JPH0613093A - Heat and electric power combined supply system and building provided with this supplying system - Google Patents

Abstract

PURPOSE:To simplify structure and provide a high temperature and good quality thermal output. CONSTITUTION:A heat and electric power combined supply system is provided with each equipment of a fuel cell 1, a reformer 2, an ejector 3, a pump 4, a boiler 5, and a valve 6, and pipings for connecting each equipment. The boiler 5 supplies steam used for the reforming of a starting gas in the reformer 2 and a cooling water necessary for the cooling of the fuel cell 1, and further generates high temperature steam for taking out a thermal output. The exhaust gas from the reformer 2 and the exhaust gas of air from the fuel cell 1 are sent to the boiler 5 through pipings 26, 27, respectively, and utilized as combustion air. The exhaust gas of fuel from the fuel cell 1 may be sent to the boiler 5 through a piping 40, and utilized as fuel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-site combined heat and power system using a phosphoric acid fuel cell and a building equipped with the system.

[0002]

2. Description of the Related Art A fuel cell power generation system has been attracting attention as a new energy system with low pollution and high efficiency. Among them, a phosphoric acid fuel cell power generation system (hereinafter, abbreviated as PAFC system) was developed from an early stage. It is being advanced and will be put into practical use. In particular, the PAFC system is installed in a building and is expected as a cogeneration system that simultaneously supplies not only electric power but also a heat source.

The development status of the conventional PAFC system is as follows: Functional Materials Vol.11, No.6 (1991) "Development and Practical Use of Phosphoric Acid Fuel Cell Power Generation System" (Katsumasatsu Tsutsumi), Fuji Time Report Vol. .1
1 (1990) "Development of on-site fuel cell power generator" (Yoshikatsu Tsuji et al.), JP-A-64-71076, JP-A-6-76
No. 1-190866, etc.

The phosphoric acid fuel cell generates electric energy by continuously supplying hydrogen to the negative electrode and oxygen to the positive electrode. That is, the hydrogen molecules supplied to the negative electrode inside the battery release electrons, and the hydrogen molecules that have moved to the positive electrode and the electrons that have reached the positive electrode through the external circuit react with oxygen supplied to the positive electrode to generate water. However, of these, the flow of electrons flowing through the external circuit is output as electrical energy.

In practice, since it is difficult to directly supply hydrogen gas, natural gas or methane gas whose main component is methane such as city gas is used as a raw material gas, and these are converted into hydrogen gas by a reformer. It is reformed and supplied to the phosphoric acid battery. Also, air is generally supplied directly instead of oxygen.

FIG. 4 shows a block diagram of the PAFC system described in “Fuji Electric Journal Vol. 63, No. 11 (1990)“ Development of on-site fuel cell power generator ”(Yoshikatsu Tsuji et al.). The above-mentioned other conventional techniques are basically the same. The present system is configured by devices such as a fuel cell 101, a reformer 102, an ejector 103, a steam drum 104, heat exchangers 105 and 107, a starting electric heater 106, and a pump 108. Further, gas pipes 120 to 128, steam pipes 130, cooling water pipes 131 and 132, and electric wiring 129 are connected to each device as shown by solid lines in the figure. In addition, these flowing directions are indicated by arrows in the drawing.

Next, the operation of this system will be described. The raw material gas is supplied to the ejector 103 through the pipe 120, and at the same time, the steam from the steam drum 104 is also supplied to the ejector 103 through the pipe 130, the raw material gas and the steam are mixed, and then enter the reformer 102 through the pipe 121. At this time, the amount of water vapor is controlled by the ejector 103. The mixed gas of the raw material gas and steam is supplied to the reformer 102 at 80
It is heated to around 0 ° C and reformed to become hydrogen, steam, carbon dioxide and carbon monoxide. Since carbon monoxide adversely affects the fuel cell, it can be converted into carbon dioxide in the CO shift converter, but it is omitted because it is not directly related to the description of the present invention.

