JP5916122B2 - Combined heat and power supply for adjustment - Google Patents

Description

  The present invention relates to a cogeneration type power supply for adjustment.

  In order to stably supply power to the distribution network for 24 hours, the electric power company includes power generation means for performing rated operation and load generation power generation means. The load adjusting power generation means operates in a standby state to generate power. For example, when the load suddenly increases during the daytime in summer, the load adjusting power generation means is operated to follow the load fluctuation (see, for example, Patent Document 1).

  However, since the load adjusting power generation means operates at the expense of power generation efficiency to some extent, there is a problem that fuel efficiency is poor.

  On the other hand, there are some which install a cogeneration device in a customer facility and perform cogeneration. As such a combined heat and power supply apparatus, there is an apparatus using an MCFC having a characteristic in which power generation efficiency peaks in the middle of the load factor (see, for example, Patent Document 2).

  When using such a combined heat and power supply device as load adjustment power generation means, generating higher power at a higher output and providing the power to the electric utility side to follow the load increase in the power system Can do. However, in the characteristics as described above, since the power generation efficiency decreases as the output increases, the fuel consumption deteriorates.

JP 2005-295713 A JP 2004-71279 A

  The present invention has been made in view of the above circumstances, and is a combined heat and power adjustment type power source that can stably supply power efficiently on the power system side and can efficiently supply heat and electricity on the combined heat and power side at low cost. The purpose is to provide.

A first aspect of the present invention that solves the above problems is a solid oxide fuel cell, a first fuel cell and a second fuel cell arranged so that generated heat is transmitted to each other, and a fuel supplier Heat supply means for supplying heat using the fuel supplied from the fuel supply means owned by the first fuel cell and the second fuel cell are supplied with fuel from the fuel supply means, The generated electric power can be transmitted to an electric power system including an electric power company-side power generation device owned by an electric power company, and the first fuel cell is operated as that of the fuel supplier and the current density is constant. so as to not operate, the second fuel cell, wherein is operated as the electric utilities, until the electric utility side power generator is rated operation from the standby state, the output of the second fuel cell Increase Certain generated electricity in cogeneration type adjustment power supply, characterized in that to the transmission in the power system.

  In the first aspect, the power provider functions as an efficient power source. Conventionally, electric utilities have had a thermal power plant for load adjustment that operates with reduced efficiency in order to absorb the increase and decrease in power demand, but this is unnecessary or the number can be reduced In particular, the cost burden can be significantly reduced.

  Moreover, the 2nd fuel cell which operate | moves as a thing of an electric power company can increase an output from the state warmed with the heat | fever by operation | movement of a 1st fuel cell. Therefore, the combined heat and power supply type adjustment power supply can function as a power supply that can respond immediately when power demand increases.

  Furthermore, the combined heat and power supply type adjustment power source can be operated at an efficient location for the fuel supplier during normal operation. In addition, when demand increases, heat can be generated from the second fuel cell operating as that of an electric power company, so that both power generation and heat can be produced with high power generation efficiency.

A second aspect of the present invention, the cogeneration type adjusting power to the first aspect, the electric utility side power plant until enters standby mode from the rated operation, the second fuel cell It is in a combined heat and power adjustment power source characterized by reducing the output.

  In the second aspect, the cogeneration-type adjustment power supply absorbs the decrease in power demand. When the decrease in power demand has been absorbed, the electric power generator-side power generator can be put into standby operation. That is, since it is not necessary to gradually reduce the efficiency and enter the standby state, the burden on the running cost is reduced. As described above, as an electric power company, it is possible to stably supply electricity while reducing the cost burden.

  According to a third aspect of the present invention, in the cogeneration type power supply for adjustment described in the first or second aspect, the first fuel cell and the second fuel cell are the first fuel cell or the second fuel cell. One of the above is the center, and the other is disposed around the other.

  In the third aspect, the heat generated in one of the first fuel cell and the second fuel cell disposed in the center can be transferred to the first fuel cell without leaving the other.

  The combined heat and power supply type adjustment power source of the present invention can stably supply power efficiently on the power system side, and can efficiently and simultaneously supply heat and power on the combined heat and power side.

It is a schematic block diagram of the cogeneration type adjustment power supply which concerns on embodiment. It is the schematic explaining operation | movement of the heat / electric supply type adjustment power supply at the time of normal driving | operation. It is the schematic explaining operation | movement of the heat / power supply type adjustment power supply at the time of the load rise of an electric power grid | system. It is the schematic explaining operation | movement of the combined heat and power type adjustment power supply at the time of load reduction of an electric power grid | system. It is a detailed block diagram of the cogeneration type adjustment power source according to the embodiment. It is a figure which shows schematic structure of a 1st fuel cell and a 2nd fuel cell. It is the schematic explaining operation | movement of the 1st fuel cell and 2nd fuel cell at the time of normal driving | operation. It is the schematic explaining operation | movement of the 1st fuel cell and the 2nd fuel cell at the time of a demand increase. It is the schematic explaining operation | movement of the 1st fuel cell at the time of a demand decrease, and a 2nd fuel cell. It is a graph which shows the relationship between the output (plant output) of the whole power supply for cogeneration type adjustment, the 1st fuel cell, and the 2nd fuel cell, and power generation efficiency. It is the schematic which shows the driving | running state of the cogeneration type adjustment power supply which concerns on embodiment. It is the schematic which shows the driving | running state of the cogeneration type adjustment power supply which concerns on embodiment.

