JPH0417268A - Co-generation system - Google Patents

Abstract

PURPOSE:To improve usage efficiency of a private power generating device by using a fuel battery as a power generating device, and setting the output of the fuel battery at a constant value more than a lowest value required by a load, and storing the surplus power and the heat generated from the fuel battery to output at the time of needs. CONSTITUTION:A co-generation system consists of a commercial power 1, a power receiver board 2, fuel batteries 41, 42, a heat storage device 5, a system controller 15, cooling air handling units 141, 142, an absorption type refrigerator 16, a cooling unit 13 and an air conditioner 17. Namely, the fuel batteries 4 of which efficiency is higher than that of an engine is used for a private power generating device, and the heat storage device 5 using hydrogen absorbed alloy is used. The output is set at a value more than a lowest load power, and during the time of the lowest load, the surplus power and the heat generated by the operation of the fuel batteries 4 are supplied to the heat storage device 5 to be stored as the heat energy, and is appropreated for the heat energy at a peak time. Co-generation system with high efficiency can thereby be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses electric power generated by a private power generation device and commercial power supplied from an electric power company, and the heat generated from the private power generation device is used for heating. and related to cogeneration systems used for air conditioning.

[Conventional Technique #r] In general, building-related energy demands are classified into electrical and thermal. Electrical energy comes from the electricity supplied by the power company, and thermal energy mainly comes from the use of electricity. was supplied by the operation of the air conditioning system. However, in recent years, from the perspective of energy conservation, instead of relying solely on electricity purchased from electric power companies, private power generators have been installed in buildings, which not only provide electricity but also use the heat generated by the generators to provide heating and cooling. The concept of the so-called cogeneration system (combined electricity and heat generation system) was born and is gradually becoming popular.

FIG. 4 is a system configuration diagram of a conventional example of a cogeneration system. This cogeneration system uses engine 32. ．． 322 and generators 31, . 312, a heat recovery device 37, a heating indoor unit 36, and an absorption refrigerator 38
, an indoor cooling unit 39 , a system controller 33 , and a power receiving board 2 . Generator 31. ．． 312 engines 32, . 322, its output connects the power line 41□, is combined with the commercial power 1 via the power receiving board 2, and is supplied to the load 3. Also, the engines 32, .
322 generates high-temperature exhaust gas, the heat is extracted from the heat medium pipe 35 of the heat recovery device 34 installed in the middle of the exhaust pipe 42 and directly heated by the heating indoor unit 36. Cooling was performed by an indoor cooling unit 39 via a medium pipe 37 and an absorption refrigerator 38. Further, the exhaust pipe 42 is provided with a muffler 40 . Further, heat generated by the engines 32□, 322 is supplied to the heat recovery device 34 via a heat medium pipe 43. The system controller 33 controls the generators 31□, 312. It controls and monitors the operation of the absorption refrigerator 38 and the power receiving board 2.

FIGS. 5(a), (b), (c), and (d) are diagrams showing the required power amount and the power supply ratio by the private power generator.

The power supply pattern shown in FIG. 5(b) is as shown in FIG.
The system relies on the supply of electricity and operates the private power generator only during the time period exceeding the standard power value, and supplies the privately generated power 21 for the amount exceeding the standard power value. Since the equipment consumes a lot of power, waste heat from power generation is also used to reduce power consumption. Also,
The pattern shown in FIG. 5(C) is such that the private power generating device is operated during the time period exceeding the reference power value to maintain a constant privately generated power 21.
This is a method in which the commercial power 1 shares the required amount of power 20, which is greater than the output of the private power generation device. Further, the pattern shown in FIG. 5(d) is a method in which a private power generator is constantly operated to supply a constant amount of privately generated power 21, and the shortfall in the required amount of power 20 is shared with the commercial power 1.

[Problem to be solved by the invention] As mentioned above, the conventional cogeneration system
The peak cut operation pattern, in which the private power generator is operated only during the hours when the required amount of electricity exceeds the standard power value, has a limited operating time and has poor economic effects as a cogeneration system. In the case of base-cut operation, in which the in-house power generator constantly generates heat, it cannot be used effectively late at night, and when the air conditioner is in full operation during the day, only exhaust heat can be used. However, there is a drawback that the capacity of the private power generator cannot be fully utilized in either peak cut operation or base cut operation.

