JP2015061358A - Waste heat power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste heat power generation system which functions, when a regular power system operates normally, as a dispersed power source for supplying power by being connected to a power system with a centralized power source, but functions as an emergency power source for supplying power within a limited small range when an abnormality occurs in an emergency power system.SOLUTION: A waste heat power generation system 1 comprises: a waste heat power generation device 10 which recovers waste heat energy so as to generate power and supplies the generated power to at least one of a power system PS and an electric load EL designed to supply power within a small range; and a storage battery device 20 which has a storage battery 23 for storing part of the power generated by the waste heat power generation device 10 and, if an abnormality occurs in the power system PS, supplies to the electric load EL an amount of power that cannot be covered by the power from the waste heat generation device 10, out of the power required by the electric load EL.

Description

  The present invention relates to a waste heat power generation system.

  Conventionally, power generation is performed by recovering waste heat energy released in factories, incineration facilities, and the like, and energy is saved by reusing electric energy obtained by this power generation. In such factories and facilities, waste heat of about 300 ° C. or higher (nearly 1000 ° C. in some cases) is used for power generation because it easily generates high-pressure steam for driving the generator. Most of the low-temperature waste heat below ℃ was still released into the atmosphere. For this reason, it is considered that further energy saving can be realized by recovering waste heat energy of low-temperature waste heat that has hardly been collected in the past and generating power.

  Patent Document 1 below discloses a waste heat power generation apparatus that generates power using waste heat energy of low temperature waste heat of 300 ° C. or lower by a Rankine cycle using a low boiling point working medium. Specifically, the waste heat power generation apparatus disclosed in Patent Document 1 below includes a waste heat recovery device, a steam turbine, a condenser, and a high-pressure pump, and the low-temperature waste heat recovered by the waste heat recovery device. Is used to generate high-pressure steam as a low-boiling working medium, and the steam turbine is driven by this high-pressure steam to generate electricity. The exhaust gas from the steam turbine is condensed and liquefied by a condenser, and the liquefied low boiling point working medium is sent to a waste heat recovery device for circulation.

JP 2000-110514 A

  By the way, in recent years, combined use of a centralized power source and a distributed power source has been promoted from the viewpoint of power supply in an emergency (for example, at the time of a disaster), the viewpoint of effective use of renewable energy, and other viewpoints. Here, the “centralized power source” is a power source in which a large-scale power generation facility is installed at a location away from the power consumption area and the power generated by the large-scale power generation facility is transmitted to the power consumption area. . In contrast, a “distributed power source” is a system that installs multiple small- or medium-scale power generation facilities near the power consumption area and consumes the power generated by each power generation facility near that power generation facility. This is the power supply.

  Since the waste heat power generator disclosed in Patent Document 1 described above can generate power with low-temperature waste heat of about 300 ° C. or lower, it can also generate power by collecting heat from a hot spring or the like, for example. For this reason, if the waste heat power generation device disclosed in Patent Document 1 described above is installed, for example, in a mountainous area where hot springs spring out, unlike a solar power generation device in which the power generation time is limited, power generation is always performed. It is considered that a distributed power source that can be used can be realized.

In the case of a centralized power source, large-scale power generation such as a thermal power plant is performed, and power generation is performed using resources such as fossil fuels. Therefore, in addition to the problem of resource depletion, there are problems such as an increase in CO ₂ emissions. Hot springs and the like are natural energy, and when they are used to generate electricity, they become one of the power generations that can be used semi-permanently as renewable energy. In particular, when an existing hot spring is used, it is not a large-scale power generation, and is often provided as a relatively small distributed power source near the source. By connecting electricity generated from energy such as hot springs to a centralized power source in this way, power can be utilized through the electric power network laid at various locations. This will also lead to a reduction in CO ₂ emissions. When connecting such a distributed power supply to a power supply system, compliance with the grid connection regulations is important for the quality and safety of the power. For example, when an abnormality occurs in the power supply system, Power transmission to the power system needs to be stopped.

  On the other hand, in the case of a distributed power source that uses natural energy such as hot springs, it is possible to continue generating power from natural energy even if the centralized power source stops for some reason. Power supply is possible within a range of scale, and it can also be used as an emergency power source. However, as mentioned above, it is connected to the centralized power supply network during normal times, generating power, and supplying power to a small-scale range in an emergency, only with waste heat power generators that comply with the grid connection regulations, Since an abnormality occurs in the power supply system and power transmission from the waste heat power generation apparatus to the power supply system is stopped, it is difficult to achieve both.

  The present invention has been made in view of the above circumstances, and functions as a distributed power source that is connected to a power source system of a centralized power source and supplies power when a normal power source system is normal. It is an object of the present invention to provide a waste heat power generation system that functions as an emergency power source that supplies power to a limited small-scale range when an abnormality occurs in the system.