<Embodiment 1>
Hereinafter, taking a gas company that supplies fuel gas as an example of a fuel supplier, the combined heat and power supply for adjustment of the present invention that is operated by the gas company and the electric company will be described.

  As shown in FIG. 1, the combined heat and power supply for adjustment 1 according to the present embodiment is deployed in a customer facility.

  The gas company owns gas supply means 20 (fuel supply means) for supplying natural gas as fuel. The gas supply means 20 can supply natural gas to the cogeneration type adjustment power source 1 of the customer facility.

The electric power company has a power system including a thermal power plant 11 ( electric power company side power generation device) that generates power and a power transmission / distribution network 10 that performs power transformation, power transmission, and power distribution. The thermal power plant 11 is provided with power generation equipment that is operated with high efficiency at the time of rating. Conventionally, an electric power company has a thermal power plant for load adjustment equipped with a power generation facility that is operated at a high efficiency at the time of rating and is operated at a low efficiency by reducing the efficiency when waiting for a load. . Although details will be described later, according to the present invention, such a thermal power plant for load adjustment becomes unnecessary or the number of facilities can be reduced. The thermal power plant 11 can transmit power to the load 4 of the customer facility via the power transmission and distribution network 10.

  Although the detailed configuration will be described later, the cogeneration type adjustment power source 1 has the following functions. One is a function of supplying natural gas as a fuel from the gas supply means 20 (fuel supply means) and generating electric power using the natural gas. The generated electricity can be transmitted to the load 4 arranged in the customer facility. Further, the electricity can be transmitted (sold) to the electric utility network 10.

  Moreover, the combined heat and power supply type adjustment power source 1 has a function of supplying heat using exhaust heat generated during power generation. Specifically, the exhaust heat can be supplied as hot water or steam to the water supply equipment 5, the heating equipment 6, the steam equipment 7, etc. of the customer facility. The warm water may be stored in a tank or the like.

  Moreover, the control apparatus 8 which controls an output is attached to the cogeneration type adjustment power supply 1 and the output of the cogeneration type adjustment power supply 1 is changed by a control signal from the control apparatus 12 on the electric utility side. It is possible.

  The operation of the combined heat and power supply type adjustment power supply 1 will be described with reference to FIGS. FIG. 2 is a schematic diagram for explaining the operation of the cogeneration type adjustment power supply 1 during normal operation. The normal operation means a time when the combined heat and power supply for adjustment 1 does not increase or decrease the output according to the power demand.

  The graph in the upper left of FIG. 2 is a graph showing the characteristics of the load factor and energy efficiency for the entire combined heat and power supply for adjustment 1. The horizontal axis represents the load factor (plant load factor), and the vertical axis represents the energy efficiency.

  The cogeneration type power supply for adjustment 1 has a characteristic that energy efficiency peaks in the middle of the load factor. The energy efficiency is the power generation efficiency of the cogeneration type adjustment power source 1. The load factor refers to the ratio between the average demand power and the maximum demand power of a load during a certain period.

  “Characteristics of the combined heat and power supply type adjustment power supply 1 have a peak in the middle of the load factor” means that the characteristic has a convex curve upward and energy at any point between the load factors (0 to 100%). It means that there is a maximum value (maximum value) of efficiency. The cogeneration-type adjustment power supply 1 of the present embodiment has a characteristic that when the plant load factor is about 50%, the energy efficiency is about 55% which is the maximum (maximum point X).

  The graph in the upper right of FIG. 2 shows the power demand transition in the power system of the electric power company. The horizontal axis represents time, and the vertical axis represents power demand. For example, the demand for electricity in the morning and night is small, the power demand increases from morning to daytime, the power demand remains high for a while, and the power demand decreases toward the evening.

  In the morning and daytime when there is little fluctuation in power demand, the thermal power plant 11 is performing rated operation. For example, in the morning time zone A, one thermal power plant 11 performs the rated operation and satisfies the power demand of the time zone A. Further, in the daytime time zone B, the two thermal power plants 11 perform rated operation to meet the power demand in the time zone B.

  During the rated operation of the thermal power plant 11, the cogeneration type adjustment power source 1 operates as shown in the lower left of FIG. That is, the combined heat and power adjustment type power supply 1 generates power using the gas supplied from the gas supply means 20 and supplies electricity to the load 4. Further, hot water / steam is generated by exhaust heat at the time of power generation and supplied to the water supply equipment 5, the heating equipment 6, and the steam equipment 7 of the customer facility. In addition, in the combined heat and power supply type adjustment power source 1, if the generated electricity is surplus, it may be transmitted to the power transmission and distribution network 10.