The generated hydrogen, water vapor, and carbon dioxide enter the fuel cell 101 through the pipe 122 and the pipe 123.
By reacting with the air supplied to the fuel cell 101, a flow of electrons flowing through the external circuit is generated as described above, and this flow of electrons (direct current) is output from the cable 129 as electric power. This electric output is converted into alternating current by an inverter (not shown) and supplied to an external device (not shown). In order to maintain the above reaction, it is necessary to keep the temperature of the fuel cell 101 at about 200 ° C., that is, to cool it. Therefore, the pipe 131 from the steam drum 104 and the pump 10 are required.
8, the cooling water of about 170 ° C. is supplied to the fuel cell 101. The cooling water is 180 due to the reaction heat of the fuel cell 101.
After being heated to about ℃, enters the heat exchanger 107 through the pipe 132, takes out the heat output, and then returns to the steam drum 104. The steam generated in the steam drum 104 is supplied to the ejector 103 again through the pipe 130 as described above.

Normally, 100% of hydrogen is not used in the phosphoric acid type fuel cell 101, and the usage rate is 80 on average.
It is controlled to about%. The remaining hydrogen enters the reformer 102 through the pipe 124 as a fuel exhaust gas together with carbon dioxide and water vapor that are not used in the battery. On the other hand, the air containing water vapor used in the fuel cell 101 is discharged through the pipe 128 as an exhaust gas of air.

In the reformer 102, the exhaust gas of the fuel from the pipe 124 and the air supplied from the pipe 125 are mixed and burned in the reformer combustion section, and discharged as exhaust gas from the pipe 126, and the heat exchanger 105. The heat output is taken out and is discharged from the pipe 127 together with the exhaust gas of air from the pipe 128 described above. As a result, the temperature of 800 ° C. necessary for reforming the raw material gas in the reformer is obtained. It should be noted that when starting the fuel cell, since there is no exhaust gas of the fuel supplied from the pipe 124 to the reformer 102, the raw material gas is burned instead of the exhaust gas of the fuel, but this is omitted because it is not directly related to the description of the present invention. . The air supplied from the pipes 123 and 125 is sent by a blower or the like, but this is also omitted.

The electric heater 106 for starting heats the water in the steam drum 104 at the time of starting, and the ejector 103 is heated.
Is used to raise the temperature of the fuel cell 101 from about 60 ° C. during storage to 200 ° C. during operation by circulating cooling water. Since the electric heater 106 for starting consumes a large amount of electric power,
There is also an attempt to heat the steam drum 104 by an auxiliary boiler (not shown).

As described above, the phosphoric acid fuel cell outputs electric power and heat at the same time. Since this phosphoric acid fuel cell uses phosphoric acid as the electrolyte, it is necessary to maintain the temperature at about 200 ° C., and the cooling water from the steam drum 104 is used as described above so as not to be overheated by the reaction heat. It is cooling. The temperature of the cooling water is controlled by adjusting the flow rate of the cooling water with the pump 108.

The cooling water of about 180 ° C. flowing out from the fuel cell 101 through the pipe 132 can be heat-exchanged by the heat exchanger 107 as a heat source to obtain hot water of about 70 ° C. as a heat output. The temperature of the exhaust gas discharged from the pipe 126 is about 400 to 500 ° C., and heat can be exchanged in the heat exchanger 105 to obtain hot water of about 70 ° C. as a heat output, which allows the heating and cooling and hot water supply to be achieved. It can function as part of a generation system.

The power generation efficiency (power generation amount / fuel gas amount) of the PAFC system as described above is about 40%, and the thermal efficiency (output heat amount / fuel gas amount) is 40%. Power generation efficiency + thermal efficiency) is about 80%. Therefore, 20% of the heat is wasted by the exhaust gas.

[0015]

In a building such as an office using a fuel cell as described above, most of its heat load is consumed as a cooling load in summer. Since an absorption refrigerator is usually used, the quality of the heat source becomes a problem. For example, in the case of cold heat production with hot water at 80 ° C, the coefficient of performance is about 0.6 when using a hot water single-effect absorption refrigerator, but for steam at 180 ° C, the results are obtained with a steam-heat double effect absorption refrigerator. The coefficient improves to 1.2. Therefore, when the heat source is used for cooling, the higher the temperature, the better the quality, and the better the steam is than the water.