In order to solve the above problems, the waste heat power generation system of the present invention is a waste heat power generation system (1) that recovers waste heat energy and generates power, and collects the waste heat energy to generate power, A waste heat power generator (10) that supplies the generated power to at least one of a power supply system (PS) and an electric load (EL) that is supposed to supply power to a small-scale range, and the waste heat power generator A storage battery (23) for storing a part of the electric power, and when an abnormality occurs in the power system, the electric power from the waste heat power generator among the electric power required for the electric load is insufficient. And a storage battery device (20) for supplying electric power to the electric load.
Further, the waste heat power generation system according to the present invention provides a charge control for controlling the storage battery device so that the state of charge of the storage battery does not exceed a predetermined upper limit threshold value when there is no abnormality in the power system. A discharge control unit (25) is provided.
In the waste heat power generation system of the present invention, the charge / discharge control unit performs charge control of the storage battery when no abnormality occurs in the power supply system, and when an abnormality occurs in the power supply system. The charging / discharging control of the storage battery is performed according to the magnitude relationship between the electric power required for the electric load and the electric power generated by the waste heat power generator.
The waste heat power generation system according to the present invention includes an evaporator (11) in which the waste heat power generator recovers the waste heat energy and generates steam of a working medium, and power generation that generates power while expanding the steam. A device (12), a condenser (13) for condensing the steam via the power generation device, and a pump (15) for sending the working medium condensed in the condenser toward the evaporator When an abnormality occurs in the power supply system, the power generation amount is reduced by reducing the amount of the working medium delivered by the pump.
Alternatively, the waste heat power generation system according to the present invention automatically starts using the power supplied from the storage battery device when the waste heat power generation device is stopped due to an abnormality occurring in the power supply system. It is characterized by that.
In addition, the waste heat power generation system of the present invention includes a switch (21) that electrically disconnects the waste heat power generation device and the storage battery device from the power supply system when an abnormality occurs in the power supply system. Yes.

  According to the present invention, the waste heat energy is collected and the power is generated, and with the waste heat power generator that supplies the generated power to at least one of the electric load assumed to supply the power to the power supply system and the small scale range, If there is a storage battery that stores a part of the power generated by the waste heat power generator, and there is an abnormality in the power supply system, the amount of power required by the electrical load is insufficient for the power from the waste heat power generator. Because it has a storage battery device that supplies electric power to an electrical load, it can be used as a distributed power source when the power system is normal, and can be used as an emergency power source when an abnormality occurs in the power system There is.

It is a block diagram which shows the principal part structure of the waste heat power generation system by one Embodiment of this invention. It is a figure which shows the principal part structure of the waste heat power generator with which the waste heat power generation system by one Embodiment of this invention is provided. It is a figure for demonstrating the normal time operation | movement of the waste heat power generation system by one Embodiment of this invention. It is a figure for demonstrating operation | movement at the time of the 1st abnormality of the waste heat power generation system by one Embodiment of this invention. It is a figure for demonstrating operation | movement at the time of the 2nd abnormality of the waste heat power generation system by one Embodiment of this invention.

  Hereinafter, a waste heat power generation system according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a main configuration of a waste heat power generation system according to an embodiment of the present invention. As shown in FIG. 1, the waste heat power generation system 1 of this embodiment includes a waste heat power generation device 10 and a storage battery device 20 connected to a power system PS and an electric load EL, and recovers waste heat energy to generate power. I do.

  The waste heat power generation system 1 functions as a distributed power source when the power system PS is normal, and functions as an emergency power source for the electric load EL when an abnormality occurs in the power system PS. Here, the abnormality of the power supply system PS is, for example, a power failure, and the frequency of the power supply system PS is out of a predetermined frequency range, or the voltage of the power supply system PS is out of the predetermined voltage range. That means.

  The waste heat power generation system 1 is installed, for example, in the vicinity of a place where hot springs spring out, collects heat from the hot springs, and generates power, and supplies the generated power to the power supply system PS and a small-scale range. In this example, the power supply system PS is a power supply system to which, for example, 200V class three-phase AC power is supplied, and the electric load EL is, for example, a device that should function in an emergency (such as a drainage pump or a meeting place light). .

  The waste heat power generation apparatus 10 generates power using waste heat energy of low-temperature waste heat (referred to as hot water in this embodiment) such as a hot spring, and supplies the generated power to at least one of the power supply system PS and the electric load EL. Specifically, the electric power generated by the waste heat power generation apparatus 10 is supplied only to the electric load EL when the power generation amount is equal to or less than the electric power amount required for the electric load EL. On the other hand, when the amount of power generation is larger than the amount of power required by the electric load EL, the power is supplied to both the power supply system PS and the electric load EL. In addition, the electric power supplied toward the power supply system PS may be used for charging the storage battery 23 depending on the state of charge of the storage battery 23 included in the storage battery device 20. That is, the waste heat power generation apparatus 10 functions as a distributed power source connected to the power supply system PS and also functions as an emergency power source for the electric load EL.

