Power generation system

Abstract

It eliminates the need for installation space to house batteries. [Solution] A power generation system that connects to the power grid to sell and buy electricity, wherein if the connection to the power grid is disconnected, a power switching mechanism stops the sale of electricity and supplies power to power-using facilities. In this way, if the connection to the power grid is disconnected, the power switching mechanism stops the sale of electricity and buys electricity and supplies power to power-using facilities, so it is not necessary to have a storage battery, and the installation area, maintenance costs, and battery replacement costs for a storage battery are eliminated.

Description

Technical Field

[0001] The technology of the present disclosure relates to a power generation system.

Background Art

[0002] The small geothermal power generation system disclosed in Patent Document 1 includes a generator that generates electricity using the rotational energy of an expander rotated by steam, a battery that stores the electricity generated by the generator, a switch that switches the DC power generated by the generator to either a route for selling power to the grid or a route for supplying power to the battery, and a sensor for detecting an emergency. In this conventional small geothermal power generation system, when there is no emergency, the switch is switched to the route for selling power to the grid, but when the sensor detects an emergency, the switch switches to the route for supplying power to the battery. This enables the small geothermal power generation system to continue operating even in an emergency.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional small geothermal power generation system, since it includes a battery, it requires an installation area for the battery. Also, since the battery deteriorates, the maintenance cost and the replacement cost when it deteriorates are high.

[0005] The technology of the present disclosure aims to provide a power generation system that can eliminate the installation area, maintenance cost, and battery replacement cost required for a battery.

Means for Solving the Problems

[0006] To achieve the above objective, a first aspect of the technology of this disclosure is a power generation system that is connected to a power grid and sells electricity, wherein if the connection to the power grid is disconnected, a power switching mechanism stops the sale of electricity and supplies electricity to power-using facilities. [Effects of the Invention]

[0007] In a first aspect of the technology of this disclosure, when the connection to the power grid is disconnected, the power switching mechanism stops selling electricity and supplies power to power-using facilities, thus eliminating the need for a battery, and thus eliminating the installation area required for a battery, maintenance costs associated with battery degradation, and replacement costs when the battery degrades. [Brief explanation of the drawing]

[0008] [Figure 1A] Figure 1A is a block diagram of an example of a power generation system 10 according to the first embodiment. [Figure 1B] Figure 1B is a block diagram of an example of a power utilization facility 50. [Figure 2] Figure 2 shows graphs (G1, G3) illustrating an example of the amount of power transmitted to each terminal of the power switching mechanism 16 of the power generation system 10 before and after the connection to the power grid is severed due to an earthquake or the like in the first embodiment, and graphs (G2, G4) illustrating an example of the amount of power transmitted to each terminal of the power switching mechanism 58 of the power utilization facility 50. [Figure 3A] Figure 3A shows an example of the connection of the movable contact 16T of the power switching mechanism 16 of the power generation system 10 when the connection to the power grid is severed due to an earthquake or the like, in the first embodiment. [Figure 3B] Figure 3B shows an example of how the movable contact 58T of the power switching mechanism 58 of the power utilization facility 50 is connected. [Figure 4A] Figure 4A is a block diagram of an example of a power generation system 10 according to the second embodiment. [Figure 4B] Figure 4B is a block diagram of an example of a power utilization facility 50H. [Figure 5A]Figure 5A shows an example of the connection of the movable contact 16T of the power switching mechanism 16 of the power generation system 10 when the connection to the power grid is disconnected due to an earthquake or the like, in the second embodiment. [Figure 5B] Figure 5B shows an example of the connection of the distribution board 54 of the power utilization facility 50. [Figure 6] Figure 6 shows an example of a plurality of power generation systems 10A, 10B, and 10C of the third embodiment, and an example of the power supply to a plurality of power utilization facilities 50A, 50B, and 50C. [Modes for carrying out the invention]

[0009] Embodiments of the technology of this disclosure will be described below with reference to the drawings.

[0010] [First Embodiment] (composition) Figure 1A is a block diagram of an example of a power generation system 10 according to the first embodiment, and Figure 1B is a block diagram of an example of a power utilization facility 50.

[0011] <Power generation system 10> As shown in Figure 1A, the power generation system 10 comprises a power generation device 12, a power switching mechanism 16, a transformer 20, a trading instrument panel 24, a steam turbine control device 18, and a generator control device 14.