  FIG. 3 is a schematic diagram for explaining the operation of the cogeneration-type adjustment power supply 1 when the load of the power system increases. As shown in the upper right graph, for example, a case will be described in which the power demand rapidly increases in the time zone A from morning to daytime.

  In the morning, when one thermal power plant 11 is in the rated operation, if the power demand increases rapidly, another thermal power plant 11 that is standing by is put in the rated operation. However, since it takes time until the thermal power plant 11 reaches the rated operation, the power demand cannot be absorbed immediately (in the past, the thermal power plant is in standby operation with low efficiency so as to cope with such an increase in demand. )

  In the present invention, when the power demand increases as described above, that is, until the thermal power plant 11 in the standby state is put into the rated operation, the electric utility transmits a control signal from the control device 12 to the control device 8. Then, the output of the cogeneration type adjustment power supply 1 is increased (the load factor is increased). At this time, as shown in the upper left graph, the combined heat and power supply type adjustment power source 1 is operated at a load factor (point Y, approximately 80%) where the load factor is higher than the peak.

  When such power demand increases, the combined heat and power supply for adjustment 1 operates as shown in the lower left of FIG. The combined heat and power supply type adjustment power source 1 generates power so as to output more than during normal operation, and supplies a part of the generated electricity to the power distribution network 10. As electricity is supplied to the power transmission and distribution network 10 in this manner, an increase in power demand is absorbed. In addition, about heat, it is supplied to the water supply equipment 5, the heating equipment 6, and the steam equipment 7 as warm water or water vapor | steam similarly to the time of rated operation.

  While the increase in power demand is absorbed by the power supplied from the cogeneration-type adjustment power supply 1 to the power transmission and distribution network 10, the thermal power plant 11 that has been in a standby state is in a rated operation state. When the thermal power plant 11 reaches the rated operation in this manner, the load factor of the combined heat and power adjustment type power source 1 is returned to the highest energy efficiency by the control device 12 and the control device 8 (point X).

  Since the combined heat and power supply for adjustment 1 responds to the increase in power demand, it is not necessary to stand by / operate the thermal power plant 11 by the inefficient standby operation as in the prior art. Therefore, on the electric utility side, the burden on facilities and running costs is reduced. Further, when the combined heat and power supply for adjustment 1 responds to the increase in power demand, it is operating in the state with the highest energy efficiency (point X). Then, the output is increased from this state to supply electricity to the power transmission and distribution network 10. That is, since the load factor of the cogeneration type adjustment power supply 1 can be increased at a high speed, it is possible to obtain electricity that can immediately absorb the sudden increase in electricity demand. As described above, as an electric power company, it is possible to stably supply electricity while reducing the cost burden.

  FIG. 4 is a schematic diagram for explaining the operation of the cogeneration type adjustment power supply 1 when the load of the power system is reduced. As shown in the upper right graph, for example, a case will be described in which the power demand rapidly decreases in the time zone B from daytime to nighttime.

  In the state where two thermal power plants 11 are performing rated operation in the daytime, when the power demand decreases rapidly, the one thermal power plant 11 is put into a standby state. However, since the thermal power plant 11 takes a certain time to enter the standby state, it cannot absorb the decrease in power demand immediately (in the past, the efficiency is low so that such a decrease in demand can be accommodated). However, the output of the thermal power plant was gradually reduced to standby operation).

  In the present invention, when the power demand is reduced in this way, that is, until the thermal power plant 11 that is operating at rated power is put into a standby state, the electric utility sends a control signal from the control device 12 to the control device 8. Transmit and reduce the output of the cogeneration type adjustment power supply 1 (lower the load factor). At this time, as shown in the upper left graph, the combined heat and power supply for adjustment type 1 operates with a load factor (point Z, about 30%) lower than the peak load factor.

  When such power demand decreases, the combined heat and power supply for adjustment 1 operates as shown in the lower left of FIG. The cogeneration-type adjustment power supply 1 generates power so as to output lower than that during normal operation. In other words, the reduction in power demand is absorbed by reducing the output of the cogeneration type adjustment power supply 1. In addition, about heat, it is supplied to the water supply equipment 5, the heating equipment 6, and the steam equipment 7 as warm water or water vapor | steam similarly to the time of rated operation.

  While the combined heat and power supply for adjustment 1 absorbs the decrease in power demand, the thermal power plant 11 that has been rated is put into a standby state. When the thermal power plant 11 reaches the standby state in this way, the load factor of the combined heat and power adjustment type power source 1 is returned to the most energy efficient state by the control device 12 and the control device 8 (point X).