  FIG. 2 is a diagram illustrating a main configuration of a waste heat power generation apparatus included in the waste heat power generation system according to the embodiment of the present invention. As shown in FIG. 2, the waste heat power generation apparatus 10 is a power generation apparatus using a Rankine cycle including an evaporator 11, an expansion turbine generator 12 (power generation apparatus), a condenser 13, a reservoir tank 14, and a pump 15. In addition, the waste heat power generation apparatus 10 includes an AC / DC converter 16 and a DC / AC converter 17, and converts the power generated by the expansion turbine generator 12 into three-phase AC power having the same specifications as commercial power. Convert. In addition, the waste heat power generation apparatus 10 includes a measurement device 18 and a control device 19, measures the internal state of the system, and makes it possible to generate the most power from the thermal energy of hot water based on the measurement result. The drive of the pump 15 is controlled.

  The evaporator 11 collects the waste heat energy of the hot water to generate a working medium vapor. The evaporator 11 is a kind of heat exchanger that vaporizes a working medium by exchanging heat with warm water. Specifically, the evaporator 11 is provided so that a flow path through which the hot water flows and a flow path through which the working medium flows are adjacent to each other, and the heat of the hot water on the high temperature side is efficient for the working medium on the low temperature side. It is designed to conduct well. Such an evaporator 11 vaporizes the liquid working medium supplied from the pump 15 and supplies the vaporized working medium to the expansion turbine generator 12.

  The working medium used in the waste heat power generation apparatus 10 is a medium having a boiling point (boiling point under atmospheric pressure) of about 15 ° C., and the pressure inside the apparatus during operation is 1 MPa (G) at maximum (1 MPa in gauge pressure). It is desirable that The reason for this is that, for example, steam can be generated from low-temperature waste heat to enable power generation using waste heat energy of low-temperature waste heat of about 100 ° C. or less, and the expansion turbine is kept low by keeping the pressure of the entire apparatus low. This is to keep the internal pressure of the generator 12 low.

  If the internal pressure of the expansion turbine generator 12 is kept low, the casing, the evaporator 11 and the condenser 13 of the expansion turbine generator 12 are not subjected to high pressure, so that it can be manufactured safely and at a low cost. A synergistic effect is also obtained. Here, hydrofluoroether (HFE), fluorocarbon, fluoroketone, perfluoropolyether, or the like can be used as the working medium.

  The expansion turbine generator 12 generates three-phase AC power using the vaporized working medium supplied from the evaporator 11. The expansion turbine generator 12 includes a turbine 12a and a generator 12b as shown in the figure. The turbine 12 a is a rotating machine that is driven by a working medium supplied from the evaporator 11. That is, the turbine 12a includes a receiving port for receiving the working medium from the evaporator 11, a discharge port for discharging the working medium to the condenser 13, a turbine impeller whose shaft (turbine shaft) is coupled to the generator 12b, and the like. Yes, the turbine impeller is rotated by supplying the working medium from the evaporator 11.

  The generator 12b is a rotating machine that is driven by the rotational power of the turbine 12a and generates three-phase AC power. That is, the generator 12b includes a substantially cylindrical rotor (field) that is axially coupled to the turbine shaft of the turbine 12a, and a stator (armature winding) provided in an annular shape on the outer periphery of the rotor. ing. In the generator 12b, an electromotive force is generated in the stator (armature winding) when the rotor (field) is rotationally driven by the turbine 12a. The three-phase AC power output from the generator 12b differs from the commercial power specification in at least one of frequency and output voltage.

  The condenser 13 cools and condenses the steam after passing through the expansion turbine generator 12 with a cooling medium such as cooling water. The condenser 13 is a kind of heat exchanger that condenses (liquefies) a working medium by heat exchange with cooling water. Such a condenser 13 supplies the reservoir tank 14 with the working medium in a liquid state. The reservoir tank 14 is a tank that temporarily stores the working medium condensed by the condenser 13. The pump 15 pressurizes the working medium condensed by the condenser 13 and temporarily stored in the reservoir tank 14 and sends it to the evaporator 11. The pump 15 is rotationally driven by, for example, an electric motor under the control of the control device 19.

  The AC / DC converter 16 and the DC / AC converter 17 are three-phase AC power (for example, 50/60 Hz, 200 V class) that conforms to the specifications of commercial power (power supply system PS) from the three-phase AC power generated by the generator 12b. ). The AC / DC converter 16 converts the three-phase AC power input from the generator 12 b into DC power and outputs the DC power to the DC / AC converter 17. The DC / AC converter 17 converts the DC power from the AC / DC converter 16 into three-phase AC power that conforms to the specifications of commercial power (power supply system PS).

  The measuring device 18 measures the current flowing through the DC / AC converter 17 and measures the amount of power generation per unit time (for example, in seconds) of the expansion turbine generator 12. Here, the measurement device 18 may measure the amount of power generated per unit time of the expansion turbine generator 12 by measuring the current flowing through the AC / DC converter 16. Note that the measuring device 18 includes a noise filter so as not to pick up noise of power generation amount (for example, noise on the order of μsec).