[0012] The power generation equipment 12 is a system that generates electricity by directing steam generated from geothermal energy onto a steam turbine 32. The power generation equipment 12 comprises a steam turbine 32, a generator 34, and auxiliary equipment 36 for the power generation equipment.

[0013] The steam turbine 32 uses steam directly from the geothermal well 2 to rotate the rotating shaft 33, that is, it converts thermal energy into mechanical energy.

[0014] The generator 34 generates electricity, that is, converts mechanical energy into electrical energy, by the rotation of its rotating shaft 33 by the steam turbine 32.

[0015] The auxiliary machine 36 for the power generation facility supplies lubricating oil to the rotating shaft 33 or bearing of the steam turbine 32 or the generator 34 under the control of the steam turbine control device 18 to prevent breakage or abnormal heating, supplies cooling water for cooling, or releases the steam supplied to the steam turbine 32.

[0016] The power switching mechanism 16 is connected to the generator 34. The power switching mechanism 16 includes a terminal 16A to which power from the generator 34 is supplied, a power selling side terminal 16B, a facility side terminal 16C, and a movable contact 16T having one end fixed to the terminal 16A and the other end switchable to the power selling side terminal 16B or the facility side terminal 16C. The movable contact 16T has the other end connected to the power selling side terminal 16B, but when the connection to the power grid 100 is disconnected, the movable contact 16T switches to the facility side terminal 16C (see also FIG. 3).

[0017] A transformer 20 is connected to the power selling side terminal 16B, and a metering panel 24 is connected to the transformer 20. The metering panel 24 is connected to the power grid 100. The metering panel 24 is a device responsible for accurate measurement of the power generated by the generator 34, data management of power selling data, and safety protection.

[0018] A power utilization facility 50 (see FIG. 1B) is connected to the facility side terminal 16C.

[0019] The generator control device 14 includes a computer and controls the steam turbine control device 18 and the power switching mechanism 16. The generator control device 14 includes a disconnection detector 14S that detects disconnection of the connection to the power grid 100. The disconnection detector 14S is constituted by an intertie inverter or the like. The disconnection detector 14S detects disconnection of the connection to the power grid 100 from the voltage or the like between the power grid 100. The disconnection detector 14S is not limited to being provided in the generator control device 14, and may detect disconnection of the connection to the power grid 100 from the power supply state of electricity in the metering panel 24 or the transformer 20.

[0020] <Power utilization facility 50> As shown in Figure 1B, the power utilization facility 50 includes a power receiving equipment 52, a distribution board 54, a transformer 56, a power switching mechanism 58, and a power demand device 60.

[0021] The power switching mechanism 58 includes a power sales system side terminal 58C, a power purchase side terminal 58B, a terminal 58A connected to the power demand device 60, and a movable contact 58T, one end of which is fixed to terminal 58A and the other end of which switches to either the power sales system side terminal 58C or the power purchase side terminal 58B.

[0022] The power utilization facility 50 is equipped with a disconnection detector (not shown) that detects the disconnection of the connection to the power system 100 based on the power supply status at the power receiving equipment 52 or the distribution board 54.

[0023] (action) Next, the operation of this embodiment will be explained.

[0024] Figure 2 shows graphs (G1, G3) illustrating an example of the amount of power transmitted to each terminal of the power switching mechanism 16 of the power generation system 10 before and after the connection to the power grid is severed due to an earthquake or the like, in the first embodiment, and graphs (G2, G4) illustrating an example of the amount of power transmitted to each terminal of the power switching mechanism 58 of the power utilization facility 50. Figure 3A shows an example of the connection of the movable contact 16T of the power switching mechanism 16 of the power generation system 10 when the connection to the power grid is severed due to an earthquake or the like, in the first embodiment. Figure 3B shows an example of the connection of the movable contact 58T of the power switching mechanism 58 of the power utilization facility 50.