However, the temperature of the cooling water output from the fuel cell is about 180 ° C., and the hot water output obtained by heat exchange is as low as about 70 ° C., and its usage is limited. Further, the exhaust gas from the reformer is 400 to 500 ° C, a large heat exchanger is required for heat exchange from the gas, and the hot water output is low at about 70 ° C. Therefore, the quality of heat output from the conventional PAFC system as described above is not very good.

As described above, the conventional PAFC system is attractive as an on-site combined heat and power system, but when it is put into practical use, the temperature of the gas and hot water used is low, so that large-scale heat exchange is required. There was a problem that the temperature of the heat output was low due to the need for a vessel.

In addition to the above, in addition to the reformer and the fuel cell main body which are basically required, many constituent devices such as a steam drum, an electric heater for starting, and a heat exchanger for heat output are required. There is a problem that the system configuration becomes complicated.

An object of the present invention is to provide a combined heat and power supply system having a simple structure and capable of obtaining a high-quality heat output, and a building equipped with the same.

[0020]

To achieve the above object, in a cogeneration system according to the present invention, a reformer for producing hydrogen by burning a fuel and reforming a raw material gas sent together with steam at a high temperature. In a combined heat and power system having a fuel cell that outputs electric power using hydrogen and air produced by the reformer, a boiler that heats water to generate steam, and steam generated in the boiler is converted to steam. As steam supply means for sending to the reformer, as cooling water supply means for sending water in the boiler to the fuel cell as cooling water, and as exhaust gas after obtaining high temperature in the reformer as combustion air It has a first air supply means for sending to the boiler, and a heat output extraction means for extracting heat output from the steam generated in the boiler.

Here, it is preferable that the fuel cell system further comprises cooling water recovery means for recovering the cooling water for cooling the fuel cell to the boiler.

Further, preferably, there is further provided a second air supply means for sending the exhaust gas of the air after electric power is obtained by the fuel cell to the boiler as combustion air.

Further, preferably, the fuel cell system further comprises fuel supply means for supplying the raw material gas as fuel to the reformer, and fuel exhaust gas supply means for supplying exhaust gas of fuel of the fuel cell to the boiler as fuel.

In order to achieve the above object, the building according to the present invention comprises a combined heat and power system as described above.

[0025]

In the present invention configured as described above, high temperature exhaust gas is sent as combustion air from the reformer to the boiler via the first air supply means, and the steam is generated by burning the fuel. To do. This steam is sent to the reformer via the steam supply means and used for reforming the raw material gas. Also,
Water in the boiler is sent to the fuel cell through the cooling water supply means and used for cooling the fuel cell. This allows the boiler to act as a conventional steam drum and a starting electric heater.

On the other hand, the heat output is taken out from the high temperature steam obtained in the boiler by the heat output extracting means. Here, the exhaust gas from the reformer contains oxygen sufficient to burn the fuel of the boiler and is heated to a high temperature (for example, 400 ° C. or higher). Since the boiler uses this heated air, more hot steam can be obtained with the same amount of fuel.

As described above, the boiler replaces the roles of the conventional steam drum, the orbital heater, and the conventional two heat exchangers, and the system configuration is simplified and high-temperature steam is output as the heat output. Therefore, the quality of heat output is improved.

The cooling water that has cooled the fuel cell is recovered again by the cooling water recovery means in the boiler. By further heating this cooling water in the boiler, the high temperature steam used for reforming in the reformer and Hot steam is readily available for extracting heat output.

Further, the exhaust gas of the air after the electric power is obtained by the fuel cell is sent to the boiler as the combustion air through the second air supply means and used for the combustion of the fuel. Here, the exhaust gas of the air from the fuel cell contains sufficient oxygen to burn the fuel of the boiler as well as the exhaust gas from the reformer,
Moreover, since it is hot and the boiler uses this heated air, more hot steam can be obtained with the same amount of fuel.