  The control device 19 controls the overall operation of the waste heat power generation apparatus 10. Specifically, the control device 19 performs control for starting the waste heat power generation device 10 using the power supplied from the power supply system PS or the power supplied from the storage battery device 20. In addition, the control device 19 controls the drive of the pump 15 (the amount of circulation of the working medium) so as to generate the most power based on the measurement results of the temperature sensor 19a and the pressure sensor 19b during normal operation.

  Further, the control device 19 operates by controlling the pump 15 when the operation of the waste heat power generation device 10 is continued by switching to the power from the storage battery device 20 when an abnormality occurs in the power supply system PS. Control is performed to reduce the power generation amount of the waste heat power generation apparatus 10 by reducing the amount of medium delivered. This is to reduce a part of the electric power generated by the waste heat power generation apparatus 10. How much the power generation amount of the waste heat power generation apparatus 10 is reduced is determined in consideration of the capacity of the storage battery 23, the power consumption per unit time in the electric load EL, and the like. In addition, although illustration is abbreviate | omitted in FIG. 2, the waste heat power generator 10 is provided with the detection apparatus which detects abnormality of the power supply system PS. The control device 19 performs the above control based on the detection result of the detection device.

  The storage battery device 20 includes an electronic switch 21 (switch), a bidirectional inverter 22, a storage battery 23, a voltage / current detection unit 24, and a control unit 25 (charge / discharge control unit), and is generated by the waste heat power generation apparatus 10. A part of the electric power is stored in the storage battery 23, and the electric power stored in the storage battery 23 is supplied to the electric load EL as necessary. Specifically, when an abnormality occurs in the power supply system PS, the storage battery device 20 cuts off the electronic switch 21 and disconnects the outside, and at the same time, supplies the power having the same voltage and frequency as the electrical system to the storage battery 23. Is supplied to the waste heat power generation apparatus 10 and the electric load EL from the amount of electricity stored in the storage. The storage battery device 20 has a function of storing a part of electric power for the waste heat power generation device 10 and a function of supplying power, and as an emergency power source for the electric load EL together with the waste heat power generation device 10. Function.

  The electronic switch 21 is a switch whose open / close state is switched by the control of the control unit 25, and in order to electrically disconnect the waste heat power generation system 1 and the electric load EL from the power supply system PS when an abnormality occurs in the power supply system PS. Provided. The electronic switch 21 is a switch provided to comply with the grid connection regulations. As this switch, a bipolar transistor, an FET (Field Effect Transistor) or the like can be used.

  The bidirectional inverter 22 charges the storage battery 23 using the electric power generated by the waste heat power generation apparatus 10 or discharges the electric power charged in the storage battery 23 under the control of the control unit 25. Specifically, the bidirectional inverter 22 includes a power converter that converts three-phase AC power into DC power, and a power converter that converts DC power into three-phase AC power. The generated power (three-phase AC power) is converted to DC power to charge the storage battery 23, and the power discharged from the storage battery 23 (DC power) is converted to three-phase AC power.

  The storage battery 23 is a rechargeable secondary battery such as a lithium ion battery or a nickel hydride battery, for example, and stores a part of the power generated by the waste heat power generation apparatus 10 and also stores the stored power as necessary. It is provided for supplying to the electric load EL and the waste heat power generation apparatus 10. The storage battery 23 only needs to be capable of charging and discharging power. In addition to the secondary battery, the storage battery 23 is a flywheel power storage device (device that stores power by converting power energy into rotational energy of the flywheel). It can also be used.

  The voltage / current detector 24 is connected to the power supply system PS through the electronic switch 21 and is connected to the electric load EL, and detects current and voltage. Specifically, the voltage / current detection unit 24 detects a current flowing from the power supply system PS to the electric load EL, a current flowing from the storage battery 23 to the electric load EL, and a current flowing from the waste heat power generation apparatus 10 to the power supply system PS or the storage battery 23. . In addition, the voltage / current detector 24 detects the voltage of the electric load EL (the output voltage of the waste heat power generator 10).

  The control unit 25 performs charge / discharge control of the storage battery 23 by controlling the bidirectional inverter 22 while referring to the detection result of the voltage / current detection unit 24. Here, when no abnormality has occurred in the power supply system PS, the control unit 25 performs charge control so that the charge state of the storage battery 23 does not exceed a predetermined upper limit threshold value. This is because the storage battery 23 can be charged with the power (surplus power) generated by the waste heat power generation apparatus 10 when an abnormality occurs in the power supply system PS.

  That is, if the storage battery 23 is charged to a fully charged state when there is no abnormality in the power supply system PS, surplus power generated by the waste heat power generator 10 when the abnormality occurs in the power supply system PS is stored in the storage battery 23. Can not be absorbed. For this reason, the state of charge of the storage battery 23 is intentionally prevented from exceeding a predetermined upper limit threshold value. The upper threshold value is determined in consideration of the capacity of the storage battery 23, the power generation amount per unit time of the waste heat power generation apparatus 10, the power consumption amount per unit time in the electric load EL, and the like.