[0025] <If the connection to power grid 100 is not disconnected> Assume that the power generation system 10 and the power utilization facility 50 started operating at time t (see graphs G1 and G4 in Figure 2). At time t, power generation by the power generation system 10 begins. At the start of operation, the power generation system 10 and the power utilization facility 50 are not disconnected from the power grid 100. In this case, as shown in Figure 1A, the movable contact 16T of the power switching mechanism 16 of the power generation system 10 is connected to the power sales terminal 16B. As shown in Figure 1B, the movable contact 58T of the power switching mechanism 58 of the power utilization facility 50 is connected to the power purchase terminal 58B.

[0026] In the power generation system 10, the steam turbine 32 uses steam directly from the geothermal well 2 to rotate the rotating shaft 33. The generator 34 generates electricity as the rotating shaft 33 is rotated by the steam turbine 32. The electricity from the generator 34 is supplied to the transformer 20 via the power switching mechanism 16 (specifically, terminal 16A, movable contact 16T, and power sales terminal 16B), where the voltage is adjusted to a predetermined voltage and supplied to the power grid 100 via the trading meter panel 24 (power sales).

[0027] At the power utilization facility 50, power is received from the power grid 100 via the power receiving equipment 52 (purchased power). Power from the power grid 100 is supplied to and consumed by the power demand device 60 via the distribution board 54 and the power switching mechanism 58 (specifically, the power purchase terminal 58B, the movable contact 58T, and terminal 58A).

[0028] <If the connection to power grid 100 is disconnected> If an emergency such as an earthquake occurs at time T (see graph G2 in Figure 2) and the connection to the power grid 100 is severed, the power generation system 10 will detect the rupture using a disconnection detector 14S. When the disconnection detector 14S detects the rupture, the generator control device 14 controls the power switching mechanism 16 so that the movable contact 16T switches to the facility-side terminal 16C, as shown in Figure 3A (i.e., the power switching mechanism 16 is activated). When the movable contact 16T switches to the facility-side terminal 16C in this way, electricity sales are stopped. Even if electricity sales are stopped, the power generation equipment 12 continues to operate, and the generator 34 generates electricity by rotating the rotating shaft 33 with the steam turbine 32. The electricity from the generator 34 is supplied to the transformer 56 of the power utilization facility 50 via the power switching mechanism 16 (specifically, terminal 16A, movable contact 16T, and facility-side terminal 16C) and transformed.

[0029] If an emergency such as an earthquake occurs at time T (see graph G3 in Figure 2) and the connection to the power system 100 is severed, a disconnection detector (not shown) in the power utilization facility 50 detects that the connection to the power system 100 has been severed. In this case, as shown in Figure 3B, the movable contact 58T in the power switching mechanism 58 switches to the power sales system side terminal 58C (i.e., the power sales system side terminal 58C is activated). When the movable contact 58T switches to the power sales system side terminal 58C, power from the generator 34 (transformed by the transformer 56) is supplied to the power demand device 60. Similar to the power generation system 10, a computer (not shown) energizes a solenoid to switch the movable contact 58T to the power sales system side terminal 58C.

[0030] (effect) In this embodiment described above, when the connection to the power grid 100 is disconnected, power from the generator 34 is supplied to the power utilization facility 50 by the power switching mechanism 16; in other words, the power generation system 10 does not have a battery. Thus, this embodiment does not require a battery, eliminating the need for installation space for a battery, and also eliminating maintenance costs associated with battery degradation and replacement costs when the battery deteriorates.

[0031] In this embodiment, a power switching mechanism 16 is included, but the installation area of ​​the power switching mechanism 16 is smaller than the installation area of ​​the storage battery. Therefore, in this embodiment, the area in the area for storage battery installation that exceeds the installation area of ​​the power switching mechanism 16 can be effectively utilized for other purposes.

[0032] Diesel generators, which are common emergency generators, carry the risk of running out of fuel, and if fuel supply is disrupted during a widespread disaster, there is a risk of power generation stopping. However, this embodiment includes a power generation facility 12 that uses geothermal energy to generate electricity, so there is no risk of running out of fuel and power generation can be continued. Also, unlike other renewable energy sources, the amount of electricity generated does not depend on the weather and can be generated stably regardless of the season or time of day. Furthermore, since the power generation facility 12 is simply a device that directs steam generated from geothermal energy to a steam turbine 32, the power generation mechanism itself can be realized with a very simple configuration. This is because geothermal steam is already steam without any processing, so there is no need for energy facilities to change the state of the fluid (for example, changing water into steam).