Further, in the conventional PAFC system, when the electric load increases, the hydrogen consumption in the fuel cell increases, the residual hydrogen amount in the exhaust gas of the fuel decreases from the steady state, and the heat amount of the reformer decreases. The reforming amount of the raw material gas is temporarily reduced. That is, even if the supply amount of the raw material gas is increased, the load response is poor and the electric output does not suddenly increase. But,
In the present invention, in order to obtain the high temperature of the reformer, the raw material gas is sent to the reformer through the fuel supply means and burned, while the exhaust gas of the fuel from the fuel cell is passed through the fuel exhaust gas supply means. It is sent to the boiler and burned as fuel. This makes the amount of hydrogen in the exhaust gas of the fuel irrelevant to the amount of heat of the reformer, so that the load response of the system when the electric load becomes large is improved.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A combined heat and power supply system according to an embodiment of the present invention will be described below with reference to FIG. A block diagram of the combined heat and power supply system according to this embodiment is shown in FIG. The present system includes devices such as a fuel cell 1, a reformer 2, an ejector 3, a pump 4, a boiler 5, and a valve 6, of which the fuel cell 1 and the reformer 2 constitute a power generator. In addition, gas pipes 20 to 27 and steam pipes 30 and 3 are provided in each device.
1, water piping 32, 33, 34, 35, fuel piping 3
6 and an electric wiring 37 for extracting an electric output are connected. These are shown by solid lines in the figure, and their flowing directions are shown by arrows in the figure. That is, the pipe 20 sends the raw material gas to the ejector 3, the pipe 21 sends the mixed gas of the raw material gas mixed by the ejector 3 and the steam from the boiler 5 to the reformer 2, and the pipe 25 burns the exhaust gas of fuel. Air for use is sent to the reformer 2. Further, the pipe 22 sends the fuel gas from the reformer to the fuel cell, the pipe 23 sends air to the fuel cell, the pipe 24 sends the exhaust gas of the fuel from the fuel cell to the reformer 2 as fuel, and the pipe 27 Sends the exhaust gas of the air from the fuel cell 1 to the boiler 5 as the air for combustion together with the exhaust gas from the reformer 2. Further, the pipe 32 sends the cooling water from the boiler 5 to the fuel cell 1 via the pump 4, and the pipe 3
Numeral 3 cools the fuel cell and heats the cooled water again to the boiler 5
To collect. Further, the pipe 34 mixes the water (cold water) whose amount is adjusted by the valve 6 with the cooling water of the pipe 32, and the pipe 30 sends the steam from the boiler 5 to the ejector 3, and the pipe 26
Sends the exhaust gas after combustion of the exhaust gas of the fuel in the reformer 2 to the boiler 5 as combustion air, and the pipe 31 connects the boiler 5 to the boiler 5.
To send steam to the boiler 5, the pipe 35 supplies water to the boiler 5, and the pipe 36 supplies heavy oil as fuel to the boiler 5.

Further, in the present embodiment, the boiler 5 burns the fuel (heavy oil) supplied from the pipe 36 to make the pipe 3
The water supplied from No. 5 is heated. The high temperature steam (180 ° C.) obtained in this boiler 5 is used in the piping 3 as described later.
0, it is sent to the reformer via the ejector 3, and is used as steam for reforming, and is also used as high-temperature steam whose heat output is taken out from the pipe 31. The hot water obtained in the boiler 5 is supplied as cooling water sent from the pipe 32 to the fuel cell, as will be described later.

Next, the operation of this system will be described. The raw material gas is supplied to the ejector 3 from the pipe 20, and at the same time, the steam from the boiler 5 is also supplied to the ejector 3 via the pipe 30, and the raw material gas and the steam are mixed to pass through the pipe 21.
To the reformer 2. At this time, the amount of water vapor is controlled by the ejector 3. This raw material gas is heated in the reformer 2 to around 800 ° C. and reformed to become hydrogen, steam, carbon dioxide and carbon monoxide. Since carbon monoxide adversely affects the fuel cell, it can be converted to carbon dioxide in the CO shift converter, but it is omitted because it is not directly related to the present invention.