The purpose of the present invention is to use a fuel cell, which has higher efficiency than an engine, as a private power generation device, use a heat storage device using a hydrogen storage alloy, and increase the output of the fuel cell to an amount exceeding the minimum load power, so that the output power exceeds the minimum load power during the minimum load period. The purpose of the present invention is to provide a highly efficient cogeneration system that supplies surplus electricity and heat generated by fuel cell operation to a heat storage device, stores the heat as thermal energy, and uses the heat energy at peak times.

[Means for solving the problem] The cogeneration system of the present invention includes at least one
a first hydrogen storage alloy with a low hydrogen equilibrium pressure, an electric heater with a switch, a heat exchanger for introducing heat generated by the operation of the fuel cell, and a cooling heat exchanger. a second hydrogen storage alloy having a hydrogen equilibrium pressure higher than that of the first hydrogen storage alloy; a heat exchanger connected to a cooling air handling unit; and a cooling heat exchanger. a second tank containing a heat storage device, and a vibrator with an on-off valve that connects the first tank and the second tank and controls the flow of hydrogen between the first tank and the second tank; a cooler that individually and selectively cools the second tank; and an absorber into which a portion of the heat generated by the operation of the fuel cell is introduced and uses the heat to cool a refrigerant in an air handling unit for cooling. a power receiving panel that receives commercial power and the electric power generated by the fuel cell and distributes the power to the load and the electric heater; and a power receiving panel that monitors the load and turns on a switch of the electric heater according to the state of the load. a system controller that opens and closes the valve, controls the introduction of heat generated by the operation of the fuel cell into the first tank, opens and closes the valve of the vibrator, and further controls selective cooling of the cooler. There is.

[Operations] As a private power generation device, a fuel cell is used that outputs a certain amount of electricity that exceeds the minimum load value, and the generated heat is used for cooling through an absorption refrigerator. Using a heat storage device containing a hydrogen storage alloy and a hydrogen storage alloy with a high hydrogen equilibrium pressure, a portion of the heat generated by the fuel cell and a portion of the heat generated by the fuel cell under the control of a system controller corresponding to a preset load and a hydrogen storage alloy with a high hydrogen equilibrium pressure are used. The heat converted from the surplus electricity of the fuel cell is added to the hydrogen storage alloy with a low hydrogen equilibrium pressure, and the hydrogen generated from the hydrogen storage alloy is thereby absorbed and stored in the hydrogen storage alloy with a high hydrogen equilibrium pressure. When power exceeds the predetermined output of the fuel cell, the system controller opens the valve of the vibrator between both hydrogen storage alloys and releases the stored hydrogen from the hydrogen storage alloy with the higher hydrogen equilibrium pressure. When the hydrogen storage alloy with a low hydrogen equilibrium pressure absorbs heat, the hydrogen storage alloy with a high hydrogen equilibrium pressure absorbs heat, so by absorbing heat from the refrigerant via a heat exchanger, the cooled refrigerant is circulated to the air handling unit. can be used for cooling.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a system configuration diagram of an embodiment of the cogeneration system of the present invention, and FIGS. 2(a) and (b).

(C) is an explanatory diagram of the operation of the heat storage device 5 shown in FIG. 1, and FIG. 3 is a diagram showing the required power amount and the power supply ratio of the fuel cell.