[0033] In power-using facilities, even if an emergency such as an earthquake occurs and the connection to the power grid 100 is severed, power can still be supplied from the power generation system 10. Therefore, in this embodiment, even if the connection to the power grid 100 is severed, power can be secured from the power generation system 10 at the power-using facility, and power can be directly supplied to the power-demanding equipment.

[0034] [Second Embodiment] (composition) Since the configuration of the second embodiment is substantially the same as that of the first embodiment, the same reference numerals are used for the same parts, and their descriptions are omitted. The different parts will be described.

[0035] Figure 4A is a block diagram of an example of the power generation system 10 according to the second embodiment. Figure 4B is a block diagram of an example of the power utilization facility 50H according to the second embodiment.

[0036] The second embodiment includes the power generation system 10 of the first embodiment (see Figure 4A).

[0037] In the first embodiment, the power utilization facility 50 is equipped with a power switching mechanism 58 (see Figure 1), but in the second embodiment, the power utilization facility 50H, as shown in Figure 4B, is not equipped with a power switching mechanism 58, and the grid power receiving distribution board 54 and the power demand device 60 are directly connected. In addition, in the power utilization facility 50H, the transformer 56 is connected only to the emergency power supply 62.

[0038] (action) Next, the operation of this embodiment will be explained.

[0039] Figure 5A shows an example of the connection of the movable contact 16T of the power switching mechanism 16 of the power generation system 10 when the connection to the power grid is severed due to an earthquake or the like, in the second embodiment. Figure 5B shows an example of the connection of the distribution board 54 of the power utilization facility 50.

[0040] <If the connection to power grid 100 is not disconnected> The operation of the power generation system 10 when the connection to the power grid 100 is not disconnected is the same as that of the first embodiment.

[0041] At the power utilization facility 50, electricity is received from the power grid 100 via the power receiving equipment 52 (purchased electricity). The electricity from the power grid 100 is supplied to and consumed by the power demand device 60 via the distribution board 54, without going through the power switching mechanism 58.

[0042] <If the connection to power grid 100 is disconnected> The operation of the power generation system 10 when the connection to the power grid 100 is disconnected is the same as that of the first embodiment (see Figure 5A).

[0043] In the power utilization facility 50, when the connection to the power system 100 is disconnected, a disconnection detector (not shown) detects that the connection to the power system 100 has been disconnected. In this case, as shown in Figure 5B, the switch connecting the power receiving equipment 52 and the power demand device 60 in the distribution board 54 is turned off (opened).

[0044] The power from the generator 34 in the power system 100 (transformed by the transformer 56) is supplied to the emergency power supply 62.

[0045] (effect)

[0046] In this embodiment, the power utilization facility 50 does not have a power switching mechanism 16, thus eliminating the need for the cost of providing a power switching mechanism 16.

[0047] This embodiment includes an emergency power supply, which can then supply power to the power demand device.

[0048] [Third Embodiment] (composition) Figure 6 shows an example of a plurality of power generation systems 10A, 10B, 10C and a plurality of power utilization facilities 50A, 50B, 50C in the third embodiment, illustrating how power is supplied to them. As shown in Figure 6, the third embodiment includes a plurality (for example, three) of power generation systems 10A, 10B, 10C and a plurality (for example, three) of power utilization facilities 50A, 50B, 50C.

[0049] The power generation systems 10A, 10B, and 10C are the same as the power generation system 10 of the first embodiment.

[0050] The power utilization facilities 50A, 50B, and 50C are the same as the power utilization facility 50 of the first embodiment or the power utilization facility 50H of the second embodiment.

[0051] Power generation systems 10A, 10B, and 10C are predetermined in order of highest power generation, while power utilization facilities 50A, 50B, and 50C are predetermined in order of highest power requirements.

[0052] In this embodiment, power generation system 10A is connected to power utilization facility 50A, power generation system 10B is connected to power utilization facility 50B, and power generation system 10C is connected to power utilization facility 50. As a result, power generation systems 10A, 10B, and 10C, in order of increasing power generation, can supply power to power utilization facilities 50A, 50B, and 50C, in order of increasing power requirements.

[0053] (action) <If the connection to power grid 100 is not disconnected> The operation of the power generation systems 10A, 10B, and 10C when the connection to the power grid 100 is not disconnected is the same as that of the first embodiment.