  The control unit 25 performs the above-described charging control of the storage battery 23 when there is no abnormality in the power supply system PS, whereas the voltage / current detection unit 24 detects when abnormality occurs in the power supply system PS. The charge / discharge control of the storage battery 23 is performed based on the voltage that is applied. Here, the voltage detected by the voltage / current detector 24 varies depending on the magnitude relationship between the electric power required by the electric load EL and the electric power generated by the waste heat power generator 10.

  Specifically, when the electric power required by the electric load EL is larger than the electric power generated by the waste heat power generator 10, the voltage detected by the voltage / current detector 24 slightly decreases. On the contrary, when the electric power generated by the waste heat power generator 10 is larger than the electric power required by the electric load EL, the voltage detected by the voltage / current detector 24 slightly increases. For this reason, the control unit 25 performs charge control of the storage battery 23 when the detection voltage of the voltage / current detection unit 24 increases, and conversely discharges the storage battery 23 when the detection voltage of the voltage / current detection unit 24 decreases. Take control.

  In addition, although illustration is abbreviate | omitted in FIG. 2, the storage battery apparatus 20 is provided with the detection apparatus which detects abnormality of the power supply system PS similarly to the waste heat power generation apparatus 10. FIG. The control unit 25 controls the open / close state of the electronic switch 21 based on the detection result of the detection device. In the present embodiment, the case where the control unit 25 controls the open / close state of the electronic switch 21 will be described as an example. However, the control device 19 provided in the waste heat power generator 10 determines the open / close state of the electronic switch 21. You may make it control.

  Next, the operation of the waste heat power generation system 1 having the above configuration will be described. Here, the operation of the waste heat power generation system 1 is largely divided into an operation when there is no abnormality in the power supply system PS (normal operation) and an operation when an abnormality occurs in the power supply system PS (operation during abnormality). Separated. In addition, the operation at the time of abnormality is an operation when the operation of the waste heat power generation apparatus 10 is continued even when an abnormality occurs in the power supply system PS (first abnormality operation), and waste heat power generation due to the abnormality generated in the power supply system PS. It is divided into an operation (second abnormal operation) when the device 10 is stopped. Hereinafter, these operations will be described in order.

<Normal operation>
FIG. 3 is a diagram for explaining the normal operation of the waste heat power generation system according to the embodiment of the present invention. In addition, in FIG. 3, the graph which shows the time-dependent change of the electric power (waste heat power generation electric power) generated with the waste heat power generation apparatus 10, and the electric power (electric load electric power) required by the electric load EL is shown. In this graph, the horizontal axis represents time and the vertical axis represents power. In FIG. 3, the curve denoted by reference symbol P <b> 1 is a curve indicating waste heat generated power, and the line denoted by symbol P <b> 2 (broken line) is a line indicating electric load power.

  Here, the waste heat power generator 10 shall be started at the time t0 in FIG. Therefore, as shown in FIG. 3, the waste heat generation power P1 takes a negative value during the time t0 to t11, becomes zero at the time t11, and thereafter has a positive value although there is some fluctuation. Shows the changes to take. Further, since the electric load power P2 is a power necessary for the electric load EL, the electric load power P2 shows irregular changes shown in FIG.

  Moreover, in the graph shown in FIG. 3, the power of the part attached | subjected code | symbol A1 has shown the electric power supplied to the waste heat power generator 10 from power supply system PS, and the electric power of the part attached | subjected code | symbol A2 is power supply system | strain The electric power supplied from PS to the electric load EL is shown. The electric power of the part which attached | subjected code | symbol B1 has shown the electric power supplied to the electrical load EL from the waste heat power generation apparatus 10, and the electric power of the part which attached | subjected code | symbol B2 is supplied to the storage battery apparatus 20 from the waste heat power generation apparatus 10 The electric power of the part which attached | subjected code | symbol B3 has shown the electric power regenerated to the power supply system PS from the waste heat power generator 10. FIG.

  The waste heat power generation apparatus 10 hardly generates power immediately after being activated. For this reason, during the time t0 to t11 in FIG. 3, all of the electric power required for starting the waste heat power generation apparatus 10 and the electric load electric power P2 required for the electric load EL are generated by the electric power from the power supply system PS. Be covered. At time t11, the electric power supplied from the power supply system PS to the waste heat power generation apparatus 10 becomes zero. When the time t11 elapses, the power generation amount of the waste heat power generation apparatus 10 gradually increases and the electric load power P2 Is covered by power generated by the waste heat power generation apparatus 10 and power from the power supply system PS.

  Here, it is assumed that the electric load power P2 is drastically reduced as compared with the waste heat power generation power P1 (time t12). Then, since all of the electric load power P2 can be covered by the waste heat power generation power P1, the power supplied from the power supply system PS to the electric load EL becomes zero. Moreover, the waste heat generation electric power P1 also has surplus. Then, in the storage battery device 20, an increase in voltage is detected by the voltage / current detection unit 24, and charging control of the storage battery 23 is performed by the control unit 25. Thereby, as shown in FIG. 3, power is supplied from the waste heat power generation apparatus 10 to the storage battery apparatus 20 and the storage battery 23 is charged.