This cogeneration system includes a commercial power supply 1, a power receiving board 2, a fuel cell 4. ．． 42, a heat storage device 5, a system controller 15, a cooling air handling unit 14I, 142, an absorption refrigerator 16, a cooler 13, and an air conditioner 17. Fuel cell 4.
．． 42 is a fuel cell power 23 whose operation is controlled by the system controller 15 and whose total output exceeds the minimum required power amount as shown in FIG. , a part of it is connected to the electric heater 8 of the heat storage device 5 via the switch 7 by the power line 191.
The heat generated during operation is used to heat the absorption refrigerator 16 and a portion of the heat is used to heat the heat storage device 5. The heat storage device 5 includes a hydrogen storage alloy with low hydrogen equilibrium pressure and an electric heater 8.
and a heat exchanger 12, . 9. a tank 61 containing a hydrogen storage alloy having a high equilibrium hydrogen pressure, and heat exchangers 92, 12 . a tank 62 including tanks 6, . 62 and a valve 101 that opens and closes the vibrator 11 under control of the system controller 15. The cooler 13 absorbs the heat generated by the tank 61.6□ through valves 102 and 103, respectively.
cooling by opening. The absorption refrigerator 16 cools the refrigerant flowing back to the air handling unit 142 by absorbing heat. The system controller 15 controls the fuel cells 4 + , 42 according to the load according to preset control instructions.
, opening and closing of the switch 7 for controlling the power supply to the electric heater 8 of the heat storage device 5, controlling the introduction of heat into the heat exchanger 12 due to the operation of the fuel cell, and controlling the introduction of the hydrogen 18 to the heat exchanger 12. A valve 101 for movement control and valves 102 and 103 connecting the cooler 13 are opened and closed.

Air handling unit 14. ．． Reference numeral 142 denotes a cooling unit in which the refrigerant is cooled by the heat storage device 5 and the absorption refrigerator 16, respectively.

Next, the operation of this embodiment will be explained.

At night, when the required power amount 20 reaches the minimum power shown in FIG. 3, the system controller 1
5 closes the switch 7, the electric heater 8 generates heat,
The heat and a portion of the heat generated from the fuel cell heat the hydrogen storage alloy in the tank 6, which has a low hydrogen equilibrium pressure. The heated hydrogen storage alloy in the tank 6 releases hydrogen 18, and the released hydrogen 18 passes through the vibrator 11 whose valve 101 is opened by the system controller 15 and flows into the tank 62. Hydrogen is absorbed by a hydrogen storage alloy with a high equilibrium pressure. At this time, the heat generated in the tank 62 is removed by the refrigerant flowing from the cooler 13 through the valve 103 via the heat exchanger 92. Thereafter, when the required power amount 20 exceeds the fuel cell power 23 or this process continues for a predetermined period of time, the switch 7 is opened by the system controller 15 and the valve 1 is opened as shown in FIG. 2(b).
0,. 103 is closed and enters a heat storage state. When the required power amount 20 further increases to a predetermined value, the system controller 15 operates the valve 10 as shown in FIG. 2(C). ,102
to open. By this opening, hydrogen 18 is released from tank 62 containing a hydrogen storage alloy with a high hydrogen equilibrium pressure to tank 6 containing a hydrogen storage alloy with a low hydrogen equilibrium pressure. At this time, the heat in the tank 62 is absorbed by the hydrogen storage alloy, so it is passed through the heat exchanger 122 to the air handling unit 14,
refrigerant is cooled, making air conditioning possible. Also, tank 6
The heat generated by the absorption of hydrogen 18 by the hydrogen storage alloy with a low hydrogen equilibrium pressure in the hydrogen storage alloy 1 is cooled down by the refrigerant of the cooler 13 passing through the valve 102 via the heat exchanger 91 .

Further, other air conditioners 37 that operate using electric power may be used depending on the energy required for cooling, and this embodiment includes this.

This embodiment uses a fuel cell 4 as a method of supplying power to the load. ．．
We have shown the configuration of a system that uses both commercial power 1 and commercial power 42, but in this case, the load fluctuation on day -1 is large and the peak value of power consumption during the day exceeds the maximum power generation amount of the fuel cell. .

In cases where 4□ cannot be used alone, and the entire required electric power of load 3 (20) can be covered only by the output of the fuel cell, it is sufficient to treat the fuel cell as an independent power source and use only this generated output. . This is only related to the existence and magnitude of fluctuations in the amount of power used by the load, and the present invention is capable of dealing with any of these, and is not limited to the embodiment shown in FIG. do not have. Furthermore, in the present invention, the fuel cell 4. ．． 42 and commercial power 1 in combination, or by using the fuel cell alone, there is no problem whether the supplied power is alternating current or direct current, and these are determined according to the conditions required by the load. Only.