The generated hydrogen, water vapor, and carbon dioxide enter the fuel cell 1 through the pipe 22, react with the air supplied to the fuel cell 1 through the pipe 23, and generate a flow of electrons flowing through the external circuit. This electron flow (DC) is in the cable 3
It is output as electric power from 7. This electric output is converted into alternating current by an inverter (not shown) and supplied to an external device (not shown). To maintain the above reaction,
Since it is necessary to maintain the temperature of the fuel cell 1 at about 200 ° C., that is, to cool it, cooling water is supplied from the boiler 5 to the cold fuel cell 1 through the pump 4 and the pipe 32. This cooling water cools the fuel cell 1, the cooling water itself is heated to about 180 ° C., and is recovered again by the boiler 5 through the pipe 33. The temperature of the fuel cell 1 is detected by a thermometer (not shown), and the valve 6 is adjusted based on the detected value to mix the cold water from the pipe 34 with the hot water from the boiler 5 in the pipe 32 to adjust the temperature of the cooling water. It is held by adjusting and further adjusting the flow rate of the cooling water by the pump 4. The cooling water collected in the boiler 5 is further heated to easily become high temperature steam,
It is used for reforming in the reformer 2 and is also used for extracting heat output.

Exhaust gas of the fuel containing hydrogen from the fuel cell 1 enters the reformer 2 through the pipe 24, while the exhaust gas of the pipe 2
5, the combustion air enters the reformer 2, and the exhaust gas of the fuel from the fuel cell 1 is mixed with this air in the reformer combustion section,
The exhaust gas after combustion is sent to the pipe 26. This reformer 2
The exhaust gas from will be described later. In the reformer, the temperature of 800 ° C. necessary for reforming the raw material gas is obtained by the above combustion. Since there is no exhaust gas of the fuel supplied from the pipe 24 to the reformer 2 at the time of starting the fuel cell, the raw material gas is burned instead of the exhaust gas of the fuel.
It is omitted because it is not directly related to the description of the present invention. Further, the air supplied from the pipes 23 and 25 is sent by a blower or the like, but it is omitted in the same manner.

Normally, the amount of air supplied from the pipe 25 is larger than that required for complete combustion of the exhaust gas of the fuel, and it is customary that the amount is about twice as much. Therefore, the exhaust gas from the reformer 2 contains sufficient oxygen and has a high temperature of 400 ° C. or higher. The air from the positive electrode of the fuel cell 1 also contains residual oxygen and is heated. Therefore, in this embodiment, these airs are used to burn the fuel of the boiler 5.

That is, in this embodiment, the exhaust gas of the reformer 2 and the air from the positive electrode of the fuel cell 1 are supplied to the boiler 5 through the pipes 26 and 27, and used to burn heavy oil as fuel. This air contains enough oxygen so that it can burn the heavy oil completely to generate enough heat to generate the above, and because this air is heated, the boiler 5 will have more than the same amount of fuel. Amount of steam can be generated. In this embodiment, the temperature of the steam 9 generated by the boiler 5 is 180 ° C., and even if a normal boiler is used, the conventional PA
It is possible to easily obtain high-quality heat output at a high temperature as compared with a combined heat and power supply system using an FC system.

When the system is started up, the fuel cell 1
1 is adjusted so that the temperature and flow rate of the cooling water are gradually changed by adjusting the valve 6 and the pump 4 in FIG. Gradually raise to ℃. At this time, the operation of the boiler 5 is not affected by the fuel cell 1, and the boiler 5
Since high temperature steam and cooling water can be easily supplied from
Further, the boiler 5 can output high-temperature steam for extracting heat output from the pipe 31 independently of the operation of the fuel cell 1. Therefore, according to the present embodiment, the system can be brought up to a steady operation state in a shorter time than with the conventional electric heater for starting.

As described above, according to this embodiment, the steam used for reforming in the reformer 2 and the cooling water for cooling the fuel cell 1 are generated in the boiler 5. The role of the drum and the electric heater for starting can be replaced with this boiler 5. Moreover, since the exhaust gas from the reformer 2 is sent to the boiler 5 through the pipe 26 and used as combustion air, a larger amount of steam can be generated with the same fuel amount in the boiler 5. Further, since this steam is used to extract the heat output, it is not necessary to install a plurality of large-sized heat exchangers as in the conventional case. Therefore, the system configuration can be simplified. Also, boiler 5
This makes it easier to obtain hot steam, that is, better heat output, than with conventional heat exchangers.

Further, the heated cooling water that has cooled the fuel cell 1 is collected again in the boiler 5 through the pipe 33 and is further heated in the boiler 5, so that high temperature steam can be easily obtained.