  It is assumed that the charge control for the storage battery 23 is performed, so that the state of charge of the storage battery 23 reaches a predetermined upper limit threshold (time t13). Then, the control unit of the storage battery device 20 stops the charging control of the storage battery 23. Thereby, the electric power supplied from the waste heat power generator 10 to the storage battery device 20 becomes zero. In the example shown in FIG. 3, since the electric load power P2 at time t13 is almost zero, most of the power generated by the waste heat power generation apparatus 10 is regenerated in the power supply system PS.

  Thereafter, the following operation is performed according to the magnitude relationship between the waste heat power generation power P1 and the electric load power P2. First, when the waste heat power generation P1 is larger than the electric load power P2, the power generated by the waste heat power generation apparatus 10 is supplied to the electric load EL, and the electric load power P2 is the waste heat power generation power P1. In addition to being covered, an operation is performed in which excess waste heat generated power P1 is supplied to the power supply system PS. On the other hand, when the waste heat power generation power P1 is smaller than the electric load power P2, power is supplied from the waste heat power generation apparatus 10 to the electric load EL, and power is supplied from the power supply system PS to the electric load EL. An operation is performed in which the supplied electric load power P2 is covered by the power generated by the waste heat power generation apparatus 10 and the power from the power supply system PS.

<Operation at first abnormality>
FIG. 4 is a diagram for explaining the operation in the first abnormality of the waste heat power generation system according to the embodiment of the present invention. In addition, in FIG. 4, the graph which shows the time-dependent change of waste heat power generation electric power P1 and electric load electric power P2 is shown similarly to FIG. Moreover, in the graph shown in FIG. 4, the meaning of the electric power of the part which attached | subjected code | symbol A1, A2, B1-B3 is the same as the meaning of the electric power of the part which attached | subjected the same code | symbol in FIG. However, in FIG. 4, the electric power of the part which attached | subjected code | symbol C1 has shown the electric power supplied from the storage battery apparatus 20 to the electrical load EL.

  It is assumed that an abnormality has occurred in the power supply system PS during the normal operation described above in the waste heat power generation system 1 (time t21). Then, an abnormality of the power supply system PS is detected by a detection device (not shown) included in the storage battery device 20. When an abnormality of the power supply system PS is detected by the storage battery device 20, the electronic switch 21 is disconnected and at the same time, the storage battery 23 is switched to the same voltage and frequency as the power supply system so far without interruption through the bidirectional inverter 22. A state in which there is no abnormality in the power supply system PS is established after the electronic switch 21 (on the electric load EL side). At this time, the electric power generated by the waste heat power generation apparatus 10 is stored in the storage battery 23 through the bidirectional inverter 22. At the same time, information is sent from the control unit 25 of the storage battery device 20 to the control device 19 provided in the waste heat power generation device 10, the pump 15 is controlled by the control device 19, and the amount of working medium delivered is reduced. Thereby, as shown in FIG. 4, the waste heat generation electric power P1 falls gradually.

  Thereafter, the following operation is performed according to the magnitude relationship between the waste heat power generation power P1 and the electric load power P2. First, when the waste heat power generation power P1 is larger than the electric load power P2, the operation of supplying power from the waste heat power generation apparatus 10 to the storage battery apparatus 20 and charging the storage battery 23 is performed. On the other hand, when the waste heat power generation power P1 is smaller than the electric load power P2, power is supplied from the waste heat power generation device 10 to the electric load EL, and the power stored in the storage battery device 20 is An operation is performed in which the electric load power P2 supplied to the load EL is covered by the power generated by the waste heat power generation device 10 and the power from the storage battery device 20.

<Second abnormal operation>
FIG. 5 is a diagram for explaining a second abnormal operation of the waste heat power generation system according to the embodiment of the present invention. In addition, in FIG. 5, the graph which shows the time-dependent change of waste heat power generation electric power P1 and electric load electric power P2 is shown similarly to FIG. 3, FIG. Moreover, in the graph shown in FIG. 5, the meaning of the electric power of the part which attached | subjected code | symbol A1, A2, B1-B3, C1 is the same as the meaning of the electric power of the part which attached | subjected the same code | symbol in FIG. is there.

  While the above-described normal operation is performed in the waste heat power generation system 1, an abnormality occurs in the power supply system PS, and power is supplied by a detection device (not shown) provided in one of the waste heat power generation devices 10 or the storage battery device 20. When abnormality of system | strain PS is detected, suppose that the waste heat power generator 10 became the stop state by this (time t31).

  When an abnormality in the power supply system PS is detected by the storage battery device 20, the electronic switch 21 is controlled by the control unit 25 provided in the storage battery device 20 to be opened, whereby the waste heat power generation system 1 and the electric load EL are It is electrically disconnected from the power supply system PS. Here, since the waste heat power generation apparatus 10 has been stopped, the waste heat power generation power P1 suddenly becomes zero. Then, in the storage battery device 20, a voltage drop is detected by the voltage / current detection unit 24, and the discharge control of the storage battery 23 is performed by the control unit 25. Thereby, as shown in FIG. 5, the electric power stored in the storage battery device 20 is supplied to the electric load EL.