[0054] When the connection to the power grid 100 is not disconnected, the operation of power utilization facilities 50A, 50B, and 50C is the same as the operation of power utilization facility 50 in the first embodiment or power utilization facility 50H in the second embodiment.

[0055] <If the connection to power grid 100 is disconnected> The operation of the power generation systems 10A, 10B, and 10C when the connection to the power grid 100 is not disconnected is the same as that of the first embodiment.

[0056] When the connection to the power grid 100 is not disconnected, the operation of power utilization facilities 50A, 50B, and 50C is the same as the operation of power utilization facility 50 in the first embodiment or power utilization facility 50H in the second embodiment.

[0057] As described above, power generation system 10A is connected to power utilization facility 50A, power generation system 10B is connected to power utilization facility 50B, and power generation system 10C is connected to power utilization facility 50. Therefore, power generation systems 10A, 10B, and 10C, in order of increasing power generation, can supply power to power utilization facilities 50A, 50B, and 50C, in order of increasing power requirements.

[0058] (effect) In the third embodiment, if the connection to the power grid 100 is disconnected, power is supplied preferentially from the power generation system with the highest power output to the power-using facilities 50A, 50B, and 50C that have the highest power requirements, thereby ensuring a stable supply of power to power-using facilities with high power requirements.

[0059] [Modified example of the third embodiment] In the third embodiment, as described above, power generation systems 10A, 10B, and 10C are predetermined in order of increasing power generation, and power utilization facilities 50A, 50B, and 50C are predetermined in order of increasing power requirements. Power generation system 10A is connected to power utilization facility 50A, power generation system 10B is connected to power utilization facility 50B, and power generation system 10C is connected to power utilization facility 50. The technology of this disclosure is not limited thereto.

[0060] <First variation> Each of the power generation systems 10A, 10B, and 10C is interconnected with each of the power utilization facilities 50A, 50B, and 50C. The power requirements of power utilization facilities 50A, 50B, and 50C fluctuate.

[0061] The power sales system, which prioritizes the amount of electricity generated, supplies power to power-using facilities, which prioritize the amount of electricity needed, by switching the connection between the power sales system and the power-using facilities according to the fluctuating electricity needs of each facility.

[0062] Therefore, in the first modified example, even if the power requirements of each power-using facility fluctuate, the power sales system is selected according to each power requirement, so power can be supplied appropriately according to the power requirements of each power-using facility.

[0063] <Second variation> In the second modified configuration, power generation system 10A is connected to power utilization facility 50A, power generation system 10B is connected to power utilization facility 50B, and power generation system 10C is connected to power utilization facility 50. Each power generation system 10A, 10B, and 10C changes the amount of power it supplies according to the power requirements of the corresponding power utilization facilities 50A, 50B, and 50C. The amount of power supplied is changed by changing the amount of steam supplied to the steam turbine 32.

[0064] Therefore, in the second modification, even if the power requirements of each power-using facility fluctuate, the power supplied from the power sales system is changed according to each power requirement, so that power can be supplied appropriately according to the power requirements of each power-using facility.

[0065] [Modified versions of the first to third embodiments] The first to third embodiments include a disconnection detector, but the technology of this disclosure is not limited thereto. For example, as disclosed in Patent Document 1 (paragraph 0045), various sensors for detecting emergencies such as earthquakes may be provided, and the system may detect that the connection to the power system 100 has been disconnected by detecting the occurrence of an emergency. Examples of these sensors include seismometers, sulfur dioxide sensors, temperature sensors, etc.

[0066] The timing at which various sensors detect an emergency is earlier than the timing at which the disconnection detector detects that the connection to the power grid 100 has been severed, so that immediate action (the above switching) can be taken in the event of an earthquake or other emergency.

[0067] In the first to third embodiments, the power generation equipment is a flash-type power generation system that directly utilizes geothermal steam to generate electricity. However, the technology of this disclosure is not limited to this, and a binary-type power generation system that indirectly utilizes geothermal steam through a working fluid to generate electricity may also be provided. In this modified example, since a binary-type power generation system is provided, relatively low-temperature geothermal energy can be utilized, and it can be applied to small-scale power generation.