  Since the combined heat and power supply for adjustment 1 responds to the decrease in power demand, the thermal power plant 11 does not need to gradually reduce efficiency to enter a standby state. The thermal power plant 11 may be put in a standby state when the combined heat and power supply for adjustment 1 has absorbed the decrease in power demand. As described above, the thermal power plant 11 does not need to be gradually put into a standby state in a state of low efficiency even when the power demand is reduced, so that the running cost can be reduced. As described above, as an electric power company, it is possible to stably supply electricity while reducing the cost burden.

  Here, a detailed configuration of the cogeneration type adjustment power supply 1 will be described with reference to FIG. FIG. 5 is a detailed configuration diagram of the cogeneration type power supply for adjustment according to the present embodiment.

  The cogeneration type adjustment power supply 1 includes a power generator 30. The power generation device 30 generates power using natural gas supplied by the gas supply means 20 (see FIG. 1). Specifically, the power generation apparatus 30 is provided with a plurality of solid oxide fuel cells (SOFC) provided in a container 31 capable of maintaining the inside at high temperature and high pressure.

  The SOFC is provided with an air electrode and a fuel electrode (not shown) with an electrolyte layer interposed therebetween. Hydrogen gas is supplied to the fuel electrode side via a fuel gas chamber, and air is supplied to the air electrode side via an air chamber.

  FIG. 6 is a diagram showing a schematic configuration of the first fuel cell A and the second fuel cell B. As shown in FIG. As shown in FIG. 6A, in this embodiment, the power generation apparatus 30 has four SOFCs in which a fuel cell main body 50 including a fuel electrode and an air electrode is accommodated in a container 51. Two of these are designated as the first fuel cell A, and the other two as the second fuel cell B. Each of the first fuel cell A and the second fuel cell B is arranged to transfer heat generated during power generation to each other. Here, the first fuel cell A and the second fuel cell B are arranged in parallel so that the first fuel cell A is on the outside and the second fuel cell B is on the inside. Therefore, the heat generated in the second fuel cell B is transmitted to the first fuel cells A on both sides. The reverse is also true.

  In addition, if the 1st fuel cell A and the 2nd fuel cell B are arrange | positioned so that heat may be mutually transmitted, it will not be limited to an aspect as shown to Fig.6 (a). FIG. 6B and FIG. 6C are top views showing the arrangement of the fuel cells. As shown in FIG. 6B, the second fuel cell B may be disposed at the center, and the first fuel cell A may be disposed around the second fuel cell B. With this arrangement, the heat generated in the second fuel cell B when the power demand increases can be transferred to the first fuel cell A without leaving any excess. Moreover, as shown in FIG.6 (c), you may arrange | position around the 1st fuel cell A, and may arrange | position the 2nd fuel cell B around it.

  Returning to FIG. 5, a reformer 32 is disposed in the container 31. The reformer 32 reforms the natural gas supplied from the gas supply means 20 to generate hydrogen gas. The reformer 32 is connected to each fuel gas chamber of the first fuel cell A and the second fuel cell B, and can supply hydrogen gas thereto.

  Further, a preheater 33 is disposed in the container 31. The preheater 33 is supplied with air from a gas turbine (GT) compressor 46 and a compressor 47, which will be described later, and preheats the air to the operating temperature of the SOFC. The preheater 33 is connected to the air chambers of the first fuel cell A and the second fuel cell B, and can supply preheated air thereto.

  The first fuel cell A and the second fuel cell B generate power by being supplied with hydrogen gas and air from the reformer 32 and the preheater 33. The generated electricity is collected and supplied to the load 4 (see FIG. 1) via the inverter 34.

  The combined heat and power adjustment type power supply 1 has a heat supply means 40 by exhaust heat of the power generation device 30. In the present embodiment, the heat supply means 40 is mounted as a so-called cogeneration system that supplies heat as hot water / steam and also generates power.

  Specifically, the heat supply means 40 includes a combustor 41 that combusts natural gas supplied from the gas supply means 20, a gas turbine 42 that is driven by combustion gas generated by combustion in the combustor 41, and a gas turbine 42. The heat exchanger 43 that generates warm water and water vapor by using the exhaust heat of the gas worked in the process is provided.

  The gas turbine 42 is provided with a generator 44 on the same axis, and generates electric power as the gas turbine 42 is operated. The electricity generated by the generator 44 can be supplied to the load 4 and the power transmission and distribution network 10.

  Further, the heat supply means 40 has a mixer 45. The mixer 45 is supplied with the unreacted portion of the hydrogen gas and air supplied to the first fuel cell A and the second fuel cell B. The mixer 45 generates a mixed gas of these hydrogen gas and air and supplies it to the combustor 41. Thereby, in the combustor 41, mixed gas is combusted with fuel gas.

  Furthermore, a gas turbine (GT) compressor 46 is connected to the gas turbine 42 on the same axis. The GT compressor 46 compresses external air by the power of the gas turbine 42. The air compressed by the GT compressor 46 is supplied to the combustor 41 and also supplied to the preheater 33 of the power generator 30.