  At this time, information is sent from the control unit 25 of the storage battery device 20 to the control device 19 provided in the waste heat power generation device 10, and automatic activation using the power supplied from the storage battery device 20 is performed (time t32). While the waste heat power generation apparatus 10 is being activated, all of the electric power required for the activation of the waste heat power generation apparatus 10 and the electric load power P2 required for the electric load EL are generated by the electric power from the storage battery device 20. Be covered. When time t33 in FIG. 5 elapses, the power generation amount of the waste heat power generation apparatus 10 gradually increases, and the electric load power P2 is determined by the power generated by the waste heat power generation apparatus 10 and the power from the storage battery device 20. Be covered.

  Here, it is assumed that the electric load power P2 is drastically reduced as compared with the waste heat power generation power P1 (time t34). Then, since all of the electric load power P2 can be covered by the waste heat power generation power P1, the power supplied from the storage battery device 20 to the electric load EL becomes zero. Moreover, the waste heat generation electric power P1 also has surplus. Then, in the storage battery device 20, an increase in voltage is detected by the voltage / current detection unit 24, and charging control of the storage battery 23 is performed by the control unit 25. Thereby, as shown in FIG. 5, power is supplied from the waste heat power generation apparatus 10 to the storage battery apparatus 20, and the storage battery 23 is charged.

  Thereafter, the same operation as the operation described in the first abnormality operation is performed according to the magnitude relationship between the waste heat generated power P1 and the electric load power P2. That is, when the waste heat power generation power P1 is larger than the electric load power P2, power is supplied from the waste heat power generation device 10 to the storage battery device 20 and the storage battery 23 is charged. On the other hand, when the waste heat power generation power P1 is smaller than the electric load power P2, power is supplied from the waste heat power generation device 10 to the electric load EL, and the power stored in the storage battery device 20 is An operation is performed in which the electric load power P2 supplied to the load EL is covered by the power generated by the waste heat power generation device 10 and the power from the storage battery device 20.

  As described above, in the present embodiment, the storage battery device 20 including the storage battery 23 that stores part of the electric power generated by the waste heat power generation apparatus 10 together with the waste heat power generation apparatus 10 that recovers waste heat energy and generates power. When the abnormality occurs in the power supply system PS, the power necessary for the electric load EL is supplied from the storage battery device 20 to the electric load EL as much as the electric power from the waste heat power generation apparatus 10 is insufficient. ing. For this reason, the waste heat power generation system 1 of this embodiment can be used as a distributed power source when the power system PS is normal, and can be used as an emergency power source when an abnormality occurs in the power system PS. .

  Further, in the present embodiment, when there is no abnormality in the power supply system PS, the control unit 25 of the storage battery device 20 performs charge control so that the charge state of the storage battery 23 does not exceed a predetermined upper limit threshold value. I have to. Thereby, when abnormality arises in power supply system PS, the electric power (surplus electric power) generated with the waste heat power generator 10 can be charged to the storage battery 23, and the waste heat power generator 10 is prevented from tripping. Can do.

  That is, if the storage battery 23 is fully charged when there is no abnormality in the power supply system PS, when the abnormality occurs in the power supply system PS and the consumption of the electric load EL is lost (no load state is entered). In other words, there is a possibility that the power generated by the waste heat power generation apparatus 10 that is difficult to construct immediately due to immediate power generation and immediate electrical interruption cannot be brought anywhere and trips. In the present embodiment, when the abnormality occurs in the power supply system PS, it is possible to charge the storage battery 23 with the electric power generated by the waste heat power generation apparatus 10, and thus it is possible to prevent the waste heat power generation apparatus 10 from tripping. it can.

  In the present embodiment, the control unit 25 of the storage battery device 20 performs charge control of the storage battery 23 when no abnormality occurs in the power supply system PS, and when an abnormality occurs in the power supply system PS, The charge / discharge control of the storage battery 23 is performed according to the magnitude relationship between the power required by the load EL and the power generated by the waste heat power generation apparatus 10. For this reason, when there is no abnormality in the power supply system PS, it is possible to store electric power required in the event of an abnormality, and when there is an abnormality in the power supply system PS, surplus power generated by the waste heat power generation apparatus 10 While storing the power in the storage battery 23, the power that is insufficient from the power from the waste heat power generation apparatus 10 can be supplied from the storage battery 23 to the electric load EL.

  In the present embodiment, the waste heat power generation apparatus 10 includes the evaporator 11, the expansion turbine generator 12, the condenser 13, the pump 15, and the like. If an abnormality occurs in the power system PS, the pump The amount of power generation is reduced by reducing the amount of working medium delivered by 15. Thereby, when an abnormality occurs in the power supply system PS, the power generation amount of the waste heat power generation apparatus 10 can be reduced to an amount corresponding to the consumption amount in the electric load EL, and the power generated by the waste heat power generation apparatus 10 can be reduced. It is possible to prevent a situation where the storage battery 23 becomes full immediately.