[0068] While the first to third embodiments utilize geothermal power generation, the technology of this disclosure is not limited thereto, and other power generation methods may be employed. For example, firstly, there is power generation using renewable energy. This includes, in addition to geothermal power generation, wind power generation, wave power generation, hydroelectric power generation, tidal power generation, or ocean thermal energy conversion. Secondly, there is power generation using non-renewable energy, such as nuclear power generation. Thirdly, there is power generation using chemical energy, such as power generation using steam turbines derived from the reaction heat of chemical plants. Geothermal power generation is limited to areas with abundant geothermal resources. However, modifications utilizing wind power generation, wave power generation, or hydroelectric power generation allow power generation facilities to be installed in a relatively diverse range of locations. Modifications utilizing nuclear power generation enable larger-scale power generation and can supply power to power-using facilities with larger power requirements.

[0069] Each power generation system may purchase electricity from the power grid 100.

[0070] [Note] Based on the information disclosed above, the following addendum is proposed.

[0071] (Note 1) A power generation system that connects to the power grid and sells electricity, A power generation system that, when the connection to the aforementioned power grid is disconnected, stops selling electricity and supplies power to power-using facilities using a power switching mechanism.

[0072] (Note 1-1) The aforementioned power generation system purchases electricity from the aforementioned power grid. The power generation system according to claim 1.

[0073] (Note 2) The aforementioned power generation system includes power generation equipment that generates electricity using renewable energy, non-renewable energy, or chemical energy. The power generation system described in Appendix 1.

[0074] (Note 3) The aforementioned power generation system includes a power generation facility that generates electricity by directing steam generated from geothermal energy onto a steam turbine. The power generation system described in Appendix 1.

[0075] (Note 4) The aforementioned power utilization facility receives power from the power grid if its connection to the power grid is not disconnected, and receives power from the power generation system if the connection is disconnected. The power generation system described in Appendix 1 or Appendix 2. (Note 4-1) If the power utilization facility is not disconnected from the power grid, it supplies power from the power grid to the power demand device via an internal power switching mechanism. If the connection is disconnected, it supplies power from the power generation system to the power demand device via the same internal power switching mechanism. The power generation system described in Appendix 3. (Appendix 4-2) The aforementioned power utilization facility supplies power from the power grid to the power demand device when the connection to the power grid is not disconnected, and when the connection is disconnected, the facility's internal power switching mechanism supplies power from the power generation system to the emergency power source. The power generation system described in Appendix 3.

[0076] (Note 5) The system comprises multiple combinations of the aforementioned power generation system and the aforementioned power utilization facility. If the power generation system with the largest power output among the multiple power generation systems is disconnected, it will supply power to the power utilization facility with the largest power requirement among the multiple power utilization facilities. A power generation system described in any one of the items in Appendix 1 to Appendix 3-2. [Explanation of Symbols]

[0077] 10. Power sales system 12 Power generation facilities 16 Power switching mechanism 20 Transformers 24. Instrument panel for trading 18 Steam turbine control device 14. Generator control device 32 Steam Turbine 34 Generators 36. Auxiliary equipment for power generation facilities 14S cutting detector 50 Electricity-using facilities 52 Power receiving equipment 54 Distribution board 56 Transformer 58 Power switching mechanism 60 Electricity demand equipment 62 Emergency power supply

Claims

1. A power generation system that connects to the power grid and sells electricity, A power generation system that, when the connection to the aforementioned power grid is disconnected, stops selling electricity and supplies power to power-using facilities using a power switching mechanism.

2. The aforementioned power generation system includes power generation equipment that generates electricity using renewable energy, non-renewable energy, or chemical energy. The power generation system according to claim 1.

3. The aforementioned power generation system includes a power generation facility that generates electricity by directing steam generated from geothermal energy onto a steam turbine. The power generation system according to claim 1.

4. The aforementioned power utilization facility receives power from the power grid if its connection to the power grid is not disconnected, and receives power from the power generation system if the connection is disconnected. The power generation system according to claim 1.

5. The system comprises multiple combinations of the aforementioned power generation system and the aforementioned power utilization facility. If the power generation system with the largest power output among the multiple power generation systems is disconnected, it will supply power to the power utilization facility with the largest power requirement among the multiple power utilization facilities. The power generation system according to claim 1.

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