  The combined heat and power supply for adjustment 1 includes a compressor 47 that is driven using electricity in the system. The compressor 47 compresses external air and supplies it to the combustor 41 and the preheater 33.

  In addition, although the heat supply means 40 is comprised as a cogeneration system, it is not limited to such an aspect. For example, a heat exchanger that supplies heat using heat of exhaust gas (gas discharged from the first fuel cell A and the second fuel cell B) generated in the power generation apparatus 30 may be used as the heat supply means. In addition, the steam turbine may be driven using exhaust heat, not for the purpose of cogeneration, and power generation efficiency may be improved.

  In the above combined heat and power supply type adjustment power source 1, the power generation device 30 can generate power using fuel gas (natural gas) and supply the generated electricity to the load 4 or the power transmission / distribution network 10. Moreover, the heat supply means 40 generates hot water or water vapor using the exhaust heat generated while generating power using fuel gas or unreacted hydrogen gas and air in the power generation device 30, and supplying water to the customer facility 5, heating facility 6 and steam facility 7 can be supplied.

  The operation mode of the combined heat and power supply type adjustment power supply 1 having such a configuration will be described in detail with reference to FIGS. FIG. 7 is a schematic diagram for explaining the operation of the first fuel cell and the second fuel cell during normal operation.

  The left side of FIG. 7 shows a first fuel cell A that is operated as a gas company and a second fuel cell B that is operated as an electric company.

  “Operating the first fuel cell A as that of the gas company” means that the gas company bears the cost (operating cost of the fuel gas, maintenance cost, etc.) related to the operation of the first fuel cell A, This means that the power generated by the fuel cell A is sold and profits are obtained.

  “Operating the second fuel cell B as that of the electric power company” means that the electric power company bears the costs related to the operation of the second fuel cell B (fuel gas cost, maintenance cost, etc.) This means that the electric power generated by the fuel cell B is supplied to the power transmission and distribution network 10 (the electric power may be sold to a customer facility).

  In the center of FIG. 7, graphs G1 to G6 relating to various characteristics of the first fuel cell A and the second fuel cell B are shown. Graphs G1 and G4 show the relationship between the output of each fuel cell and the current density. Graphs G2 and G5 show the relationship between the output of each fuel cell and the cell voltage. Graphs G3 and G6 show the relationship between the output of each fuel cell and the power generation efficiency. The upper limit of the output of the first fuel cell A is Pmax (A), and the lower limit is Pmin (A). The upper limit of the output of the second fuel cell B is Pmax (B), and the lower limit is Pmin (B).

  As shown in the graph G3, the first fuel cell A has characteristics α and β. The characteristic α is a characteristic in which the power generation efficiency decreases as the output of the first fuel cell A decreases. The characteristic β is a characteristic that the power generation efficiency increases against a decrease in the output of the first fuel cell A.

  When the combined heat and power supply for adjustment 1 is in normal operation, the first fuel cell A has an intersection of characteristics α and β, that is, the output of the first fuel cell A is maximum (Pmax (A)). It works at the point. On the other hand, as will be described in detail later, the first fuel cell A operates at a point on the characteristic α when the output of the second fuel cell B is decreased in response to a decrease in power demand. Also, the first fuel cell A operates at a point on the characteristic β when the output of the second fuel cell B is increased in response to an increase in power demand.

  As shown in the graph G6, the second fuel cell B has a characteristic that the power generation efficiency decreases as the output increases.

The graph G7 on the right side of FIG. 7 is the same as the characteristics of the cogeneration type adjustment power source 1 shown in FIG. The plant output when the power generation efficiency is best to P _C.

The output of the first fuel cell A is represented as P _A , and the output of the second fuel cell _B is represented as P _B. During normal operation, the output P _A of the first fuel cell A is set to Pmax (A). The output P _B of the second fuel cell B is determined to Pmin arbitrary point (midpoint in the figure) between (B) and Pmax (B).

The _{value P} A, the sum of _{P B} at this time is _{P C.} However, in the present embodiment, the combined heat and power supply for adjustment type 1 has an output from the generator 44, while there is a device that uses electric power such as the compressor 47, and these are taken into consideration. In other words, in consideration of the output for the generator 44 and the compressor 47 (+ _alpha), so that the _{P C = P A + P B} + α, setting the P A, _{P B.}

  Further, as shown in the graph G1, the first fuel cell A is operated so that the current density is constant during normal operation. Specifically, it is performed by adjusting the amount of hydrogen gas or air supplied to the first fuel cell A. Accordingly, the current density is constant no matter how the output of the first fuel cell A varies.

In this way, during normal operation, that is, when the power demand is stable in the electric utility's transmission and distribution network and the thermal power plant 11 is performing rated operation, the combined heat and power supply for adjustment 1 is It is operating like. That is, (see G7) as the most power generation efficiency of the entire cogeneration type adjusting supply 1 is high, the first fuel cell A and a second fuel cell B is the output P _A, running P _B (G1 To G6).