  That is, when an abnormality occurs in the power supply system PS, a part of the power generated by the waste heat power generation apparatus 10 that cannot be consumed by the electric load EL is stored in the storage battery 23. However, the waste heat power generation apparatus If the power generation amount of 10 is large, the storage battery 23 will soon be full. If the power generation amount of the waste heat power generation apparatus 10 is reduced to an amount corresponding to the consumption amount of the electric load EL, it is possible to prevent the storage battery 23 from becoming full. In addition, by reducing the amount of power generated by the waste heat power generation apparatus 10, when the electric power required by the electric load EL is reduced, the electric power that cannot be consumed by the electric load EL is stored in the storage battery 23 and the electric load EL is used. When the required power increases, it is possible to perform control such that power that is insufficient for the power generated by the waste heat power generation apparatus 10 is supplied from the storage battery 23.

  Further, in the present embodiment, when the waste heat power generation device 10 is stopped due to an abnormality that has occurred in the power supply system PS, the waste heat power generation device 10 is automatically activated using the power supplied from the storage battery device 20. I am doing so. As a result, even if the power generated by the waste heat power generation apparatus 10 temporarily becomes zero, the waste heat power generation apparatus 10 is in a state in which power can be generated quickly, and is stored in the storage battery 23 when the waste heat power generation apparatus 10 is stopped. It is possible to prevent a situation in which the consumed power is consumed immediately.

  In the present embodiment, when an abnormality occurs in the power supply system PS, the waste heat power generation device 10 and the storage battery device 20 are electrically disconnected from the power supply system PS by the electronic switch 21. Thereby, the waste heat power generation system 1 based on the grid connection regulations can be realized.

  As mentioned above, although the waste heat power generation system by one Embodiment of this invention was demonstrated, this invention is not restrict | limited to the said embodiment, It can change freely within the scope of the present invention. For example, the waste heat power generation system 1 described in the above embodiment includes the waste heat power generation device 10 and the storage battery device 20 one by one, but a plurality of the waste heat power generation devices 10 and the storage battery devices 20 are provided. Alternatively, the number of waste heat power generation devices 10 and the number of storage battery devices 20 may be different.

  Moreover, in the said embodiment, the waste heat power generator 10 and the storage battery apparatus 20 detect abnormality of power supply system PS separately, and various control (For example, control of the electric power generation amount of the waste heat power generator 10, or charge of the storage battery 23). An example in which discharge control or the like is performed individually has been described. However, any one of the waste heat power generation apparatus 10 and the storage battery apparatus 20 may collectively detect the abnormality of the power supply system PS and the various controls described above.

DESCRIPTION OF SYMBOLS 1 ... Waste heat power generation system, 10 ... Waste heat power generation device, 11 ... Evaporator, 12 ... Expansion turbine generator, 13 ... Condenser, 15 ... Pump, 20 ... Storage battery device, 21 ... Electronic switch, 23 ... Storage battery, 25 ... Control unit, EL ... Electric load, PS ... Power supply system

Claims (6)

A waste heat power generation system that recovers waste heat energy and generates power,
A waste heat power generator that recovers the waste heat energy to generate power, and supplies the generated power to at least one of a power system and an electrical load; and
A storage battery that stores a part of the electric power generated by the waste heat power generator, and when the abnormality occurs in the power supply system, the power from the waste heat power generator among the power required by the electric load Then, a storage battery device that supplies the electric load to the electric load is insufficient.   The storage battery device includes a charge / discharge control unit that controls charging so that a state of charge of the storage battery does not exceed a predetermined upper limit threshold when no abnormality occurs in the power supply system. Item 1. The waste heat power generation system according to item 1.   The charge / discharge control unit performs charge control of the storage battery when no abnormality occurs in the power supply system, and when the abnormality occurs in the power supply system, the power required for the electric load and the power The waste heat power generation system according to claim 2, wherein charge / discharge control of the storage battery is performed according to a magnitude relationship with the electric power generated by the waste heat power generation apparatus. The waste heat power generator includes an evaporator that recovers the waste heat energy to generate steam as a working medium, a power generator that generates power while expanding the steam, and a condensation that condenses the steam via the power generator. And a pump for delivering the working medium condensed in the condenser to the evaporator,
4. The power generation amount is reduced by reducing the amount of the working medium delivered by the pump when an abnormality occurs in the power system. 5. Waste heat power generation system.   The said waste heat power generator performs automatic starting using the electric power supplied from the said storage battery apparatus, when it will be in a stop state by the abnormality which arose in the said power supply system | strain. The waste heat power generation system according to any one of 3.   6. The switch according to claim 1, further comprising a switch that electrically disconnects the waste heat power generation device and the storage battery device from the power supply system when an abnormality occurs in the power supply system. The waste heat power generation system described.

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