fuji Jiho" in Fuji Electric Co., Ltd. in 1990) pp. 719-748 (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01M 8/00-8/24

Claims (3)

(57) [Claims] 1. A plurality of low power fuel cell power generation units having a package structure accommodating all component devices required for power generation, and a small power fuel cell power generation unit on the first floor.
A distributed fuel cell power plant characterized by being three-dimensionally arranged in a building having a hierarchical structure in which common utilities related to common utilities are arranged . 2. A power plant comprising a plurality of small power fuel cell power generation units having a package structure accommodating all component devices required for power generation, and operating in accordance with a power load. An operation control method for a distributed fuel cell power plant, wherein the number is set in advance, and the operated small-power fuel cell power generation units are controlled so as to operate at a high power generation efficiency load factor. 3. A power plant having a plurality of small power fuel cell power generation units having a package structure accommodating all component devices necessary for power generation, wherein a plurality of the low power fuel cell power generation units are grouped by a plurality of power generation units. The number of groups of low power fuel cell power generation units to be operated is set in advance in accordance with the above, and each of the low power fuel cell power generation units to be operated is controlled to operate at the same load factor. An operation control method of a distributed fuel cell power plant.