Further, since the exhaust gas of air from the fuel cell 1 is sent to the boiler 5 through the pipe 27 and used as combustion air, a larger amount of steam can be generated with the same fuel amount in the boiler 5.

Further, at the time of start-up, the operation of the boiler 5 is not affected by the fuel cell 1 at all, and high-temperature steam and cooling water can be easily supplied from the boiler 5, which is shorter than the conventional electric heater for start-up. The system can be brought up to a steady operation state in time.

Next, a combined heat and power system according to another embodiment of the present invention will be described with reference to FIG. Next, the block diagram of the combined heat and power supply system according to the present embodiment is shown in FIG. In this embodiment, the exhaust gas of the fuel of the fuel cell is supplied not as the fuel for obtaining the high temperature of the reformer but as the fuel of the boiler,
The embodiment differs from the embodiment of FIG. 1 in that a raw material gas is used as a fuel for obtaining an appropriate temperature of the reformer. Other configurations and functions of the device are similar to those of the embodiment shown in FIG. That is, as shown in FIG. 2, the exhaust gas of the fuel from the fuel cell 1 is supplied to the pipe 40.
The steam is sent to the boiler 5 by (gas pipe), burns together with the fuel supplied from the pipe 36 in the boiler 5, and steam used for reforming in the reformer and high-temperature steam as a heat output are produced. On the other hand, as the fuel for obtaining the proper temperature of the reformer 2, a part of the raw material gas supplied from the pipe 20 is supplied through the pipe 41.

By the way, when the electric load becomes large in the conventional PAFC system, the amount of hydrogen consumption in the fuel cell 1 increases. Therefore, the residual hydrogen amount in the exhaust gas of the fuel from the fuel cell 1 is reduced to less than 20% of the steady state, and the exhaust gas of the fuel with the reduced residual hydrogen amount is sent to the reformer 2, so that the reformer 2 The amount of heat decreases and the amount of reforming of the raw material gas temporarily decreases. Therefore, the amount of fuel gas supplied to the fuel cell decreases, and the electric output does not suddenly increase even if the amount of raw material gas supplied is increased. That is, the conventional P
The load response of the AFC system is not very good. However, in this embodiment, since the exhaust gas of the fuel from the fuel cell 1 is sent to the boiler 5 through the pipe 40 and burned as the fuel, the raw material gas is used as the fuel for obtaining the proper temperature of the reformer 2. However, the amount of hydrogen in the exhaust gas of the fuel and the amount of heat of the reformer 2 become irrelevant, and the phenomenon as seen in the conventional PAFC system as described above disappears. Therefore, as the electric load increases, the raw material gas supplied from the pipe 41 can be immediately increased to increase the reforming amount in the reformer 2, so that the load response of the system can be improved.

As described above, according to this embodiment, not only the same effect as that of the embodiment of FIG. 1 can be obtained, but also the raw material gas is used as the fuel of the reformer 2, while the fuel cell 1 The exhaust gas of the fuel of the boiler 5
Since the amount of hydrogen in the exhaust gas of the fuel and the amount of heat of the reformer 2 are irrelevant because the fuel is sent to the fuel cell and burned as fuel, the reforming amount in the reformer 2 can be immediately increased as the electric load increases. The load response of the system can be improved.

Although the boilers in the above two embodiments are heavy oil fired, other types of boilers such as coal fired can also be used.

Further, in the above two embodiments, the combined heat and power supply system is constructed by incorporating the boiler into the power generator which is composed of the fuel cell and the reformer in advance. However, the fuel cell and the reformer are installed in the boiler installed in advance. The combined heat and power supply system can be configured by attaching the power generation device configured by.

Next, one embodiment of a building equipped with either of the combined heat and power supply system according to the above two embodiments will be described with reference to FIG. As shown in FIG. 3, the combined heat and power supply system 50 is installed in the basement of the building 60, to which the reforming source gas gas pipe 20 and the air are supplied from the pipe 25, and the boiler is supplied with water from the pipe 35. Further, the fuel is supplied from the fuel tank 51 through the pipe 36, and the electric output and the heat output are output by the process described above. The electric output is connected to an electric system from the outside by a system interconnection device (not shown), and is supplied to the air conditioner 52 and the lighting fixture 53 through the electric wiring 37. Further, the heat output is directly supplied to the heater 54 and a water heater (not shown) via the pipe 31, and is also used as a heat source of the air conditioner 52 via the absorption refrigerator 55. As described above, according to this embodiment, the building 60 is used by using the combined heat and power supply system.
Can meet the demand for electric output and heat output.