  FIG. 8 is a schematic diagram for explaining the operation of the first fuel cell and the second fuel cell when demand increases.

As shown in FIG. 3, in the time zone A in which the power demand increases, in order to absorb the increase in the power demand, the combined heat and power supply type adjustment power source 1 needs to increase the plant output (P _C → P _C ′).

Therefore, the output of the second fuel cell B operating as that of the electric power company is increased, and the generated electricity is supplied to the power transmission and distribution network 10. At this time, as shown in the left side of FIG. 8, the second fuel cell B is supplied with more fuel gas (hydrogen gas) and air by increasing the current density, as shown in the graph G6. 2 Increase the output of the fuel cell B (P _B → P _B ′).

  The characteristics of the second fuel cell B when such demand increases are as follows. First, as described above, the current density increases (see G4), and more fuel gas and air are supplied, so the output of the second fuel cell B is improved (see G6). However, as the current density increases, the cell voltage of the second fuel cell B decreases (see G5). And power generation efficiency falls by a cell voltage falling (refer G6).

  On the other hand, the characteristics of the first fuel cell A operating as that of the gas company are as follows. First, as shown on the left side of FIG. 8, the first fuel cells A are arranged side by side so that the heat of the second fuel cell B is transmitted. Since the second fuel cell B generates more heat as the output increases, the first fuel cell A is heated by the heat from the second fuel cell B.

  Here, the SOFC must be maintained at a high temperature (for example, 600 to 800 ° C.) in order to operate properly. For this reason, part of the fuel gas supplied to the first fuel cell A is also used to maintain this temperature. However, since the first fuel cell A is heated by the heat from the second fuel cell B accompanying the increase in power demand, the fuel gas supplied to the first fuel cell A can be reduced.

That is, when the output of the second fuel cell B increases, the first fuel cell A receives one of the heat from the second fuel cell B. For this reason, the temperature of the first fuel cell A rises, and further, the fuel gas for maintaining the temperature can be reduced to increase the fuel utilization rate, so that the power generation efficiency of the first fuel cell A is improved (see G3). , E _A → E _A ′). However, since the first fuel cell A operates at a constant current density (see G1), the voltage decreases (see G2) and the output decreases as the amount of fuel gas is reduced (G3). Reference, P _A → P _A ′).

The cogeneration type adjusting supply 1, as shown in the graph G7, amount that the output of the second fuel cell B is increased, the output is improved _{(P C → P C ')} .

  FIG. 9 is a schematic diagram for explaining the operation of the first fuel cell and the second fuel cell when the demand decreases.

As shown in FIG. 4, in the time zone B in which the power demand decreases, in order to absorb the decrease in the power demand, the combined heat and power supply type adjustment power source 1 needs to reduce the plant output (P _C → P _C '').

Therefore, the output of the second fuel cell B operating as that of the electric utility is reduced. At this time, as shown on the left side of FIG. 9, the second fuel cell B is supplied with lower fuel density (see G4) than during normal operation and with less fuel gas (hydrogen gas) and air than during normal operation. As shown in the graph G6, the output of the second fuel cell B is lowered (P _B → P _B ″).

  The characteristics of the second fuel cell B when the demand is reduced are as follows. First, as described above, the current density decreases (see G4), and less fuel gas and air are supplied, so the output of the second fuel cell B decreases (see G6). Further, the cell voltage is improved as the current density is decreased (see G5). As the cell voltage is increased, the power generation efficiency is improved (see G6).

  On the other hand, the characteristics of the first fuel cell A operating as that of the gas company are as follows. First, as shown in the left side of FIG. 9, the first fuel cells A are arranged side by side so that the heat of the second fuel cell B is transmitted. The temperature of the first fuel cell A is lowered because the second fuel cell B operating at a low load is deprived of heat from power generation.

For this reason, the first fuel cell A requires more fuel than during normal operation in order to maintain the operating temperature. Therefore, as shown in the graph G3, the power generation efficiency of the first fuel cell A decreases (E _A → E _A ″). Further, the cell voltage decreases (see G2), and the power generation efficiency and output decrease (see G3, P _A → P _A ″).

Further, as shown in the graph G7, the combined heat and power supply type adjusting power source 1 has an output corresponding to the amount of decrease in the output of the second fuel cell B (or in addition to this, the amount of decrease in the output of the first fuel cell A). It is decreasing (P _C → P _C ″).

  When the demand decreases, the first fuel cell A is operated at a low efficiency as a gas company. However, for example, it is possible to prevent the electric power company from being disadvantageous to the gas business, for example, by compensating the cost. Alternatively, in place of such compensation, the heat generated in the second fuel cell B when the power demand increases described with reference to FIG. That is, it is good also as compensation by transferring the heat which arises in the 2nd fuel cell B at the time of electric power demand increase to a gas company. As a gas company, if heat is obtained, it can be sold to a customer facility as hot water or steam.