Although the present invention has been described using two fuel cells, the number is not particularly limited. Similarly, there is no limit to the number of heat storage devices, absorption refrigerators, etc. that use hydrogen storage alloys.

In this way, when a heat storage device using this hydrogen storage alloy is used, cold air can be stored as long as there is some kind of heat source. Therefore, in the present invention, a fuel cell, which is suitable for continuous operation with a constant output rather than frequent startup and shutdown, is used in the power generation device, and instead of changing this electrical output in accordance with load fluctuations, The fuel cell is not operated only during the daytime when electricity usage is high on days 1 and 2, but the fuel cell is always operated at a constant output that exceeds the minimum power value required by the load (Figure 3). In this case, all of the generated power during the day is sent to the load, and at night, the power that exceeds the required amount is used to operate the heat storage device mentioned above, so the surplus power at night can be used effectively. This allows air conditioning to be carried out using the air conditioner, and it is also possible to reduce the amount of electricity that was previously used to operate air conditioners during the day. Further, the output value when the fuel cell is operated continuously only needs to be determined according to the energy required for cooling.

[Effects of the Invention] As described above, the present invention uses a fuel cell, which has higher power generation efficiency than the engine, as a power generation device instead of the engine that has been used so far, and uses this and a hydrogen storage alloy. It is configured so that a part of the electric output of the fuel cell can be sent to the heat storage device using this hydrogen storage alloy, and the output of the fuel cell is kept constant and kept at the lowest value required by the load. By setting the value to a higher value and storing energy for cooling using surplus electricity and heat generated from the fuel cell, and outputting it when needed, cogeneration allows for high usage efficiency of private power generation equipment. This has the effect of making it possible to operate the system.

In particular, in telephone exchanges, where exchanges are housed in a building in high density, air conditioning is often required even in winter, and the present invention has an extremely large effect on such buildings.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of an embodiment of the cogeneration system of the present invention, and FIGS. 2(a) and (b). (C) is an explanatory diagram of the operation of the heat storage device 5 shown in FIG. 1, FIG. 3 is a diagram showing the required power amount and the power supply ratio of the fuel cell, and FIG. Figure 5 (a), (b), (c), (d)
is a diagram showing the required power amount and the power supply ratio by the private power generation device. 1...Commercial power, 2...Power receiving board, 3...
Load, 4. ．． 42-... Fuel cell, 5... Heat storage device, 6. ．． 62-...Tank, 7...Switch, 8...Electric heater, 9□, 92,12. ．． 1
2□...Heat exchanger, 10,. 102. t O3-...
valve, 11-...vibrator, 13...cooler, 14, .
142-... Air handling unit, 15-... System controller, 6... Absorption refrigerator, 17... Air conditioner, 8...
・Hydrogen, 19. ．． 192... Power line, 0... Required electric energy, 22... Commercial electric energy, 3... Fuel cell electric energy, 25... Signal line, 6... Heat medium piping. Patent applicant Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. Cogeneration in which electric power from a private power generation device and commercial power supplied by an electric power company are combined and used, and the heat generated from the private power generation device is used for heating and cooling. The system includes at least one set of fuel cells, a first hydrogen storage alloy with a low hydrogen equilibrium pressure, an electric heater with a switch, and a heat exchanger that introduces heat generated by the operation of the fuel cell. a first tank including a cooling heat exchanger; a second hydrogen storage alloy having a hydrogen equilibrium pressure higher than that of the first hydrogen storage alloy; and a heat exchanger connected to a cooling air handling unit; , a second tank including a cooling heat exchanger, and a pipe with an on-off valve that connects the first tank and the second tank and controls the flow of hydrogen between them. , a cooler that separately and selectively cools the first tank and the second tank, and a part of the heat generated by the operation of the fuel cell is introduced, and the heat is used to cool the air handling system. An absorption chiller that cools the refrigerant in the unit, a power receiving panel that receives commercial power and the power generated by the fuel cell and distributes it to the load and the electric heater, and a power receiving panel that monitors the load and responds to the load status. to open and close a switch of the electric heater, control introduction of heat generated by operation of the fuel cell into the first tank, open and close a valve of the pipe, and further control selective cooling of the cooler. A cogeneration system having a system controller.