[0049]

According to the present invention, since the steam for reforming and the cooling water for the fuel cell are supplied by the boiler, it is not necessary to install a steam drum or an electric heater for start-up as in the conventional case, and the boiler is not required. Since the steam from is used to extract the heat output, it is not necessary to install a plurality of large-sized heat exchangers as in the conventional case, and the system configuration can be simplified. Further, the boiler can easily obtain a higher temperature steam than that of the conventional heat exchanger, that is, a good heat output.

Further, since the high temperature exhaust gas from the reformer is used as the combustion air in the boiler, a larger amount of steam can be generated in the boiler.

Further, since the heated cooling water of the fuel cell is collected again in the boiler and is further heated in the boiler,
High temperature steam is easily obtained.

Further, since the exhaust gas of high temperature air from the fuel cell is used as combustion air in the boiler, a larger amount of steam can be generated in the boiler.

Further, the system can be brought up to a steady operation state in a shorter time than the conventional electric heater for starting at the time of starting.

Further, since the raw material gas is used as the fuel of the reformer and the exhaust gas of the fuel from the fuel cell is burned as the fuel in the boiler, the amount of hydrogen in the exhaust gas of the fuel and the amount of heat of the reformer are irrelevant. Therefore, it is possible to improve the load response of the system with respect to an increase in electric load.

Further, by utilizing the above-mentioned combined heat and power supply system in a building, it is possible to meet the demand for electric output and heat output of the building.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a combined heat and power supply system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a combined heat and power supply system according to another embodiment of the present invention.

FIG. 3 is a diagram showing an example of a building equipped with either the combined heat and power system of FIG. 1 or FIG.

FIG. 4 is a configuration diagram of a PAFC system in the conventional combined heat and power supply system.

[Explanation of symbols]

 1 Fuel Cell 2 Reformer 3 Ejector 4 Pump 5 Boiler 6 Valve 20-27 Pipe (Gas Pipe) 30, 31 Pipe (Steam Pipe) 32-35 Pipe (Cooling Water Pipe) 36 Pipe (Fuel Pipe) 37 Electric Wiring 40 Piping (Gas Piping) 50 Combined Heat and Power System 51 Fuel Tank 52 Air Conditioner 53 Lighting Fixture 54 Heater 55 Absorption Refrigerator 60 Building

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Sumida 1168 Moriyama-cho, Hitachi-shi, Ibaraki Energy Research Institute, Hiritsu Manufacturing Co., Ltd. (72) Inventor Takao Sato 3-1-1, Saicho-cho, Hitachi, Ibaraki Stock Hitachi Works Hitachi Factory

Claims (5)

[Claims] 1. An electric power is output using a reformer that burns a fuel and reforms a raw material gas sent together with steam at high temperature to produce hydrogen, and hydrogen and air produced by the reformer. In a combined heat and power system having a fuel cell, a boiler that heats water to generate steam, steam supply means that sends the steam generated in the boiler to the reformer as steam, and water in the boiler as cooling water. As a cooling water supply means for sending to the fuel cell, a first air supply means for sending the exhaust gas after obtaining a high temperature in the reformer as combustion air to the boiler, and heat from steam generated in the boiler. A combined heat and power supply system, comprising: a heat output extracting means for extracting an output. 2. The combined heat and power supply system according to claim 1, further comprising cooling water recovery means for recovering cooling water for cooling the fuel cell to the boiler. 3. The second exhaust gas, which is the air after the electric power is obtained by the fuel cell, is sent to the boiler as combustion air.
The combined heat and power supply system according to claim 1 or 2, further comprising: 4. A fuel supply means for sending the raw material gas as fuel to the reformer, and a fuel exhaust gas supply means for sending exhaust gas of the fuel of the fuel cell to the boiler as fuel. The combined heat and power supply system according to any one of claims 1 to 3. 5. A building provided with the combined heat and power supply system according to claim 1.