  As explained above, according to the combined heat and power supply for adjustment 1 according to the present embodiment, the first fuel cell A and the second fuel cell B are operated by different operators, so that the energy on the power system side is increased. It is possible to stably supply power efficiently and efficiently and simultaneously supply heat and power at low cost.

  That is, the combined heat and power supply for adjustment 1 functions as an efficient power supply for the electric power company. Conventionally, electric utilities have had a thermal power plant for load adjustment that operates with reduced efficiency in order to absorb the increase and decrease in power demand, but this is unnecessary or the number can be reduced In particular, the cost burden can be significantly reduced.

  Furthermore, the second fuel cell B operating as that of the electric power company can increase the output from the state heated by the heat due to the operation of the first fuel cell A. Therefore, the combined heat and power supply type adjustment power supply 1 can function as a power supply that can respond immediately when power demand increases.

  Further, the combined heat and power supply type adjustment power supply 1 can be operated at an efficient place for a gas company during normal operation. In addition, when demand increases, heat can be generated from the second fuel cell B operating as that of an electric power company, so that power generation and heat can be combined with high power generation efficiency. When demand decreases, it will operate at a slightly lower efficiency, but it can be offset by the cost of heat received from the electric utility when demand increases. In other words, there is no actual loss in operation with low efficiency when demand decreases.

Further, in the present embodiment, the description has been given by taking the electric power company as the business operator and the thermal power plant 11 as the electric power company-side power generation device, but the present invention is not limited to such an aspect. For example, the present invention can also be applied to a business operator having factory equipment and using a power generation device that supplies power to the factory equipment as an electric power company side power generation device. In this case, in order to absorb the electric power demand which increases / decreases in the factory equipment, the combined heat and power supply type adjustment power source 1 can be used.

Additional power generation device by natural energy such as wind and solar and electric utility side power generator, the power generator may be operators who sell electricity used. In this case, in order to stabilize the power generation by the unstable natural energy, the combined heat and power supply for adjustment 1 can be used.

<Analysis example>
The result of having analyzed about the output etc. of the combined heat and power type adjustment power supply 1 of the structure shown in Embodiment 1 is shown using FIGS.

  FIG. 10 is a graph showing a relationship between the output (plant output) of the cogeneration-type adjustment power supply 1 as a whole, the first fuel cell A and the second fuel cell B, and the power generation efficiency. The horizontal axis is the plant output of the combined heat and power supply for adjustment type 1. The plant output is a sum of outputs of the first fuel cell A and the second fuel cell B (further includes an output (+ α) of a gas turbine or the like). The vertical axis (left side) shows the power generation efficiency.

  As shown in the drawing, the characteristic L1 represents the characteristic of the combined heat and power supply type adjustment power source 1. This is equivalent to the upper left graphs of FIGS. 2 to 4 and the right graphs of FIGS. 7 to 9. That is, L1 has an upwardly convex characteristic such that the plant output is about 28,000 kW and the power generation efficiency reaches a maximum value (about 55%). L2 represents the characteristics of the first fuel cell A (“power generation efficiency of the combined heat and power module”), and L3 represents the characteristics of the second fuel cell B (“power generation efficiency of the load adjustment module alone”). ing.

  When the power demand increases, the output of the second fuel cell B operating as that of the electric utility is increased as indicated by L3. Then, the plant output of the thermoelectric cogeneration type adjustment power supply 1 as a whole increases, and the increase in power demand can be absorbed.

  As the output increases, the efficiency of the second fuel cell B decreases as indicated by L3. At this time, the heat generated in the second fuel cell B heats the first fuel cell A. Thereby, as shown by L2, the efficiency of the first fuel cell A is improved.

  That is, although the power generation efficiency of the combined heat and power supply type adjustment power source 1 decreases with an increase in output, the efficiency of the first fuel cell A as viewed from the gas business operator is improved. That is, it becomes possible for gas companies to efficiently produce thermoelectric power. As an electric utility, the second fuel cell B functions as a power source that can immediately respond to a rapidly increasing power demand, although the efficiency is reduced. Thereby, while responding to the increase in electric power demand, the cost of preparing and operating the thermal power plant 11 that performs the standby operation as in the past can be reduced.

  FIG. 11 is a graph showing the relationship between the output of the second fuel cell B, the power generation efficiency, and the cell voltage. M1 is a characteristic indicating the output (horizontal axis) and power generation efficiency (left vertical axis) of the second fuel cell B, and M2 is a characteristic indicating the output and cell voltage (right vertical axis) of the second fuel cell B. is there.

  As indicated by M1, the efficiency tends to decrease as the output of the second fuel cell B increases. Further, as indicated by M2, the cell voltage tends to decrease as the output of the second fuel cell B increases.

  Thus, the efficiency decreases as the output increases. However, the output of the second fuel cell B can be increased from a state where it is warmed by heat from the operation of the first fuel cell A. Therefore, the combined heat and power supply type adjustment power supply 1 can function as a power supply that can respond immediately when power demand increases.

  FIG. 12 is a graph showing the relationship between the output of the first fuel cell A, the power generation efficiency, and the cell voltage. N1 and N2 are characteristics indicating the output (horizontal axis) and power generation efficiency (left vertical axis) of the first fuel cell A. Of the same characteristics, the portion that rises to the left is N1 (corresponding to β in FIGS. 7 to 9), and the portion that falls to the left is N2 (corresponds to α in FIGS. 7 to 9). N3 is a characteristic indicating the output of the first fuel cell A and the cell voltage (right vertical axis).

  The intersection of N1 and N2 is the maximum output Pmax (A) of the first fuel cell A. The first fuel cell A operates at this maximum output during normal operation.

  As described above, when the output of the combined heat and power supply type adjustment power source 1 increases, the first fuel cell A is transmitted with heat accompanying the increase in the output of the second fuel cell B. For this reason, as shown by N1, the fuel gas to be used is reduced and the cell voltage is lowered, so the output is slightly reduced, but the efficiency is improved.

  On the other hand, when the output of the combined heat and power adjustment type power supply 1 decreases, the heat transmitted to the first fuel cell A also decreases as the output of the second fuel cell B decreases. Therefore, since it is necessary to input more fuel in order to maintain the temperature of the first fuel cell A (still the temperature decreases), the efficiency decreases and the output decreases as indicated by N2.

  A dotted line between N1 and N2 and N3 represents a cell voltage corresponding to an output indicated by each point of N1 and N2. As indicated by N3, when the output of the first fuel cell A increases or decreases around the intersection of N1 and N2 due to the increase or decrease of the output of the second fuel cell B, the cell voltage of the first fuel cell A increases or decreases.

  Thus, the characteristics of the first fuel cell A indicate that it operates with high efficiency and maximum output during normal operation, and that it operates with higher efficiency when demand increases. It also shows that efficiency and output are slightly reduced when demand decreases.

<Other embodiments>
The combined heat and power supply for adjustment according to the present invention may be exclusively used by the fuel supply company and the electric company (company), or may be shared. It may also be owned by a third party equipment company. Any one of them constructs and operates a combined heat and power supply for adjustment. That is, the initial cost of the combined heat and power supply type adjustment power supply 1 can be divided by any one.

  Use of the cogeneration type adjustment power supply 1 may be different from the owner. In Embodiment 1, the gas company and the electric company used it, but it may be a third party. For example, the third party may be a business operator who purchases fuel from a gas business operator, operates a cogeneration-type adjustment power source, and produces and sells power and heat together.

  Furthermore, although the 1st fuel cell A was operated so that a current density might become constant, it is not limited to such an aspect. For example, even if the output of the first fuel cell A is operated to be constant, the above-described effects of the present invention can be obtained.

  Note that the numbers of the first fuel cell A and the second fuel cell B are not particularly limited. If there is at least one each, the effects of the present invention are achieved.

  INDUSTRIAL APPLICABILITY The present invention can be used in the industrial field of a cogeneration type power supply for adjustment.

A 1st fuel cell B 2nd fuel cell 1 Cogeneration type power supply 4 Load 5 Water supply facility 6 Heating facility 7 Steam facility 8 Controller 10 Power distribution network 11 Thermal power plant 12 Controller 20 Gas supply means 30 Generator 40 Heat supply means 41 Combustor 42 Gas turbine 43 Heat exchanger 44 Generator 45 Mixer

Claims (3)

A first oxide fuel cell and a second fuel cell, which are solid oxide fuel cells, arranged so that generated heat is transmitted to each other;
A heat supply means for supplying heat using the fuel supplied from the fuel supply means owned by the fuel supplier,
The first fuel cell and the second fuel cell can be supplied with fuel from the fuel supply means and can transmit the generated power to an electric power system including an electric power company-side power generator owned by an electric power company. ,
The first fuel cell is operated as that of the fuel supplier, and is operated so that the current density is constant,
The second fuel cell is operated as that of the electric utility,
A combined heat and power type adjustment characterized in that the output of the second fuel cell is increased and the generated electricity is transmitted to the electric power system until the electric power generator on the electric utility side is in a rated operation from a standby state. Power supply. In the cogeneration type adjustment power supply according to claim 1,
The combined heat and power supply type adjustment power supply, wherein the output of the second fuel cell is reduced until the electric power generator side power generation device is in a standby state from a rated operation. In the cogeneration type power supply for adjustment according to claim 1 or claim 2,
The first fuel cell and the second fuel cell are centered on one of the first fuel cell and the second fuel cell, and the other is disposed around the first fuel cell and the second fuel cell. Power supply.